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Author Topic: Amp rating for power supply  (Read 3293 times)

cuivenion

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Amp rating for power supply
« on: February 13, 2016, 03:32:14 »
Hi, I'm going to be using astroeq with two 0.5a stepper motors. If I'm using it out in the field would I be ok using a lower amp rating power supply like 1 or 2 amps rather than my 5 amp one.
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TCWORLD

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Re: Amp rating for power supply
« Reply #1 on: February 13, 2016, 03:52:15 »
2A should be fine for a 0.5A stepper. Remember that with two motors there are four coils, so in the worst case when all coils are on, then you should have a supply of 4 times the current rating.
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Tom Carpenter (AstroEQ)

cuivenion

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Re: Amp rating for power supply
« Reply #2 on: February 13, 2016, 04:06:35 »
Thanks, as a follow up question I've just realised my motors have a rated voltage of 7.5v per phase and an inductance of 26mh which is outside your guidelines of under 5v and 10mh. Will this be a problem?
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TCWORLD

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Re: Amp rating for power supply
« Reply #3 on: February 13, 2016, 15:10:03 »
Shouldn't be an issue. It may reduce the top speed slightly, but equally you may get better performance at low speeds (there is a thread around here somewhere about the DRV8825 driver and low voltage motors having some trouble).
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Tom Carpenter (AstroEQ)

cuivenion

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Re: Amp rating for power supply
« Reply #4 on: February 13, 2016, 15:21:43 »
That's great thanks.
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