I have a 6674A (option J06, 70 V, 30 A), and are thinking of buying another 6674A, although I'd rather have a standard model (60 V 35 A) or one of the lower voltage / higher current models.
I've looked at a Keysight document "10 Fundamentals You Need to Know About Your DC Power Supply" and gather one needs to be run in constant voltage, and the others in constant current. I'm a bit puzzled by this statement:
"The output load must draw enough current to keep the CC unit(s) in CC mode."
My load current is likely to change from about 1 A to 54 A @ 50 V, although for test purposes, I'd run at lower voltage and current (probably 25 V with a limit of 5 A).
Does this mean I'm basically stuck, and can't do this? I can add a bit more load resistance, and push the "no load" current to a few Amps, but I'm not going to be able to run much load current continuously, otherwise the power supplies will not have enough capability.
A few questions arise, which are not answered by that application note. These are:
1) Is it possible to run two similar, but not identical 6674A PSUs in parallel, given one is 60 V and the other 70 V? I only need 50 V.
2) Given two similar, but not identical 6674A (one 60 V 35 A, the other 70 V, 30 A), is there any advantage in running either the 60 V or 70 V unit in CC, and the other in CV? Or does it not matter?
3) What sort of load do I need to ensure the one running in CC mode is working as it should? (You may have seen from another post, my 6674A arrived damaged, so at this point I can't do any testing with it).
4) If power was to fail to one of the PSUs, (either the CC or CV), would the other get damaged as it tried to sink a lot of power?
I don't need particularly good regulation for this, so I am tempted to diode OR the outputs. With carefully adjustment of the voltages, it should be possible to get the currents about equal, or a bit more supplied from the higher current power supply. But if I can achieve better regulation, whilst not running into problems, that would be a bonus of course.
1) Identical model numbers are required to ensure current sharing is performed correctly, also, because frequency response/operational bandwidth is equivalent and stable.
2) To ensure successfully parallel operation, both supplies require the capability to attain the same output voltage level.
3) Operating two (2) supplies in parallel, now with the capability of supplying ~60A, at the 1amp level is a miss application of the product(s).