Vanagon EuroVan
Previous messageNext messagePrevious in topicNext in topicPrevious by same authorNext by same authorPrevious page (September 2007, week 3)Back to main VANAGON pageJoin or leave VANAGON (or change settings)ReplyPost a new messageSearchProportional fontNon-proportional font
Date:         Tue, 18 Sep 2007 15:32:23 -0700
Reply-To:     David Kao <dtkao0205@YAHOO.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Kao <dtkao0205@YAHOO.COM>
Subject:      Re: 2 LEDs
Comments: To: Mike S <mikes@FLATSURFACE.COM>
In-Reply-To:  <20070918220902.303271165C3@hamburg.alientech.net>
Content-Type: text/plain; charset=iso-8859-1

I never said it won't work. You are dealing with 20 ma LEDs with a large (390 ohm) current limiter. I am talking about high brightness LEDs for lighting applications usually operating at hundreds of miliamps. Don't jump on a conclusion with a wrong experiment. Your 390 ohm resistor takes the majority of the voltage (8 volt). Of course you are not going to burn out your LEDs. If one LED shorts out the remaining LED will increase its operating current from .02A to .024A. Try two 3 watt LEDs with a resistor of single digit value. Set LED current to 0.7A. Then short out one LED.

David

--- Mike S <mikes@FLATSURFACE.COM> wrote:

> This is for David Kao, who asked for help in running a simple > electrical experiment with 2 LEDs. I used a 12V regulated source. > > (12V - (2 x 2.1V)) / 0.02A = 390 ohms. > > http://www.flatsurface.com/pics/2LEDs.jpg > > Works great! Neither is significantly brighter than the other, and > neither blew up, despite dire predictions. >

____________________________________________________________________________________ Check out the hottest 2008 models today at Yahoo! Autos. http://autos.yahoo.com/new_cars.html


Back to: Top of message | Previous page | Main VANAGON page

Please note - During the past 17 years of operation, several gigabytes of Vanagon mail messages have been archived. Searching the entire collection will take up to five minutes to complete. Please be patient!


Return to the archives @ gerry.vanagon.com


The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.

Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.