Date: Thu Apr 12 12:32:40 2007

Author: Michael Timmins

Subject: Re: Monkey Gun/Shoot Demo

I had trouble with ours a few years ago, sometimes it failed to trigger. It
uses an ir emitter and receiver. I found I had to shield the receiver better
from the room lighting. It hasn't failed since. Ours has a manual reset
button. Do you know what the failure mode is for yours?

Mike Timmins

On Thursday 12 April 2007, Douglas Johnson wrote:
> On our Monkey Shoot or Monkey Gun Demo, we have an electronic
> trigger circuit that trips off the power to the electromagnet that
> holds the monkey up and then resets after 5 seconds after it falls.
> Lately, it hasn't been very dependable. Does anyone out on Tap-L
> have a bullet proof circuit for such a demo? I am tempted to go
> back to our mechanical trigger.
> ....Doug J.
> PS.. Right now we use a laser diode and a photo detector at the end
> of the barrel of the gun for the switch sensor circuit.

Mike Timmins

University of Virginia
phone: (434) 924-6800
mail address:
382 McCormick Rd
Charlottesville, VA 22904