| Home | Terms of Use | Site Map | Contact Us |
IndustryCommunity.com > Electrical and Electronic Community > Analog Circuit Design Forum > Message
Main Menu

[ List Subjects ][ Main Page ]
[ View Followups ][ Post Followup ]

Subject: Re: LED lights for car (police style)

Date: 07/22/02 at 9:31 PM
Posted by: Ned Stevens
E-mail: k7elp@xmission.com
Message Posted:

In Reply to: LED lights for car (police style) posted by john on 07/12/02 at 7:34 AM:

I think what you want can be accomplished with a single 555 timer, 1 NPN darlingtion transistor,1 PNP darlington transistor, a couple of LM317T regulators and some passive components, namely resistors and capacitors. The darlington transistors will turn on the LED's alternatly at the flash rate. The LM317T will work as constant current sources. The LED's by nature are current devices, and generally have resistors in series with them to limit the current. In this case by using a constant current source below the peak current of 100MA you won't have to worry about the forward voltage and the varying voltage of the automobile power source. If this sounds good to you let me know and I will breadboard a typical circuit and then email you the schematic
to you.

Follow Ups:

Post a Follow-up:


Message to Post:


1999-2001 Sunlit Technology Co., Ltd. All rights reserved.