Thread Starter


Joined Nov 7, 2021
I'd like to make a coffin for next halloween that rattles and has audio play when anyone walks past it. I've got ptc circuit for audio and I have an idea about using a cam and motor for the rattling door but is there a way I can get the audio circuit to work with the motor controls? I was thinking maybe there might be a device that could replace the push to close button on the audio. One where when power is supplied by the control unit to the motor, the divice will close the circuit on the audio divice so it plays the audio at the same time. Failing that I could just set it up so the cam hits the ptc button but then I'd have to pad out the area where the cam makes contact with the door which might ruin the effect


Joined Jan 15, 2015
On the bright side you have plenty of time. :)

Here is what I would do. Sit down with a pencil and a clean white piece of paper or two. Also a large eraser. Work out a scheme on paper of exactly, in detail what you want to happen and a sequential order of events. This is where it all begins. Everything you want to do is very doable. You want a mechanical means to open your casket so think about things like a automotive power window motor from a scrap yard. Maybe a few limit switches for raise and lower the lid. Audio is no problem and you just have to sync your audio and mechanics. There are chips similar to those used in greeting cards which you can place your audio on. Analog recording chips have come a long way. It all starts with a blank sheet of paper. Then you tweak and peak your thoughts.



Joined Apr 11, 2010
Do you know about the Halloween Monster List?

It’s a web site for Halloween enthusiasts to share the special effects that they’ve developed. You might find exactly what you’re looking for their. It’s a good resource, because the emphasis is on the effect and not the electronics.

People here will help you. But you’ll have to teach them as much about special effects as they can provide electronics answers.

No disrespect to the members here, but you may find help there as well.

Update: the “monster” in the title refers to the size of the list in a pun, not to Frankenstein and Dracula.


Joined Jan 23, 2018
The solution is simple. Get a relay with a normally open contact and a coil voltage matching the motor voltage. Connectthe relay coil in parallel with the motor, anc conect the relay contacts in parallel with the audio push button.


Joined Jul 18, 2013
For an Audio project, I picked up one of the cheap circuit boards that has the audio programmable ISD 1820 audio IC
The door bell triggers mine.
$3.70 Ebay item343713592