I have a standard issue desk lamp that uses halogen bulbs. I don’t know the brand name of the lamp, I threw out the box and it’s not indicated on the lamp. I do recall that it was a cheap model, $20 or less.
I’ve had it less than one year and the stupid thing has gone through at least four bulbs. The bulbs are ‘20 watt / 12 volt JC Type T’. The packaging of the bulb indicates “Average Life (hours) = 2,000”.
Some quick math here – at 12 hours per day (although I use it usually less than that), 2000 / 12 = 167 days. I work 5 or 6 days per week. 167 / 5.5 = is about 30 weeks. At my usage rate I should go through bulbs at roughly two per year. I’ve gone through four in less than one year.
The only good thing about the situation is that the bulbs are about $1.70 each at Radio Snark, and I’m thinking of buying by the case. I’ve heard that finger oil on the bulb is detrimental, so I install the new one using a tissue to hold it.
Any idea why this is happening? What is happening?
It’s impossible to say for sure without taking some measurements, but offhand I’d say cheap lamp = cheap electronics, and it’s possible the lamp’s power supply is putting more than 12 V across the bulb. If that’s the case, then all bets are off where bulb life is concerned.
Another factor is heat. Bulbs burn out faster when they are overheated.
Halogen bulbs burn hot, and a cheap lamp fixture may have skimped on the ventilation & heat-conducting features so that the bulbs are overheated in this fixture. That might explain the fast burnouts.
I used to use an outdoor Halogen floodlight. It was nice in that it lit up the entire yard. But it to would require a new bulb almost every two months (it ran all night). At some point I noticed that every time it wasn’t the filament that had burned out, but the ceramic mounts on the ends had burned and cracked thru. Finally replaced it with a regular incandescent. Not as bright for the wattage but lasts nearly a year.
[slight hijack]
Do yourself a favor and get rid of it. Indoor Halogen lamps are much too big a fire risk for the small light/power advantage they have…
1.) Most facial tissues contain oil to pamper your poor nose. That why dogs like to eat them, and that could be putting a little oil on the bulb you were trying to keep clean.
2.) As t-bonham said, overheating kills bulbs. If there aren’t enough vent holes, you can make some. (Obviously, you’ll want to unplug the lamp when you’re making holes in it.)
I would agree with bonham that the first thing to try is to improve the ventilation if you can. Most desk lamps that I have seen have a reflective hood over the bulb with NO provision for good air circulation past the bulb.
If you can you might try a ventilation hole above the bulb if that is at all possible.
