Concerns, Questions, and Comments About the BigBite Power Supply

The small transition board by the transistor bank has wiring installed to use an off board transistor to boost the drive current to the transistor bank. The spare of this small board does not have this wiring, so this needs to be installed. As it is, when the spare board is installed the transistor bank starts to oscillate when the output reaches a little under 20 amps. This could be due to not using the extra driver transistor or that pins 13,14, and 15, of the 25 pin connector, are not all tied together. Scot re-wired the spare transition board, it still needs to be verified that it is now correct.

When the transistor bank begins oscillating it can be expected to generate a lot of heat in the filter capacitors mounted just behind the transistor bank. The capacitors can burn up.
I noted the output current was 700A and the output voltage, when first turned on, was 152.9V on the meter on top of the supply. The output voltage was slowly increasing over time. After a few minutes it was 155.0 and still climbing a bit. This was in the early part of March, 2009. A note below the voltage meter stated "will trip @ 165V".