23 Nov
2014
23 Nov
'14
1:05 p.m.
I understand that parts of Europe were also slow to abandon DC
residential lighting.
I believe the last non-50Hz domestic AC supply in the UK was the 100Hz one from the
hydroelectric power station in Lynmouth, North Devon. It was destroyed in the floods
of 1952, and after that Lynmouth (and Lynton, etc) got the normal 50Hz supply from
the national grid.
I suspect DC was around as long, or maybe even longer. Of course a lot of (valve) radios
and TVs sold over here into the 1960s were claimed to be 'AC/DC universal' models,
although
of course this was often just a cost-cutting design with no mains transformer (series
string
heaters and half wave rectifier for the HT (B+) line). On the other hand I remember 1960s
TVs with different strapping of the dropping resistor for AC and DC mains (I guess because
the
heaters depended on the RMS value of the input, the HT on the peak). So I guess DC mains
was
still around. And I have a Mullard book on making audio amplifiers (must be 1960s), which
gives a
design for one that will run off DC mains (no, I don't like the idea of a live chassis
for such a thing either!)
so I guess there was a need for it.
-tony