Let me start by saying that I am a programmer-type that is new to electrical design. I've built 1 line follower robot where the motors are driven by an npn transistor. So, now I have a new project and need to control the speed of the motor and would like to use MOSFETs. However, I have am suffering from information overload and need to sort some things out...
Okay, I need to control the speed of a DC direct drive motor with a PWM signal. I only need to turn the motor in 1 direction, so I don't need a full H bridge. What I am not sure about is if I even need a half bridge. Can I get away with a single MOSFET (N or P) or do I have to have both? It seems like having both just allows you to reverse the signal but I don't need that. If I can just use one, which type should I use? Either way, what parameters should I look for when choosing MOSFETs?
Also, I realize I could just buy an H-Bridge IC and use it but I am kind of trying to learn the inner workings here, so I want to do it myself, just this once. I plan to make a small motor driver board with 5 header pins: power, ground, signal (PWM), and the 2 motor connections. I think I can just use a P-MOSFET (or N) a schottky diode, and perhaps a 5V regulator unless anyone thinks I need anything else.
Oh, one parameter for this project is that the motor draws 2A at nominal speed and up to 8A when stalled, so I need to be able to handle up to 8A, I guess. I plan to use a 5V regulator since 8A isn't going to happen very often, but maybe I should go higher.