HOME Schematics Discover Forum Hobby Corner Dave's Circuits Electronic Resources Book Corner Contact Info


  Experimenter's Corner

  Previous Issues

Ultra Low Current Circuit Examples
By: Dave Johnson

There are some wonderful new integrated circuits coming out. Some are designed for very low power applications.  I encourage you to play around with some of these new devices.  One application example is shown below.  It is a LED flasher circuit which draws about 2ua of total current from a 3v supply.

It uses a tiny ultra low power voltage comparator IC from National Semiconductor.  The LMC7215 itself draws less than one microamp from a 3v supply.  The device is wired into a pulse generator circuit, which flashes a super efficient green LED from KingBright.  The pulse rate is about 0.5Hz.  The LED flash duration is 20ms and the peak LED current is about 100ua.  Although the LED current is low, the efficiency of the LED is high enough that the flash is still quite bright.  Using surface mounted components, the complete circuit would take up less space than a postage stamp. This circuit might be useful to wire into a flashlight, so the light can be found in the dark.  The 2ua current drain is so low that it would not tax any battery.  In the future, I will post some more examples of very low power circuits.  I will also show some techniques to keep the average current of some circuits in the microamp range.

Please send comments to me


Issue 2 -2011     February

Page 1 Back
Envelope
Circuit
Diagnosis
Experimenter's
Corner
Good Idea
gone Badly
New Products Rants &
Raves
What the World
needs Now
Wily Widget


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  2002 - 2015 David A. Johnson & Associates.  All Rights reserved. 
 Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.