Clap Controlled Electronic Switch by 555 Timer and 4013 D Flip-Flop

Description

This electronic switch allows you to control an electronic device by only clapping your hands

twice. It is based on three integrated circuits; 741 Op-Amp, 555 timer, and 4013 dual D flip-flop.

A 9V battery is ample to operate the circuit.

When you first clamp your hands, mic detects the sound and triggers the 555 timer via the

operational amplifier. The timer stretches the signal and applies it to the clock input of the flip-

flop. Because of the three state arrangement of the flip-flop , one more clamp is needed to

change the output state. Second clamp sets the flip-flop output to high and this forward biases

the 2N2222 BJT. Relay closes so the device connected to the relay switches on. Same

procedure applies for the opposite. When you clap your hands twice, relay closes and turns off

the device connected to it.

R3 trimpot adjusts the sensitivity of the circuit. You should turn it till the room noise does not

effect the switch operation.

Components

IC1: 741 Op-Amp

IC2: 555 Timer

IC3: 4013 Dual D Flip-Flop

Q1: 2N2222 NPN Transistor

C1, C2, C3, C4: 0.1uF Ceramic Capacitor

C5: 47 uf Electrolytic Capacitor

R1, R2, R4, R5, R10: 10 KOhm

R6: 150 KOhm

R7, R9: 100 KOhm

R8: 1 MOhm

R11: 220 Ohm

R3: 100 KOhm Trimpot

B1: 9 Volt Battery,

K1: SPST Reed Relay 5 Volt DC Coil

MIC: Electret Microphone