The big idea: I have two motors that slowly lift marbles into a really big rube goldberg machine. I would like these motors to be motion activated, meaning when someone walks by, they run for just a second or so. It had a very old timer device and motion sensor on it, but they seem to be malfunctioning. I tried for a while to get them to work, but I give up. Instead, can anyone link me to some parts that can handle this task? This is all running at 120V, and the motors have no ground attached to them. Just a good ol black and white on each. The two motors should be running at the same time, so it could be looked at as one load, and I just need a motion sensor + timer to vary the time that it runs. Thanks!

 

Some motion sensor light fixtures have an auxiliary output wire to run extra lights. That may work, assuming your motors are small. Otherwise, it could operate a relay for large motors. They have a timer setting of 2 minutes, 5 minutes or 10 minutes. You need to cover the light sensor to make it work with lights on.

 

This might do the job - minimum on time is 10seconds.

 

The on time needs to be more like 1 second though, and I'd like the motion sensor to be a little more hidden. It used to use an old photoelectric switch sensor, which hides nicely under the machine.

 

Just brainstorming.

I took a yard motion sensor floodlight and disassembled it for an application in a Haunted House. It could drive a relay for the motors, but the on time would be a challenge.

Another option is a microprocessor driving a relay. Use a PIR sensor as your detector. Click on the link to see what I mean. Drive a relay from on of the microprocessor pins. You might need a transistor/ resistor/ diode relay driver, depending on the relay chosen.

I did almost exactly this for an artist.

Just a thought? Can the motors be replaced with ones of lower voltage? There are many 12VDC geared motors which might work.

It sounds like this might be a learning curve for you. So it can be done if you can spend the time.

 

Nah the motors have to stay, it's an old machine that I'm not really gonna tinker with, just the operation of it that I can change. However, the microprocessor route might be the right idea. I was hoping for just a plug and chug device solution, but it wouldn't hurt to get it done with some code ^_^

 

I might have some code for you to look at, if you're considering something in the Arduino family. Sparkfun (or is it Adafruit) have the Trinket which is sufficient for your requirement.