This is a fascinating read!
http://spectrum.ieee.org/geek-life/history/the-great-lightbulb-conspiracy
http://spectrum.ieee.org/geek-life/history/the-great-lightbulb-conspiracy
The great Lightbulb conspiracy of 1920s and its legacy
- Thread starter kenmore71
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Longer life incandescent bulbs are a mixed bag. In addition to giving less light output for a given wattage, they along with other incandescents get darker and darker due to bulb blackening. 1000 hours might have been a good compromise between efficiency and long life -- though I'm sure the main motivation was to sell more bulbs!
Excellent article.And yes the ghost of short lamp life is still with us---the electrolytic caps in the power supplies in the bases of both CFL and LED bulbs.The electrolytics filter out the AC ripple from the rectifier in the bulb-for LED they need DC to work-for CFL to convert the DC to high frequency AC for the bulbs ballast.The elctrolytic caps are typically the first parts to fail.And with LEDs,like Incandescent,Flourescent, and even HID the light output drops as the device ages.
Osram is now with Sylvania-and they make Xenon projection lamps constantly berated by projectionist and theater operators becuase of their shorter life and exploding in the lamphouse-blowing up mirrors and light engines.Christie is the favored bulb for projection lights.
there is a lighting chip discussed on the Candlepower Forums that allows LED elements to be driven directly from the chip-feed 120VAC into the chip-its out then feeds the LED elements.Problem-there are no capacitors to filter out the ripple-hence the light will give 60Hz flicker.Annoying to some folks.
Osram is now with Sylvania-and they make Xenon projection lamps constantly berated by projectionist and theater operators becuase of their shorter life and exploding in the lamphouse-blowing up mirrors and light engines.Christie is the favored bulb for projection lights.
there is a lighting chip discussed on the Candlepower Forums that allows LED elements to be driven directly from the chip-feed 120VAC into the chip-its out then feeds the LED elements.Problem-there are no capacitors to filter out the ripple-hence the light will give 60Hz flicker.Annoying to some folks.
firedome
Well-known member
this was on here a few years ago...
winder if the NJ firehouse bulb is still going strong!?
winder if the NJ firehouse bulb is still going strong!?
Longest Burning Light Bulb
I think the city of Livermore, CA would take issue with Mangum's claim.
http://www.centennialbulb.org/
I think the city of Livermore, CA would take issue with Mangum's claim.
http://www.centennialbulb.org/
The
Livermore, CA bulb was made here in my home town of Shelby, OH. Some of my no longer living family worked in the plant which has long ago been taken down. There are still some bulbs here in Shelby working. I have "inherited" some from my family members but they no longer work.
Livermore, CA bulb was made here in my home town of Shelby, OH. Some of my no longer living family worked in the plant which has long ago been taken down. There are still some bulbs here in Shelby working. I have "inherited" some from my family members but they no longer work.
"Dreadful CFL bulbs that last 15 Yrs" Don't know if I quoted this exactly-the failure is most likely due to the electrolytic cap in the bulbs power supply.If the bulb-CFL or LED is left running continuously-it could possibly last for many years.Its the ON-Off cycles that kill them-and ironically the energy folks ask you to shut the bulb off when not in use.The on-off cycles kill the caps-charge and discharge cycles.The more its done-the less life the cap will have.And the quality of the components in the bulb-poor quality components will of course not last long-so the bulbs will meet the low prices wanted by consumers-of course bulb makers will put the lower quality-cheaper electrical components in them.
arbilab
Well-known member
I bought exactly one CFL (when they weren't cheap) and put it in a low duty cycle socket in the back bathroom. It failed completely within 90 days. At least it didn't go up in smoke and flames like they are known to do. All of which explains why I bought 'exactly one' and never again.
Besides that annoying delay starting, dim operation until it warms up, and rendering brown objects as green, I could have bought a decade worth of incandescents for what that stupid thing cost.
Besides that annoying delay starting, dim operation until it warms up, and rendering brown objects as green, I could have bought a decade worth of incandescents for what that stupid thing cost.
davetranter
Well-known member
CFL and LED lights
I have exactly one of each installed. The CFL is timer controlled for one on-off cycle per day, and, if it is to give it's rated 10,000 hour life, should fail sometime in August 2018 (Watch This Space!!). The LED lamp is switched probably about 2-3 times per day (usually a couple of short 'looking for something' periods, and one 'all evening' period). I was able to purchase this as 'clearance stock' back at the beginning of June, and it should have already saved enough in electricity cost to have 'paid for itself'. It is lighting this room as I type.
I'll keep everyone posted as to lamp longevity
All best
Dave T
P.S. I have dismantled several 'failed' 12V and 240V LED 'downlighter' type lamps. In all cases the actual LEDs are in working order, only the built-in 'Ballast/convertor' has failed.
I have exactly one of each installed. The CFL is timer controlled for one on-off cycle per day, and, if it is to give it's rated 10,000 hour life, should fail sometime in August 2018 (Watch This Space!!). The LED lamp is switched probably about 2-3 times per day (usually a couple of short 'looking for something' periods, and one 'all evening' period). I was able to purchase this as 'clearance stock' back at the beginning of June, and it should have already saved enough in electricity cost to have 'paid for itself'. It is lighting this room as I type.
I'll keep everyone posted as to lamp longevity
All best
Dave T
P.S. I have dismantled several 'failed' 12V and 240V LED 'downlighter' type lamps. In all cases the actual LEDs are in working order, only the built-in 'Ballast/convertor' has failed.
arbilab
Well-known member
Correct Dave. The lamps themselves DO have greatly extended lifetimes. But the cutcorner electronics to which they are connected most assuredly do not.
