I have breadboarded a simple H-bridge shown further down using the mosfets linked below the schematics.
Ultimately I ultimately want to use the motor pictured below: (so if you have tips concerning this motor and how it will behave let me know because I have not gotten past the small motor to test the big one)
Ok so I originally had no Cap across the little motor, in that scenario the switching mosfet got really hot at low duty cycles and just motor just turned off at 20% duty cycle.
Adding a capacitor across the Drain of the two mosfets as pictured in the schematic made a world of difference! Mosfets stayed cool and worked through the entire pwm rang and the voltage spiking because of switching transitions remained low. But the cap got hot as hell. its a tiny ceramic 50V , but i think the current through it is whats making it hot.
Next I moved the cap closer to the motor, in fact right at the connectors as you can see and that helps also, now I can have a smaller cap near the mosfets and all works well.
from some reading I have read about RC snubbers, I tried that but my Resistors quickly burn off.
So my question is how do I fix the issue of my caps getting hot? Because imagine if I am using the bigger motor I am sure they'll get hotter. Do I just need a higher voltage rated cap?
One way that i found worked was that since I am using a 5uF that is getting hot I used 5 1uF in parallel and that stopped the heating since they share the current.
Any other tips are welcome. I see some off the shelf motor drivers with SMD components and no huge power resistors or caps to snubb spikes etcc..... how do they do it?