Well, This may help but I am new to electronics and am not familar with any of the items you mentioned. I might add, This motor run's at over 5,000 rpm, the coils need to be powered two times per revolution of the motor, so they will need to be powered on/off at over 10,000 time per minute. To make a little more clear. I need someone to look up the H21A1 opto sencer from www.fairchildsemi.com and find out the voltages it needs at the anode to light up the diode. Also need to know how much voltage the mosfet needs at the gate to open it up. And how to setup the circut to get these voltages when using 36 vdc at the input. Any and all help would be appreciated. Later,,,,Jack