This document describes a wireless switch circuit control system that uses a light dependent resistor (LDR) to detect hand gestures and switch electronic appliances on and off. When a hand is placed over the LDR, it causes the circuit to toggle a JK flip-flop, changing the output and switching the appliance. The circuit provides contactless switching to reduce electric shocks while allowing children to safely operate devices. It uses common electronic components like an LDR, capacitor, resistor, transistor, diode and operational amplifier.

1. WIRELESS SWITCH CIRCUIT CONTROL
SYSTEM

2. 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.

3. 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.

4. Block diagram

5. CIRCUIT DIAGRAM
Fig: showing wireless control switch

6. 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.

7. 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.

8. 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.

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

10. The waveform of JK flip flop is as
follows:-

11. 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.

12. 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.

13. 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.

14. 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.

15. 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.

16. 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.

17. 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.

18. 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.

19. 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.

20. 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.

21. 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

22. 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

23. 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.

24. 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