Beaglebone Black PWM Driver for 12VDC 1.05A Motor | Drive from Positive Side

beaglebone blackdc motordrivermosfetpwm

I have several 12VDC 1.05A pumps I am using in my hombrew system which I would like to drive via PWM on my BBB. Each one will have a hall effect flowmeter attached so that I can get flowrates, totals, and drive the pump to maintian a flowrate. I have seen how to control the motor using a mosfet (on the bldr website), but it drives from the negative side of the motor. Is there a way to control the motor from the positive side? The reason I ask is that I would like to use a common ground for the pump and flowmeter, and if I am driving the pump from ground, it will throw off the flowmeter readings.

Any thoughts?

Best Answer

You can use a P channel mosfet to control the DC motor from the positive side: -

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You've got to be careful though if you are using a common ground for both motor andf sensor - you could get false triggers in the sensor if sharing a common wire that is too long/ too flimsy.

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