Separating the LEDs from the power conversion & control would greatly increase the repairability, an spreading them out can increase the reliability. Designers can cool them better. 12 volts is a common standard, and you can use less insulation.
seems the best way around this is to have a DC circuit running around (eg for the whole ceiling of one room) with a single higher quality controller unit that is readily serviceable/replaceable without buying replacement bulbs. This unit can then support dimming etc quite easily (dimming LEDs themselves is relatively easy using simple digital PWM)
The problem is all being caused by fitting LED bulbs into existing 120-240v AC fixtures
Drivers for the LEDs need better design for the long life of the LEDs. Today there are LED Lamps and LED fixtures available from many different manufactures, but in most of the cased due to poor designs of the drivers, driver fails before the life of LED. This makes the LED lamps costlier than CFLs.
I love incandescant bulbs. The light can't be beat. I buy them now and I'll keep buying them until I can't. And then I'll probably go black-market if the lumo-fascists ever get their way. The last time I bought a four pack they cost me around a buck. Can you beleive that? What a deal!
And with the money I save I buy modest bottles of wine like nobodies business. Next time I'll raise my glass to all suckers.
In my experience with CFLs, lifetime is much, much longer than with incandescent bulbs, although I don't use CFLs in the refrigerator or in the oven.
I've found that in fixtures where incandescent bulbs were very short-lived, i.e. two lamps in particular, CFLs also fail sooner than normal, for whatever reason. But my sample size is too small to say that for sure yet. And in this involves CFLs with the small candelabra base, which most likely means that cooling of the electronics is inadequate. (I've changed the socket of one lamp to regular Edison, but still have some candelabra-to-Edison CFLs, with adpater, to use up. And these adapters look terrible for heat dissipation.)
In fixtures that use the regular Edison base, 60W or 40W equivalent CFLs, they soldier on for many years. Way longer than incandescents.
I'm sure that in time, the failure modes will be taken into consideration. Also, for oven or refrigerator use, it seems really trivial to use glass fibers to bring the light into the unfriendly environments, and locate the light source where the climate is more temperate. Otherwise, you're looking at hardening like for automobile engine electronics.
If the power electronics is the weakest point, does it make sense for each household to have a low voltage DC circuit? Most consumer electronics only need low voltage DC power source anyway. That will be more energy efficient and save a lot of copper. NSF has a model house where there are USB wall plugs.
NASA's Orion Flight Software Production Systems Manager Darrel G. Raines joins Planet Analog Editor Steve Taranovich and Embedded.com Editor Max Maxfield to talk about embedded flight software used in Orion Spacecraft, part of NASA's Mars mission. Live radio show and live chat. Get your questions ready.
Brought to you by