Project 6: DIY Hand Clap Switch

Objective:

To create a hand clap switch circuit that turns an LED ON/OFF using sound (claps).

Components Required:

Electret Microphone
NPN Transistor (BC547)
Resistors – 1KΩ, 10KΩ, 100KΩ
Capacitor – 10µF
555 Timer IC
Relay Module (5V)
LED (or any small appliance like a fan)
9V Battery
Breadboard & Connecting Wires

Circuit Diagram:

(A schematic can be designed in Fritzing or Tinkercad.)

Step-by-Step Instructions:

Step 1: Connect the Microphone

Connect the electret microphone with a 10KΩ resistor in parallel.
One leg connects to GND, the other connects to the base of BC547 via a 1KΩ resistor.

Step 2: Amplify the Sound Signal

The collector of BC547 connects to +9V via a 10KΩ resistor.
The emitter goes to GND.
The amplified signal is passed to a 555 Timer IC to create a pulse.

Step 3: Control the Relay

The output of the 555 Timer triggers a 5V relay module.
The relay controls the LED or any other AC/DC device.

Step 4: Power the Circuit

Connect a 9V battery or any suitable power source.

How It Works:

When a clap sound is detected, the microphone generates a small voltage.
The transistor amplifies the signal and sends it to the 555 Timer.
The timer generates a pulse, triggering the relay module.
The LED (or appliance) turns ON/OFF with each clap.

Customization Ideas:

💡 Use Arduino for more accurate sound detection.
💡 Add Multiple Clap Control (e.g., 1 clap for ON, 2 claps for OFF).
💡 Use a MOSFET instead of a relay for silent switching.