# Pneumatic Sit-up Ghost Triggering Issue



## Richie (Jan 4, 2007)

Hi gang,

2006 was the first year we added a pneumatic prop to our haunt. Aside from ghost triggering issues, it was a wonderful working prop.

I did come across DeathLord's web site showing how to add the 120v ice cube relay to help prevent the ghosting, but the same thing kept happening even after adding it. I tried two different brand motion sensors, one had the test switch on it, and the other didn't have a test switch, but when the timer knob was set to minimum, it worked just the same as having a test switch. Walking past the motion sensor the prop would activate and rise and lower about 8X before finally stopping.

I'm beginning to wonder if having all the white wires (3 neutrals) twisted together could be the problem and perhaps further isolation is required. I even removed my prop from the motion sensor, simply having the motion sensor hooked up to the relay, and you can see the relay opening and closing about 8 times before it would stop. Obviously it's the motion sensor that is the problem and not any type of EMI from the pneumatic 12v 5-port valve.

Does anyone know of a different type of motion sensor that is less prone to cause ghosting? I'd really like to work this out so that when you walk past the sensor, the prop rises once for about 2 or 3 seconds and then resets. 

BTW...I don't know how many different types of motion sensors there are out there, but the one I'm using is from an outdoor garage security light. I'm going to be also adding a Trash Can Trauma, which is almost finished, so getting this worked out would be great. Thanks in advance for any assistance.


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## Sickie Ickie (Jun 20, 2006)

Heyya Richie, just checked out your fun stuff link. Very cool!


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## Otaku (Dec 3, 2004)

I hacked this PIR forthe $20 Prop Contest last year and they work really well. The timer circuit that is shown in the instruction manual is easy to build and has a range of 2 secs. to 90 secs. The hack involved changing the "off" times from 15 secs. and 15 mins. (factory default settings) to a more usable 30 and 60 secs. You can see the hack here:
http://www.thefrighteners.com/Gary's .htm
I use two of these for triggering local sound and light effects. So far (about 100 hrs use on each) I've had no problems at all.


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## Richie (Jan 4, 2007)

Hi Sickie,

Glad you enjoyed my website. I haven't updated it in a while. I'm going to be adding many more props and life size figures that I have later this year.

Otaku...that looks like a great design. When using the 30 second delay with a pneumatic pop-up, I assume the prop would remain in the "Up" position for the entire 30 sec before resetting. I'll have to try it out and see how that is. Funny thing is that when I set either of my motion sensors to stay on for a 60 second duration, they don't ghost at all. Very weird these new motion sensors. Unfortunately, having a "Sit-up" or Trash Can Trauma in the "up" position for that amount of time is to long. 

I'll certainly see if I can live with a 30 second duration. Thanks for the responses.


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