Oscilloscopes: 2 TYPES, ANALOG,DIGITIALSEE APPENDIX i
ANALOG:DIRECTLY APPLIES THE VOLTAGE BEING MEASURED TO AN ELECTRON BEAM WHICH MOVES UP, DOWN AND ACROSS THE CRT SCREEN.
DIGITIAL: SAMPLES INPUT WAVEFORM AND USES A TO D CONVERTER TO CHANGE VOTLAGE INTO DIGITAL INFORMATION.
DIGITAL OSCOPES HAVE MOSTLY REPLACEDANALOG SCOPES.SMALLER,LIGHT WEIGHT4 CHANNELMULTIPLE MENU.
LIGHTWEIGT DIGTIAL LCD OSCOPE, GREAT FOR TROUBLESHOOTING IN CRAMPED SPACES
Illustration showing the interior of a cathode-ray tube for use in an oscilloscope. Numbers in The picture indicate:
1.Deflection voltage electrodes 2.Electron gun
3.Electron beam 4.Focusing coil
5.Phosphor-coated inner side of the screen
MAKE presents: The Oscilloscope http://www.youtube.com/watch?v=SxZWcku_Sw0
Old school analog
CYCLE P.203: ONE WAVEFORM THAT DOES NOT REPEAT ITSELF
½ CYCLE
PERIOD (T) : TIME TO COMPLETE ONE CYCLE.( IN THIS CASE .25 SECONDS)
.25 S
SAME THING
FREQUENCY( f ) : # OF CYCLES/SECOND
Time (sec) FOR THIS WAVEFORM f = 1 CYCLES/SEC
HERTZ: UNIT OF FREQUENCY . FOR THE ABOVE WAVEFORM f = 1 Hz f =1/T OR f =1/λ
AMPLITUDE: (a) HEIGTH OF THEWAVEFORM.
=1/T = 1/20ms = 1/.002 = 500Hz
EXAMPLE: FIND THE FREQUENCY FOR THE WAVE FORM BELOW.
ANALOG SCOPES MAKE 2 BASIC MEASUREMENTS, AMPLITUDE AND TIME.
TYPICAL WAVEFORMS THAT CAN BE SEEN ON AN OSCOPE
TRIGGERING: USES THE SAME TRIGGER POINT ON A CONTINUOUS WAVE FORM TO CREATE A STABLE DISPLAY.
You tube: Oscilloscope Tutorial Part 1 - Choosing an oscilloscope http://www.youtube.com/watch?v=qIfo_-d82Co
TYPES OF PROBES
TIMES ONE PROBE( X1) (SHIELDED WIRE)
TIMES TEN PROBE (X10)(LOW CAPACITANCE PROBE)
YOU TUBE: Oscilloscope Tutorial Part 2 - Basic usage http://www.youtube.com/watch?v=hUIgAu3QQWQ
FUNCTION GENERATOR
BASIC MEASUREMENTS WITH OSCOPESVPP=# OF VERTICAL DIVISIONS x VOLT/DIVISIONT (PW) = # OF HORIZONAL DIVISIONS x SECOND/DIVISION
f = 1/T VRMS =VPP/2 X .707
PW: PULSE WITDHNONSINUSOIDAL WAVE FORMS (PULSES)PULSEWIDTH
prt
PULSE REPETITION TIME (prt)
PULSE REPETITION FREQUENCY (prf)
prf = 1/prt
SCOPE SETTINGSX: SEC/DIV = 0.2 MS/DIVY:VOLT/DIV = 0.5 V/DIV
SET SIG. GEN. TO SAWTOOTHF =1KHz AT 1.7 Vp AMPLITUDE
FROM SCOPE SCREEN COUNT VpK SHOULD BE 3.4 VERTICAL DIV X 0.5V/DIV VpK=1.7VVPP=2xVPK=2X1.7V=3.4V
T = 5 HORZ. DIV X 0.2MS/DIV = 1ms
f = 1/T =1/1ms =1KHz
.5
1.0
1.5
2.0FIND Vpp, T ,f OF THE DISPLAYED WAVEFORM
.2 .4 .6 .8 X
Y
YOU TUBE: Oscilloscope Tutorial Part 3 - Advanced functions http://www.youtube.com/watch?v=g_KuGEh0PyA
3.4
FROM SCOPE FIND PW, prt, Vpk
SET SIG. GEN. TO SQUARE WAVEAMPLITUDE = 20VF = 125 KHz
SCOPE SETTINGX: SEC/DIV = 1us/DIVY: V/DIV = 5V/DIV
PW = 4 HORZ. DIV X 1us/DIV = 4us
prt = 9.6 HORZ. DIV X 1us/DIV = 8us
KHzfHzxf
Hzxf
usprtf
1251025.1
10125.
8/1/1
5
6
us1 2 3 4
5
10
15
20
YOU CAN CONFIRM THIS RESULT
LISSAJOUS PATTERNSARE MADE BY APPLYING TWO AC SIGNALS TO THE HORZ. AND VERT. INPUTS OF AN OSCOPEAT THE SAME TIME. SET THE TIME DIVISION SWITCH TO X/Y POSITION ON THE OSCOPEWITH THE TWO FUNCTION GENERATORS SET TO THE SAME FREQUENCY, A CIRCLE SHOULDAPPEAR ON YOUR OSCOPE.
1:1
YOU TUBE: Function Generator Tutorial http://www.youtube.com/watch?v=mLKPwWGBtIw
WITH 1FUNCTION GENERATOR
WITH 2 FUNCTION GENERATORS
Basics of Lissajous Patterns on an Oscilloscope http://www.youtube.com/watch?v=t6nGiBzGLD8
http://www.youtube.com/watch?v=U8bXpzppdR0Oscilloscope for iPad, iPhone and iPod touch
FREQUENCY RATIO
