"William Sommerwerck" wrote in message
...
So, perhaps a US 110v bulb, does take twice as long to reach 'full'
output,
as a 240v one, and that is indeed enough to be able to see ?

I don't know. A 100W 240V bulb would have 4 times the resistance, so I
don't
see it "warming up" any more quickly (or slowly).



But if the filament is of a more 'delicate' CSA, that might well give it
less thermal inertia, leading to it heating quicker ? Based on what you are
saying, there is no reason why a low voltage 50 watt car bulb, should heat
any slower than a 50w 240v bulb, but obviously it does, as the ramp up time
can be very clearly seen on them.

Anybody over there got a photodiode, a storage 'scope, and the time to hook
'em together to have a look at just how long the time delay is? Once that
was known, I could do the same here to get a rough comparison.

Arfa