Web DiscoverCircuits.com

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

DiscoverCircuits.com, has 28,000+ 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 your design.

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

DiscoverCircuits.com  --   Dave's Circuits
Circuits designed by David Johnson, P.E.

Find Dave's Circuits by Category
Last Updated on:  06/17/2009 03:30:30 PM


The contents & graphics of Discovercircuits.com are copyrighted.
LINKING to Dave's circuits is permitted
but DO NOT COPY this data to your WEB SITE server.

Click on Drawing Below to view PDF version of Schematic

Ramping LED Driver  
The circuit below was designed to drive a LED with an intensity ramping mode.  Two 555 timers generate two different triangle waveforms.  The upper device generates a 10KHz signal while the lower unit produces a 1Hz signal.  The two signals are fed to a voltage comparator.  The result is a pulse width modulation (PWM) signal, which with the aid of the FET, drives the LED in such a way that its average light output slowly ramps from about zero light to maximum and then slowly dims back down.  The circuit should operate over a supply voltage ranging from 3v to 12v. You can easily vary the ramping time by changing the value of the 1M resistor.  For an interesting effect, you can place a 1N4148 diode in parallel with the 1M resistor, with the cathode (banded end) side connected to pin 3. 

Driver Circuits       LED - White
Master Schematic Category List - David A. Johnson, P.E.

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

 Linking is welcomed but COPYING any content or graphics to your web site is expressly prohibited.

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