These are autoranging SWITCHERS.
The 6038 is a 200 watt model i believe. 0..10 amps and 0.. 50 odd volts..
This means at 20 volts you can indeed pull 10 ampere.. go to 25 volts and you only get up to 8 ampere... go to 50 volts and you only get 4 ampere.
in other words : you can not go 'over' the maximum power draw.
if you want 5 volts you still can only draw 10 ampere. so it is the lowest of the three that is at play.
These are good power supplies , but , they are notoriously difficult to repair. They use a resonant converter technology. the switching transformer in that beast is huge ... If you take a 500 watt computer power supply the transformer is 2 by 2 by 2 inch... the transformer in this thing is more like 4 by 5 by 4 inches... and there is another , equally large common mode transofrmer behind the secondary rectifier.. to keep the output free from switching noise.
There is a truckload of analog electronics in this machine. Very well built. Has great step response and packs some serious 'kick'.
service manual :
http://cp.literature.agilent.com/litweb/pdf/5959-3346.pdfif you buy it and decide to do a teardown.. do NOT poke your fingers around in this thing until you made sure the mains capacitors are discharged... There's three honking big capacitors charged to 400 volts... I made the mistake once , while troubleshooting one of these, by powering it down and not waiting long enough before i pulled the drive board out.. i grabbed it by the heatsink which was at 400 volts level and had my other hand on the chassis... not a fun day ...
The tank capacitors are so large they would blow the fuses if it were not for the soft start ... they charge these through a resistor and only once a certain level is reached does a relay short the charge resistor. you hear a noticable 'kloink' when you power it up ... followed by a 'click' about 2 seconds later ...