Re: Stepper motor voltage VS amps.

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:

>
>
> turbulatordude wrote:
>
> >
> >Am I correct in saying that you are describing something like a

pulse

> >width output ?
> >
> >and that even though it may be connected to 40 volts, the actual
> >voltage reaching the motor will be 2 volts ?
> >
> >
> In all chopper drives, some form of pulse width modulation (some

use

> pulse frequency
> modulation, but with fixed on or off time, the result is the same)

is

> used to regulate
> current in the motor windings. The AVERAGE voltage across the

winding

> will work
> out to about 2 volts in your case, but the full 40 volts is applied

to

> the winding during the
> on time. So, the on time needs to be about 2/40 in this case, or

1/20th

> of the time on,
> 19/20th of the time off. (There are numerous variations on this in

how

> the on/off
> time is managed, or whether it uses time ratios of forward vs.

reverse

> current, with no
> current recirculation.)
>
> Jon

There you go, that jives with what Harvey said.

the pwm is zero and full power supply voltage, the average is near
motor nameplate. the motor 'sees' nameplate voltage, but the PS
voltage injects the current into the coils at a rate proportional to
the voltage.

the coils are energized faster at higher voltages and therby more
power is delivered than allowing the low voltage to ramp up the amps.