11 May
2010
11 May
'10
2:14 p.m.
On 11/05/2010 19:37, John Foust wrote:
At 01:05 PM 5/11/2010, Chuck Guzis wrote:
I think Chuck's got it. Electrical resistance (at least for common
metals, as in a lightbulb filament) rises with temperature, sometimes
dramatically. That's why, incidentally, light bulbs nearly always blow
when first switched on rather than after running for a while: there's a
high inrush current when the filament is cold.
So what's probably happening is that the bulbs are indeed mismatched.
At switch-on, one gets a bit more of the voltage across it, heats up
more quickly, the resistance rises, so it gets even more of the voltage,
and so on, while the other is starved.
--
Pete Peter Turnbull
Network Manager
University of York
Quite possibly Far East-origin flashlights? Put
together from
whatever the local spot market makes available.
More likely, mismatched bulbs. Incandescent Christmas-tree strings
are typically series-connected with good results.
Yes, four seemingly identical bulbs from identical flashlights
from Walmart. I tried any two in series. Only one lights.