On Oct 15, 19:18, Tony Duell wrote:
> > Now I've never used a RL02 drive on 50Hz power, but I'm 99% certain
that
> > the motor speed in a RL02 is determined by a servo loop, and thus
> > not locked to a multiple of the AC frequency.
>
> Currect. From the RL01/RL02 Technical Manual :
>
> 'RL01/RL02 drives are shipped from the factory as 115Vac/60Hz units.
> Field change to 230Vac 50 or 60Hz is acoomplished by reversing either of
> two terminal block covers located externally at the rear of the drive.
> The RL drives run the motor at considerably below synchronous speed. They
> control the motor speed with a couple of triacs on the AC Servo Module,
> and measure the speed (IIRC) using the sector pulse timing. That's why
> the disk spins _very_ fast if you forget to plug the transducer in...
Or if the AC servo board goes in certain ways, as I discovered in one of a
pair I got from Heriot-Watt University: the local DEC engineer had at some
time in the dim and distant passed fixed one drive by swapping the AC servo
for one that was rarely used.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Received on Fri Oct 15 1999 - 16:56:52 BST