Re:The Great Lightbulb Conspiracy
by GuB-42 on Tuesday March 06, 2018 @11:34AM
(#16529871)
While most people forget to mention when discussing the Phoebus cartel is that with incandescent lightbulbs, lifespan and efficiency are inversely correlated.
It is actually quite simple: incandescent lightbulbs are blackbody radiators. Efficiency depends only on the temperature of the filament, the hotter the better, but lifespan decreases drastically as temperature increases.
There isn't much that can be done in an incandescent light bulb. The filament is tungsten, voltage is fixed by the grid, power is the rated power. So, the only choice is to make the filament longer/thinker or shorter/thinner. The former will be dimmer and longer lasting compared to the latter.
Requiring a set lifespan also ensures consistent brightness and color temperature (a real temperature in this case), it also requires reasonably precise manufacturing. These are generally good things.
Well obviously, a lot of it is motivated by profit, but there are also very good technical reasons behind it too.
The situation today with LED lighting is actually much worse. LEDs could last a lifetime, unlike with incandescent light bulbs, there is no reason for them to burn. However, a lot of them fail because they are under-engineered.
It is actually quite simple: incandescent lightbulbs are blackbody radiators. Efficiency depends only on the temperature of the filament, the hotter the better, but lifespan decreases drastically as temperature increases.
There isn't much that can be done in an incandescent light bulb. The filament is tungsten, voltage is fixed by the grid, power is the rated power. So, the only choice is to make the filament longer/thinker or shorter/thinner. The former will be dimmer and longer lasting compared to the latter.
Requiring a set lifespan also ensures consistent brightness and color temperature (a real temperature in this case), it also requires reasonably precise manufacturing. These are generally good things.
Well obviously, a lot of it is motivated by profit, but there are also very good technical reasons behind it too.
The situation today with LED lighting is actually much worse. LEDs could last a lifetime, unlike with incandescent light bulbs, there is no reason for them to burn. However, a lot of them fail because they are under-engineered.