Web DiscoverCircuits.com

Electronic Circuits and electronic circuits, electronic schematics plus an extensive resource for hobbyists, inventors and engineers

DiscoverCircuits.com, has 28,000+ electronic circuits, cross-referenced
into 500+ categories.    We have searched the web to help you find quick design ideas.
We make every effort to link to material posted by the designer. 
Please let us if you would like us to link to your design.
HOME Schematics Discover Forum Hobby Corner Dave's Circuits Electronic Resources Book Corner Contact Info

DiscoverCircuits.com  --   Hobby Corner
"Hobby Circuits for your Hobby Projects"

Last Updated on:  06/19/2009 02:56:00 PM

Audio Signal Detector/Switch Circuit
designed by David A. Johnson, P.E.

Click on Schematic below to view PDF version of this Circuit
For some audio systems it is desirable to have an automatic switch circuit turn on other devices, such as an amplifier, if an audio signal is detected on one line.  The hobby circuit below will activate a transistor switch when it detects at least 50mv peak to peak of an audio signal.   The switch could be used to turn on a relay, routing the signal to where it is needed.  A single 3v lithium cell will power the electronic circuit for about 5 years.

Circuit Audio Activated Switch Circuit designed by David Johnson, P.E. (June 30, 2006)
HOME Schematics Discover Forum Hobby Corner Dave's Circuits Electronic Resources Book Corner Contact Info

 Linking is welcomed but COPYING any content or graphics to your web site is expressly prohibited.

 About Us   |  Advertise on DiscoverCircuits.com   |   Report Broken Links  |    Link to DiscoverCircuits.com  |    Privacy Policy