Why dc Supply used in Control circuit.

Answer Posted / rvg

Control circuits are sensing the healthy status of the
system, and there are many areas, where the system is to be
monitored even if there is no power supply at all.(eg: in
sub stations. during lightning stroke its very necessary
that, the system to be isolated.)
In this case, DC is the only choice that, we can provide
with battery supply. So most critical control systems
designs with DC only( pref. 24 to 48 volts DC)

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