I'll put in a plug for Litetronics'
Neolites. I also had troubles with generic brands, including some from 1000bulbs.com, such as having 40% of a batch of about 12 die in less than 6 months, regardless of how often they were power cycled.
(My own informal testing, and some other data I've seen, shows that each power-on removes 35-60 minutes of life from a fluorescent tube.)
The Neolites have had a much lower failure rate, maybe 1-2 out of 20 over more than a year. Still certainly not exactly what I'd consider to be "good" though. My guess is that, in the interests of keeping the up-front cost low, manufacturers strip out things like filtering and spike protection. Consumers generally seem to care most about the sticker price, and not the fact that it won't be nearly as durable or long-lasting.
(Many people still think that rechargeable batteries aren't worth the cost, because a good charger may cost $40+, and the batteries are a few dollars each - completely ignoring the fact that they should be able to get 1000 uses out of a NiMH cell. By the time the batteries have paid for themselves
and the charger, they'll still have a few
hundred more charge cycles of life left. But oh look, those alkalines are soooo cheap!)
For that reason, I'm wary of the move to LED lighting. Sure the lights can last a long time, assuming they're properly driven and properly cooled. But if the power supply circuitry has no protection against irregularities in the incoming line voltage, or if it uses conventional electrolytic capacitors in a very hot location within the fixture, thus drying out their electrolyte more quickly, the unit could end up dying long before the LEDs reach their end of life.
Problem is, protection circuitry adds cost. Power circuitry without electrolytics adds cost. Using solid organic polymer electrolytics adds cost.
Cheap construction aside though, LED lights should easily be able to handle multiple power cycles. The emitters themselves don't care at all about power cycling, as evidenced by the fact that they can be cycled at a rate of hundreds or thousands of times per second using PWM.
While you can't do this to the 120VAC inputs of a power supply, you can feed a 0-10VDC or PWM signal to some supplies, and they will in turn translate that signal to their outputs to effect dimming on the LEDs.
(If LEDs are improperly driven, and inadequately cooled, you can be looking at dropping down to 50% brightness within 1000 hours, which the Department of Energy's testing has shown in some units. Some manufacturers
really overdrive the LEDs for greater brightness, so the LEDs overheat and sustain damage, resulting in a very rapid decline in brightness.)
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