4 Feb
2011
4 Feb
'11
1:16 a.m.
Weren't
there also some European countries (or parts thereof) that
used various DC voltages for lighting and small appliances? (Belgium
or Italy?).
We had DC mains in England into the 1950s in some areas. A lot of radios and TVs weew 'AC/DC',not just to save the cost
of the mains transformer.
I rememebr working on TVs (long after the 1950s, of coruse) with
different voltage selector settings for AC and DC mains (possibly due to
fact that the smoothing capacitor would charge to the peak and not the
RMS votlage of AC mains). One of the Mullard books of audio amplfiier
cirucits (including things like the 5-10 and 5-20) includes a circuit
for an amplifier (4 valves, something like UF86, 2 * UCL82, UY85) for
AC/DC mains. Of coruse it was hot-chassis which is a right pain...
Hmm, I shall have to have a look at my Mullard book. I seem to remember
that one.
Jonas
4 Feb
4 Feb
10:36 a.m.
On 4 Feb 2011 at 9:16, Jonas Otter wrote:
Gothenburg, Sweden had 127 VDC in some parts of the
town in the late
60s/early 70s, even though almost all of Sweden had 220/380 3-phase
since ages.
I was looking at the schematics (email me if you want the scans--I
found them on a Polish site in rather ugly self-extracting form) of
the 1960's Ionika EMP-1 organ (made in the DDR, but used throughout
the SSRs). Interesting design in its use of neon lamps and very
distinctive in tone.
At any rate the power supply transformer is switchable between 220
and 125 volts. What country used 125V, 50 Hz?
--Chuck
11:34 a.m.
and TVs weew
'AC/DC',not just to save the cost of the mains transformer.
I rememebr working on TVs (long after the 1950s, of coruse) with
different voltage selector settings for AC and DC mains (possibly due to
fact that the smoothing capacitor would charge to the peak and not the
RMS votlage of AC mains). One of the Mullard books of audio amplfiier
cirucits (including things like the 5-10 and 5-20) includes a circuit
for an amplifier (4 valves, something like UF86, 2 * UCL82, UY85) for
AC/DC mains. Of coruse it was hot-chassis which is a right pain...
Hmm, I shall have to have a look at my Mullard book. I seem to remember
that one.
5069
days inactive
5069
days old
2 comments
3 participants
participants (3)
-
ard＠p850ug1.demon.co.uk -
cclist＠sydex.com -
jonas＠otter.se