i would like to ask if my schematics is ok.
I have one (or more) device (here symbolic as "R") which are supplied by a main power supply. I would like to support them also with an usv for the emergency case when the main supply is down then the the devices should be supplied from the usv.
I suppose that there should be some management device which would switch between the two power supplies but this schematics is much simpler.
But i have concerns:
- For reasons i have not under control i can´t provide a common ground for the two supplies so i suppose that the (not existing) common ground could cause problems.
- Is it possible that there will flow something like an offset or "balancing" current between the separated systems?
- while there are diodes with different characteristics is would be difficult to define which power supply will supply the devices. It could be that the usv will supply the device (R) the whole time, then the first power supply would be useless
Is there a other way, some schematics or devices to manage the switching better than with this primitive schema?