On 2010-06-08, Karl Townsend wrote:

Which servo amps are you describing? It is not true of *all*
possible implementations of EMC. Many DC servo amps accept tach
feedback and automatically adjust the power to the servo motor so the
speed indicated by the tach feedback matches the speed commanded by the

Don't make life hard for iggy. It's his first one. Or that is, he's a virgin
or at least he used to be.VBG

I'm not trying to make things hard for him -- I'm trying to make
sure that ne knows the possible options for *his* motors and amps. He
will learn quickly enough -- he is good at that.

Iggy has some brush type analog servo amps made by AMC. They work extremely
well with only +/- 10 volt from the control. Simple to install and reliable.

Again -- which amps? I note that at least some of the AMC amps
use tach feedback.

Get the model number, and check against the data he

http://www.a-m-c.com/searchtool/

Of course -- it could be using intervals between pulses of power to
check generated voltage using the same brushes as drive and tach. But
this means that there must be dead periods during which there is no
drive. More common with PWM than with a DC servo amp in my experience.

Enjoy,
DoN.

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