Re: Declining motor torque with lower voltage.

Wally:

Correct me if I am wrong:

That is why varying speeed with voltage does not work well. I
understand the correct way to vary the speed of a DC motor is with
PWM.

One of my lathes (not CNC) is powered by a DC motor. It has an
encoder in it. The controller that came with the motor allows
setting of the speed with a pot. The controller will maintain the
set speed. When I set it at the minimum speed (about 60 RPM) and try
to stall it, I immediately sense a surge of power, and it resumes the
set speed.

This motor appears to be a servo with an intelligent controller.

Vic

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "cnc_4_me" <cnc4me@g...>
wrote:

>
> I think you hit the nail on the head...That formula probably deals
> with AC motors...
>
> I googled around some more looking for answers on the torque verses
> voltage question for DC motors. I found about a half a dozen

torque verses voltage curves on the bodine-electric site. Every
curve was the same...

>
> If you half the voltage, you half the torque...Direct

relationship...

>
> Wally
>
>