|Geoff G3YVF was given the task by
G4VSZ to design a power supply for the value version of the paraset but it
needed to run off a 12v DC battery.
2N3773 devices are much more robust than
the originally selected 2N3055.
of multimeter destruction
The design of some
transformers may cause very large spikes to be produced at the A.C. output
of the transformer. So when testing DO NOT connect a digital type multimeter
directly across the transformer A.C. output in an attempt to measure the
A.C. output voltage. Failure to observe this might result in your multimeter's
It is considered that the best way
assess the output of the transformer is :-
to measure the D.C. (NOT THE A.C.)
output after the rectifier and smoothing part of the circuit, no spikes there
and after all we are interested in the D.C voltage NOT the A.C.