Re: [CAD_CAM_EDM_DRO] small amp recommendation needed

Chris Stratton wrote:

> >
> > The most obvious is a Copley Controls DC servo amplifier. See
> > http://www.copleycontrols.com/
> > OR, he could build one of my velocity servo amps
> > http://pico-systems.com/servo.html
> > but, the Copley comes completed for about the same price as my
> > kit costs to build!
>
> Jon,
>
> Thanks for the tip on Copley - we will look into that.
>
> > Audio amps are totally unsuited for this. I assume he is pulling out any
> > DC coupling capacitors, or any caps in the feedback that reduce gain
> > below a few Hz. Most amps have this to prevent shoving a lot of DC
> > through the speakers.
>
> Actually, he wasn't modifying the audio amps at all as the kind of
> frequencies he wanted to use were within the audible range.

HMMM? Is this a linear motor, like out of a hard drive? Most DC
brush motors have so much inertia, you don't get any response other
than audible tones when you go much over 25 Hz.

Jon