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

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

HOME Schematics Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches
Welcome to DiscoverCircuits.com - online since 2002

See Media Kit for
Advertising Opportunities

Attention Designers:  Please alert us by eMail if we have linked to sites
where your original material has been copied without your permission.
We will change to the LINK to your site.  
Thank you.

 

DiscoverCircuits.com -- Hobby Corner
Last Updated on: Wednesday, October 18, 2017 05:04 AM

Hobby Circuits List

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

More  Remote Control       Switches

Isolated Remote Switch Circuit   January 4, 2009


There are many applications when a remote switch’s on/off status needs to be monitored. Reed relay sensors, toggle control switches and security alarms contacts are just a few examples.  Routing a switch directly to a computer system hundreds of feet away can often lead to erratic operation and noise problems.  If such a control switch is required, a fully isolated circuit is strongly recommended.  The circuit below provides such isolation.  When properly wired, it will have 5000 volts of isolation and can be positioned 1000 feet away.

The circuit uses a custom ferrite toroid type transformer.  About 20 turns of magnet wire forms the primary winding and 10 turns forms the secondary winding.  A simple Schmitt trigger oscillator drives the primary winding of the transformer with a 100KHz signal.  The voltage at the transformer secondary is rectified to produce a DC voltage. That voltage is routed to the remote switch and is used to drive the LED side of an optoisolater.  The phototransistor side of the optoisolator can be used in either a source or sink type logic level swing.  Both type circuits are shown. 

Click on Drawing Below to view PDF version of Schematic

Circuit Isolated Remote Switch Schematic

More  Remote Control       Switches

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

 


Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches



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


Discovercircuits.com endeavors to credit original designers.   Please alert us by eMail so we can
delete links to material that have been copied without your permission
.   Thank you.


© Copyright of all original material on this website is the property
of David A. Johnson, P.E. (Dave Johnson & Associates ) unless otherwise noted.  

Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.
All material is provided "as is" without guarantees or warranty of any kind, either expressed or implied.