I need to draw approx 4 amps for 10-15 hours at a minimum of 18V.
I have hooked up two 300 watt power supplies in series:
- +12V on one and +5V on the other: the output is only +15.8V rather than the 17 point something that I was expecting
- +12V from each: then one power supply shuts down.
Why does this happen and how can I get the +18V (or more) that I am after?