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Old 07-10-2006, 07:38 PM   #1
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Default Is it OK to run ESC or motor from a switching power supply?

Hi guys,

I have a switching power supply with variable voltage 5v to 15v. It says in the instruction not to run motors from it. Why is that? Would I be able to connect an ESC to the power supply and run the motor that way? The reason is I would like to test the motor at lower and higher voltages (within reason).

Thanks!
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Old 07-11-2006, 03:15 AM   #2
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If the SMPS can deliver enough "clean" (steady voltage) amps it shouldn't be a problem to run motor or ESC from it. If the output is "dirty" (choppy voltage) it might kill your ESC.

Since the ESC is switching the motor (big load) on and off at high frequency, the ESC might kill your SMPS. Check manufacturers specs.

Ideally you'd get Oscilloscope and monitor the voltage from the SMPS at load to see if it's safe.

Adjustable voltage SMPS are usually too low amperes to run motors from.
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Old 07-11-2006, 03:52 AM   #3
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What about using a charger? Most of the current chargers have some sort of run in mode. If you know anyone with a GFX, ask them if they can do it for you.
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Old 07-11-2006, 04:09 AM   #4
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Quote:
Originally Posted by andsetinn
If the SMPS can deliver enough "clean" (steady voltage) amps it shouldn't be a problem to run motor or ESC from it. If the output is "dirty" (choppy voltage) it might kill your ESC.

Since the ESC is switching the motor (big load) on and off at high frequency, the ESC might kill your SMPS. Check manufacturers specs.

Ideally you'd get Oscilloscope and monitor the voltage from the SMPS at load to see if it's safe.

Adjustable voltage SMPS are usually too low amperes to run motors from.
My power supply is rated at 30Amps continuous, which I think should be enough for low power motors under no load. You stated that the ESC's switching may kill the SMPS. What would remedy this? Could a large capacitor smooth out the on/off load? What if I run the motor directly off of the power supply? Would this be unsafe? Why? Is it the back EMF?
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Old 07-11-2006, 06:40 AM   #5
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Diodes prevent back EMF
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Old 07-12-2006, 02:56 PM   #6
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Would it be safe, then, if I added a schottky diode to the motor? What would be a good rating for the diode?
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Old 07-12-2006, 04:57 PM   #7
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I'd be inclined to follow the instructions. The switching supply may not like inductive loads. What was this supply made for?
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Old 07-14-2006, 03:37 AM   #8
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It's this power supply, from KO propo:

http://www.shopatron.com/product/pro...0.4839.0.0.0.0
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