Idea request for motion detection delima

Thread Starter

David R_1492090294

Joined Apr 13, 2017
5
I have a specific function i'm trying to do that i'm looking for ideas on how to accomplish.
My situation is this- I have a trackless train ride that has rotating decorative train "wheels" on the sides that i want to spin when the train is in motion. I have the wheels attached to small dc motors and they work and look great spinning while driving the train. However, I want an automatic triggering device that senses when the train starts moving to close a relay to energize the wheels. once the train stops, the relay needs to open to deenergize the wheels, so the wheels only spin while the train is actually moving. Ive toyed with ultrasonc sensors pointed at the ground, but with no luck. Im perplexed on how to do this so to all you engineering thought people out there I am looking for yor input!
Many thanks in advance!
 

MaxHeadRoom

Joined Jul 18, 2013
25,469
What is the drive method of the unit, I assume there must be some kind of initiation for whatever the motive force is.
Whether it is by a switch or a handle etc, then a simple limit switch placed on whatever initiates the motion would switch the motors on/off.
If it is presently done electrically, then it may be even simpler with a relay wired in.
Max,
 

Thread Starter

David R_1492090294

Joined Apr 13, 2017
5
What is the drive method of the unit, I assume there must be some kind of initiation for whatever the motive force is.
Whether it is by a switch or a handle etc, then a simple limit switch placed on whatever initiates the motion would switch the motors on/off.
If it is presently done electrically, then it may be even simpler with a relay wired in.
Max,
 

Thread Starter

David R_1492090294

Joined Apr 13, 2017
5
Thanks for your input Max. The unit is powered by a 36 volt DC series Drive motor with an electronic motor controller and resistive throttle pedal similar to an electric golf cart. The problem I encounter is that the drive mechanism and circuits are not always powered when in motion such as when coasting or braking down a hill. I want the wheels to spin any time the train is moving not just when it is being powered.
 

MaxHeadRoom

Joined Jul 18, 2013
25,469
Do you want an off the shelf solution or can you make up a simple circuit?
A simple detector on a moving part, either a photo slot opto or a small hall effect with a 555 watch dog timer, that will pick up a relay only when in motion.
The hall effect can be found at a auto wrecker in the shape of a gear tooth sensor for timing.
Max.
 

Thread Starter

David R_1492090294

Joined Apr 13, 2017
5
What is the drive method of the unit, I assume there must be some kind of initiation for whatever the motive force is.
Whether it is by a switch or a handle etc, then a simple limit switch placed on whatever initiates the motion would switch the motors on/off.
If it is presently done electrically, then it may be even simpler with a relay wired in.
Max,
Do you want an off the shelf solution or can you make up a simple circuit?
A simple detector on a moving part, either a photo slot opto or a small hall effect with a 555 watch dog timer, that will pick up a relay only when in motion.
The hall effect can be found at a auto wrecker in the shape of a gear tooth sensor for timing.
Max.
Yes that is what I was thinking would work too but having trouble finding something to do the job of just engaging a relay when in motion then disengaging when motion stops. Also wanting something that can run off 12volts preferably and a pre-made unit would be best
 

MaxHeadRoom

Joined Jul 18, 2013
25,469
Nothing readily comes to mind but the 555 circuit solution is about half dozen components.
A prox can be had off ebay cheap.
Max.
 

scscorpion

Joined Apr 14, 2017
9
Does the train stop in the same place? if so you could use a magnetic switch. when train stops over the magnet it opens the circuit and stops the motor. when you start moving it closes and the motor starts up.

I want one of them trackless trains in your profile pic. Love the roundhouse one.
 
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