This may be considered more of an elecrtic than electronic question, but I suspect someone here can answer it.

I want to run a 95v 18a DC treadmill motor on 120v AC via a bridge rectifier. Can someone recommend the correct size resistor (ohms and watts) to cut the voltage down? Thank you.

Rick A

 

18A is a lot of juice ..... apart from being a nice room heater the resistor doing the requested job will be huge, expensive and probably not available ..... also apart from the fact that resistors can not be used to regulate voltage .....

do you have the said rectifier? 18A through the rectifiers will also be quite a lot ...

IMHO what you suggest is not viable ....

 

For safety reasons, we can only insist you find a way to isolate the motor from the line. Not only can the motor not be run off a huge dropping resistor, but using no transformer will make it a lethal shock hazard, even if fused.

If you can't find a 66 VAC transformer rated to 18 amps or a proper 95 volt power supply, then this is not a safe project.