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Upper limit of current supply to motor shield
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Upper limit of current supply to motor shield

by razarizvi on Wed Aug 07, 2019 9:52 am

I am running two motors (each 12V, 0.5A max) on the Adafruit motor shield. However, the power supply adapter I have is rated at 12V, 10A. Would it be okay to hook up this power supply to the adafruit motor shield or is there a risk of damage? Is there an upper limit to the current if the power supply is rated at 12V? Thanks.
razarizvi
 
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Re: Upper limit of current supply to motor shield

by adafruit_support_bill on Wed Aug 07, 2019 9:59 am

The power supply rating is an upper limit. The actual current flow is determined by the load.

I am running two motors (each 12V, 0.5A max)

Motor voltage and current ratings don't always mean what they appear to. This is especially true of stepper motors. Do you have a more complete electrical specification?

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Re: Upper limit of current supply to motor shield

by razarizvi on Wed Aug 07, 2019 10:44 am

Thank you for the response. I have a setup that involves running two 12V DC geared motors (description below) one at a time using an Arduino Mega 2560 with an Adafruit Motor Shield. I had the 12V 10A power supply handy but was wanting to make sure I don't damage the motor shield with it. Since the motors are running one at a time, the current drawn at any time from the motors would not exceed 0.75A (max) I'd expect.

https://www.pololu.com/product/3046
voltage: 12 V
No-load performance: 35 RPM, 60 mA
stall extrapolation: 10 kg⋅cm (140 oz⋅in), 0.75 A
razarizvi
 
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Re: Upper limit of current supply to motor shield

by adafruit_support_bill on Wed Aug 07, 2019 11:26 am

You should have no problems with those motors at 12v. The stall current at 12v is well within the limits of the shield.

Pololu in general publishes accurate and complete specs for their motors. Unfortunately, that is not true of some other vendors.

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Please be positive and constructive with your questions and comments.