this post was submitted on 07 Aug 2024
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Hi there

The purpose of this schematic is to control a DC motor that runs at 8V max. That is why I chose 4 N-channel mosfets in the H bridge. P-channels would not fully activate at voltages above -10Vgs but the N-channels can handle 18V at the gate.

The 5v switches represent an Arduino's digital output pins. One to turn forward, one for reverse. To prevent a failure scenario where both pins are HIGH I added a transistor that prevents current from flowing through the optocoupler on the second half bridge.

Does this circuit make sense? I'm not an electronics engineer, just a hobbyist and have doubts about how effective the gate driving circuit is of the mosfets.

Thanks!

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[โ€“] Tolookah@discuss.tchncs.de 3 points 4 months ago (1 children)

Are you trying to run your motor at 5v? that's what it reads to me.

If your current draw is under like 700ma, Consider a bridge driver like the L9110, it'll get you the with minimal effort. There are other drivers out there as well. https://www.adafruit.com/product/4489

[โ€“] Rolive@discuss.tchncs.de 1 points 4 months ago

Between 4 and 8V. I'm driving a pump with a 12V rated 775 motor. Running it at full power makes the pump go too fast and with a lot of noise.

It's kind of an overpowered motor for this project but I have a couple of spare ones.