Sound Activated Switch

Proceded by

DC Motor & Switch

Succeded by

Adjusting Sound Level

Project No.


New Pieces

4, 5, J1, J2, SP, WC, U1

Manual Included



To show how sound can turn “ON” an electronic device.


Build the circuit shown on the left by placing all the parts with a black 1 next to them on the base grid first. Then, assemble parts marked with a 2. Finally, lay the speaker (SP) on the table and connect it to the circuit using the jumper wires as shown. When you close the slide switch (S1), the music may play for a short time, and then stop. After the music has stopped, clap your hands close to the whistle chip (WC) or tap the base with your finger. The music should play again for a short time, then stop. Blow on the whistle chip and the music should play. You could connect the speaker using snap wires instead of the jumper wires, but then the speaker may create enough sound vibrations to reactivate the whistle chip.