Thread: Calling all electronics experts!

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I am in need of a simple circuit for a new attraction at our Halloween event. I know the basics of what the circuit needs to do, but don't know how to draw up a schematic.

When an IR Receiver detects IR light, it needs to activate a 555 timer. The 555 timer then needs to turn a light or LED on for three seconds.
It would be nice if the circuit could run off a battery, as we will need 25+ of them. I have no reservations as to the type of light or LED it would use, but the brighter the better.
I would love to be able to submit this to BatchPCB and order the PCBs so all we have to do is solder the parts on. So if anyone can quickly come up with a schematic and/or file to submit to have the PCB made, it would be greatly appreciated.

Two ideas:

1. I haven't tested this out, but there's a circuit diagram on Scary Terry's site for using a PIR without a microcontroller (scroll to the bottom):
http://www.scary-terry.com/itw/pirsensor/pirsensor.htm

Then have that flip on the "Timer Plus Relay" circuit on page 9 of Forrest Mims "Engineer's Mini-Notebook 555 Timer Circuits." Google this, you can find it online.

Overall, the PIR triggers a transistor which flips on a relay...that triggers the 555, and it turns on another relay for your specified time. Adjust the time with various components. Disadvantage is that you can't deal with debounce issues on the PIR or customize things easily, but that may not matter.

2. Consider using a Picaxe 08M on the Rev-Ed AXE021 - PICAXE-08 Proto Board Kit. Cost of Picaxe chip is $2.65 and the protoboard is $4.50. You can get these immediately, build it into something similar to the VLC Prop Controller:
http://hauntforum.com/showthread.php...&highlight=vlc

While the Picaxe is more expensive than a 555, you should be able to use it, a PIR, a relay and a couple of other parts, a tiny bit of protoboard, and you're good to go, without having to order custom-made PCBs. Then you can also program these for different timings/effects if you want.

This will work by having the PIR attached to the Picaxe, a small protoboard with the relay also connected to the Picaxe, and a couple of supporting parts with the relay. The Picaxe watches the PIR for a signal, turns on the relay for the specified amount of time, and then waits as long as you want (30 seconds, whatever) until the PIR can be triggered again. Advantage is the ease of tweaking the PIR debounce and retrigger times, plus not having to design and have custom PCBs made.

Both circuits should be able to run from batteries, then they trigger whatever you want (LED spotlight, etc) and that will need its own power supply.

Here's a couple of circuits I've put together using the Picaxe. I use PIR's for triggers and 5V regulated wall warts for power supplies but the Picaxe can be run on 3AA batteries.
Dirt Cheap and Tiny Micro Controller
Super Versatile, $10 Complete Prop Controller
Otaku has also designed a 2 stage timer that should work for you. You can find it here - http://www.hauntforum.com/showthread.php?t=20849
I've built several and they work great.

Otaku's design is the equivalent of what I suggested in #1. If you go to the end of his thread, it turns out you can get circuit boards for it made for you from http://simplecircuitboards.com/ for five bucks each. Not bad, but you still might want to look at the Picaxe for versatility. Halstaff's "Dirt Cheap and Tiny Micro Controller" comes in at $4.00 and does everything!