How Can I Build a Simple IR Signal Detector Circuit for a Church Choir?

[farhad ali]

I've been looking all over the Internet for what I thought would be an easy thing to find instructions on. Unfortunatley, anything that comes close either complicates the matter with extra features or assumes I know a lot more about electronics than I do...

I need to build a very simple circuit: When it detects an infrared signal, it lights up an LED which stays lit for as long as the IR signal is active.

The problem is that it needs to not drain it's battery much when it is subjected to ambient light, including some sunlight through stained-glass windows. (This is going to go into a church and will serve as a stand-up signal for the choir.)

Everything I have found online is either too sensitive to ambient light, or has decoding chips for complex signals. I just need something very simple.

If I had just a components list of stuff that I could get at Radio Shack or similar places, I'm sure I could easily figure out how it works and build it.

Does anybody have any suggestions on where I could start? (I used to think I was a little proficient with electronics. In researching this, and seeing the "simple" circuits offered up on the Internet, I've come to realize that I'm much more clueless than I ever imagined.) :(

Any pointers would be greatly appreciated.

Thanks,
Farhad

 

[aresnick]

So I don't think Radio Shack sells these, but you can purchase photodiodes or phototransistors with coatings that select for certain wavelengths. With that, a battery, and a resistor, you should be able to hook up an LED between them, and when IR hits the photo{diode,transistor}, current flows and lights up the LED.

Unfortunately, I can't post links, yet, but if you Google (ir detector circuit "junk box") the first link should give you an idea. . .

Hope this helps,
a.