Control of a DC motor with a microcontroller or RPY.

[luiHS]

Hi.
Won't these two circuits work exactly the same to control a motor using a microcontroller or a Raspberry?. I don't understand the need to use two NPN transistors, when apparently just one NPN and the MOSFET would be enough.

In my case, the load will be an electromagnet at 50v DC, so I don't know if using the circuit with a single NPN, the base resistor R1 of Q1 would have to be increased or the 100K resistor would be the same. Or is there any advantage to using the circuit with two NPN transistors and the MOSFET.

[pcprogrammer]

The difference between the two is the first one is active on GPIO low, and the other one on GPIO high.

The IRFZ44 might even work without the transistor, but it depends on where it sits in the range. The gate on voltage can be as low as 2V, but also as high as 4V according to specs.

I myself would use a 2N7000 before the IRFZ44 instead of a BJT. Makes a better separation between the low 3V3 and the high 50V you need. The IRFZ44 is rated to 60V so might be a bit low.

[bidrohini]

You can also use L298 dual DC motor driver. This is an H-bridge MOSFET.
https://www.theengineeringprojects.com/2018/05/how-to-control-dc-motor-with-raspberry-pi-3.html

[drvtech]

In the second schematic you show the supply as 24V. This means the gate will be going up to 24V which exceeds the Vgs (max) of the IRFZ44 (+/- 20V).