Power Supply

As many of you know, I am electronically impaired.

I have slowly been aquiring "stuff" to put together a servo system
for my Shoptask.

I have a half dozen 76V 5.5A motors, encoders, etc.

I have aquired a power supply that was advertised as 90v, 20A, but
happily find that it puts out 71.5 volts, just about exactly what I
need for the motors and some Gecko 320,s, or 340's,,,I think.

Anyway this power supply uses 115V on the primary, and has a center
tapped secondary. The center tap is grounded to the chassis, and each
half of the secondary feeds a baseball sized capacitor after running
through two, (total 4), diodes or rectifiers, and a single winding
transformer looking thing, that I assume from something I learned way
back somewhere, is a choke. There are a couple other doodads in there
that totally escape my identification.

The front panel has connections labeled +, common, and -. + and
common read 71.5 Volts, Common and - read -71.5 Volts, and + to -
reads 143 Volts.

There are two Voltage meters and two amperage meters.

If this really is a 20 amp supply, is each side only 10 amps, and if
so, can I use both sides in a Gecko four axis system? Is there a
problem having the potential of two control units below "ground", and
two above?

Jerry