rear flashing light?

[FlatFender]

hey folks
im wanting to make a rear flashing light for my commuter bike. Ive got the housing, and the battery and everything all ready to go, BUT... heres the kicker..... I dont know how to make it flash. Its a K2, and im driving it at 1000ma.
please help
Luke

 

[greenLED]

Bflex with bike interface:

http://taskled.com/bflex.html

Check out what Darell and georges80 are up to:
https://www.candlepowerforums.com/threads/169898


I mention that because you may not want to blink that puppy at 1000mA.

 

[FlatFender]

well, see, heres what I have. I bought the little strobe in the center of the picture for $.50 at the store a while back. it used 2 little button cells to flash a 5mm red led.
Now, last night just to see if it would work I cannabalized one of my headlights and wired it all up to the board, sure as poop it will flash the K2 in the light really well, im just worried that it wont last too long given the ammount of current im pushing through it.
Im pretty new with all this, so gimme your honest opinion.

 

[greenLED]

How much current are you passing through that circuit? (you sure it's 1000mA?) It's really hard to comment on the durability of that circuit since I have no idea what the specs on that circuit are.

One sure way of figuring things out is to let it run its course and see how long it lasts... :devil: If it works, good for you. If it doesn't... well, that's what the bFlex is for.

Looks like you got the heatsinking part worked out nicely.

 

[Darell]

Wow! I can't believe it worked at all! Are you really getting 1000mA to the emitter through that blinker? Dang.

As Green said - you're gonna tick some people off if you flash 1000mA at 'em too long. With the new emitters, I wonder if we'll see some brightness regulation on these things. If I'm driving along and am blinded by 1000mA of red light, I'm not going to be very happy! Being seen is one thing - blinding drivers is another. Imagine another bicyclist behind you!

 

[FlatFender]

I was totally surprised myself that it worked! Its very bright, and it WAS 1000ma when I built the headlight, but im not sure how much is making it through the little circuit, ill bust out the multi-meter in the morning and find out what it really is.

BTW, yeah the heatsinking works very well, its a k2 star dremeled down to fit inside the mini mag, arctic alumina'd to a 1.5" piece of alum inside the mag body.

 

[FlatFender]

Ok, so, when I hooked up my other light with the same optics that IS getting 1000ma is considerably brighter. so, no, the led isnt getting 1000ma, but its very much bright enough for my blinky.
I think at this point im just going to run it, and see how it holds up.
When it burns up, ill find something else!

thanks guys

 

[AndyTiedye]

I don't see why it shouldn't go on working.

The circuit is probably running the LED at a pretty low current, since it
was designed for button cells and a 5mm LED.

That LED should last forever at that current. You aren't driving the
circuit much harder assuming the original button cells were 3 volt lithiums.

 

[FlatFender]

I don't see why it shouldn't go on working.

The circuit is probably running the LED at a pretty low current, since it
was designed for button cells and a 5mm LED.

That LED should last forever at that current. You aren't driving the
circuit much harder assuming the original button cells were 3 volt lithiums.

they were 3v lithiums...thats good to hear, im going to run it and we'll see how she holds up.

 

[will]

Is that flashing RED in the back? Most drivers expect to see red in the back, white in the front. If they see white, they are likely to assume that you are traveling towards them and have them in site.

 

[FlatFender]

Sure is red!