Probably forgot more about electronics then I knew back when I attended electronics school. What can I say, over the years it's been simpler to just buy something than to make it.

But now I have an application where I'm needing a 'simple' photoelectric beam, that will be hooked into a 12 volt alarm circuit. Found a lot of off the shelf miniature photoelectric beams, but were all just too big, having all the circuitry in a housing. Even found a strip, (also called a curtain), in various lengths that had several beams along the length for protection, say across doors, windows and the such.

What I would like to do, is just mount the transmitter and receiver L.E.D.'s or other opto type components where I need them, and run wires back to a central point where the rest of the circuitry and relay would be.

Again, the off the shelf units I have seen had all the circuitry in a housing which is going to make it too big, and noticeable for my applications, even being maybe an inch square, or others I had seen, that were a small round shape, but 2 1/2 inches deep.

Can anyone suggest the right parts, and a diagram of this simple circuit? All i need to do is activate a 12 volt relay when a beam is broken.

If I can just mount the transmitter and receiver discretely, then the rest of the circuitry a few feet away in a housing, I'll probably do a curtain type of layout, mounting maybe 4 to 6 beams across the opening I need to protect.

Just found this forum... don't suspect I'll spend a lot of time here, so if someone out there can help me out with a parts list and a diagram, I would sure appreciate if you would contact me directly instead of posting a reply here. Don't know if it's allowed to post direct addresses here, but will give it a try... jkb at comcast dot net.

Thanks!

 

There's a circuit here: Infra Red Alarm System HELP.......

You can mount the IR leds on an extension lead. For the receivers, you will want a capacitor across the power supply for each tsop37xx device if they're mounted remotely.