DiscoverCircuits.com, has 30,000+ 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 or post your
design.
The contents &
graphics of Discovercircuits.com are copyright protected.
LINKING to Dave's circuits is permitted but DO NOT COPY any files to your WEB
SITE server
This circuit uses a surplus geophone to detect human footsteps from 100 feet away.
It was designed for monitoring the Mexico/USA border. This preamp part of the
system draws about 50 microamps from a 12 volt supply.
Click on Drawing Below to view PDF version of Schematic