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DC motor speed control and over current protection
Stew
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Posted on 01/18/2019 7:07 PM
I have a 24v DC gear motor I purchased used and a speed control power supply that I just got. In the description for the power supply it said that it was for DC 24v, 36v and 90v motors with permanent magnets. Should work! When I unpacked the power supply I noticed that it had a 90v sticker on it. I looked again at the description and what I missed was that it was for "over current protected and short circuit protected" motors. So it is relying on the over current protection to work with less than 90v motors (in reality it is only giving 80v). My question is how do I determine if the motor is protected? It is a Baldor motor and I couldn't get any info off there site or from searching Baldor and any of the numbers on the plate.
 
oldgrumpus
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Posted on 01/18/2019 8:28 PM
An over current condition doesn't normally happen unless the motor is overloaded by working too hard or if it can't rotate. If your motor is sized correctly for your situation or oversized which is even better, than there shouldn't be any reason for concern.

You could also just add a fuse that would pop at the rated current.

Just my 2 cents.
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Stew
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Posted on 01/18/2019 9:31 PM
Motor is over size by quite a bit I think. It?s good for 110 ft/lbs of torque. My concern, at full speed would?nt I be sending 80v to a 24v motor. When I turn the knob on the power supply the voltage goes from 0v - 80v. So it seems it is controlling the speed by changing the voltage. I could see maybe using a voltage limiter but would the potentiometer only work from 0-3 where it seems to reach 24v. Would like as much fine control as I can get.
 
BobbyS
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Posted on 01/19/2019 12:37 AM
Here is the speed controller I am using for drum control and cooler stir
control. One for each.


https://www.amazo...controller
 
Stew
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Posted on 01/19/2019 10:04 PM
Thanks for that Bobby. I looked at speed controllers like that but I would also need a power supply and the one I got did /does both. Figured I had the cat by the tail ... or so I'm hoping. Here is a link to the one I got. https://www.amazo...&psc=1
Here is a picture of the motor I have that I was hoping the speed controller would work with.
Stew attached the following images:
img_0295.jpg img_0296.jpg img_0303_1.jpg
 
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