Mosfet questions

Other Hardware Motors, Mechanics, Power and CNC
1

Hi,

I'm planning to create my own motor controller using mosfets in an H-Bridge configuration for forward and reverse, but also to use PWM to vary the DC motor speeds. (it will then eventually be put into the heng long tiger 1 tank I'm pulling apart!)

What mosfet characteristics make it compatible with PWM from the arduino when I look at datasheets?
Am I able to connect two mosfets in parallel to a single arduino PWM port without frying things so they can be PWM at the same time?
What additional components will I need for shortcomings of 2-wire 7.2v DC motors and mosfets to protect components and the battery they will run off?

I'm currently salvaging components from retired computer power supplies and motherboards, I have a wide selection of mosfets that hold far more current than needed but I do not understand which ones are better suited to my project.

Thank you.

2

Its not the current rating that matters, its the Rds(on) resistance at Vgs=5V. If that resistance is low enough to avoid wasting too much power in the device you'll be running well below the current rating (which is the abs max with infinite heatsink - never a realistic situation).

For an H-bridge that's a bigger problem - you have high-side MOSFETs to drive and that's not so simple - probably easiest to go with an integrated MOSFET H-bridge chip in this situation.