Step Pak SPD-6U Motor Driver

[Guy Jennings <jennings@berlin.bessrc.aps.anl.gov>]

Here is some information that users of the ACS Step Pak SPD-6U motor
drivers might find useful:

With low-voltage, high current motors - for example the SloSyn motors
generally used on the APS standard tables etc. - the front panel 'current'
control on the SPD driver has little effect on the torque generated by the
motor!!   You must, instead, change the internal link (the 'holding
current') to increase the torque.

I found that, using an M061 or M062 motor - the torque was only increased
by about 5% going from the '0.5A' setting to the '6A' setting on the front
panel, whereas changing from '4V' to '6V' on the internal link more than
doubled the generated torque!!!

Hopefully this will be useful to somebody,

Guy Jennings,
BESSRC CAT