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 design ideas.
We make every effort to link to original material posted by the designer. 
Please let us if you would like us to link to or post your design.

HOME Schematics Index Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches


DiscoverCircuits.com -- Hobby Corner
Last Updated on: Thursday, November 30, 2017 07:42 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  Driver Circuits   Relay Circuits    PWM
 

Reduced Power Relay Driver  Aug 3, 2008


Relays can handle a lot of power.  However, for certain power sensitive designs you would like to reduce the power needed to hold a relay closed.  The circuit below performs such a task.  It uses a single CD4093 quad NAND gate. 
When the “on” logic input signal is detected, the relay is first pulsed on for about 500ms.  This is sufficient time to insure the relay is fully closed.  After that initial pulse the relay is then driven with a square wave signal, whose duty cycle can be adjusted.  The signal duty cycle can be adjusted from about 10% to 90%.  In most cases a 50% duty cycle will hold the relay closed.  This reduces the average DC current required by the same factor, which means a 4:1 reduction in power. The circuit can operate over a wide 3v to 15v range.

Click on Drawing Below to view PDF version of Schematic



More  Driver Circuits   Relay Circuits    PWM

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


HOME Schematics Index Hobby Corner Dave's Circuits Electronic Resources Contact Info
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


Copyright  January, 1998 - November, 2017     David A. Johnson & Associates.  All Rights reserved. 


 Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.