The document describes a clap switch, which uses a microphone to detect the sound of clapping and convert it into an electrical signal. This signal is amplified by transistors and used to power a relay that switches electrical circuits on or off, allowing loads to be controlled remotely through clapping or other sounds. It is a low-cost and energy efficient way to control appliances without physical switches but could be triggered accidentally by other noises.

3.  It is a switch which can switch on/off any
electrical circuit by the sound of clap.
 Electric microphone picks up the sound of
clap and produces small electrical signal
which is amplified by the succeeding
transistor. The two transistor change state
at each signal.

4.  Converts the sound signal into an
electrical energy.

5.  The basic idea of Clap Switch is that the
electrical microphone picks up the sound
of your claps, cough, the knocked on your
door or any sound that can switch
ON/OFF the circuit. It produces a small
electrical signal which is amplified by the
succeeding transistor stage.

6.  Resistors
 Capacitor
 Semi conductors
 Transformer
 Condenser microphone
 12v relay
 Bulb or load

9.  You can turn anything ON from any
location, simply by clapping your hands or
producing any kind of sound.
 It turns OFF automatically.
 It involves mobility-impaired person.
 Low cost and reliable circuit.
 Complete elimination of man power.
 Energy efficient.

10.  Unnecessary disturbances may occur.
 Generally seen as simpler for most use
cases to use a traditional light switch.