Re: Blowing light bulbs

Don Klipstein wrote: 
In art. <C_WdnWrgysPJN3vfRVn-ow@xxxxxxxxxxx>, CL (dnoyeB) Gilbert wrote
in part:


you can try installing a dialed dimmer switch. or see if you can find any of those devices that go in the socket that are supposed to extend the life of the bulb, not sure what they do.

could it be the room temperature is too low? Soft starting of lights definitely extends the life.


Usually not much (there are some exceptions), despite lightbulbs typically blowing during a cold start.

What usually happens is that cold starts do surprisingly little damage to the filament, while a filament that is approaching end-of-life (due mainly to operating hours and filament temperature during steady operation) becomes unable to survive a cold start a little before becoming unable to survive steady operation.

A filament that has suffered uneven evaporation to the extent to become unable to survive a cold start is already in bad shape, and this condition is accelerating at a rate that increases worse than exponentially while the filament is running.


yes. Its kind of playing a game. Like using something thats broken, but using it very gently so as to keep using it...


Now a bit of specific data: I actually got one of those soft-starting "buttons" to attach to the bottom of a lightbulb to supposedly double its life. I managed to get an indirect reading of voltage drop across the "button" and the lightbulb while the "button" was in place and fully warmed up, and it turns out the "button" dropped enough voltage to dim the lightbulb enough to extend its life 50%. Also: Using the usual rules of lightbulb performance as a function of voltage, light output went down 11% while current consumption (and power consumption, counting watts dissipated in lightbulb and button combined) went down 1.7%.

- Don Klipstein (don@xxxxxxxxx) 

Nice.  We do the same thing to car headlamps when possible.

--
Respectfully,


CL Gilbert
.