multiple power sources?

#1

Hello there, I’m new to this forum so I hope I am posting in the right place. We use these VHK200W-Q24-S24 a lot to regulate power to our devices, often from solar or electric and in most cases to 24 or 12 v load.

Recently I connected two different power sources to the VHK200W-Q24-S24, one from an AC-DC power supply and one from a charge controller powered by a solar array and a battery bank.

Both pushing about 12.5 to 13v but certainly different types of power sources. This seems to work well for us as it’s acting like a UPS. Am I doing something I shouldn’t or is the wide range of input on these devices makes it possible? I realize that the two sources are not sharing the load equally and that it’s not the ideal power source sharing, but I wanted to get an opinion if I am “ok” or completely out of order here.

Load is about 4amps at 24v and so far nothing is heating up, nothing is melting, and load continues to operate when the AC-DC is off or when the solar is in LVD.

#2

Unless both of the power sources are designed to have external power applied to their outputs continuously (extremely rare) then in the long run one or both may die prematurely. You can isolate them from each other’s output by using a high current diode in series with the positive lead of each sources output. The diodes will ensure that current won’t flow backwards into either of the sources and will automatically switch between sources.

isolating_ps

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