LH thread lamps

[Ian]

I have purchased some recessed light fittings for my bathroom, it states on the boxes that they require left hand thread ESS lamps.

I have never seen these are they Australian.

[Lee Blaver]

I'm obviously missing a joke here, but I do know that left hand thread lamps are available. Any clue why though?

Lee

[Christian McArdle]

Presumably in the hope that they are so unobtainable, you'll buy the replacement bulbs from the light fitting manufacturer's scandalously overpriced spares department.

Christian.

[Andrew Gabriel]

They used to be used in public places, so there was no point stealing the lamps to use at home. I heard the NY subway still uses them, but I would have thought they were pretty obsolete now. Don't recall seeing them in any lighting catalogues for perhaps 25 years now.

[Dave Plowman]

Perhaps it's to do with the way water swirls down the plugole down under?

Or for those who always try and unscrew something the wrong way?

[Christian McArdle]

Do the Japanese still use left hand threads a lot?

Christian.

[froggers]

Theft reduction I think - the bulbs on the old underground train were some weird voltage for that reason as well - something like 80 volts I seem to remember........

Nick

[Andrew Vevers]

Similarly when I worked on the Christmas post as a student I discovered that GPO bikes are made of non standard parts to discourage theft.

Andrew

[Christian McArdle]

I seem to recall that 80V is near to the optimum voltage for an incandescent bulb. It is something about the thickness of the filament being just right for the most efficient operation.

Christian.

[Andrew Gabriel]

55V is normally held to be the optimum for 100W lamp. However, it doesn't drop away quickly as you move away from 55V. There have been 84V lamps made which are designed to run on half-wave rectified 120V US mains, with the aim of getting higher efficiency than 120V lamps. Unfortunately, designing lamps to run off 240V is about as bad as it gets in this respect (on the basis that no one uses even higher voltage filament lamps).

[N. Thornton]

Lol, smart move mate. Something tells me you'll be replacing the bulbholders.

Regards, NT