I need to build an H bridge to drive a 1/8 HP DC 220 volt motor. I started trying with mosfets from International Rectifier (IR350).But I'm now facing another problem,probably because of some mistake I'm making in the circuit.I'm driving the transistor with 15 volt in the gate,but somehow I can't get the voltage drop between collector an emiter to go under 12 volts,even when it's only 35 volts I am using to power a small 12V permanent magnet motor with no load,and I keep having this drop even if I'm turning a led on through a 2,2 kohm resistor. You can imagine how hot the mosfet gets with that voltage drop and the inductive load of the motor. Can you show me how the circuit should be like? I intend to build an H bridge for driving 220 volts of DC current.The only components I have are some opto-photo-darlingtons (the optocouplers work fine) which opto isolate the microprocessor signal from the mosfets,a 16c74,and the mosfets of course. How should I build that bridge? There is a fifth mosfet,between the bridge and ground,which is the only one working at 10 kherz (doing the Pulse width modulation).In that way,the bridge conducts pulsing current either on one direction or the other,to make the motor run clock or counterclockwise at the desired speed. This configuration worked fine for a 12 volt supply,but it somehow didn't for a 35 volt supply. Thanks in advance, Walter Markiw