"Dale Parfitt" wrote in message
news
Has anyone connected a pair of identical computer supplies in parallel for
additional current capabilities? Did it require a low R resistor to allow
for any mismatch?


Since you've asked a general question, I'll give a general answer.
The problem with paralleling power supplies is that the voltage regulators
will fight each other if they are not set to regulate at the same voltage.
Using a low value resistor to isolate the outputs will work, but it will use
power you may not want to waste and your voltage regulation will not be as
good. A technique that was used on mainframe power supplies was to put low
value resistors (actually, calibrated current shunts) on both outputs into a
common load. Then the regulator on one power supply would be adjusted so
that the voltage drop across its resistor would match the voltage drop
across the other resistor. Once the regulators were balanced in this
fashion, the resistors were removed from the circuit and the power supplies
were connected directly to the load. As long as the power supply regulators
tracked identically, there was no problem.

HTH,

-NM