Trying to make a LED triggered by a break in an IR beam

[Glitch1502319641]

Ok, I'm competent in soldering, but have minimal knowledge in building a circuit, or components. Basically I'm trying to build an LED light that will fit inside a mock silencer of my airsoft gun, and when a BB breaks an IR beam the LEDs in the silencer turn on, charging the glow-in-the-dark BBs.

Any help in this would be appreciated. Thanks!

 

[Joe G]

have you thought about a flash circuit from a camera or timing light. it might work better? also thats a small target moving at a pretty-quick speed??

 

[crutschow]

It may take a rather bright light to charge the BBs in that short period, thus Joe G's suggestion to use a flash may be better.

 

[#12]

If an LED will stimulate the BB enough, you can just leave the LED on all the time. Twenty milliamps out of a 9 volt battery will allow the battery to last 22 hours.

Have you tried putting LED light on a BB for a thousandth of a second to see if it works?

 

[Glitch1502319641]

I have considered the flash out of a disposable camera. The problem is it takes 30+seconds to charge. They do have these 'full auto tracer' units available for $60-$100. but I was thinking it would be cheeper to guild one, and I could outfit a couple friends for cheap too.
The 'always on' isn't a bad idea. I was planning on using a LiPo battery as the power source, I already have a charger for it, and it's small and flat so it would fit in pretty easily. My plan was to have a IR emitter and detector actualy trigger a row of LEDs. That way I wouldn't have to work out where the BB would be mamoseconds after the beam was broken. If I use a strip of UV LEDs that's roughly 3-4" long, that should charge the BBs enough.
In the past I had modified a magazine to have a white LED built into it, but it would only charge them so-so, and if the BB sat in the barrel, even briefly, it would be significantly dimmer.

Thanks for the input, I'll have to see which is better, UV or white. My money's on the UV, but a one watt White might do better.

 

[Glitch1502319641]

Sorry it took so long. I recently moved and had to find my uv flash light... Just doing some basic experiments, the 9-UV LED flashlight charges better than a 1w led. Also, what if instead of an IR beam, just have it sound activated? I'll continue brainstorming and see if I can come up with anything else, thanks for the input.

 

[SABorn]

Why not just work off the trigger and have a slight off delay within the circuit, or just hold the trigger for the fraction of a second after firing.
It could be worth still having the led in the mag for a pre charge and a led on the barrel as a top off as the BB exits.

Pete.