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LED Flasher Relay Answered

Can anyone help me build a LED flasher replay capable of running approximately 100 LED's. I would like it to alternately flash and have a strobe like effect, similar to what most emergency vehicles have!!! Thanks Dave



11 years ago

Hello, I'm trying to do something similar to jeepcop274. I'm looking for a circuit to flash a Luxeon 3 watt LED at around 5 Hz or so. I want to drive it at about 1000ma & 3 volts. Thanks for any ideas. Ed65

The circuit I attached above should work, as well as this one:
it uses a transistor to drive a coil. Just substitute a relay for the coil. Should work fine. The solid state version may be better for blinking at higher frequencies.

Just create a simple 555 timer circuit, with a variable resistor pot and connect the output to a 5v relay that can drive the LED's. I would recommend a solid state relay, if you are not under a budget crunch. If you want a variable pattern of flashes, you may want to look at a PICAXE controller to drive the relay. they can be had for a dollar or two, and are not hard to program at all. Let me know if you meed help with any of that...

Photozz, Thanks for your reply. To be completely honest with you I have no idea what I am doing!!! Would you be able to draw me a schematic and list the parts I need? I am a Deputy Sheriff and my department doesn't use the most up to date equipment and I would like have this light bar on my back deck so when my trunk is up I still have rear lights visible. I have everything I need to build the bar, but want the flasher self contained in it so I can just plug it in to a cigar plug and not catch any grief from my superiors. If you can help, I'll post it on this site and give you all the credit if that means anything to you. Thanks for your help. Dave

wow.. OK.. no prob. so.. lets get more specific.. are you looking to strobe all 100 lights at the same time, or are you looking for them to "crawl" like the car light in "Night Rider" ? Flashing them all at once is quite simple, doing the crawl is quite a bit more complicated. .. would several larger lights flashing randomly work?

I want them to flash together, fast like wig wagging headlights on a police car!

OK.. cool. that's easier. give me a bit and I'll draw it all up for you. it should be simple enough for just about anyone to put together.

hey photozz, I'm also interested in flashing a Luxeon 5W led I have for my bike light. AM I able to use this same circuit?

OK.. I attached a DOC file with a basic diagram and parts list. I have not tried it yet, but I have built similar circuits before. I'll even go so far as to say I would be happy to build the circuit for you, if you want. let me know. You can get me direct at Photozz@yahoo.com