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

DiscoverCircuits.com, has 45,000+ electronic circuits, cross-referenced into 500+ categories.
We have searched the web to help you find quick solutions & design ideas.

Got Designs?
Please eMail
if you want me to link to and/or post your original design
NOTE:  We make every effort to link to original material posted by the designer. 
Please contact us if our link is not to your site!  Thanks.

DiscoverCircuits.com -- Hobby Corner
Last Updated on: Wednesday, June 02, 2021 01:18 PM

Hobby Circuits List

The contents & graphics of Discovercircuits.com are copyright protected.
LINK to Dave's circuit, but DO NOT COPY any files to your WEB SITE server

More  Switch Circuits, Micropower Circuits

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

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.

Click on Circuit Below to view PDF of Schematic

Audio Activated Switch Circuit designed

 by David Johnson, P.E. (June 30, 2006)

More  Switch Circuits

Hobby Circuits List
eMail David A. Johnson, P.E. about this circuit

HOME Schematics Index Hobby Corner Dave's Circuits Contact Info
Imagineering Ezine Dave Johnson, P.E. Faraday Touch Switches

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

Copyright  January, 1998 - June, 2021     David A. Johnson  All Rights reserved. 

 COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED!