Clap Switch

Here's a Hobby Circuit for electronics hobbyists that can change on and off a light, Fan, Radio, etc by the sound of applause. The sound of applause is received by a small microphone that is shown biased by resistor R1 in the circuit. The microphone changes sound waves to electrical waves is further amplified by Q1. The transistor Q1 is used as a common emitter circuit to amplify weak signals received by the microphone. Amplified output from the collector of transistor Q1 is then fed to the flip-flop multivibrator aka flip- flop circuit.


Flip flop circuit is made by using 2 Transistor, our circuit Q2 and Q3. In a flip- flop circuit , at a time when a single transistor behavior and other cuts and when a trigger pulse source gets out first transistor is then cut and second transistor leads . Therefore, the output transistor is either logic - logic 0 or - 1 and remains in a state 0 or 1 until trigger pulse is obtained from the external source .
The pulse of gonorrhea , which is a trigger for flip- flop that makes changes to the output that is complementary (reverse) . Bistable output is in the form of low current is unable to drive the relay directly so we used an amplifier circuit using Q4 which is a common emitter circuit . Q4 output is connected to a relay ( electromagnetic switch ) that functions as a mechanical switch and it becomes easy to connect any electrical appliance.
The relay contact is connected to the power line and therefore enables / disables any electrical appliance connected all the way through the relay .