Re: [CAD_CAM_EDM_DRO] Re: Declining motor torque with lower voltage.

According to many here on the list and elsewhere that design drives: Voltage dictates the speed, Amperage dictates the torque. Thats why running a 100 volt 14 amp continuous servo at 65 volts only limits the speed. If the motor stalls it will still fry because the neccesary amperage is still available. Providing the power supply has a high enough Kva rating. If the opposite was correct they would stall with no damage to the motor, only the electronics.

Ron

victorlorenzo@... wrote:


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"
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
>
>

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