Re: Low cost Servo Controller

Steve Carlisle wrote:

> From: "Steve Carlisle" <quatsein@...>
>
> Jon, I am a little confused, you say you have made your own
> PWM amps, are you saying you are using these with the
> -/+ 10 volt signal on the STG card ? I have looked at many sites
> that sell servo amps, and they all seem to list seperate models
> for PWM, and Analog. Maybe you could explain this more
> thouroughly.

As far as the signals the amp needs, there is no difference.
The difference is that the amp uses a LOT less power, usually
staying well above 90% efficiency. All the PWM generation
hardware is in the amp. I do use the +/- 10 Volt analog signal
from the STG card, but I could also use any other reasonable
range, like +/- 5 Volts. My servo amps DO require a DC
tach, but I have found a good Maxon DC motor that makes
a great tach, and it is available from H&R in NJ for $7.95.
The current model of the amp uses a DC voltage of somewhere
in the range of 48-96 Volts, and produces outputs of 5 to 10
amps, depending on heat sinks and cooling.

Jon