Floating DC power supplies

Sep 19, 2005 11 Replies

I have a floating AC/DC unregulated 48vdc (nominal) linear power supply ,just a transformer,rectifier bridge and filter caps.No problems so far.The manufacturer has opted to tie the positive output to ground for safety.Can someone explain why no current flows from the positive output to ground in this case please ? I need to study some more theory methinks !



Current through a circuit requires a circuit (circle). Connecting ground or your left pinky or any other object to a supply at one point, only does not complete a circuit. It creates a branch. A dead end.

Just realised what a dumb question this was.If one connects the positive terminal of a car battery ( 'floating') to earth nothing happens,no current flows....

Nice to see it making intuitive sense to you, now.

Nice to see it making intuitive sense to you, now.

the current has to flow in a circuit for some were current flow to ground there would have to be a path from ground to the negative terminal.

Bye. Jasen

48 volts nominal with the + end grounded suggests that it may have been designed for operation of electromechanical telephone equipment purposes.

Correct.It's a P/S for a C-Band upconverter in a Satellite News Gathering flyaway kit.

Sorry,not telephone equipment but close enough.Stock standard telco P/S.But designed to be outdoors rain,hail and shine

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