[N4niner206]

As most of you probably know, the "motion sensors" on many store bought props actually are some form of resistor that senses abrupt changes in light. The other day while playing with some of my store bought props, I had an idea that I'd like to use for next year. I would like to set up each room in our house as a separate scene that can be viewed through our outside windows (they're low enough for kiddies to look in). Each TOT would get a flashlight to shine through the window. A sign would be posted at each window with a list of objects to spot in the room. Along with it, "ghosts" can be freed from various objects (props) when they are triggered by the beam of these special flashlights. Additionally, extra ghost targets could be placed around the room for them to aim for. the So in essence, its part scavenger hunt and part shooting gallery.

So my questions are...

1) how could someone build their own prop trigger to be set off by light using these sensors? Ideally, maybe a circuit board that has the sensor and an outlet for the prop. When the sensor is triggered, the relay would allow power to the prop (ie an fcg or haunted bookcase).

2) Does any existing prop controller or other device do this?

3) Could a simple "target" be built that would allow a 9-volt battery to illuminate an LED for a minute or so when the light sensor is triggered (thus making targets that will illuminate after being hit by the beam).?

4) Would IR sensors be a better route, and how would that work?

5) Any suggestion for sources of the parts/sensors?

I don't currently own any prop controllers and have VERY limited knowledge about electronics. I came on the idea after triggering my props with the flashlight and thought this could be fun. Im thinking along the lines of laser tag... using that idea to make my home haunt display interactive. Someone savvy and enterprising could even make and package sets for this... wouldn't that be fun! In the meantime, anyone care to give advice?

 

[N4niner206]

Wow.... nothing? Lol guess ill try to figure it out the hard way ;-)

 

[untillater]

I would imagine you could hook up a photocell to just about any prop controller and use as a trigger. I haven't tried it, but in theory it should work.

 

[Vysse]

Oops I meant to respond to this. Your best bet is to find something that reacts to light. I think there's some Christmas controllers that do. The idea is your prop triggers when a light is flashed on it.

 

[untillater]

here is what a photocell looks like along with a data sheet. Depending on the prop, simply putting one of these in place of the "foot switch" may work, if not then a relay attached to one of these will. and much cheaper than buying christmas controllers and hacking them, why hack twice.

https://www.sparkfun.com/products/9088

 

[N4niner206]

Awesome, guys! I knew I could count on this group to provide some useful info! I'll do a little research and see if i can figure this stuff out. I'm probably getting a little in over my head, but thats part of the fun.

Anyone have any ideas on how I could scratch build the "targets" from electrical components? (the ones that would light LED(s) when the photo cell is hit by light?) I was kinda thinking of something that would involve the photocell, some sort of timer relay, the LEDs, and 9-volt battery.

Any electrics wizards out there have any thoughts?

 

[EviLEye]

My initial thought on this would be to use the photocell in conjunction with a 555 timer circuit. Google 555 timer and you'll get a lot of hits for various circuits. The photocell will trip the timer and the output can then be used to light the LED for a period of time (e.g. couple of seconds). You would need one of these for each target and would need the power supply to drive the circuit and LED for the night. I'd likely look at getting a small, 5v power supply (e.g. walwart) so you wouldn't have to worry about batteries going dead on you. I pickup power supplies at my local electronics shop that has them as a surplus and voltages range from 3v to 24v for instance over a variety of amperages. I think you'd collectively be into each circuit (parts, board, & power supply) for about $15-20.