WIRELESS SWITCH CIRCUIT CONTROL

SYSTEM

INTRODUCTION

It will help the society with gesture of any human hand to switch the electronic home appliances on or off. The possibility of shocks to human becomes very low.

Technical concept

It uses LDR as the light detecting element which gives response inversely proportional to the intensity of light, depending on which the electronic appliances are switched on or off.

Block diagram

CIRCUIT DIAGRAM

Fig: showing wireless control switch

WORKING OF CIRCUIT

WHEN WE DON’T PUT HAND ON LDR.

Device remains off and as a result pin 2 of IC1 goes high. Consequently, output pin 6 of IC1 remains low.

When we put hand over LDR. PIN 2 of IC2 goes low in comparison to pin 3 of IC1. Pin 6 becomes high

thus providing a clock pulse to pin 13 of IC2 which is a flip flop whose stage is controlled by the logic levels present at J and K input with some internal control.

Triggering of circuit.

is triggered on the leading edge of the switch pulse means output changes when we again put our hand over LDR

both J & K are tide to high input so at every negative or positive transition, the clock pulse pin 13 toggles between high to low.

This can be verified with the help of truth table of the JK flip flop.

The truth table of JK flip flop is as follows:-

The waveform of JK flip flop is as follows:-

COMPONENTS REQUIRED AND IT’S SPECIFICATIONS

LDR (LIGHT DEPENDENT RESISTOR):-

LDR is variable resistor which has very low resistance in the presence of light and very high resistance in the absence of light.

CAPACITOR Capacitor is a passive component used to store

charge. The charge (q) stored in a capacitor is the product of its capacitance (C) value and the voltage (V) apply to it. Capacitor offer infinite reactance to zero frequency so they are used for blocking DC components or bypassing the AC signals.

Resistor A resistor is a device which is used to produce

opposition in the flow of electron that is flow of current. The unit of resistance is ohm (Ω) which is defined as resistance offered by the material when a current of 1 A flow between two terminals with 1V applied across it.

Transistor Transistor is a solid state device whose

operation depends upon the flow of electric charge carriers within the solid which is capable of amplification and in most respect it is analogous to a vacuum triode.

Variable resistor The resistor whose electrical resistance value

can be adjusted as per requirement by adjustable component attached to it is called variable resistor. It is an electronic component which applied in electronic circuits for adjusting circuit resistance to control or current of that circuit.

Diode

.It is the simplest 2 terminals unilateral semiconductor device .It allows current to flow only in one direction and blocks the current that flows in opposite direction .The two terminals of the diode are called as anode and cathode.

OP-AMP (OPERATIONAL AMPLIFIER)

It is a linear integrated circuit. It has a very high input impedance, very low output impedance and infinite gain. It has eight terminal. Terminal 2 is inverting input terminal, 3 is non- inverting terminal and 6 is output terminal. The terminals 4 & 7 are used to connect positive and negative power supply voltages respectively.

MASTER SLAVE JK FLIP FLOP ( CD4027BC )

The CD4027BC dual JK flip flop are monolithic complementary MOS (CMOS) integrated circuits constructed with N & P channel enhancement mode transistors. Each flip flop has independent J, K, set, reset and clock inputs and offered Q and Q— inputs.

RELAY Relay is an electrical switch that opens and

closes under control of another electrical circuit. The switch is operated by an electromagnet (solenoid) to open or close one or many sets of contact points. It is able to control an output circuit of higher power than the input circuit.

LED ( LIGHT EMMITTING DIODE ):-

A LED when charge carriers are injected across P – N junction (forward biased) , the current is due to recombination in the depletion layer & in neutral region near the junction. For indirect recombination the energy will be realised as heat.

OBSERVATION

When the circuit is connected on the breadboard as per the circuit diagram and 6V DC supply is applied across the circuit we observed that LED start glowing and remain ON when we pass our hand over LDR one time. Now when we again pass our hand over LDR the LED stop glowing and remained OFF till we again pass our hand over LDR and hence working of wireless switch circuit control is observed and verified

CONCLUSION

In this circuit the delay time between input and output is very less time to produce an output for an applied input.

The power wastage in this circuit is very less because of low current sinking property of the op-amp because of its high input impedance.

The circuit doesn’t require any manual touch to switch ON or OFF the electronics appliances.

Because of the non-ideal behavior of op-amp & flip-flop the circuit output may deviate from the ideal value

FUTURE SCOPE The WIRELESS SWITCH CIRCUIT CONTROL SYSTEM

can be employed as ordinary switch. It will reduce to getting electric shock as we getting from

ordinary switch if it was damaged. It gives a main advantage to children who operates

electronics home appliances.

REFERENCE

J.B Gupta, electronic devices and circuits, Kataria publications

D. Roy Chaudhary, Linear integrated circuits, New age techno press.

A.Anand Kumar, Fundamental of Digital Circuits,PHI Learning private limited.

www.electronicshub.com/mini project www.wikipedia.com