I entered this problem yesterday as an article, because I am not familiar with how to use this site(it isn't easy). I will repeat the problem. I have the parts from a 20 year old Trotter 225 treadmill. The 2 hp baldor motor runs on a separate doc source. I cannot get the power supply to energize the motor. It supposedly ran before the junkyard dismantling. The motor control power supply has a Crydom CY 4913 scr/relay. Which a Crydom tech told me was a custom mfg and he doesn't believe has variable doc control. 125 vac goes in, dc is supposed to come out. There are dc control input terminals. Does anyone know how to get this power supply to put out variable dc up to 90 volts? I have all sorts of numbers off the board and components, or could try to attach a photo if it would help.