clap switch
Here is a circuit for electronics hobbyists that can switch on and off, a fan or a Radio etc. by the sound of a clap.
The sound of clap is received by a small microphone that is shown biased by resistor R1 in the circuit. The signal is further amplified by transistors Q1,Q2,Q3. The relay contact is connected to the power line and hence turns on/off any electrical device at output socket.
PARTS LIST:
RESISTORS:
R1 – 15K
R2,5,12 – 2M2
R3 – 270K
R4 – 3K3
R6,10 – 27K
R7,11 – 1K5
R8,9 – 10K
R13 – 2K2
MISC:
X1 – 12V / 300mA Transformer
NIC – Condenser Mic
RLY – 12V Single charge over relay
CAPACITORS:
C1 – 10KPF Disc
C2,3 – 47KPF Disc
C4 – 1000uF/16V
SEMICONDUCTORS:
Q1,2,3,4 – BC 149 B OR C
D1 – IN 4002
D2,3,4,5 – IN 4148
