Tone-actuated relay

Posted on Jan 24, 2013

The circuit is built around the LM567 tone decoder IC that requires about 100 millivolts at its operating frequency. The frequency is set by a 10 K variable resistor and can be between 700 and 1500 He

Tone-actuated relay
Click here to download the full size of the above Circuit.

When a tone at the set frequency is present, the 567"s output goes low to energize a relay through a 2N3906 PNP transistor.

Leave Comment

characters left:

New Circuits



Popular Circuits

Audison LR604XR car audio amplifier
20 watt amplifier with LM1875
Speed alarm
Carrier Current Transmitter For Data Transmission
DIY Sound Activated LightsCircuit
transistors audio controlled relay circuit
cheap motors with arduino
Arduino Analog Read Potentiometer to Digital Out LED
VLQC circuit
Vibrato circuit
Low-noise preamplifier circuit