8' drive on PC troubleshooting

[Dwight K. Elvey]

>From: ard at p850ug1.demon.co.uk
>
>> Be sure to check the labels on the stepper motor. Some years ago I had a
>> brief "aquintance" with a SSSD drive from Control Data. I binned it
>> immediately, as it showed that the steppermotor needed 115VAC !
>
>Never! I've enver seen am 8" drive with anything but a 24V stepper motor.
>
>The spindle motor is often mains powered (and often 115V, to be powered 
>by an autotransformer if you have 230V mains). It's a capacitor-run 
>induction motor, and you generally have to change the pulleys (and maybe 
>the belt) when going between 50Hz and 60Hz mains, to get the spindle 
>speed right.
>
>My P851 and P854 systems have CDC floppies (and I have the CDC service 
>manual for them). They have 24V steppers and AC-line powered spindles.
>
>-tony
>

Hi
 I looked at the manual for the SA800/801 and the +24V is used
for the stepper and head load but it is also used for some
of the electronics. Where the exact voltage is critical, there
is a zener. It would nost likely work anywhere +- 2 or 3 volts.
Dwight