Infrared Project

8/8/2019 Infrared Project

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INTRODUCTION

Wireless control or Remote control of electronics gadget has become a part of our

daily life. Even the technology has developed so much but wireless controlling ofelectrical appliances is not a part of our life. In domestic fields and industrial fields

everywhere it is seen. Here we have tried to control the electrical appliances

through IR method i.e. Infra Red technology. We are successful to control some of

the electrical home appliances in this field. IR technology uses the bandwidth of

infra red radiations. In this technology IR bandwidth coveys the data and

instructions remotely.

In our circuit we have used IR receiver, IC-4017, n-p-n transistors, 6v relays, 12v

transformer, bridge rectifier, resistances and 220F, 10V capacitor to control

various electrical appliances. The working principle is based on the Infra-Redradiations. An IR transmitter and an IR receiver is used to control the electrical

appliances.


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COMPONENTS USED

y IR RECEIVER

y IC 4017

y N-P-N TRANSISTORS

y RELAYS (6V)

y CAPACITOR

y RESISTANCE

y TRANSFORMER

y L.E.D.


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COMPONENTS DESCRIPTION

1) IR Receiver :- Many different receiver circuits exist on the market. The mostimportant selection criteria are the modulation frequency used and the availability

in our region.

In the picture above we can see a typical block diagram of such an IR receiver.

Here everything is built into one single electronic component.

The received IR signal is picked up by the IR detection diode on the left side of

the diagram. This signal is amplified and limited by the first 2 stages. The limiter

acts as an AGC circuit to get a constant pulse level, regardless of the distance to

the handset.

As we can see only the AC signal is sent to the Band Pass Filter. The Band Pass

Filter is tuned to the modulation frequency of the handset unit. Common

frequencies range from 30kHz to 60kHz in consumer electronics.The next stages are a detector, integrator and comparator. The purpose of these

three blocks is to detect the presence of the modulation frequency. If this

modulation frequency is present the output of the

comparator will be pulled low.

As we know, all these blocks are integrated into a single

electronic component. There are many different

manufacturers of these components on the market. And

most devices are available in several versions each of

which are tuned to a particular modulation frequency.

Please note that the amplifier is set to a very high gain. Therefore the system

tends to start oscillating very easily. Placing a large capacitor of at least 22F

close to the receiver's power connections is mandatory to decouple the power

lines. Some data sheets recommend a resistor of 330 Ohms in series with the

power supply to further decouple the power supply from the rest of the circuit.


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2) IC-4017 :- The count advances as the clock input becomes high (on therising-edge). Each output Q0-Q9 goes high in turn as counting advances. For

some functions (such as flash sequences) outputs may be combined using

diodes.

The reset input should be low (0V) for normal operation (counting 0-9). When

high it resets the count to zero (Q0 high). This can be done manually with a

switch between reset and +Vs and a 10k resistor between reset and 0V.

Counting to less than 9 is achieved by connecting the relevant output (Q0-Q9) to

reset, for example to count 0,1,2,3 connect Q4 to reset.

The disable input should be low (0V) for normal operation. When high it disables

counting so that clock pulses are ignored and the count is kept constant.

The 10 output is high for counts 0-4 and low for 5-9, so it provides an output at1/10 of the clock frequency. It can be used to drive the clock input of another 4017

(to count the tens).


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3) n-p-n Transistors :- The operation of a transistor is difficult to explain andunderstand in terms of its internal structure. It is more helpful to use this

functional model:

The base-emitter junction behaves like a diode.

A base current IB flows only when the voltage VBE across the base-emitter

junction is 0.7V or more.

The small base current IB controls the large collector current Ic.

Ic = hFE IB (unless the transistor is full on and saturated)

hFE is the current gain (strictly the DC current gain), a typical value for hFE is 100

(it has no units because it is a ratio)

The collector-emitter resistance RCE is controlled by the base current IB:

IB = 0 RCE = infinity transistor off

IB small RCE reduced transistor partly on

IB increased RCE = 0 transistor full on ('saturated')


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4) Relays (6V) :- A relay is an electrically operated switch. Many relays use anelectromagnet to operate a switching mechanism, but other operating principles

are also used. Relays find applications where it is necessary to control a circuit

by a low-power signal, or where several circuits must be controlled by one signal.

The first relays were used in long distance telegraph circuits, repeating the signalcoming in from one circuit and re-transmitting it to another. Relays found

extensive use in telephone exchanges and early computers to perform logical

operations. A type of relay that can handle the high power required to directly

drive an electric motor is called a contactor. Solid-state relays control power

circuits with no moving parts, instead using a semiconductor device triggered by

light to perform switching. Relays with calibrated operating characteristics and

sometimes multiple operating coils are used to protect electrical circuits from

overload or faults; in modern electric power systems these functions are

performed by digital instruments still called "protection relays".


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5) Capacitor :- A capacitor or condenser is a passive electronic componentconsisting of a pair of conductors separated by a dielectric. When a potentialdifference exists across the conductors, an electric field is present in thedielectric. This field stores energy and produces a mechanical force between theconductors. The effect is greatest when there is a narrow separation between

large areas of conductor, hence capacitor conductors are often called plates.

An ideal capacitor is characterized by a single constant value, capacitance,

which is measured in farads. This is the ratio of the electric charge on each

conductor to the potential difference between them. In practice, the dielectric

between the plates passes a small amount of leakage current. The conductors

and leads introduce an equivalent series resistance and the dielectric has an

electric field strength limit resulting in a breakdown voltage.

Capacitors are widely used in electronic circuits to block the flow of direct current

while allowing alternating current to pass, to filter out interference, to smooth theoutput of power supplies, and for many other purposes. They are used in

resonant circuits in radio frequency equipment to select particular frequencies

from a signal with many frequencies.


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6) Resistance :- A resistor is a two-terminal electronic component that producesa voltage across its terminals that is proportional to the electric current through itin accordance with Ohm's law:

V= IR

Resistors are elements of electrical networks and electronic circuits and are

ubiquitous in most electronic equipment. Practical resistors can be made of

various compounds and films, as well as resistance wire (wire made of a high-

resistivity alloy, such as nickel/chrome).

The primary characteristics of a resistor are the resistance, the tolerance,

maximum working voltage and the power rating. Other characteristics include

temperature coefficient, noise, and inductance. Less well-known is critical

resistance, the value below which power dissipation limits the maximum

permitted current flow, and above which the limit is applied voltage. Criticalresistance depends upon the materials constituting the resistor as well as its

physical dimensions; it's determined by design.


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7) Transformers :- When Faraday discovered electromagnetic induction, hehad virtually invented the transformer. Any transformer simply consists of two

coils positioned so that the magnetic flux from one passes through to the other. A

transformer changes a given electrical current into another current of different

voltage. There are two kinds of transformers:

i) Step-up transformer to increase the voltage

ii) Step-down transformer to decrease the voltage.

It consists of insulated wires wound around a conductor, such as an iron loop. A

changing current in the first circuit (the primary) creates a changing magnetic

field; in turn, this magnetic field induces a changing voltage in the second circuit

(the secondary). By adding a load to the secondary circuit, one can make current

flow in the transformer, thus transferring energy from one circuit to the other.


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8) LED :- A light-emitting diode (LED) is a semiconductor light source. LEDs areused as indicator lamps in many devices, and are increasingly used for lighting.

Introduced as a practical electronic component in 1962, early LEDs emitted low-

intensity red light, but modern versions are available across the visible, ultraviolet

and infrared wavelengths, with very high brightness.

The LED is based on the semiconductor diode. When a diode is forward biased

(switched on), electrons are able to recombine with holes within the device,

releasing energy in the form of photons. This effect is called electroluminescence

and the color of the light (corresponding to the energy of the photon) is

determined by the energy gap of the semiconductor. An LED is usually small in

area (less than 1 mm2), and integrated optical components are used to shape its

radiation pattern and assist in reflection.


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CIRCUIT DIAGRAM


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CIRCUIT DESIGN

The circuit design of Wireless Control of Electrical Appliances is done as per the

circuit diagram shown above. Here we have connected all the components on an

EPOXY GLASS zinc plated holes board.

The connection details for the IC 4017 used in the circuit is as follows:

PIN 2 :-Connected to base of transistor-1 with a series resistance of 170 K.

PIN 3 :-Connected to base of transistor-2 with a series resistance of 170 K.

PIN 4 :- Connected to base of transistor-3 with a series resistance of 170 K.

PIN 7 :- Connected to Pin 15 of the IC 4017.

PIN 8 :- Connected to Pin 13 of the IC 4017 and is grounded.

PIN 14:- Connected to output pin of IR receiver with a series resistance of 220 .

PIN 16:- Connected to the emitters of the Transistors-1, 2 & 3.

PINS 1, 5, 6, 9, 10, 11 and 12 are kept open of the IC 4017.

The connection details for Transistors are as follows:-

COLLECTOR:- One branch from each collector is connected to L.E.D. of

different colors with a series resistance of 1 K and then grounded. Other branch

from collector is connected to the Relays 1, 2 and 3.

BASE:- Bases of Transistors 1, 2 and 3 are connected to Pins 2, 3 and 4

respectively.

EMITTER:- Emitters of all the transistor are connected to the Pin 16 of the IC4017.


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WORKING

The 38kHz infrared (IR) rays generated by the remote control are received by IR

receiver module TSOP1738 of the circuit. Pin 1 of TSOP1738 is connected to

ground, pin 2 is connected to the power supply through resistor R5 and the output

is taken from pin 3. The output signal is amplified by transistor T1(BC558).The

amplified signal is fed to clock pin 14 of decade counter IC CD4017 (IC1). Pin 8 of

IC1 is grounded, pin 16 is connected to Vcc and pin 3 is connected to LED1 (red),

which glows to indicate that the appliance is off. The output of IC1 is taken from

its pin 2. LED2 (green) connected to pin 2 is used to indicate the on state of the

appliance. Transistor T2 (BC548) connected to pin 2 of IC1 drives relay RL1.

Diode 1N4007 (D1) acts as a freewheeling diode. The appliance to be controlled is

connected between the pole of the relay and neutral terminal of mains. It gets

connected to live terminal of AC mains via normally opened (N/O) contact when

the relay energizes.


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USES

This circuit can be used to control various electrical home appliances. It can also

be used to control various electrical industrial machines which run at 230V.

Here we have three outputs to connect three appliances, it is variable, we canincrease or decrease the no. of outputs as per our requirement. Using this we can

control fan, lights, T.V., radio, motor, etc.


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DISADVANTAGES

y One and only one appliance at a time can work.

y Infra red appliances such as T.V. working at same frequency can be

affected.

y Circuit can be operated within a range of 10 meters only.

y Appliances which works at higher voltages can not be operated.


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CONCLUSION

We have successfully designed the circuit for Wireless Control of Electrical

Appliances by using the IR (Infra Red) technology. The concept of IR technology

to control Electrical Appliances worked successfully in our project.

The circuit has three outputs which can be used to control different appliances. We

have successfully controlled bulbs, fans, hand drill, etc.


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BIBLIOGRAPHY

y Electronics for you magazine.

y Electrical India magazine.

y

www.sbprojects.comy Wikipedia.

y Projects in electrical engg.-by M Morris

y www.google.com

Date post:	10-Apr-2018
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Infrared Project

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