In uk.transport.london message , Mon, 14
Apr 2008 14:10:17, funkmish posted:
Andy Burns wrote:
On 11/04/2008 12:23, funkmish wrote:

Four regular 40w lamps wired in parallel should do the trick. The
problem comes when one of them blows
Four 240V lamps wired in parallel across a 750V supply would blow
rather quickly I'd expect. You should try to explain that you meant
to say "in series" at this point ;-)

Yes, I meant in series, hence my comment about when one of them blows!

When one blows, the full voltage will appear across it and its socket;
that is undoubtedly more that their designers expected them to receive,
and may be more than they can reliably stand, especially in an
environment which may be damp or mucky.

I am reminded that I once inherited an equipment which included a 3 kV
DC supply charging a cubic metre or so of capacitors via a couple of
dozen ordinary 200 V bulbs in series and an ordinary 1.25" cartridge
fuse and holder. One day, the fuse blew. The current continued, only
slightly impeded, until the burning fuse holder disintegrated.

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(c) John Stockton, nr London UK.
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