
Power supplies 259
large uncharged capacitor is connected across the
output of the supply when it is already on, tripping
may still occur, but if the capacitor is connected
before the supply is switched on there should be no
problem, since with this type of supply the output
voltage is usually ramped up linearly by the control
circuit, precisely to cope with loads containing
capacitors. With all these ifs and buts, it might be
asked why trip protection is ever used: the answer
is simply economy. The prospective internal dissi-
pation, on short-circuit, in a stabilized supply is
simply equal to the maximum raw voltage (at top
mains voltage) time ...