great information here, thanks all for sharing. :-)
I just came from testing my 24v PSU, and have a **HUGE and DANGEROUS** problem, hope you can help me.
One 12v HP PSU is "normal", so no disconnected AC ground or something. On the 2nd PSU I disconnected AC ground from the inside 3 pin connector inside the unit.
When I put them in series, I tried two scenarios:
1) The modified PSU with no AC ground provides the (+) for 24v, the other one provides the (-)
RESULT: I have 24v for 2 seconds, then the voltage drops to 12v again. Not good
2) The modified PSU with no AC ground provides the (-) for 24v, the other one provides the (+)
RESULT: I have a steady 24v on the output, however both AC power cables of the PSUs went crazy hot (! almost melted!) after only 10-20 sec. run. I instantly disconnected both units from power, smoke came up.
Does anyone of you experts have an idea what went wrong?!
Thanks a lot in advance,