WABCD ~
SERVICE MANUAL 5873
H~STALLATION AND MAINTENANCE
INSTRUCTIONS
AUDIO FREQUENCY TRAIN DETECTION AND
CAB SIGNALING SYSTEM
May, 1973 AO. 7 3- 2 0 0-1 7 4 7 • 2
WESTINGHOUSE AIR BRAKE COMPANY UNION SWITCH & SIGNAL DIVISION Swissvale Post Office, Pittsburgh, Pa. 15218
An American-Standard Company ·
Section
I
II
III
IV
v
CONTENTS
INTRODUCTION
1-1 GENERAL 1-2 PURPOSE OF EQUIPMENT 1-3 GENERAL DESCRIPTION 1-4 EQUIPMENT SPECIFICATIONS
PRINCIPLES OF OPERATION
2-1 SYSTEM DESCRIPTION 2-2 AF TRACK CIRCUIT 2-3 AF CAB SIGNALING 2-4 TRAIN EQUIPMENT
COUPLING UNITS
3-1 INTRODUCTION 3-2 TYPE A COUPLING UNIT 3-3 TYPE B COUPLING UNIT 3-4 TYPE c COUPLING UNIT 3-5 TYPE D COUPLING UNIT 3-6 TYPE E COUPLING UNIT 3-7 CAPACITOR SELECTION
INSTALLATION INFORMATION
Page
1-1
1-1 1-1 1-2 1-2
2-1
2-1 2-3 2-6 2-8
3-1
3-1 3-2 3-3 3-6 3-7 3-9 3-9
4-1
WABCO ~
4-1 CARRIER FREQUENCY ALLOCATION 4-1 4-2 CARRIER FREQUENCY ASSIGNMENTS 4-2 4-3 CODE RATES 4-2 4-4 MINIBOND APPLICATION 4-2 4-5 DETECTOR TRACK CIRCUIT DETAILS 4-4
MAINTENANCE
5-1 5-2 5-2.1 5-2.2 5-3 5-3 .. 1 5-3.2 5-3.3 5-3.4 5-3.5 5-3.6 5-3.7' 5-3. 8 ·
INTRODUCTION FIELD .MAINTENANCE Tuning and Level Adjustments System Troubleshooting SHOP MAINTENANCE . Recommended Test Equipment Coder PCB Maintenance Oscillator PCB Maintenance Mixer PCB Maintenance Pre-Amplifier PCB Maintenance Power Amplifier PCB Maintenance Receiver PCB Maintenance Coupling Units
i
5-1
5-1 5-1 5-1 5-7 5-8 5-8 5-8 5-14 5-14 5-23/24 5-29 5- 33/34 5-41/42
FIGURE
2-1
2-2 2-3 2-4
3-1 3-2
3-3
3-4
3-5
3-6 3-7 3-8
3-9
4-1
5-1 5-2
5-3
5-4
5-5 5-6
5-7 5-8
5-9 5-10
5-11 5-12
5-13
LIST OF ILLUSTRATIONS
Typical Application of the Audio Frequency Coded Train Detection and Cab Signaling System AF Track Circuit Block Diagram Speed Command Block Diagram Cab Signaling Block Diagram
Typical Coupling Unit Chassis Type A Coupling Unit Schematic Diagram Type B Coupling Unit Schematic Diagram Calculated Values for Determining Capacitors C2 and C3. Type B Coupling Unit (Sheet 1) Calculated Values for Determining Capacitors C2 and C3. Type B Coupling Unit. (Sheet 2) Type C Coupling Unit Schematic Diagram Type D Coupling Unit Schematic Diagram Capacitor Values for Capacitor C4 of Type D Coupling Unit Type E Coupling Unit Schematic Diagram
Maximum Track Length for Various Operating Frequencies and Ballast Conditions.
Simple Track Circuit ISC Current Calculations for 1100 ft. (approximate) Track Circuit. Typical Track Circuit Tuning Problem Using Type B Coupling Coder PCB Schematic Diagram (UN451054-1202-1208) Coder PCB Parts Location Diagram Oscillator PCB Schematic Diagram (UN451054-1302 to 1313) Oscillator PCB Parts Location Diagram Mixer PCB Schematic Diagram (UN451054-1502-1503)
Mixer PCB Parts Location Diagram Pre-Amplifier PCB Schematic Diagram (UN451054-1602) Pre-Amplifier PCB Parts Location Diagram Power Amplifier PCB Schematic Diagram (UN451054-1702) Power Amplifier PCB Parts Location Diagram
ii
PAGE
2-2 2-4 2-7 2-9/10
3-1
3-2
3-3
3-4
3-5 3-6 3-7
3-8 3-10
4-5
5-2
5-4
5-6
5-9 5-11
5-15 5-16
WABCD ~
5-19/20 5-21
5-25/26 5-27
5-30
5-31
FIGURE
5-14
5-15 5-16
TABLE
3-1
3-2
3-3
LIST OF ILLUSTRATIONS (CON'T)
Receiver PCB Schematic Diagram {UN451054-1401 to 1412) . Receiver PCB Parts Location Diagram Coupling Units Schematic Diagrams
LIST OF TABLES
Capacitor Values for Type A Coupling Units Capacitor Values for Type c Coupling Units Values of Rl
iii
WRBCD ~
PAGE
5-35/36 5-38 5-43/44
PAGE
3-3
3-6 3-7
WABCO ~
SECTION I
INTRODUCTION
1-1 GENERAL
This manual is provided as a guide for the installation, maintenance and operation of the Wayside Equipment of the Audio Frequency Coded Train Detection and Cab Signaling System.
Section I of this manual provides a general description of the system. The principles of operation are described in Section II to aid the reader in obtaining a broad understanding of the system without a detailed discussion of circuit theory. The Coupling Units are covered in Section III, and Section IV contains information necessary for installation of the system.
The Maintenance Section, Section V, is to enable the maintenance pers0nnel to take a logical and systematic approach to the general area of a malfunction. This section also includes information for making any adjustments that may be necessary and information to aid maintenance personnel in troubleshootinq and repairing printed circuit boards. It is assumed through-· out this manual that assigned maintenance personnel have a basic electronics background.
System and apparatus described in this manual are protected inpart by U.S. patents 3268, 843 and 3,345,511. Other patent protection is pending.
1-2 PURPOSE OF EQUIPMENT
In the automatic territory that lies between interlockings, the sections of track are sub-divided into a number of AF detector track sections. Usually, in a Rail Mass Transit System, the length and location of these detector track sections is determined by the control limit diagrams which are established to provide the required headway and to take care of restricted speed zones. Seldom is the maximum operable length of a track circuit a controlling factor in determining the length of a detector track section. Where it is a factor however, cut sections mcy be added as required.
The Audio Frequency Coded Train Detection and Cab Signaling System continually functions to provide a constant indication of track occupancy. When track occupancy is indicated, the cab signaling circuits provide suitable cab signaling information based on the occupancy condition of the detector track sections. Thus, when a train occupies an AF detector track circuit, cab signaling energy is applied to the exit end of the track circuit at a code rate dependent on traffic and track conditions ahead.
5873, p. 1-1
WABCO ~
1-3 GENERAL DESCRIPTION
The WABCO Coded Train Detection and Cab Signaling System utilizes Audio Frequency (AF) Track Circuits and is adaptable to either AC or DC propulsion systems. The system does not require insulated joints except at interlockings and can be installed with just the train detection or with the additional cab signaling.
The Cab Signaling System has provisions for expansion to include speed control, semi-automatic or completely automatic train operation. Capabilities of up to seven (7) separate and distinct cab signal indications or speed commands can be transmitted to the train through the rails. The cab signal indications or speed commands can be controlled automatically by the Train Detection Track Circuits or can be controlled by an attendant or automatic dispatcher within safe limits, determin~d by the Train Detection Track Circuits and interlocking system. Wayside signals are not required for train control but may be included if desired.
With this system, the AF Track Circuit Receivers require coded AF signals to operate, but will not respond to the code itself. The codes are used to control the speed of the train and are regarded as part of the cab signaling system. The AF Track Circuits on the other hand identify the presence of trains and through the receiver relay logic, the control of cab signaling codes for automatic and semi-automatic train operation is possible.
In this system the same transmitter is used for both track circuit detection and cab signaling, the essential difference being the necessity of various low frequency codes to modulate the carrier frequency for the cab signaling, whereas any single low frequency code is for for modulation of the track circuit frequency. For train detection only, the total system configuration is shown in the block diagram on Fig. 2-2. For train detection and cab signaling see Fig. 2-1 and 2-3. The car-carried equipment is not included as part of this service manual.
1-4 EQUIPMENT SPECIFICATIONS
1-4.1 Frequencies
1-4.1.1 Cab Signalling System Carrier Frequency - 990 Hz.
5873, p. 1-2
1-4.1.2 Detector Track Circuit Frequencies:
Class I Class II
Fl - 2550 Hz F2 - 2490 Hz F3 - 2730 Hz F4 - 2670 Hz F5 - 3270 Hz F6 - 3210 Hz F7 - 3810 Hz F8 - 4110 Hz F9 - 4170 Hz FlO - 5190 Hz
AUX - Fll - 6090 Hz
NOTE
Class I frequencies are used on one track and Class II frequencies are used on the adjacent parallel track.
1-4.2 SEQUENCES
1-4.2.1 Four-way sequence
WABCC ~
F5 - F9 - Fl - F7 - (F5) F8 - F6 - F4 - FlO - (F8)
1-4.2.2 Five-way sequence
F5 - F9 - Fl - F7 - F3 - (F5)
F8 - F6 - F4 - FlO - F2 - (F8)
1-4.3 CODE RATES
There are seven code rates or speed commands available. They are selected with the highest code rate normally the hiqhest speed cornrnan d.
The code rates are as follows:
20.4 Hz, 16.8 Hz, 13.6 Hz, 10.8 Hz, 8.6 Hz, 6.6 Hz, and 5 Hz.
1-4.4 TRACK RELAY
PN150 B, 400 ohm, 6FB, UN322500-001
1-4.5 M.INIBOND (UN451003-0101)
Track terminal blocks hold two 350 mcm or 250 mcm cables, DC resistance - .00003 ohms, continuous unbalance current rating -200 amps.
5873, p. 1-3
WABCD ~
1-4.6 POWER REQUIREMENTS
Coder - .04 amp feeding 20 power amplifiers .01 amp with no load
Oscillator - .02 amp feeding 20 power amplifiers .005 amp with no load
Mixer, Pre-Amplifier, and Power Amplifier 3.2 amp at maximum output for longest block len~th an~ 3 ohms ballast.
Receiver - .1 amp when relay is energized .05 amp with no signal
1-4.7 POWER SUPPLIES
1-4.7.1 There must be separate supplies for the following groups:
1. Coders and Oscillators 2. Receivers 3. Mixer, Pre-Amplifier and Power Amplifier
1-4.7.2 The Power Supplies used are:
24 VDC, 1 Amp, UJ725599 } 24 VDC, 20 Amp, UJ725597 Or Equivalent 24 VDC, 10 Amp, UJ725598
1-4.8 CABLE
'rwisted pair #14 with less than 30 picofarads per. foot. Maximum lenqth from central case to minibond is 5,000 ft.
1-4.9 PRINTED CIRCUIT BOARD MOUNTING
The printed circuit boards are mounted in a card file assembly that is mountable on a communications rack. Circuit boards are plug-in types for ease of maintenance.
1-4.10 OPERATING TEMPERATURE RANGE
-40 to+ 11°c.
5873, p. 1-4
"""\
SECTION II
PRINCIPLES OF OPERATION
2-1 SYSTEM DESCRIPTION
A typical application of the Audio Frequency Coded Train Detection and Cab Signaling System (Wayside Equipment) is shown in Figure 2-1. The AF detector track circuits A3T and B3T are fed coded frequency F3 at Minibond MT3, circuits A9T and B9T are fed frequency F9 at MT9, and circuits A7T and
WABCD ~
B7T are fed frequency F7 at MT7. Minibond MR39 is connected to receivers for frequencies F3 and F9 to energize track relays B3TR and A9TR. Minibond MR97 is connected to receivers for frequencies F9 and F7 to energize track relays B9TR and A7TR. T~is arrangement permits the use of one transmitter to feed two AF detector track circuits, minimizing equipment.
A train occupying detector track circuit B3T will be fed cab signaling coded energy from Minibond MR39; amplifier A2 being fed the 16.8 Hz code rate over the front contacts of A9TR and B9TR and the cab oscillator frequency being turned on over the back contact of B3TR and front contact of A9TR. This would provide the highest speed command. If detector track circuit B9T were occupied, then amplifier A2 would be fed the lower (13.6 Hz) speed ,command over the back contact of B9TR. If detector track circuit A9T were occupied, then the cab oscillator would be turned off and the code rate would be zero since relay A9TR would be deenergized. The train would then be given the most restrictive (stop) command.
All of the wayside equipment can be housed in a centralized housing at convenient locations such as stations, except for Minibonds and connecting cables.
The system may be applied to either direction of operation by suitable change in the selection circuits for the cab signal energy. No change is required in the AF detector track circuits. However, suitable traffic control must be provided to safeguard reversal of traffic.
Insulated rail joints are not required in automatic territory with the system. However, insulated rail joints are required at interlockings where a train move may be made in one detector track circuit adjacent to another occupied detector circuit.
5873, p. 2-1
u, ex:> -...)
w ... 'U
N I
N
A3T
PR
MT3
CODE: RATE:
CAB"ON''
CAB OSC FC
WAY OSC F3
B+ FOR CAB OSC "ON'' •
NOTE:
I\ - DE:NOTE:S ~ MIXE:Rt PRE:AMPt
AMPL.IFIE:R AND
PR
B3T
~ - DE:NOTE:S COUPL.JNG UNIT
MR39
PR PR MT9
A9T B9T
~ W ~ WI I B
9
TR A7TR
p I- C ~ I- WAY m < c o <. osc ,(0: t 0: F9
u w m w 0 ,( 0 O U O u u
PR
MT7
A7T
CODE: RATE:
CAB "ON"
CAB OSC FC
WAY OSC F7
CAB OSC, FC
CAB"ON"
CODE: RATE:
16. 8 HZ
CODER
13,6 HZ CODER
FIGURE 2-1 TYPICAL APPLICATION OF THE AUDIO FREQUENCY CODED TRAIN DETECTION AND CAB SIGNALING SYSTEM
~I B7T
)
2-2 AF TRACK CIRCUIT
2-2.1 GENERAL
WABCD ~
A track circuit as defined by the I.c.c. is an electrical circuit of which the rails of the track form a part. It comprises a source of electrical energy, the running rail of a section of track, a detecting means, usually a track relay, and a means for coupling the source and detecting means to the rail.
Generally, track circuits have been confined to sharply defined sections of track by insulated rail joints at the ends of each section. With the use of Audio Frequency in the range of 2.5 to six KHz however, it is not necessary to use insulated rail joints to define a track section. The rail impedance is sufficiently high at audio frequencies to confine the ,track circuit to within satisfactory limits.
Elimination of the requirement for insulated rail joints is a decided advantage in Rail Mass Transit System Operations, where many short track circuits are required for establishing close headway, particularly where welded rail is used.
2-2.2 AF TRACK CIRCUIT OPERATION
Figure 2-2 is a block diagram of an AF Track Circuit. The circuit consists of transmitting equipment, the running rails of a section of track, receiving equipment, Minibonds and cable. Signals applied to the rails are coded (alternatley turned on-off) at any code rate between 5 and 20.4 Hz. The carrier for the coded signal is between 2.49 and 6.09 KHz.
2-2.3 TRANSMITTER
The transmitting equipment consists of an oscillator (0) to generate a particular audio frequency, a coder (CO) to generate the code rate, a mixer (M) to alternately switch the cab or wayside frequency, a pre-amplifier (P-A), a power amplifier (A) to produce an ample signal to properly energize the track circuit, and a tuned coupler (C) to minimize energy requirements.
2-2.4 RECEIVER
The AF receiving equipment consists of a tuned coupler (C) to minimize system energy requirements, a track receiver (R) to produce sufficient output to energize a relay, and a vital track relay (TR). The receiver will respond only to a coded signal of the proper code frequency.
5 873 I P • 2-3
u, 00 --.! w ...
i-o
,~ ~B
• N I I ~ ~
LS ~1 .. LT ., .. LS ., ZS/2 MR ZT/2 MT
ZT/2
PR PR
r------ ---, r-- -------,
c c
RECEIVER TRANSM JTTER
TR
0 co
L __________ _J L __________ _J
FIGURE 2-2 AF TRACK CIRCUIT BLOCK DIAGRAM
)
WABCD ~
NOTE
There are 11 different audio frequencies and 7 different code rates used in the track circuits of this system. The fre~ quencies and code rates are covered in Section IV.
2-2. 5 MINIBONDS
Where running rails are used for the negative propulsion return, it is usually necessary to cross bond parallel track to minimize the rail voltage drop. The Minibonds (MR and MT) serve this purpose. The track winding is center tapped to equalize the propulsion return current in the two running rails of one track and to provide a return path to the propulsion return (PR) system, or for crossbonding to Minibonds on parallel tracks. A higher voltage winding on the Minibonds is used ~o couple the AF transmitters and receivers to the running rails through cable; this arrangement permits centralized housing for components of the AF transmitter and receivers, eliminating the need for extra housing between central points.
2-2.6 SHUNT AREAS
Since insulated rail joints are not used, except at interlockings, there is a short extended shunt area (Ls) beyond the limits of the track circuit defined by the rail connections for the AF transmitter and receiver. The length of the extended shunt area (Ls) depends upon the adjustment, frequency, length of circuit (Lt) and ballast resistance.
For instance, at two KHz the rail impedance is approximately five ohms per thousand feet, so if the AF circuit is adjusted for 0.06 ohm shunting sensitivity, the extended shunt area would be about 12 feet, increasing a small amount at low ballast resistance.
2-2.7 MULTIPLE TRACK CIRCUIT FEED
A single AF transmitter may feed two track circuits, one in each direction along the track. Different AF frequencies must be used on adjoining track circuits but frequencies may be repeated at suitable intervals.
2-2.8 COMPONENT DESCRIPTION
Components of the AF track circuit are designed for convenient mounting in centralized housing. The electronic parts of the system are mounted on printed circuit cards and enclosed in a card file. The sub-assemblies include the oscillators, the coders, the mixer and pre-amplifier, the power amplifier, the receivers, and coupling units.
5873, p. 2-5
WABCD ~
2-3 AF CAB SIGNALING
2-3.1 GENERAL
In order to provide up to 7 separate and distinct cab signal indications or speed commands, a 990 Hz carrier frequency is applied to the track circuit and is coded at one of seven code rates - 5, 6.6, 8.6, 10.8, 13.6, 16.8, and 20.4. The highest code rate is used for the highest indication. The absence of any coded cab signaling carrier frequency provides the most restrictive indication - STOP.
Generally, seven speed commands are not necessary. If fewer than seven speeds are needed, only a portion of the available code rates are used. Absence of a coded signal will still provide the most restrictive command.
Cab signal commands are applied to the track circuit during the off time of the coded wayside command if both are employed. Thus, one power amplifier with a two channel (oscillator) input can be used to supply both the wayside and cab signals.
The Cab Signaling Circuit consists of a group of code generators, code selecting relays, cab frequency oscillator, transmitter, minibonds, and cable (coupling means). The transmitter equipment is similar to that used for the track circuits, except that the code selecting relays are required and more than one code rate is used.
2-3.2 SPEED COMMAND SELECTION
There are seven discrete speed commands available. These are selected individually by the code selecting relays. The code rate is selectively applied to the power amplifier, depending on track condition, where it modulates the 990 Hz cab frequency. The cab frequency is turned on only when a train is occupying the track circuit. If the wayside frequency is transmitted from this location, then it w1ll be coded also at the selected code rate.
Each coder, through relay selection circuits (Figure 2-4), can drive as many as twenty power amplifiers.
The means by which each output is produced can be understood by considering the block diagram shown in Figure 2-3. For the purpose of describing the system operation, a functional description of each block and the relation of the blocks to each other is given below. For a more detailed explanation of the operation of the circuits within each plug-in unit, refer to the individual descriptions given in Section V.
5873, ~- 2-6
U'l CX)
....J w ...
"Cl
N I
....J
COUPL.ING
UNIT
TYPE 11 B11
BOND
CAB 1 - - - - -, ON-OFF I I
I _!.-..A------1 ---1 I OTHER CODES { I
LJ ___ J
NOTE
(I) SEPARATE POWER SUPPL.JES ARE USED FOR GROUPS OF
A, RECEIVERS B, CODER AND OSCIL.LATORS C, POWER AMPL.IFIERS, MIXERS
AND PRE-AMPS
(2) CODE RATE MUST AL.WAYS BE TRANSMITTED
CODER
(I OF 7)
WAYSIDE
OSCIL.LATOR
(I OF II)
MIXER
FIGURE 2-3 SPEED COMMAND BLOCK DIAGRAM
CAB
osc
COUPL.ING
UNIT
TYPE "c"
RECEIVER
RELAY
BOND
~i
WABCCJ ~
2-3.3 CODER (MODULATION FREQUENCIES)
A twin-tee type oscillator is employed to generate a low frequency code rate. By proper selection of tuning components, a discrete frequency in the range of 5 to 20.4 Hz is established.
2-3.4 OSCILLATORS (CARRIER FREQUENCIES)
The oscillators are simple Colpitts type that produce a sinusoidal output at the assigned frequency.
2-3.5 MIXER AND AMPLIFIER
These units accept signals from the oscillators and coders. A dual channel or a single channel oscillator input unit is available. The oscillators are connected directly to the amplifier but are gated by the code circuitry to the amplifier stages. The code ,·rate is applied separately to one channel. An internal phase inversion network applies the same code rate to the other channel. Thus, each channel is alternately switched at the code rate. Individual output level adjustment for each channel is obtained by control potentiometers. The output signal is comprised, therefore, of two frequencies; each being alternately transmitted at the code rate. At locations where only the cab signal frequency is transmitted, a single channel mixer can be used.
2-4 TRAIN EQUIPMENT
The train equipment, although not part of this system, is discussed here because of its effect on the system and its relationship to the system. Refer to Figure 2-4.
The train receivers {R) are located ahead of the front axles in the direction of movement and pick up the transmitted energy through magnetic coupling with the rail current. This energy is filtered (F), amplified (A), and decoded (D) to provide outputs which may be used for cab signaling or semiautomatic or completely automatic train operation in conjunction with a speed sensing device.
Usually Rail Mass Transit trains are operated in either direction, and as a result, receiver coils (R) must be installed on both ends of the train. The coils must be suitably interlocked with the propulsion control equipment on the train so that only the receiver coils at the head end of the train are connected to the cab signaling equipment. With exception of the receiver coils, only one set of cab signaling equipment is required per train. However, where multiple units are used in various combinations of train lengths, it may be necessary to fully equip each unit to provide a suitable interlocking and to assure control from the head end in the direction of traffic.
5873, p. 2-8
Ul co ....J w ...
'"d
N I
\0 .......... I-' 0
R
---r----,---,
---... •,. I ..._ I' I
I TRAIN .... ...... ·--, I I ......... I I r - , ... , r -, '-l ... I ...... , ._ ____ .J'1 ... I OUTPUT. D l--<,A,--1 F .... -----t-,r> I L - .J ',J L _.J ........... I I
,... I I ,... ,... ,.- - .J I
,... ,... '- I
L - - - - - - - - - _ ...... ,.... ~ (_ __ ..J
R
NOTE:
TRAIN RECEIVING EQUIPMENT SHOWN IN DOTTED LINES IS NOT FURNISHED AS PART OF CAB SIGNALING SYSTEM,
!II ONLY REQUIRED AT LOCATIONS WHERE TRAIN DETECTION SIGNALS ARE ALSO TRANSMITTED.
PR
DETECTOR
osc. *
M
CAB
osc. FC
FIGURE 2-4 CAB SIGNALING CIRCUIT BLOCK DIAGRAM
c
AMPLIFIER
PREAMPLIFIER
MIXER
CODE SELECTOR
RELAYS
21314151617
CODERS
~
WABCD ~
SECTION III
COUPLING UNITS
3-1 INTRODUCTION
3-1.1 General
There are five basic coupling units used in the AF System to handle the various combinations of receivers and transmitters. All five units are built on a common type chassis (Figure 3-1) or housed in a box adjacent to the Minibond, and consist of· the various electrical components described in this section.
TERMINAL BLOCK
FIGURE 3-1 TYPICAL COUPLING UNIT CHASSIS
5873, p. 3-1
WABCD ~
3-1.2 Purpose
The purpose of the coupling units is to provide a means of transferring maximum power into the rails from the transmitters and of extracting maximum pow.er from the rails for the receivers. Values of capacitance and inductance can be calculated, but due to variations in minibond and receiver input transformer inductance, commercial tolerance of capacitors and cable lengths the calculated values will not be exact. Generally, it is necessary to use two or more standard capacitors connected in parallel to achieve the correct value; this is a "trial and error'' procedure carried out in the field at the time of installation. By calculating the capacitor values ahead of time, however, the amount of actual work in the field can be greatly reduced. The curves and tables given in this section can be used to determine capacitor'values. Resistors used for setting receiver sensitivities and filter response are described in Sections 3-4, 3-5, 3-6 and 5-2.L
3-2 TYPE A COUPLING UNIT
The type A coupling unit (Figure 3-2) is for coupling a single channel transmitter to a rail minibond (single coded frequency transmitted). The unit incorporates one capacitor, the value of which is tabulated in Table 3-1. This value should be altered in field adjusting the unit by subtracting the cable capacitance (CO) from the tabulated value. Approximate values for CO can be obtained from chart shown in Figure 3-5.
/M1
1
NIBOND CABLE CAPACITANCE
Ir \-----41~~~--r---~-Q) Cl TRANSMITTER TO RAILS
FIGURE 3-2 TYPE A COUPLING UNIT SCHEMATIC DIAGRAM
5873, p. 3-2
WABCO
TABLE 3-1. CAPACITOR VALUES FOR TYPE A COUPLING UNIT
Cl (mfd) FREQ. Cl (mfd) FREQ •
• 553 990 .144 2490 .0485 3810 .108 2550 .0417 4110 .099 2670 .0406 4170 .0945 2730 .0262 5190 .0684 3210 .019 6090 .0658 3270
3-3 TYPE B COUPLING UNIT
The type B coupling unit (Figure 3-3) is used to couple the dual channel transmitter (cab signal and detector track circuit frequencies). The unit incorporates a toroid and two capaqitors (Cl and C2). To determine the values of capacitors Cl and C2, refer to Figures 3-4 and 3-5. Approximate values for CO can be obtained from the chart shown in Figure 3-5.
G)-v· -0 CABLE CAPACITANCE l FOR TWO CHANNEL
BOND --CO 23
M THE CAB SIGNAL AND
~
Hc2 TRANSMITTERS WHERE
[
DETECTOR TRACK CIR-llM l2MH ]-C3 CUIT FREQUENCY IS 9MH TRANSMITTED
2 ~-----e-------'1 7MH G)
FIGURE 3-3 'I'YPE B COUPLING UNIT SCIIfil1ATIC DIAGRAM
3-3.1 Choosing Values From Graphs
Find the appropriate CO curves in Figures 3-4 and 3-5, then use the detector track circuit frequency in conjunction with a selected value of inductance on the first curve (C2 curve) to find the value of C2 as shown to the left of the graph. Then use the same inductance value on the second curve (Cl curve) and find the value of Cl as shown on the right of the graph. The cab frequency is already accounted for in the graph and not required in choosing values.
5873, p. 3-3
u, 00 -...)
w ... "O . I
w I I ,i:,.
MFD Cc2) .35
.3
.25
.20
.15
.10
.05
---- -r---r- :-1-r r1Tr- -- --:- --T-, - r-:-:-:--rr- ----r- ---:--;--:--:- T; ri-- ---1- -r-y-rrTn : : I I I I : : ! ! : I I j : : l: I : : : : j 1 : : I : I I : I I I I I : I f I I I I I I I I I I I I I ; I I I I I : I I f 1 f f j I f: ---- - -'- - -1- - .., --'- .! -;.. J.. LL _____ .!. - __ J. --~-1.....:.. t-l-~l--------r----1...--L-.J _ _._..,_r_,,..1 _____ --I..- --+--+-.i.- r-+-~, : I j..).-J,1
11 : : I :1,111 : ···;::,:: I '!.....!..-,,II,
, , <:12MH(c1) ; , : , : , : :1 , , , , , , , ,: 7MHCc1>--;--1, 1 11
MFD (CI)
.45
: ~ I I ; : I i j I I I I : : I : : I I : ! I : I : : i : I t I I I I ______ .. __ T-- ... ---r---r-L-~ .. --------7MH (CI) I • .. -J.--,------7MH (CJ) "'K.JJ_,._,__._J_r .. ---------,----.. ---r-,--.-J-1.-i-f 40
I I I I I I I I I I I I . I I I I I I I I I • I I I I I I I I : I I I I I I I I I I I I 1 I' I l I I I I If I : I I I : I I I I I : I : I : I I I I I I I I I: I I I I I I I I : I : I I I I I I I I I I I I I I J I : : : I I I I I I : I I I I I I
- ---- __ .,__ - -'- --T--+ -L - -~ .!;---- -- --1--- -•- ...... 1- --t ... - L. ... L .. I... J ... ,. ..... --- ......... l ........ -........ ..1.. ... -a. -·'--~-t .. L .,: ___ ...... ------ -- -'·- J - -r-.J... .... .J. J : I I:: I:. I : : ~ I 11 : ! : : I' I~: I I I '• 1 I! , , : : , ; ,: i i---+J!12.MH(cl) • , : • 1 ! • ,: : : 12MH(ct)
... ----· .. --+--- .. 1 1 , • : • : , : 1 1 , : : , l 1 1 112MH (cl): , 1 • 1 , , ..
:- .. - .. t" •; • -~-j -:-1-r---- ...... -·t ........ -:--- -, ---:--+- ~-~· t-:-·--·--- -~---- - -~ I ... ,. ... ii~ -- - -- .. -;- -• -t • - 't-•1"• t·-f-t~-l ,35 I
' ' '
I I I I I I I I I I I I I I: I I I I,! I I I t I I I I I I I I I I I . • I I I I I I I I : I I I I I I I I I I I I I
________ .,_,,,._ I
: ' I ------"---' I I I I I I ------:----r I O
' I I O
' I --'----r --- -- I I
' I
• 23MH Cc t) : : : : ! : : : : : l : : ! : . : ! : ' 1 1 1 : I : -f:'-,- -r-r .. i -r i-- ......... --,-- .. -~ - - -~--,--,-1-t-:-r - - - -- -r-- -T -- ~ -~ --,- .,. ... ..,. 7~ - - - - - - T - - -~-- ---,- ..J -r..,..-r I I I I I I I I I I I I I I I I I I I: I I I : I I I
1 , : , : : : : J : 1 I 1 : , : l : '1 , : , ! 1 1 , , t,
: : 1 , : 1 , J 1 : : : 1
, 1 1 1 l I l : I 1 1 23MH (C 1) -•r ----'-L- ...J- 1-- - - --.,- 23MH (c I) --1--i- .... ..,_, __ --- _ _,_ - --t-- .._ ·-i--1 3
I I I I I I I I I I l I I I I I I I I I I ,, • I : : : : : I : I : I I: I ! ! I I I : : I I I I I , , , , , ' , ' , • : , : 23MH (c 1) ' 1 1 I 1 1 1
I I I I I I ' I I I I I I , ·, .• I I I I I I --,\_ J_..__,~,,. -------"'--- -i- .... ...l-t-{-- ----'- -- -r.--_ .... _,, ______ ..J __ -, --1 _...,_-+-,-T".J I : : I : : : : I I I ; : I : : I i : : i I I I I I I I I I I I I I I I I : : I I I I I I ! I I I: I I I I I I I I I ' : : : : : I I : I I : : ; : I : : I : I: I : I : I I ) I
-!'-~-~~ ,-~ --- - - -:- -- - i-- --t' 1-t-i ,-------t-- - '" - t-i-~7"1-:--------:-- - L -t--,-+ ... rti .25 I I I I I I I I I ; I I l I : I I I I I I I I I I I I
I I I I I I I I I I I I I : I I I I I I I I I I : I : I I I I ! : : l J : l I I : : I : : I I I I
-- -"f-~'j'-J-,- --- - -,:- - - - , - ... -.- .... 7' ,--- ----,----, -- -- --t-t-1-1-T _.:_ __ -- ""-- - -r...J- ,l....L, I I I I I I I : I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I: I I j I I
: ; I\ I I I I ; I I ~ ! I I ; I I I I I I I I : I I I I I I I ------,---~--1.~ ... - -'-'-,.....-------.----,- _...i-W------'----,- •• L.1.-.-i------r--- - --1. :1-r+1-1 23 ( ) I ' ' I I ' I I I I I I . : MH C2 • 1 , 1 : :
1 7' H. · • ) , , i • , : , i ' 1 (C2) I I I I I I I I I I I 1 M (C2 I I I I I : I I I ' I i : : : : 12MH (c2) : : , : , i • , : l , ; l , I I : : i 1 7MH I ---- - -:-- --i·--1--,--r-,-~~-.-- ---- -;-- .. 1---: r-r 1-:-~--- - ... --:----1-- -:- ----!--·-------,-- --r -r-ji-r, .. 1 , , , , , , , , ,
1 , , , , , , , , , 1 7MH (c2) , ,'
1 1 1 1 1 , I I I I I I I I I I I I I I I I I I I I r f I I I I : • : • ,
1 • i : ! : : • 12MH (C2) : 1 : : l l : : : I J : I I I ------:----~--r-~-i-~~-rr-------:----1---r- -1-i-~"i _______ T___ -,-rrTT--------,----,--- - - - ... -._,....,
I I I I I I 1 I I I I I I I 1, I : I I : I : : I I (CZ) I 1'
I 1 I I I I It I I I • I I I I I I I • I I I 12MHI , , , : : , , : : : , 1 , ! , : ' 1 , ; , 1 12MH (cz) :23MH(c2? I .. 1 1 ' --- --~-- --:- --~ -~-,-,... ~-:-:---------+----+- -r- -r--, 23MH (c2)·----r ---+- -~--:- ,-T -,-,- ;-- --- -+- - -i- -+-r- --'-n-: I I I I I : I I I : ' I I I i I I I I I I I I I I I I I I I I I I
CO= o. : : : I : : : i co= .025 : : : : : co= .05 23MH (C2) : : co= .075 ', : I .I 0 ' , i • ' , ' 'I ' ' ; ' ' , i • I I I r
2 3 4
FIGURE 3-4
567891 2 3 4 567891 2 3 4 567891 2
DETECTOR TRACK FREQUENCY (KHZ)
CALCULATED VALUES FOR DETERMINING CAPACITORS C2 AND C3. TYPE B COUPLING UNIT (SHEET 1)
3 4 5 67891
,~ \8
U1 co -...]
w ... '"O
w I
U1
MFD (C2.)
.35 ....... .
MFD (c I)
.45
.30 .40
.15
C2
i i 7iH(c1) i i l i i i i i i i j l i : j i : : i MINIS
··············!····· t· +·++H+l··············f ...... j .. ?~H ~c ';'--1-·H·f ···-·········(····+···1----1---f ··l· i : 1_2MH (Cl): : : : : : : i : : : j i : : : : :
............. t····-- I I ··i··-~·-+·i·-~-~---···········i---·-- 1. .. : .. L .. L.l..i..L.~--···········~--······L----l .... L .. L.L I : j I I I i j i : 12MH (CJ) i i i i i I I i
············+·-···- ··· t--+-H--H+-------------~-----·-1
-··· :·---l···f·-1--[-H--··---------+······-l---·-l--)---~--l _J 1 • -. • i·JO 23MH (c 1) i i i I l i i i i i i i i i I i i i I CABLE CAP. FEET OF CABLE
·············-;--··· . ··+·l··+·H·i···········-) ....... ··· ... L..l..i .. : . .;..( ............. .;. ....... l.. 7MH (c 1) L (CO) I i , i i Iii j i l , i l 1 i Ii 9MH(~I)~: j ----0---+--------! : ! : : i i : i 23MH (c I): i : l : l l i 12MH ( ) i : i : O ·············-r··· ··i· .. , ·+·+·i-·i··t·:··············~··· ... : ... ; .. : ... : .. : .. : . .)..j. •..••.••••••• , •.•.•. ':.1..'.':".'t: .. :. .. ~ .. !. .025 1000 l ! ! ! l i ! i ! i i i i i i i i i i ! ! i i l .050 2000 ! ! ! i ! i i ! ! i i i i ! ! ! ! ! 17MH (c1)V! i i ! .075 3000
············+···· i··· + -i--·:·+H·i·············-~---- ··i· .. t -i---i--J..;-i.~t. .... 23MH (ci°)~---l ... ~ • .l. .100 4000 l ! : ! ! ! : ! l ; : : : : : : l : : : :· i : ! • 15 6000 ! ! i i i ! i i ! i ! i ! ! i i i i ! ! i ! i i ~25 10,000
-·••••••••••·•too••• 1
... : •• :•••t··i••~•-t•i•••••••••••••+••••• i•• ·1·· i---~•·f··~-~--~·••••••••••••J.•••••• : ..... L ... L.l .. L+ .. J .. +•••••••--•o•J•H•-•••lu•••i • ._.;. .... + .... ~ .. ~.J., .20 ! ' : ! ! : 1 : : : ! l : : ! 1 23MH (C2.) 17MH (C2) i i ! : ! i ! ! : i : i I
············+·····+ ···1 ···j ··H··l·-H·······23~J-(c2) i l··· i ···H+H············-1····· .. : . !i.~.~r-~t-~;.+-1-t·············l········~·-···f ···+··t··P-1) ! i i i ! ! i ! i f : : : 7
1MH ·~~) l i . ~·MH (cz) i ! ! i i ! i i I i ----·------··t··-----1··- ·1·· -f-· }··i--f·t·t·------------i-·······f ···· ----~ ··:-·- .. ·~-~-"'··-··-·······-L·-·u i -.i - -i---+--i-+.LJ ....................... i. .......... i-----~---!--+·f-! .. f .. J
! ! l i 7MH (C2) l i : 1 l .. l 1 ! : i ! i ! !, i ! ! ! ! ! : : i ! ! )
• I • • • • ' • ' l I I I I ' I ' I I . I 23MH (C2 • • : : : : : : : l : : : : : : : : 1 i : ! : ! : : : : 1 ! :
........ _.. ............. r-·····-~----· ......... L .. ~--~-..i...t .............. ~ ........ ; . .. :. --~--. --~- ~.: ;... : ' ' : • l • : : : : : I i I ! : : 12MH ( 2) : : : : : ·: :·~ ....... ·····:········ •.••• ··t··t·t·:·i··············:·······+·····~···+··+·+·+·y·~
.20
.25 Cl
co
• 10
.05
.35
.25
: : : : C . : : : : : : : : : : : : l:: I : : l I ! I I I I 1 : : : ! : : 1 ; : : • ' ' : I I I
1: : : l I 1 t : :
O co=· JOO : i ! : : : ! co=. 15 i 12MH (CZ) 9MH (c2): : ! ! r ! I i ! i 1 2 3 ~ 56~~91 2 3 ~~67891 2 3 456;8~: : ''': I•
FIGURE 3-5
DETECTOR TRACK FREQUENCY (KHZ)
CALCULATED VALUES FOR DETERMINING CAPACITORS C2 AND C3. TYPE B COUPLING UNIT (SHEET 2) J~·
~lJ
~B
WABCD ~
Example:
co
1. 2. 3. 4.
.025
Select Inductance = Find C2 to left = Pick Cl inductance curve Find Cl to right =
3-4 TYPE C COUPLING UNIT
Detector Frequency - 5 KHz
12 MH 0.1 mfd
for 12 MH 0.37 mfd
The type C coupling unit (Figure 3-6) is used to couple a single receiver to the track. The unit incorporates one capacitor (Cl). The values of Cl are tabulated in Table 3-2 and values for Rl in Table 3-3. These values should be adjusted to compensate for cable capacitance (CO) as described for Type A units. Approximate values for CO can be obtained from chart shown in Figure 3-5.
RI
TO BOND co Cl p s TO RECEIVER
-------46 CABLE CAPACITANCE
FIGURE 3-6 TYPE C COUPLING UNI'I1 SCHEMATIC DIAGRAM:
TABLE 3-2. CAPACITOR VALUES FOR TYPE C COUPLING UNITS
Cl (mfd) FREQ. Cl (mfd) FREQ •
• 65 2490 .25 3810 .91 2550 .so 4110 .94 2670 .46 4170 .78 2730 .158 5190 .46 3210 .155 6090 .63 3270
-
5873, p. 3-6
Resistor Rl is used to set the frequency response of the tuned circuits and should be a 1 watt 5% unit selected from the following table:
TABLE 3-3. VALUES OF Rl
FREO. RANGE VALUE Rl ORDERING REFERENCE
2490 to 3270 Hz 0.27 ohm '1735458 3810 to 6090 Hz 0.56 ohm J735457
Resistor R2 is selected to set the receiver sensitivity and is installed as a fixed resistor during the initial installation. Use 10%, 1/2 watt carbon resistor.
3-5. TYPED COUPLING UNIT
The type D coupling unit (Figure 3-7) is used to couple a combination of a cab signaling transmitter (single channel) and a track circuit receiver to the tracks. The unit incorporates two capacitors (Cl and C2). Since capacitor C2 and the input transformer of the receiver form a parallel resonant circuit, it will offer a very low impedance to the cab signal transmitter frequency. Therefore, in calculating the value of c_apacitor Cl, simply subtract cable capacitor (CO) from .553 mfd. To determine the value of C2, refer to Figure 3-8. Approximate values of CO can be obtained from chart shown in Figure 3-5.
WABCD ~
Cl TO CAB
TRANSMITTER
TO BOND CO
I CZ
CABLE CAPACITANCE
RI
p s TO RECEIVER
FIGURE 3-7 TYPED COUPLING UNIT SCHEMATIC DIAGRAM
5873, p. 3-7
WABCO 'v..A.'v
Ul a ( 0:
~ 0 0: u :E
N u
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
O. I
0 0
FIGURE 3-8
5873, p. 3-8
.05 • JO .15 .20 .25 CO CABLE CAPACITANCE MICROFARAD$
CAPACITOR VALUES FOR CAPACITOR C2 OF TYPED COUPLING UNIT
3-5.1 Selecting C2 From Graph
With CO known, find the curve for the particular receiver frequency, then refer to the left column for the value of C2.
See Table 3-3 for values of Rl.
WABCD ~
Resistor R2 is selected to set the receiver sensitivity and is installed as a fixed resistor during initial installation. Use 10%, 1/2 watt carbon resistor.
3-6 TYPE E COUPLING UNIT
The type·E coupling unit (Figure 3-9) is used to couple one cab signaling (single channel) transmitter and two different track circuit receivers to the tracks. The unit consists of three capacitors (Cl, C2, and C3). As was the case for the type D coupling unit, the value of Cl is .553 mfd minus the cable capacitance (CO). To determine the values of capacitors C2 and C3, refer to Figure 3-8. Approximate values of CO can be obtained from chart shown in Figure 3-5.
See Table 3-3 for values of Rl or R3.
Select Rl for receiver #1 frequency. Select R3 from Rl Table for receiver #2 frequency.
Resistors R2 and R4 are selected to set the associated receiver sensitivity and is installed as a fixed resistor during initial installation. Use 10%, 1/2 watt carbon resistor.
3-7 CAPACITOR SELECTION
The following capacitors have been tested and are recommended for use on the coupling units especially with transmitters where large AC voltages·are encountered:
.5 MFD, 600WV - J706702
.25 MFD, 600WV - J706700
.10 MFD, lOOOWV - J706701
.05 MFD, lOOOWV - J706698
.03 MFD, lOOOWV - J706697
.02 MFD, lOOOWV - J706696
.01 MFD, lOOOWV - J706695
.005 MFD, lOOOWV - J706699
5873, p. 3-9
WABCO ~
TO BOND co
CABLE I CAPACITANCE
Cl
CZ
C3
R3
TO CAB
TRANSMITTER
TO RCVR #I
TO RCVR #z
FIGURE 3-9 ?YPE E COUPLING UNIT SCHEMATIC DIAGRAM
5873, p. 3-10
SECTION IV
INSTALLATION INFORMATION
4-1 CARRIER FREQUENCY ALLOCATION
WABCD ~
Audio frequencies selected for use in the track circuits were determined by theoretical and empirical data and are designated as Fe and Fl through Fll. The allocation of these frequencies is described in the following sub-paragraphs.
4-1.1 CAB SIGNALING SYSTEM CARRIER FREQUENCY
The cab signaling system uses one frequency, Fe - 990 Hz
4-1.2 DETECTOR TRACK CIRCUIT FREQUENCIES - AUTOMATIC TERRITORY
The detector track frequencies used in the automatic territory are grouped into two classes as follows:
Class I Class II
Fl - 2550 Hz F2 - 2490 Hz F3 - 2730 Hz F4 - 2670 Hz F5 - 3270 Hz F6 - 3210 Hz F7 - 3810 Hz F8 - 4110 Hz F9 - 4170 Hz FlO - 5190 Hz
4-1.3 DETECTOR TRACK FREQUENCIES - INTERLOCKING
The Detector Track Frequencies used in the interlocking territory are as follows:
F3 - 2730 Hz F5 - 3270 Hz F7 - 3810 Hz
4-1. 4 SEQUENCES
FlO - 5190 Hz Fll - 6090 Hz
A four or five way sequence may be used in assigning track circuit frequencies. Each of these sequences follows:
A. Four-Way Sequence
F5-F9-Fl-F7-(F5) F8-F6-F4-FlO-(F8)
B. Five-Way Sequence
F5-F9-Fl-F7-F3-(F5) F8-F6-F4-Fl0-F2-(F8)
5873, p. 4-1
WAEiCD ~
4-2 CARRIER FREQUENCY ASSIGNMENTS
Frequencies should be applied in the following order:
A. In double track automatic territory, Class I frequencies should be applied to one track and Class II to the other. With additional parallel tracks, classes should be alternated.
B. When assigning frequencies to a track in an automatic territory, the same class of frequencies and direction of sequence should be used throughout the territory between interlockings. A sequence may be started with any frequency and in either direction. Five-way and four-way sequences may be alternated as desired (four-way sequences are derived from five-way sequences by dropping frequencies F2 and F3). Nonadjoining detector track circuits do not require much frequency separation.
C. In interlocking territory bounded by insulated rail joints, frequencies F3, FS, F7, FlO, and Fll may be used in any configuration, but must not be repeated unless separated by insulated rail joints. In effect, all of the detector track circuits may be adjoining in an interlocking territory.
D. It is desirable to use the lower frequencies in each class where possible, for the longest detector track circuits or for the longest cable runs to the centralized housing, to provide maximum operating margins. Usually, the two conditions occur together.
E. In multiple track territory where Minibonds are nearly opposite, a detector transmitter should not be applied to one Minibond with a 60 Hz separation from a detector receiver on the opposite Minibond (Fl-F2; F3-F4; F5-F6).
4-3 CODE RATES
Seven code rates are available. The number used in any given system depends on the number of speed commands desired. The code rates are 20.4, 16.8, 13.6, 10.8, 8.6, 6.6 and 5 Hz. They are selected with the highest code rate giving the highspeed command and lower code rates (in descending order) giving the lower speed commands. All systems require at least one code whether speed commands are required or not, in order to operate the wayside receiver.
4-4 MINIBOND APPLICATION
A. The Minibonds and cables are the only equipment required outside of the centralized housinq for the AF detector track circuits and cab signaling track energy transmission.
5873, p. 4-2
WABCD ~
B. The Minibond is a small impedance bond particularly designed for use with the AF circuits. It is 6 inches in width and depth and 10 inches in length and weighs approximately 60 lbs. An extension is provided on the top plate for mounting on a single crosstie, either between the rails or on the end of a crosstie, or it may be inverted and mounted on a concrete roadbed or pedestal. The core and coils are encapsulated, the track terminals protruding 3 inches from the encapsulation. The terminals for the higher voltage winding are covered by a water-tight cover with a self-sealing cable outlet. The track terminal lugs each capable of holding two 350 MCM or 250 MCM cables, are bolted to the track terminals, either at right angles or crosswise.
C. The track winding of the Minibond has DC resistance of 0.00003 ohm. It is rated at 2,000 amperes per rail continuously, but can stand many times this current for short periods since it'has a large thermal capacity. The track winding is center-tapped for connection to the propulsion return feeders or structure or for crossbonding. Two terminals are provided for mounting terminal lugs, which may be stacked, if necessary.
When running rails are both used for propulsion return, the Minibond center-tap provides for crossbonding to minimize voltage drop in the propulsion system. Even in propulsion systems which do not employ the running rails, the Minibonds provide a grounding path for the running rails so that insulation failures in the propulsion system will not create a safety hazard to people on trains.
D. The Minibond will function properly in the AF circuits with an unbalanced current of up to 200 amperes. To minimize unbalance, the track leads should be connected to the two running rails exactly opposite, and should be equal in length when the center-tap is ·used for propulsion return. At insulated rail joints and at other special points in interlockings, it may be necessary to run the track lead along the rail for a short distance to insure cab signaling continuity.
E. The cable used between the Minibond (higher voltaqe winding and the centralized housinq should be twisted pair #14 copper wire cable with a capacitance of not over 30 picofarads per foot. In general, l~ngth of cable should not exceed one mile, although somewhat longer cables may be used at the lower frequencies and with shorter track circuits.
F. The Minibonds are tuned in the centralized housing by the coupling units for the AF transmitters and receivers. Tuned impedance, referred to the full track winding, is approximately 0.25 ohm at 1 KHz to .4 ohms at 5 KHz.
5873, p. 4-3
WABCCJ ~
4-5 DETECTOR TRACK CIRCUIT DETAILS
A. Maximum operable length of AF detector track circuits depends upon many factors including the ballast_leakage resistance, size and type of running and guard rails, gage, spacing between tracks, crossbonding, AF frequency, interference levels and transmitter capacity, adjustment for extended shunt area and shunting, and the characteristics of the AF equipment.
B. For maximum track circuit length (transmitter to receive bond) for various operating frequencies and ballast conditions, refer to Figure 4-1.
For center fed circuits the longer track circuit side should be within the maximum length in Figure 4-1, and the shorter side no less than one-fourth the longer side to prevent unbalance in loading on the transmitter.
C. Ballast leakage resistance is not likely to fall below three ohms per thousand feet in well maintained track with good drainage. However, ballast resistance will be lower when wet and dirty, particularly if crossties are in poor condition or ballast is in intimate contact with the rails. Guard rails have lower ballast resistance because of increased contact with crossties and ballast.
D. Size and type of running and guard rails, gage, and spacing between tracks affect the impedance of the rails and have a slight effect on the operable length. They also have an effect on the crosstalk between tracks which may be a limiting factor. Crossbonding may affect broken rail protection. Normally, the broken rail protection can be obtained (unless guard rails are connected to the running rails) with crossbonding at every Minibond location within the lengths specified. If welded rails are not used, joints should be bonded with capacity bonding.
E. The cab signaling track energy transmi'tter is designed to limit the rail current so that it will not induce enough current in the parallel track to cause interference. Consequently, the same cab signaling carrier frequency is used throughout the system, greatly simplifying controls and carcarried equipment. Detector track circuits are protected from crosstalk by the use of different frequencies. According to field tests, the energy level at which the detector and cab signaling receivers operate is considerably above the noise level. The AF transmitters are designed with sufficient output capacity to handle the track loads.
F. The track relay is a Style PN-150 B vital relay. The receiver circuitry provides quick shunting and slow pickup time
5873, p. 4-4
(J w 0: b.
CJ z
~ 0: w n. 0
NOTE
3 OHMS BALLAST 5 OHMS BALLAST
I I I I I '/' ; I I '/' : I I I I I I I I : : I : : I I I l I : I I : ; s.o ---:---"---J----1----1---' -i----,----:---'--t- -r---1---.&.--J---r' --~--.1
I I I I I I I I I • : I I : I I I I I I I I I I I I I I • I I I I I I I L I I • I I ---'---T---1---r---l---t- .1---r---t---r- --.l--- ---t---,---'--,---: I I I I t I I I I I I I I I I I : I I I : I I I I I I I I I I I I I I
s.o __ ,. - - •- - :---,---1---t---, 4- -'---1- - T- +--L--1- --t---'-- t---, I : I I I I I ' l I I : I I I I I I I I I I ' I I I I I I I I I
' ---.. ---l.--"1---1- --l---'---T ---' --- - ·'---,- _.J - -'--t- -'---'- --+-- -1 . I : t I I : 1 I : I I I I I I I , 1 • I I I I I I I I I I I I I I I I I I I I' .J I .l I
4. 0 ---r- -1-- -1---;---i - _,._ --t--"t--- - ---,-- ... --... ~,---, -- --+--• : i I : : : : : : : I I l : : : : :
---}--.,--...:-- .... --.&.---t- _.__+-..:.-- -l -1-~-+- -1--t--r---' I j I I I I : 1 I : I I I I I : I I • I I I ' I I I I I I I 3 0 ---'--,- -L- ..J __ J._ -t- --'- -T- -'---,- -+ _._ --1--t- -1- .l--r--;
• : I : : : I ; I : I I I I I I I I I I I I I I I I I I I I I I I ---t- - t--1---t - -f---t---1---,- -,- --.- --'-r,- - ---t---1--L.- - - I I I I I I I I I I I I I I I I I • I . I I I I I I I I IL It I I I I
2.0 ·--..---•---t--1---,---+--1---1--1--T--I-1--~-- --1--1---1--- 1
I • I i I I I I I I I I ' I I '
: : : • I ' : I I I ii ' I I I I I ---;--~-r--:--~--:--i--i- -i--:--.-1-:--t-- - ~--:--t--:
' : I : I ' I I I I I I I I I I I 1.0 --:- - L -t- - r-,- ..1--L- L - '--;- ...!. ,-1-- r' - --i- --•--,---'
I I I I I I I I I I I I I I I I I I I I I I I I I • I : I I I I I I I ~ I I I I - --'- - t- - 'T - -,- -•- -..I. --T--, ---, - -J.--•-t-1---1- -- - -+-- -'-- ----, f • t • : ' • I • I • • I I I • I
: : : : : : : 1 : : I I t I ; I I
1000 1200 1400 1600 1800 2000 2200 2400
MAX LENGTH (FT.)
I. CURVE SHOWS MAXIMUM WORKING LENGTH FOR DETECTOR TRACK CIRCUIT WITH BROKEN RAIL PROTECTION.
2. WHERE CAB SIGNALING IS INCLUDED THE MAXIMUM RANGE IS 1850 FT. AT 3 OHMS BALLAST AND 2100 FT. AT 5 OHMS BALLAST (DOTTED LINES)
FIGURE 4-1 MAXIMUM TRACK LENGTH FOR VARIOUS OPERATING FREQUENCIES AND BALLAST CONDITIONS
w~sca ~
5873, p. 4-5
WABCO ~
guards against momentary loss of shunt, producing good shunting performance.
G. Adjustment of the detector transmitter and receiver along with track circuit length, ballast leakage resistance, and frequency, determines the shunting sensitivity and extended shunt area. The transmitted signal voltage can be controlled by adjusting the potentiometer in the power amplifier. Separate potentiometers are used to adjust the wayside and cab signaling output.
H. The receiver sensitivity is set at the time of installation of the system by putting fixed resistors on the coupling unit. When a detector transmitter feeds two track circuits, it should be adjusted first to provide an adequate signal for the longer track circuit, then the receiver of the shorter track circuit is adjusted.
I. Basically, the higher the rail voltage and receiver sensitivity the lower will be the shunting sensitivity, and the shorter will be the extended shunt area under high ballast conditions. Thus, the adjustment of the AF transmitter and receiver determines the extended shunt area, which is about the same at both ends. At low ballast resistance, because of the greater attenuation, the shunting sensitivity and extended shunt area will increase. The amount of increase depends upon the length of track circuit and frequency used.
J. Power Requirements:
1. Coder
2. Oscillator
- 0.04 amp. feeding 20 power amplifiers 0.01 amp. (no load}
- 0.02 amp. feeding 20 power amplifiers 0.005 amp. (no load}
3. Mixer, Preamplifier & Power Ampli-fier 3.2 amp. at max±mum output
4. Receiver -0.1 amp. when relay is energized 0.05 amp. on no signal
K. Maximum cable capacitance for track leads is 30 picofarads/ foot.
L. Maximum distance Minibond to central house is 5000 feet.
5873, p. 4-6
WABCC ~
SECTION V
MAINTENANCE
5-1 INTRODUCTION
This section is provided to aid maintenance personnel in servicing the wayside equipment of the Audio Frequency Coded Train Detection and Cab Signaling System. Two levels of maintenance are covered, field level maintenance and shop level maintenance. The shop maintenance portion is supplied for users who desire to repair malfunctioning printed circuit boards themselves. It is assumed in this section that the required equipment is available - a list of recommended equipment is included, and that shop maintenance personnel possess the skill required to repair, test, and calibrate the printed circuit boards.
5-2 FIELD MAINTENANCE
5-2.1 Tuning and Level Adjustments
This section provides the procedures for tuning the Minibonds, adjusting the signal levels for the cab signaling and track receivers and adjusting the gain of the track receivers.
5-2.1.1 General Tuning Procedure for Wayside Detection Receivers
The simple circuit shown in Figure 5-1 is used to illustrate the general procedure of tuning a track circuit and should be helpful in understanding the procedure of adjusting more complex circuits. This circuit is comprised of a single channel mixer and amplifier for transmitting the wayside frequency controlling two track circuits (center fed).
1. Disconnect,at the main terminal board the cable leading to the Minibonds at terminals 1 and 2 of each coupling uni~ and with the use of a multimeter; e.g., Simpson Model 260, adjust the track resistors RT until the total resistance of the track leads pluo the Minibond secondary is 25 ohms. Reconnect cables at the main terminal board.
2. From the tables and curves of section III determine the values of capacitance C and resistor Rl. Install the next lowest commercially available capacitor or capacitors to bring the total capacitance 20% below the calculated value.
5873, p. 5-1
u, 00 -..J w ...
I'd
u, I
N
r I I L
! lsc
I.. ....
RT
I TYPE "c"
I COUPLING UNIT
I R21
Sl I _J
1500' ........ ... ,-
RT
-, I TYPE ''A' I COUPL.ING I UNIT
_J
r-!---1, I POWER AMP I
i-f---f-~ I PRE AMP I
~f---t~ L+::"-y-J
,---!--, rf---, I I I WAYSIDE I I CODER I I ~6~; I L ____ _J L ___ ..J
soo•
FIGURE 5-1 SIMPLE TRACK CIRCUIT
~ ...,
r I I L...
RT
., I I I
Rtj
I TYPE"c" lcOUPL.ING 'UNIT
I I I I
'_j
'
I m n 0
WABCD ~
3. Before attempting to tune the type A.coupling unit, determine which side of the track circuit is longer. It will be necessary to set the current level to guarantee operation of the track relay on the longer side (in this case TRl) first.
4. Jumper terminals 1&2 of both type C coupling units with a short clip lead and install a current probe, e.g. Tektronix Type P6016, on the shorting wire on the longer side. This will be used to measure the short circuit current (ISC) and will guarantee operation of track relays. In lieu of using a current probe a known one ohm resistor may be connected in series with one track lead and the voltage drop across the one ohm resistor monitored with an AC voltmeter such as Hewlitt-Packard Model 4 03A. (See Figure 5-2)
5. Set the coder input so that a steady output signal is obtained from the power amplifier.
6. Install a decade capacitor box across C of the type A coupling unit and adjust until the maximum LSC reading is obtained.
7. Refer to Figure 5-2 to determine the correct value of ISC--in this case (for frequency 2670) 6.2 ma peak-to-peak or 6.2 millivolts across the one ohm resistor. Adjust the transmitter output level by turning the screwdriver adjustment potentiometer on the mixer PCB until the proper ISC level is attained. Then tighten the potentiometer locknut. Recheck the capacitor setting as in (6) above and install permanent fixed capacitors.
8. Remove the short across Cat TRl end, and with a decade capacitor box adjust the capacitor value until the maximum voltage is obtained across Cat this end. Repeat this procedure for the short track circuit side. (Adjust cat the TR2 end for maximum voltage).
9. With a decade resistor box select the value for R2 at the TRl end which just picks up the relay (5.3 VDC). Permanently fix equivalent 1/2 watt carbon resistor in place of the decade box.
10. Repeat step (9) to adjust the other receiver (TR2) relay.
5873, p. 5-3
WABCO ~
!•sc r--u---1 I I OHM I
ALTERNATE I I
-----
1 - I I I L _______ ...J
FREQUENCY (CPS)
990 (Fl) 1080 (Fl &F2 mean) 1170 (F2) 2490 (F4) 2550 (F3) 2670 (F6) 2730 (F5) 3210 (F8) 3270 (F7) 3810 (F9) 4110 (FlO) 4170 (Fll) 5190 (Fl2) 6090 (Fl3)
ISC CURRENT
PEAK-TO-PEAK (MA)
17.2 15.8 14.4
G.8 6.8 G.2 G.2 5.4 5. 1 4.5 4.2 4.0 3.4 2. 8
TRANSMITTER
RMS (MA)
6.1 5.6 5. 1 2.4 2.4 2.2 2.2 1. 9 1. 8 1. 6 1. 5 1. 4 1. 2 1. 0
FIGURE 5-2 ISC CURRENT CALCULATIONS FOR 1100 FT. (APPROXIMATE) TRACK CIRCUIT
11. Measure the transmitted voltage at terminals 1 & 2 of coupling unit A. Re-adjust the transmitter output level to obtain a voltage which is twice the measured value. Retighten the potentiometer locknut.
12. This completes adjustment of the track circuit.
5873, p. 5-4
5-2.1.2 General Tuning Procedure with Cab Signaling and Wayside Detection Circuits
WABCD ~
Figure 5-3 shows a typical tuning problem where both cab and wayside frequencies are coupled thru a type B coupling unit to the rails and two receivers and a cab signal feed are coupled to the rails· thru a type E coupling unit. The problem is to determine the exact values of the capacitors and to set the signal strength for proper operation of receivers and cab signaling. The following procedure is recommended:
1. Adjust the track resistors as described in a of para. 5-2.1.1
2. Install the approximate capacitor, resistor, and inductance (Ll) values as described in (a) of paragraph 5-2.1.1. Set inductance (Ll) to proper value by selecting proper terminal on coil.
3. At the entering end of the track circuit, install a jumper across the type E coupling unit which will be used to monitor the cab signaling ISC. (Use current probe around jumper.)
4. See the code input to the amplifier so thnt the power amplifier is applying only cab signaling energy to the rails.
S. Install a decade capacitor box across Cl of the type B coupling unit and a9just until ISC is a maximum at the entering end. Set the ISC level by the procedure as outlined in 7 of paragraph 5-2.1.1, .but do not install permanent capacitor yet.
6. Set the coder input on the amplifier so that the wayside frequency is transmitted continuously and the cab signaling frequency is turned off. With a decade capacitor box across C2, adjust C2 of the type "B 11 couplinq unit and the power amplifier output on second.channel to produce the proper ISC at the long end of the track circuit. Alternately apply and remove the 24 VDC from coder input and recheck and adjust Cl, C2 and output until adjustment is optimum. Using the procedure outlin~d in (9), (10) and (11) of paragraph 5-2.1.1, adjust C2 of the Type E coupling unit and set the receiver sensitivity. (The lowest code rate on the type B coupling unit should be applied when adjusting the receiver.)
5873, p. 5-5
u, co ....... w ...
"O
u, I
°"
ENTERING END
----+
RCVR 2670
REL.AV 2
RT RT
r-1----1-ISINGL.E r ,----,-, DUAL.
I • • !CHANNEL. • • I CHANNEL. NIT UNIT
POWER AMP ~CAB) I POWER AMP (CAB Be I PRE-AMP I I PRE-AMP I WAYSIDE)
I MIXER I I MIXER I L_T ____ T_J LT_T_T_T_J
WAY OSC
CAB osc.
CAB
osc t 990
CAB ON-OFF
CODE·,------...1.----------, REL.AV
CODE SELECTOR
Be CAB ON-OFF
CODERS
WAY OSC t
2670
FIGURE 5-3 TYPICAL TRACK TUNING PROBLEM USING TYPE B COUPLING
~I
7. The determination of capacitors C3 and Cl of the type E coupling unit will be determined during the tuning of the next track circuit located to the left and the procedure will be essentially the same as outlined for the two specific examples given.
8. Note that the cab signal transmitting voltage should also be increased to twice the level required for ISC similarly to the detection signals as described in step 11 of 5-2.1.1.
5-2.2 System Troubleshooting
WABCD ~
This section outlines the procedures to be used in restoring a faulty system to an operational state. This may involve a re-adjustment or troubleshooting, depending upon the nature of the failure. Before proceeding, however, system performance· ·should be compared with the parameters outlined under the adjustment procedures given in Section above. Wherever possible, re-adjustment should be accomplished and then if necessary, troubleshooting procedures should be performed.
5-2.2.l Troubleshooting
Since field troubleshooting involves component replacement the procedures herein are designed to aid in rapidly locating a faulty component. Based on this, there are two approaches that can be followed: (1) component substitution and (2) signal input and output checks.
5-2.2.2 Component Substitution
When substituting components, make sure that the new component is operating correctly and that it is properly installed in the panel. A visual inspection of the connector and leads should also be performed at this time to insure that the fault does not lie in the wiring.
5-2.2.3 Signal Checks
Where it is not possible to carry a complete set of replacement components, the output of the various components can be measured to locate a faulty component. After the faulty component has been located, it should be returned to the shop for service and repair. Information for shop maintenance is given in the Shop Maintenance portion (paragraph 5-3) of this section.
5873, p. 5-7
WABCD ~
NOTE
Following the replacement of a component, the system should be readjusted in accordance with the procedures outlined in paragraph 5.2.1.
5-3 SHOP MAINTENANCE
This section is provided to aid maintenance personnel in servicing the printed circuit boards of the Audio Frequency Coded Train Detection and Cab Signaling System (Wayside Equipment).
The following information is included for each printed circuit board: schematic diagram, circuit description test procedur~, parts location drawing, and parts list .•
5-3.1 Recommended Test Equipment
Oscilloscope
Signal Generator
Power Supply
Power Supply
Resistance Decade Box Transformer Relay
Resistors (2) Resistor Resistor Resistor
Tektronix 531 or equivalent
Wave Tex 115 or equivalent
24 VDC less than 0.2V P-P ripple.
7 VDC, less than 0.2V P-P ripple.
0.25 Kohm, 1% UN434762 PN150B
10 K ohms 1000 ohm, 75 watt 10 ohm, J.O watt 100 ohm, 1 watt
5-3.2 Coder PCB Maintenance (UN451054-1202 to 1208)
5-3.2.1 Coder PCB Circuit Description
The Coder PCB generates the code rates that are used to modulate the signals applied to the rails. The available code rates are 5, 6.6, 8.6, 10.8, 13.6, 16.8, and 20.4 Hz. The output of the coder is a 24 V DC square wave at 50% duty cycle into a 560 ohm load. Power input required is 0.04 ampere at 24 V DC. A twin tee oscillator is used to generate the code rates.
5873, p. 5-8
U1 co -..J w .. tel • U1 I ~
Cl
RI
RB 22k.
I
RZ
RS CZ ~ T.'S:D.,
.SV/DIV SO MS/DIV* gnd. common
I -----C.3 ~ Reo •
R£J /,SK
RIO C4 S3.9K . , MFD.
8/Z.K
l<.15 G,Si'.
DI HD441B
F1 B24(+)
1 1 AMP.
lOV/DIV SOMS/DIV* gnd. conunon
~ ,4 OUTPUT
G,Nt)
* Period of wave is dependent on ass~gned Code rate
17&.te. .c OM MON
FIGURE 5-4 CODER PCB SCHEMATIC DIAGRAM (UN451054-1202 to 1208) ~I
WABCD ~
The amplifier portion of this oscillator consists of transistors Ql, Q2 and Q3 in a direct coupled gain stabilized amplifier. Ql is a unity gain emitter follower. Q2 is a grounded base stage whose gain is determined by the ratio of R8 to R7, and Q3 is a grounded emitter stage with emitter degeneration to stablize its gain. Capacitor C4 eliminates high frequency parasitic oscillations. Frequency and feedback within the twin Tare fine tuned by resistors R4 and RS, whereas, Rl, R2, R3, Cl, C2 and C3 are selected to establish the approximate operating point.
Emitter follower Q4 provides isolation from the oscillator and QS acts to square up the sine wave output from the oscillator section. Diode Dl and resistor RlS help to establish the 50% duty cycle for the output.
5-3.2.2 Test Procedure for the Coder PCB
5873, p. 5-10
1 Connect a 24.0 ± 1 voe power supply (with ripple factor less than 0.2V P-P to pin 1 (+) and pins 17/18 (-).
2 Connect a 560 ohm, 1 watt resistor between pins 4 and 17/18.
3 Verify that the output at pin 4 is a 24.0 to O.OV square wave with a frequency of within± 1% of the specified value.
I
L ..
C:J re•, L _J
uo c ::::J
Ill c ::::J ~
()03 fl
112LJ ()
14
HZ CODER VN451054·120
r ·L _,-
I
_ _J .,. r-: ::::J
Rt c ::::J . ,~
112\.) c ::::J
19
113 c :::::J
R14 c ::::J ,-- -'- ±..::::i
C5
Fl -r--, -L- _J
RS c :::::] r-L_
' L
RIS c ::::J 116
C:J
C2
Cl
P.6 r=: :::::J
' _J
i _J
, R3n
(_)01 lJ
( JI! DI
C) 05
nnnnnnnnn ~·
WABCC ~
FIGURE 5-5 CODER PCB PARTS LOCATION DIAGRAM
5873, p. 5-11
WABCO ~
LEGEND
Q2,Q4,Q5 Ql,Q3
Dl Rl,R2 R3 R4 RS R6 R7 R8 R9 RIO, Rl2 Rll Rl3 Rl4 lUS Rl6 Cl,C2 C3 ~4 cs 1<11
SUFFIX
--1202 ,...1203 ,...1204 ,...1205 ,...1206 ,...1207 ,...1208
5873, p. 5-12
,.
PARTS LIST
CODER PCB UN451054-1202 to 1208
QUANT. DESCRIPTION
Board,Printed Circuit 3 Transistor, 2N3644 2 Transistor, 2N3643 5 Pad, Transistor Mtg. 1 Diode, HD4418 2 Resistor 1 Resistor 1 Resistor 1 Resistor ohm 1 Resistor,8.2K, l/2W 1 Resistor, 390 ohm l/2W 1 Resistor, 22K ohm, l/2W 1 Resistor, l.8K ohm, l/2W 2 Resistor, 3.9K ohm, l/2W 1 Resistor, 6.2K ohm, l/2W 1 Resistor, 2K ohm, l/2W 1 Resistor, 3K ohm, l/2W 1 Resistor, 68K ohm, 1/2W 1 Resistor, 30K ohm, 1/2W 2 Capacitor, 200V, 5% 1 Capacitor 1 Capacitor, • lMFD , 2 0 0 V, 5 % 1 Capacitor,33MFD,20WVDC,10% 1 Fuse, 1 A., 3AG
FREQ. RESISTOR Rl & R2 HZ (1/8 WATT 1%)
OHM
. 5 UJ735322 40 .2K 6.6 UJ735320 31.6K 8.6 UJ735321 33.2K
10. 8 UJ735317 26.?K 13.6 UJ735319 30.9K 16. 8 UJ735316 25.SK 20.4 UJ735318 30.lK
PART NO.
UM45105.4-1201 UJ731283 UJ731282 UJ7920 72 UJ723742 See Below See Below T.B.D. T.B.D. UJ720775 UJ720763 UJ720843 UJ720825 UJ720764 UJ720771 UJ7210 80 UJ721256 UJ720850 UJ721260 See Below See Below UJ706827 UJ706618 UJ710007
RESISTOR R3 (1/8 WATT 1%)
OHM
UJ735315 10. 7K UJ735097 8.25K UJ735100 llK UJ723806 7.5K UJ735097 8.25K UJ72 3806 7.SK UJ735097 8.25K
WABCD ~
PARTS LIST CODER PCB UN451054-1202 to 1208 continued
CAPACITOR Cl & C2 CAPACITOR C3 FREQ. (100 VDC, 5%) (100 VDC, 5%)
SUFFIX HZ PART NUMBER MFD. PART NUMBER MFD.
-1202 5 UJ706808 1 UJ706810 2 -1203 6.6 UJ706808 1 UJ706 810 2 -1204 8.6 UJ706807 .68 UJ706809 1.5 -1205 10. 8 UJ706807 .68 UJ706809 1.5 -1206 13.6 UJ706806 .47 UJ706808 1 -1207 16. 8 UJ706806 .47 UJ706808 1 -1208 20.4 UJ706805 .33 UJ706807 • 6 8
5873, p. 5-13
WABCO ~
5-3.3 Oscillator PCB Maintenance (UN451054-1302 to 1313)
5-3.2.1 Oscillator PCB Circuit Description
The Oscillator PCB generates the carrier frequencies for train detection and cab signaling. The frequencies are 2.49, 2.55, 2.67, 2.73, 3.21, 3.27, 3.81, 4.11, 4.17, 5.19, 6.09 KHz (wayside) and 990 Hz {cab). Only one frequency is used for the cab. The oscillator output is a .73 V rms sine wave into a 2 Kohm load. Power input required is 0.02 ampere at 24.0 V DC.
The carrier oscillator empl9ys a conventional Colpitts circuit with frequency determined by adjustable inductor Ll and capacitors C2, C3, and C4. The L-C ratio of this tuned circuit, as well as the feedback ratio determined by C2, C3, and C4 insure good frequency stability and waveform. A thermistor across a portion of the emitter resistance R4 compensates for temperature effects on the Q of the tuned circuit, therefore the output level will be fairly constant with temperature changes. R4 also sets the output amplitude to the specified value. Emitter followers Q2 and Q3 serve to isolate the oscillator from the circuitry that it must drive. Cl and R8 provide decoupling from the power line.
5-3.3.2 Test Procedure for Oscillator PCB
1. Connect a 24.0 ± 1.0 VDC power supply to pins 1 (+) and 17/18 (-). (Power supply ripple should not exceed 0.2 V P-P).
2. Using an oscilloscope verify that the output, pin 8 is a 0.73 ± 0.03 RMS sinewave, the frequency of which is within± 0.1% of the specified value.
3. Verify that the DC voltage at the output, pin 8, is 13.5 ± 1.35 VDC.
5-3.4 Mixer PCB Maintenance (UN451054-1502 and 1503)
5-3.4.1 Mixer PCB Circuit Description
The mixer PCB accepts inputs from the oscillator PCB's and from the switching section of the Pre-Amplifier PCB. The Coder PCB alternately switches - at the code rate - the two oscillator inputs to the output circuitry.
5873, p. 5-14
u, 00 -...)
w .. i-0 • u, I .....
u,
Cl 21. IY\rD,
SOMV/DIV
.lMS/DIV
+
RI Ill<.
1 C2 4tv'\S:l).
C3
CQ 1 2N3~43
R.3 1"'8l>
R.5 .3(.
200.n.. 1<8
2N3'=>43 ~2.
101<. R,
Fl
B24C+) 1
.SV/DIV - *.l MS/DIV
Q3 . / 2N2270/
• > S O vT P lJ T 5.~K 1210
I L • • • ' • > 11 &.18 c OM M ON 7 A G6JD.
R" .JK.
Rto l<E{i)UIR.E.'D ON 990 H'Z. Osc.,1..t..AToR. OAJt..Y
*Period of Waveshape is Dependent on Operating Fre~uency.
NOTE - GND. COl~~ON
FIGURE 5-6 OSCILLATOR PCB SCHEMATIC DIAGRAM (UN451054-1302 to 1313) ~I
WABCD ~
HZ OSCILLATOd UN451U54-13
r -,_ L _J-
rt
r+l n n Cl i]2 Rl
l J LI C4 •
L_
' L_ r'
··~)
s3:i
C3
-, _J -, _J
14 C:J
r- ,
L .J R5
,. , '- .J II
Fl _,--- --, -L- _J
Y. BK.
17 C:J
RIO C:J
C2
I _J
RII c :J ,..... \... )03
C19
:J ('02 ..._/
~1111111111111111 FIGURE 5-7 OSCILLATOR PCB PARTS LOCATION DIAGRAM
5873, p. 5-16
WABCCI ~
PARTS LIST
OSCILLATOR PCB UN 451054-1302 to 1313
ITEM QUANT. DESCRIPTION PART NUMBER
1 Board, Printed Circuit UM451054-1301 Q3 1 Transistor, 2N2270 UJ731186 Ql, Q2 2 Transistor, 2N3643 UJ731282
3 Pad, Transistor Mtg. UJ792072 Rl 1 Resistor, llK ohm, l/2W UJ721258 R2 1 Resistor, 18K, 9ohm,l/2W UJ720826 R3 1 Resistor T.B.D. R4 1 Resistor See Below RS 1 Thermistor, 3000 ohm
, .. ' GE 10201 UJ735368 R6 1 Thermistor See Below R7 1 Resistor, 3K ohm, l/2W UJ721256 R8 1 Resistor, 200 ohm, l/2W UJ721250 R9 1 Resistor,lOK ohm, l/2W UJ720 8 83 RlO 1 Resistor,5.6K ohm, l/2W UJ720768 Cl 1 Capacitor,22mfd., 10% UJ702956 C2 Capacitor See Below C3 Capacitor See Below C4 1 Capacitor See Below Ll 1 Choke, Pot Core See Below Fl 1 Fuse, l/4A., 3AG UJ710006
POT CORE CHOKE FREQ. RESISTOR R4 THERMISTOR R6 UN451030
SUFFIX HZ (1/2 WATT (GE-10201) Ll, C2 & C3 OHM OHM SUFFIX C4
-1302 990 UJ723134 9. lK UJ73536 8 3000 -0820 WITH -1303 2490 UJ721256 3K -0821 --1304 2550 UJ721256 3K -0822 --1305 2670 UJ721256 3K -0823 --1306 2730 UJ721256 3K -0824 --1307 3210 UJ721256 3K -0825 --1308 3270 UJ721256 3K -0826 --1309 3810 UJ721256 3K -0827 --1310 4110 UJ721256 3K -0828 --1311 4170 UJ721256 3K -0829 --1312 5190 UJ721256 3K -0830 --1313 6090 UJ721256 3K -0831 -
5873, p. 5-17
WABCCI ~
Since the Mixer PCB consist of two similiar channels only one of the two channels will be described below: Rl prevents excessive loading on the oscillator where multiple mixers are connected to the same oscillator. Ql is an emitter follower with unity gain. Q2 is an amplifier with a gain of approximately three as determined by the ratio of R3 and R4. C2 is an AC by-pass capacitor. With the collector supply removed, it can be seen that Ql cannot have a gain of more than 1/10, determined by the ratio of Rl/R2 and Q2 will also have a low gain. If either transistor becomes shorted, the gain for Ql still cannot exceed 1/10. Gain for Q2, if it were shorted, would remain very low because this would upset the DC operating conditions of Ql and Q2. A necessary characteristic of this switching circuit, as well as the amplification which follows it, is that no type of failure can result in a sizable increase in gain or a unwanted signal gated through since this would result in putting a larger signal out than desired and false train detection and signaling,may result.
The output from Q2 is coupled by means of Tl to the coding modulator Q3. This is a transistor amplifier that is biased on and off by coder output voltage fed from the pre-amp switching section to the base of Q3 through the transformer secondary. R8 increases the DC level at the emitter of Q3 to provide positive turn off when the code is off. Note that two out-of-phase outputs are provided from the pre-amp switcher, so that Q3 and Q6 are switched on alternately. Level setting pots, R6 and Rl5 are provided for adjusting track circuit carrier level and cab signal carrier level in a safe fashion. The two carriers are coupled by means of R9, C3 and Rl8, C6 and applied to the output. With a .73 V RMS input from an oscillator board, the mixer output is a 0.3 V RMS sine wave into a 3 K ohm load.
5-3.4.2 Test Procedure for Mixer PCB
5873, p. 5-18
1. Connect a 24.0 ± 1.0 VDC power supply to pins 3, 9, and 15 (+) and to pins 17/18 (-). (The power supply should have a maximum ripple of 0.2V P-P).
2. Connect 10 Kohm resistors between the input terminals, pins 6 and 13, and the power supply, pins 3, 9 or 15. (This supplies the necessary bias for transistors Ql and Q4.)
3. Connect a 7.0 ± 1.0 voe power supply to pins 2 and 5 (+) and pins 17/18 (-). (Power supply ripple should not exceed 0.2 V P-P.)
lV/DIV-.lMS/DIV
IN PVT (o
CAB C~ANNEL 2
R3 G80..n.
- f .., ..., ' :.,NQ ..:J?G:.4-~3 • 47 m<:n~~ - / /.
~ I ,,,.....;._ ,··.-----~, . c i 'SR.
--+/\Qi 20K I G/2N3h43 I ~ f- ________ j ~ R4
' .( 240-"-,.
<
<: i< 2 \ .:k ··1 ' '
R5 IK
11-18 ,-E .... --- • -~-- --· · -----· > 6ND. !
l ( { •:, ! 1 ·, ,, ! \
.5V/DIV-.1MS/DIV 15-- . 1
I.Nt->J1
.. ;.::·:::-. CHANNE..L
\ . -· . -= - --
Q4 2t,J:;b43
...
1'213 ! , 240.n.
5
Y.
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~
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8.'2K f\N\,-
R~
C3
• '21. MFD.
J. 5V /DIV-. U.1SfDIV
C<o
Rl8 .2'2.MFl>.
FIGURE 5-8 .11IXER PCB SCHEBATIC DIAGRAM (UN451054- 1502 to 1503)
. 2V /DIV-. U1S /DIV
NOTE--1. GND COMMON.
2 • WAVEFORMS FOR CAB AND WAYSIDE CHANNELS ARE SIMILAR
PERIOD OF WAVESHAPE WILL DEPEND UPON CARRIER FREQUENCY.
:wABCC
'V"•""'
5873, p. 19/20
c
115
IR.
MIXER UN45i054·150
C. rt. I. 0. V. IU. BR.
,.
C6 I -, _J RIB
c ..:J
C3 r Laa
C:J Rll c J
c: J RI&
r -, + = '- -'C5
c::: :J 1114
c ::J 111
CJos C:J C2 U r . ...,
+ = ·- 115 .....J c :J
~2 c: ::J
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BU.
--, _J R9
c (~
03'
c R4
02( ~
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FIGURE 5-9 MIXER PCB PARTS LOCATION DIAGRAH.
5873, p. 5-21
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PARTS LIST
MIXER PCB UN451054-1502 & 1503
-1503 -1502 I ITEM QUANT. ITEM QUANT. DESCRIPTION PART NUMBER
1 1 Board, Printed Circuit UM451054-1501 Ql Q2 Q3
Ql Q2 Q3 3 Q4 Q5 Q6 6 Transistor, 2N3643 UJ731282 3 6 Pad, Transistor Mtg. UJ7920 72
Rl 1 Rl RlO 2 Resistor, 20K ohm l/2W UJ721211 R2 1 R2 Rll 2 Resistor, 2K ohm 1/2W UJ721080 R3 1 .• R3 Rl2 2 Resistor, 680 ohm 1/2W UJ720773 R4 1 R4 Rl3 2 Resistor, 240 ohm 1/2W UJ73733
RS Rl4 RS R7 2 R7 Rl6 4 Resistor, lK ohm l/2W UJ720 882 R6 1 R6 Rl5 2 Potentiometer, lK ohm 2W UJ62300 R8 1 R8 Rl7 2 Resistor, 3. 9K ohm l/2W UJ720764 R9 1 R9 Rl8 2 Resistor, 8.2K ohm UJ720 775 Cl 1 Cl C4 2 Capacitor, .47 mfd.lOOV
10% UJ706806 C2 1 C2 cs 2 Capacitor, 15 mfd. 35V
10% UJ706683 C3 1 C3 C6 2 Capacitor, . 22 mfd.
lOOV, 10% UJ706858 r1 1 Tl T2 2 Transformer, TR66 UJ731314
5873, p. 5-22
4. Connect a 1 KHz signal with an amplitude of .73 V RMS to pin 6 through a 1 MFD capacitor.
5. Connect a 3 Kohm resistor between pins 10 and 17/18.
6. Using an oscilloscope verify that the output at pin 10 is a 0.3 ± 0.03 V RMS signal with no noticiable distortion.
7. Remove the 7 volt power supply from pin 2 and verify that the output goes to zero.
8. Remove the lKHz signal from pin 6 and connect it to pin 13 through the 1 MFD capacitor.
9. Turn R 15 fully clockwise and repeat step 6.
10. Remove the 7 volt power supply from pin 5 and verify that the output goes to zero.
5-3.5 Pre-Amplifier PCB Maintenance (UN451054-1602)
5-3.5.1 Pre-Amplifier PCB Circuit Description
The Pre-Amplifier PCB consist of two separate sections. An amplifier section that accepts signals from the mixer and a switching section that shapes and phase-inverts the signals from the Coder PCB.
A. Switching section - A network made up of D2, RlS, Rl6, and C6 alter the 24 volt square wave output of the coder to make it suitable for operating the mixer, Principally, the voltage swing is reduced to about 7 volts and the corners are rounded off by C6 to avoid producing sharp transients which would pass on through the power amplifier. Transistor Q8 serves as a 180° phase inverter and is followed by another shaping network comprised of D3, Rl9, and C7. Thus, two outputs of similar wave shape and 1800 out of phase are produced.
B. Amplifier Section - Transistors Ql, Q2, and Q3 provide signal amplification for the input from the mixer and provide enough gain to drive the quasi - complimentary power amplifier stage, Q4, QS, Q6, and Q7 {Q6 and Q7 are mounted on a separate PCB). C4 and CS couple the signal to the output. With a .3 VRMS input the output is 5.0 V RMS into a 10 load. R7, Cl and R9, C3 provide power line decoupling.
WABCCI ~
5873, p. 5-23/24
RI 20K
13 < e II
.IN Pur
R2 3.'=» K
'23 3K
220A-1<7
.. C.'2..
. 22MF.D
2V/DIV-.2M.S/DIV
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I OVTPUT Co ----- !Ii,!.
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1-+sw,TcH,t.JG
SEC.TtOt-l SECT\ON S
2V /DIV-50:tv:IS/DIV
PERIOD OF WAVESHAPE WILL DEPEND UPON FREQUENCY USED.
NOTE-GND. COMMON
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FIGURE 5-10 PRE-AMPLIFIER PCB SCHEMATIC DIAGRAM (UN451054-1602) 5873, p. 5-25/26
WABCD @ ~."V'
PRE-AMPLIFIER UN4510 54· 1602
l l 17 06
c: R4
r- -, +:
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r- +'-'- .:.r
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L _J
J
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C7
OJ [\ nLJ· R7 \.._)
l _J
n J 02
l J
111111111111111 FIGURE 5-11 PRE-AMPLIFIER PCB PARTS LOCATION DRAWING
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S873, ~?o 5-27
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PARTS LIST
PRE-AMPLIFIER PCB UN451054-1602
ITEM QUANT. DESCRIPTION PART NUMBER
1 Board, Printed Circuit UM45105 4-160] Ql Q2 Q3 QB 4 Transistor, 2N3643 UJ731282 04 1 Transistor, 2N2270 UJ731186 QS 1 Transistor, 2N4037 UJ731291 Q6 Q7 2 Transistor, 2N3055 UJ731263 IC! 1 Caoacitor, 22mfd., 35V, 10% UJ702956 IC2 1 Capacitor, 22mfd.,15V,10% UJ706526 ~3 1 Capacitor, 4 7mfd., 35V, 10% UJ706419 IC4 cs 2 Capacitor, 150mfd., lSV, 10% UJ706391 C6 C7 2 Capacitor, lmfd. ,lOOV,5% UJ706808 Rl " 1 Resistor, 20K ohm, l/2W UJ721211 R2 1 Resistor,3.6K ohm, l/2W UJ721191 R3 R4 2 Resistor, 3K ohm, l/2W UJ721256 RS 1 Resistor, 120 ohm, l/2W UJ72101 R6 1 Resistor, 620 ohm, l/2W UJ721253 R7 1 Resistor, 220 ohm, l/2W UJ720887 R8 1 Resistor, 5.lK ohm, l/2W UJ721179 R9 1 Resistor, 10 ohm, lW UJ721157 RlO 1 Resistor, 200 ohm, 2W UJ721161 Rll 1 Resistor, 820 ohm, l/2W UJ720774 Rl2 1 Resistor, 20 ohm, 1 W UJ721207 Rl3 Rl4 2 Resistor, 1 ohm, 3W UJ723210 RlS Rl8 2 Resistor, 12K ohm, l/2W UJ720821 Rl6 Rl9 2 Resistor, 6 .2K ohm, l/2W UJ720771 Rl7 1 Resistor, 51K ohm, l/2W UJ721213 ID! 02 o3 3 Diode, DI-52S UJ72 3555 !Use On K:14 & Q5 2 Sink, Heat, Wakefield Ena NF207 UJ792254
6 Pad, Transistor Mtq UJ792072 Dissipator,Heat
2 Thermouane Staver V3-3 UJ792 32 4 Fl 1 Fuse, 1 Amp. 3AG UJ710007
5873, p. 5-28
5-4.5.2 Test Procedure of Pre-Amplifier PCB
1. Connect a 24.0 ± 1.0 voe power supply to pin 1 (+) and pin 17/18 (-).
2. Connect a signal generator set for a 1 KHz output with and amplitude of 0.3 ± 0.01 V RMS to pin 13 though a .22 MFD capacitor.
3. Connect a 10 ohm, 10 watt resistor between pin 6 and pin 17/18.
4. Using an oscilloscope, verify that the output at pin 6 is a sinewave with an amplitude of
WABCO ~
5.0 ± 0.5 VRMS and with less than 8% distortion.
5. Connect a squarewave generator set for a 24.0 ±0.2 volt positive going squarewave with a frequency of 10 ± 2 Hz to pin 2 (+) and pin 17/18 (-).
6. Verify that the outputs at pins 3 and 5 are 180° out-of-phase with an amplitude of 7.0 ± 1.0 volt, and a waveshape as follows:~
5-3.6 Power Amplifier PCB Maintenance (UN451054-1702)
5-3.6.1 Power Amplifier PCB Circuit Description
Power Amp- The Power Amplifier PCB raises the power level of the signal from the pre-amp to drive the track circuit, and consists of a conventional push-pull class B amplifier. Diodes Dl and 02 protect the emitter base junction of power transistors Ql and Q2.
R6 provides enough emitter degeneration to insure that the amplifier looks essentially like a constant current source. The network made up of 03, D4, Cl, ~nd RS serves to protect the power amplifier transistor collectors from over-voltage transients. Cl will be charged to the peak value of any voltage regularly appearing at the collector of either Ql or Q2. Any sudden sharp transient will be dissipated because Cl cannot be suddenly charged to a higher voltage. With a sine wave input of 5 V RMS from the pre-amp, the output of the power amplifier is a 250 V RMS sine wave into a 1000 ohm load. Both Tl and T2 provide a voltage step-up.
5873, p. 5-29
U1 (X)
-..J w .. I'd . U1 I
w 0
2V /DIV-. 2MS/DIV
15 < w.
~ 1..n. RESISTOJ:2. &.. (2) ZN 3055 TRANSlSTORS MARK.5.1:> "l"l-{0S
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PERIOD OF WAVES.HAPE IS DEPENDENT ON OPERATING FREQUENCY
NOTE-GND. COMMON
a-,
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!£! T2
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FIGURE 5-12 POWER A.l.vlPLIFIER PCB SCHEMATIC DIAGRAM tUN451054-l 702)
~I
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.2MS/DIV
L
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POWER AMPLIFIER UN451054·1792
BK.
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n 3P IP
J=ID2 ~DI n n u LJ u R3 R4
·LILI r 1 ... n •• II( • 15 Cl ( ' u L+J
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~1111111111111111 FIGURE 5-13 POWER AMPLIFIER PCB PARTS LOCATION DIAGRAM
5873, p. 5-31
WABCCI ~
Dl Rl R2 R3 RS Cl
Tl T2 Fl
ITEM
02 03
R4
5873, p. 5-32
PARTS LIST
POWER AMPLIFIER PCB UN451054-1702
QUANT. DESCRIPTION PART NUMBER
1 Board, Printed Circuit UM451054-1701 04 4 Diode, DI-52S UJ723555
1 Resistor, 15 ohm lW UJ722631 1 Resistor, 360 ohm, 3W UJ73917 2 Resistor, 24K ohm, l/2W UJ721212 1 Resistor, 2.2K ohm l/2W UJ720842 1 Capacitor, 25 mfd.,SOV
+150% -10% UJ702465 1 Transformer UN451039-1001
,. 1 Transformer UN451039-0214 1 Fuse, 4 Amp. 3AG UJ710064
NOTE:
Power Amplifiers Transistors o1 and o2 are mounted on a separate PCB.
NOTE
Power-.transister Ql and Q2 are mounted on a separate PCB.
5-3.6.2 Test Procedure for Power Amplifier PCB
1. Connect two 2N3055 transistors.and the 1 ohm resistor to the PCB as shown on the schematic diagram.
WABCD ~
2. Connect the positive lead of a 24.0 ± 1.0 voe power supply to pins 1,2, and 3 and the negative lead of the supply to pins 16,17, and 18.
3. Connect a 1000 ohm, 75 watt load across pins 4 and 5.
4. Connect a 5 V RMS, 1 KHz sinewave to pin 15 and pins 16,17, and 18.
5. Verify that the output is 250 V RMS output with less than 8% distortion.
5-3.7 Receiver PCB Maintenance (UN451054-1402 to 1412)
5-3.7.1 Receiver PCB Circuit Description
The Receivers PCB accepts only coded signals with the proper code range and carrier frequency--correspondinq to that generated by the code and oscillator boards. Signals from the rails showing track occupancy are received and eventually operate the track occupancy relay. The several sections of the receiver serve to amplify and select the appropriate carrier frequency, to detect the modulation of the carrier, to amplify and rectify this modulation, and to apply the rP.sulting DC through the appropriate timing circuits to the relay, in a fail safe fashion. A grounded base amplifier Ql is used, which cannot fail in a fashion that would result in the gain increasing and which will tolerate a large range of signal input, particularly, signals of several volts. Ll and L2 are part of a coupled circuit filter which is driven by a high impedance source,Ql,and which is connected to a high input impedance amplifier, Q2. Coupling capacitor C2 determines the bandpass of this filter. The output of emitter follower Q2 is connected to the class B detector stage Q3. To insure fail-safeness, carrier ripple is removed by using a four terminal capacitor CS. A large amount of ripple passing beyond this point might be able to pick up the relay and thereby operate it unsafely on an unmodulated signal. Two versions of the modulation voltage which differ
5873, p. 5·-33/34
1 :ez4(+)
F'' 1.AMP 2
RZG 10...n...
5V/DIV-50MS/DIV
R'4 080 .n..
Y, l "'{. R8
I 10 I<..
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5V/DIV-20MS/DIV
Rl7 2 .7 K.
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5V/DIV-20MS/DIV
_c~ .1 c.10 LI I L?,:.) \ . .'2
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DS I ~10'1<." <47K.
Dl R 1 H.D44tB
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17-18< 6 ~ / G ND. 'T • -• - . \ \ ' • ID • 41 . ' I C.oMMON
5V/DIV-20MS/DIV 5V/DIV-20MS/DIV
5V/DIV-50MS/DIV - PERIOD OF WAVESHAPE WILL DEPEND UPON FREQUENCY USED.
FIGURE 5-14 RECEIVER PCB SCHEMATIC DIAGRAM (UN451054-1401 to 1412)
Ztl2.270
OUTPUT
NOTE--GND. COMMON
5873, p. 5-35/36
WABCC ~
by 180° are obtained by split load phase inverter Q4. A further detection is performed on these two modulation voltages by class B stages Q5 and Q6. The output of Q5 and Q6 is a voltage waveform similiar to that which would have been obtained by amplifying and full wave rectifying the original modulation voltage. A further current amplification of this signal is accomplished by complimentary emitter followers Q7 and Q8. Capacitor C8 and diode D3 serve to zero reference this wave shape so as to produce a replica of a negative full wave rectification of the original modulation signal. The circuitry after D3 serves to provide slow pick-up and fast drop-away of the relay. Voltage appearing across D3 will be applied to the relay coil only if transistors Q9 and QlO are conducting. However, if volt
age suddenly appears across D3, QlO cannot conduct until capacitors C9 and ClO have been charged enough to bring Q9 and QlO into conduction. This delays the energization of the relay by about 0.9 sec. The arrangement of R23, R24, and R25 with zener diode D7 insures that the current into the base of QlO will stop when the voltage across D3 has fallen off moderately. Diode D6 insures that transistor Q9 and QlO will be allowed to stop conducting as soon as Q9's supply of base current falls off. Capacitor Cll serves to prevent an excessive voltage rise across the inductance of the relay coil which might otherwise damage transistors Q9 and QlO.
With a coded 1 volt rms sine wave of proper frequency applied to the primary of the coupling unit transformer, the output of the receiver is about 10 volt DC into a 400 ohm PN 150 B relay. Power input required is .1 ampere at 24 V DC with relay energized.
5-3.7.2 Test Procedure for the Receiver PCB
1. Connect a 24.0 ± 1.0 VDC power supply to pin 1 (+) and pin 17/18 (-).
2. Apply a 1.0 VRM.S (2.8 V P-P) signal with a frequency± 0.05% of the specified frequency to pin 14 (+) 17/18 (-) via a UN434762 transformer. (Black and Blue leads of transformer are secondary winding).
3. Connect a PN150B relay (UN322500-001) to pin 16 (negative side of relay) and pins 17/18 (positive side of relay).
4. Switch the signal input at a rate of 5 cycles per second (50% duty cycle) vary the input signal amplitude and verify the following:
5873, p. 5-37
WABCD ~
HZ RECEIVER Ctl · ®
UN451054·14 'r ~ L , _J
r - 1 n n n \ )01
13 Dl,.,_ RI R2 '- L U ei LI U / ~ Y. Cl
C~ l 2 0 \_"\ ~ ~C2~
I ] ,- c~. =i . I _.// ·,:, LI . C R4 ~-1
FIGURE 5-15 RECEIVER PCB PARTS LOCATION DIAGRAM
5873, p. 5-38
WABCCI ~
PARTS LIST
RECEIVER PCB UN451054-1402 to 1412
ITEM QUANT. DESCRIPTION PART NUMBER
1 Board, Printed Circuit UM451054-1401 Ql Q2 Q4 :}5 Q6 Q9 6 Transistor, 2N3643 UJ731282 :}3 1 Transistor, 2N3644 UJ731283 :}7 QlO 2 Trans is tor, 2N2270 UJ731186 :28 1 Transistor, 2N4037 UJ731291 Pl 02 04 05 06 5 Diode, HD4418 UJ723742 iD3 1 Diode, DI-52S UJ723555 ID7 l Diode, IN748 UJ723779 Rl RS Rl3 Rl4 R23 5 Resistor, lK ohm l/2W UJ720882 ~2 1 Resistor, 4.7K ohm l/2W UJ720892 R3 1 Resistor, 390 ohm, l/2W UJ720 76 3 R4 R20 2 Resistor, 680 ohm, l/2W UJ720773 R6 1 Resistor, 510 ohm, l/2W UJ721081 R7 1 Resistor, 3K ohm, l/2W UJ721256 R8 Rl5 Rl6 R24 4 Resistor, lOK ohm, l/2W UJ720883 R9 1 Resistor, 270 ohm, l/2W UJ720 75 7 RlO R21 2 Resistor, 2.2K ohm, l/2W UJ720842
Thermistor, 100 ohm Rll 1 Gen. El. D-109 UJ72 3209 Rl2 1 Res is tor, 15K ohm, l/2W UJ720885 Rl7 1 Resistor, 2.7K ohm, l/2W UJ720 758 Rl8 Rl9 2 Resistor, 75 ohm, l/2W UJ723222 R22 1 Resistor, lOOK ohm, l/2W UJ720838 R25 1 Resis-tor, 47K ohm, l/2W UJ720 846 R26 1 Resistor, 10 ohm, l/2W UJ720881 Cl C3 2 Capacitor See Below C2 1 Capacitor See Below C4
~ 1 Capacitor, .22mfd.,100V,10% UJ706858
CS& l Capacitor, 3mfd. ,400V,10% UJ706676 C6 C7 2 Capacitor, lOOmfd.,lOV, 10% UJ706416 ca 1 Capacitor, 600mfd. UJ706821 ~9 ClO 1 Capacitor, 2 7:mf d • I 2 0 v • I 10 % UJ706678 Cll 1 Capacitor, lmfd. ,lOOV. ,5% UJ706808 Cl2 1 Capacitor, 33mfd., 35V., 10% UJ706159 tLl L2 2 Choke, Pot Core See Below Fl 1 Fuse, 1/2 Amp. 3AG UJ71190
5873, p. 5-39
WABCCI ~
PARTS LIST (cont)
RECEIVER PCB UN451054-1402 to 1412
POT CORE CHOKE UN451030 CAPACITOR C2
FREQ. Ll & Cl L2 & C3 (500 VDC) INDEXING SLOTS SUFFIX HZ f-SUFFIX SUFFIX PART NUMBER PFD. AT CONTACT PADS
-1402 2490 -0809 -0809 UJ702999, 5% 2000 2 & 13
-1403 2550 -0810 -0810 UJ702999, 5% 2000 3 & 13
-1404 2610 -0811 -0811 UJ702817, 2% 1800 4 & 13
-1405 2730 -0812 -0812 UJ702817, 2% 1800 5 & 13
-1406 3210 -0813 -0813 UJ706454, 2% 1600 6 & 13
-1407 3270 -0814 -0814 UJ706 454, 2% 1600 7 & 13
-1408 3810 -0815 -0815 UJ706546, 2% 1500 8 & 13
-1409 4110 -0816 -0816 UJ70606 8, 5% 1300 9 & 13
-1410 4170 -0817 -0817 UJ706521, 5% 1200 10 & 13
-1411 5190 -0818 -0818 UJ701578, 5% 1000 11 & 13
-1412 6090 -0819 -0819 UJ706652, 5% 910 12&13 (1) Slot (1/4 x 3/8
5873, p. 5-40
(a) Relay picks up with and input of 1.4 VP-P ±0.1 V P-P.
WABCD ~
(b) Relay drops-out between l.OVPP and l.3VPP.
5. Verify that with a steady signal input the relay voltage is near O VDC.
6. Verify that the voltage across the relay is between 8 and 11 VDC with the input signal switched at a rate of 5 to 20 cycles per second.
5-3.8 COUPLING UNITS
The track coupling units can be mounted to the frame of a communications rack or in a box adjacent to the Minibond and consist of a micarta board with terminals and components as required. These units serve as interface boards between the track minibonds and the various transmitter and receiver units. Space is provided to mount capacitors to tune the minibonds for different operating frequencies and to mount fixed resistors to set the receiver sensitivity. Five different boards are standardized to cover the various application needs. The coupling units are covered in detail in Section III.
5873, p. 5-41/42
