Great thread Bill.
Good it got bumped up.
Never read this one yet at ECN.
I'm aware of the fireststion lamp, amazing 100 years of service.
I'm into meters a lot and about 15 of my in house lamps have hour meters on them.
Most lamps last around 800 hours out of the claimed 1000 hrs.
Some so called long life lamps are actually rated for 250 Volts! while our nominal voltage is 230 - 235 V.
These appear to go for around 2300 hrs.
Certainly the voltage is critical for the life of the lamp, overvoltage is fatal undervoltage even 10 or 15 volts makes the bulbs last a lot longer although with less light output.
My outside lights which are on all night via a timeclock last around 8000 hrs with standard lightbulbs. These have a 1 N 5408 diode in series in the fitting to halfwave the voltage. and from the control point a 200 watt lamp in series to smooth in inrush peak. replacement around every 2 years, sometimes longer. the 3 bulbs used are 40 watts each.
Vibration is not good for filament lamps as are enclosed fittings where excess heat will cause early faillure.
Then the inrush current at switch on is hard on the filament too. most lamps tend to fail at switch on with the usual "ping"
I guess the US 110 or 130 Volt lamps last a lot longer due to the thicker filaments ?
or they are claimed to last 1000 hrs too ??
I got some of the CFL's too which have done 12349 hrs out of the claimed 15000 hrs. These are still going strong.
