Why Do Light Bulbs Fail Early?
I read the answers to the questions about fast burnout of light bulbs in the Oct. 1997 issue. Although all of the answers are helpful, I believe I have another answer to solve the problem.
Standard incandescent lamps are manufactured with a coil filament.
The lamp could be energized when the voltage sine wave is near zero,
but changing at the most rapid point of the sine wave. At this point,
the observed laws of electromagnetics dictate a large transient current
will exist in the filament. The filament heats quickly and experiences
transient physical forces. As a result, the filament pops—even if
it is a new bulb! The contributing factors of ambient temperature and
manufacturing tolerances add to the chance point of switching to cause
premature failure. A good solution to this problem is to install a
dimmer and bring the lamp on “slowly.”
—L.D.E.
--------
I don’t agree to several points about the short life of light bulbs in the Oct. 1997 issue. First, in the second paragraph, a sentence states: “They are less likely to take variations of voltage.” Shouldn’t that be “more likely?” The 130V bulbs tend to be high-quality bulbs, whereas you can purchase 120V bulbs from good to trash. This could account for any improved life span of the 130V bulbs.
Second, the idea that vibration can harm a hot filament vexes me. Isn’t it true forensic engineers use filament damage as a way of telling which bulbs were burning during plane crashes and the like? The theory is: If the lamp is on during the crash, the filament will normally not break because the heat created allows the filament to stretch. Would this eliminate vibration in any situation where bulbs burn constantly? —T.F.
Want to use this article? Click here for options!
© 2012 Penton Business Media, Inc.
Latest Articles
EV charger tester
May 25, 2012 8:26 AM
CFL/LED dimmer
May 24, 2012 8:48 AM
Load bank
May 23, 2012 9:33 AM
Trending Articles
Acceptable Use Policy blog comments powered by Disqus
advertisement
what's wrong here?
What's Wrong Here?
May 10, 2012 12:44 PM
View all What's Wrong Here?
What's Wrong Here
Sponsored By:
product spotlight
EV charger tester
May 25, 2012 8:26 AM
The Electrician is portable tester that verifies critical power and safety requirements of electric vehicle (EV) chargers...
View all 2012 Product Spotlights
Free Product Info
Our Product Information site is the ultimate online resource for products and services offered by Advertisers featured in our Magazine. This service is provided as a quick and easy way to request Product Information online. Get FREE product information now.



































