3W LEDs in a Police Strobe/Flasher

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Thread Starter


Joined Oct 4, 2011
Hi All,

Just to start: before anyone mentions it, I have a valid state issued permit that allows me to use Emergency (Flashing) Lights (of the colors Red and/or White) in certain situations. I am willing to provide proof if necessary. If this discussion is inappropriate for the public forum, I would be willing to (and would appreciate) discussing it in a more private manner. I would also like to state that my background in ece, circuitry, and programming is limited, but I am trying to improve. I think this project is a step towards that, as well as reading some resources such as Bill_Marsden's notes here -> http://forum.allaboutcircuits.com/blog.php?bt=684

Essentially I want to construct this: http://www.youtube.com/watch?v=DvpTnBfVKGw

This video shows a circuit that flashes 3 LEDs twice, and then the other 3LEDs twice, and repeats (rate is adjustable).

From what I've read on the forum it seems a suitable approach is with the use of a 555 and 4017 chip, and I believe that is also used in that video.

For my project I would like to increase the amount of LEDs to 4 per side. So I would have four 3W LEDs (Red) flash(2x) and then four 3W LEDs (White) flash(2x). I would also aim to have this powered through my vehicle's cigarette lighter. With my limited knowledge, I am not sure what modifications I would need to make to pre-existing circuit diagrams to accommodate these LEDs. I have heard that a BuckPuck may be of use, but I have really no idea how to integrate that into this final product. If the general consensus is that a total of eight 3W LEDs is overkill I would be willing to bring it back down to 6.

I am also aware that a microcontroller (such as a PIC), would be more powerful, but I would have difficulty in the programming. Perhaps this can also be part of the discussion, but for my initial purposes the flasher shown in the video would suffice.

I apologize for the length of this post, I just wanted to be clear and thorough. Thank you.


Joined Mar 24, 2008
I am one of the guys who have designed these in the past, but the rules have changed a lot here on AAC. Note the new TOS:

6. Restricted topics. The following topics are regularly raised however are considered “off-topic” at all times and will results in Your thread being closed without question:

  • Any kind of over-unity devices and systems
  • Automotive modifications
  • Devices designed to electrocute or shock another person
  • LEDs to mains
  • Phone jammers
  • Rail guns and high-energy projectile devices
  • Transformer-less power supplies
This comes from our Tos:
Terms of Service
There will be enough sites where automotive questions can be discussed :
Member selected automotive forums

This definitely falls under automotive.

You can pick up on another site I'm fond of, ElectroTech.


I do not believe their rules cover this there. Please feel free to come back to AAC, we aim to be one of the friendliest groups around.

If you want to suck me into a conversation over at Electro-Tech I'm pretty easy, and cheap too.
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