Treadmill motor 180VDC running from mains...

[Externet]

Rectifying 120V mains AC should be good to test a 180VDC motor; any considerations ?

 

[dknguyen]

Just a smoothing cap. Might want a fuse too just in case **** hits the fan. But not really.

 

[Externet]

Thanks. Plenty of those capacitors available from defunct universal switching power supplies in the junk box... Is a 'flywheel' diode convenient too ?

 

[dknguyen]

Thanks. Plenty of those capacitors available from defunct universal switching power supplies in the junk box... Is a 'flywheel' diode convenient too ?

You shouldn't need one since you aren't doing high frequency switching the motor. Putting in a flywheel diode means you will have to mind the polarity when you hook up the motor to the mains and will just reduce the arcing when you shut the motor down which may be desirable and make thing less scary.

 

[MaxHeadRoom78]

No cap required, the SCR bridge drives all work without one.
It is normal to place a reverse biased rectifier on the output of the bridge.
Max.

 

[MaxHeadRoom78]

BTW, if running full voltage with no control, you need to remove the flywheel.
Max.

 

[dr pepper]

If you raid a smps for its bulk cap also raid the Ntc thermistor, big caps esp low esr ones in smps's can take out a breaker or short the rectifier on power on.
Plenty of older Dc industrial drives do not have a bulk cap, the motor will hum a bit without but it should still run fine.

 

[gary350]

120 VAC with full wave bridge rectifier and good filter capacitor will give you 169.68 VDC.

 

[MaxHeadRoom78]

If just needing to test the motor use a 12vdc automotive battery.
It will show up any problems.
Max.