On Fri, 21 Mar 2014 08:53:14 +0000, Nightjar
wrote:



The difference in light output between those to voltages is quite
considerable. In the days when the UK had various mains voltages, you
could buy lamps of 210, 220, 230, 240 and I think 250v ratings.


We used to have a wide variety of different voltage lamps in the
Electricity Museum. DC systems were often 100V or 110V, but could be
used to charge lead acid batteries in houses, with house voltages
anywhere between 12V and 96V.

After WW2 before Dad settled down he worked with an electrician in a
rural area. We ended up with a large box of SBC lamps of various
voltages rendered redundant by the coming of std AC mains replacing
home generators .
Too tempting for a youngster so experimentation was undertaken.
Some lamps just shattered others had a short but brilliant career.
24V was found to take out the circuit fuse but the filament remained
intact. Adding a 0 with a chinagraph pencil and replacing one of the
lamps in a school corridor ensured the caretaker would go from his
usaul mild mannered self to a swearing purple coloured monster over an
hour or so. Some of the 200V+ lamps were coloured so for years the
outside loo was bathed brightly in green/red, orange and blue as the
lamps were used up.

G.Harman