Re: [CAD_CAM_EDM_DRO] Re: Big servo motors drive recommendations

David G. LeVine wrote:

> At 12:32 PM 5/27/2007, you wrote:
>
>>You mentioned that
>>your motors were about 1 ohm resistance. Do you know the inductance?
>>The PWM drives usually have a minimum inductance specification that
>>will work with the PWM rate.
>
>
> An interesting thought from an old analog engineer (late 1960s!), why
> not put an inductor is series with the motor? It will degrade
> performance if too large, but if it changes the problem, it may point
> to the answer. Remember that noise is ALWAYS affected by the rate of
> rise of signals...

This was often done on some old-style servo amps that had a
limited range of loop compensation on the current (torque) loop.

Jon