At 12:31 PM 8/5/2005, PicDude wrote: >Hi all, > >I need to supply power to a large number of LED's in a vehicle, where all >LED's will be on or off simultaneously, and with 2 brightness levels. > > I came up with this circuit, though I'm not sure if it >would work properly... > http://www.narwani.org/neil/electronics/Const-2Cur-Ckt.gif What is the voltage at the top of the LEDs? In other words, how much base current will you have when the brake line goes HI? If these LEDs have the usual 1.7V forward drop each, your circuit should work just fine. Base resistor value needs to be fairly low or, better yet, perhaps consider the use of a logic-level FET instead of the transistor. dwayne -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 21 years of Engineering Innovation (1984 - 2005) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist