Led bulbs

[Mize]

Mize you are right about the ballast probably, but I don't know what is actually breaking there.

For your information when we moved I replaced all the incandescents with CFLs and only had CFLs fail in one light fixture over the 5 years.

I rewired that light eventually b/c it was hooked to some sketchy wiring and the lights quit failing. Anyway anecdotal evidence is anecdotal, but I have had good luck. There seems to be a lot of quality difference between various CFLs.

Where are you located? The US has notoriously bad power issues (90% of our powerlines are overhead wires that suffer weather issues - we didn't rebuild after WWII so we have that legacy). CFL ballasts have capacitors in them that likely degrade with time and transients. I suppose a whole-house surge system would help (they make them). The LED "ballast" is basically a resistor which is why they get so hot.

 

[Sxotty]

I am in PA. The wiring in our house had some knob and tube mixed in, not sure about the quality of the power coming into the meter though.

 

[Grall]

The LED "ballast" is basically a resistor which is why they get so hot.

I would have hoped it was some kind of proper voltage regulator. I bought a couple many years ago for some ancient case LED modding. They looked basically like a FET, there was a metal heat spreader with a screw hole through it, but it didn't produce that much heat all the same. You put in 230V AC in one end, and out came DC, what voltage you decided with some passive components connected to it as I recall. I just soldered everything onto the regulator's legs. Worked out OK.

 

[Mize]

Well, of course you need a rectifier and regulator with some passives to get from 110 or 230 AC to DC, but the ballast is the current limiting part which, for an LED, is essentially a resistor.

 

[Silent_Buddha]

I have 10 LED bulbs in use. Two are outdoor floods, two are outdoor porch lights and the rest are in the house. I like them roughly a bazillion times better than the CFs I've been using for years. I have 7 incandescent bulbs that were in use when we bought the house in 2005 that *ARE STILL WORKING* while we've replaced every CF (all the rest of the bulbs in the house up until LEDs) multiple times. CFs are, IMHO, utter shit and I will never, ever, buy another. I'll take LED or incandescent over CF every single day.

Same here with CFL experience. Myself I'm hoarding incandescent lights for when the government decides that its citizens have too much money and thus decide to try to force us to use expensive and wasteful CFLs.

I'm not going down the LED light route until they get a ton more reliable, and more natural looking. I have one desklamp that I bought with a LED bulb. And it lasted all of 2 weeks before it started randomly deciding when it wants to work and when it doesn't want to work. When it does decide to work it gives everything a slightly bluish tinge.

Regards,
SB

 

[Simon F]

When it does decide to work it gives everything a slightly bluish tinge.

No, incandescents give everything an orange tinge. Trying turning on one type and then the other during the day.

 

[Grall]

but the ballast is the current limiting part which, for an LED, is essentially a resistor.

Yeah, but it could have been a proper high-frequency PWM voltage regulator, as seen in modern electronics/power supplies...

Even if lights don't feature this now, it will probably happen later, when manufacturers strive and compete for even greater efficiencies.

 

[Mize]

I've been quite pleased with the recent LEDs I've purchased. I have downward floods over my kitchen counters and over my reading chairs by my fireplace and the "directness" of the LED light is actually a benefit. The only ones I have that are "too white/blue" are the porch lights and outdoor floods and I don't really care about that. I also have several of the newer ones with diffuser glass over my kitchen table and the light is quite warm.

 

[Grall]

I've wanted to pick up some LED fluorescent tube replacement devices, but last I heard on that front was that several brands were banned last year because you could get shocked by high voltage while removing them due to shoddy electrical design (originating in China, no doubt...)

Apparantly, the exposed terminals carry live current if one end of the tube is removed while the light switch is turned on.

 

[Silent_Buddha]

No, incandescents give everything an orange tinge. Trying turning on one type and then the other during the day.

It's always a bit more yellowish tinged to my eyes, but that's far more pleasing and natural looking than the obvious bluish tinge from most LED lights I've used. Or even the rather sterile light that flourescents give off.

And yes, I've turned on both during the day to compare.

Regards,
SB

 

[Sxotty]

No, incandescents give everything an orange tinge. Trying turning on one type and then the other during the day.

I find the daylight CFLs to be quite nice in terms of working light. I am still used to the yellowy orange of incandescents though.

 

[Grall]

Dailytech reports (again) on the US gov't's "L-Prize" win by Philips Electronics:
http://www.dailytech.com/article.aspx?newsid=24082

There's a bunch of statistics attached to the article, and the most interesting one IMO is Lumen maintenance at 25,000 hours. The competition rules required above 70%, and the Philips LED lamp maintained over 99% on average for 200 units! Pretty fecking impressive IMO.

...Then again, it costs $50 per unit too, so...

*Edit: I just realized the female narrator in the in-line Youtube clip on that page sounds A LOT like the voice welcoming players to Black Mesa from the original Half-Life game and the Blue Shift expansion...

 

[Vadi]

The problem I have is that they're screwing their customers by having no meaningful standard of the quality of the light produced. So you have to actually see them in action, great.
Then you have the power efficiency which also seems not to be required to be on the package. Then again we can't bring our supermarkets to properly declare the ingredients of the food we eat either.
They seem to be a good alternative for those reflector halogen light sources. I'd guess a complete very low voltage installation without the need for ballast for the old transformers would be better still.

I find the daylight CFLs to be quite nice in terms of working light. I am still used to the yellowy orange of incandescents though.

Yes, the yellow light is better for "home usage", daylight for a "workplace".

 

[Grall]

The problem I have is that they're screwing their customers by having no meaningful standard of the quality of the light produced.

In the EU manufacturers must declare both intensity (in lumen) and color temperature I believe. At least major brands do, and since no manufacturer really seem to want to do stuff like this voluntarily, I assume there's a regulation behind it...

 

[Vadi]

Quality was the wrong word, I meant the kind of colour spectrum emitted by these devices.

 

[mczak]

In the EU manufacturers must declare both intensity (in lumen) and color temperature I believe. At least major brands do, and since no manufacturer really seem to want to do stuff like this voluntarily, I assume there's a regulation behind it...

Hmm not sure if there's really regulation saying the color temperature must be printed on it too. It is pretty much needed though I would say, I'd never buy one without knowing the temperature (how else do you know it's the color you want?), that should be enough incentive to print it .
One problem though is it is printed quite small usually (as a 3-digit number, like 827, meaning color index 80, 2700 Kelvin) - instead relying on the much less informative "warm-white". The problem with "warm-white" is that this is anything from 2400-3300K or so and that's definitely quite a big difference (newer osram ccfl for instance are usually 2500K and I can't stand them). Better color index (927 instead of 827) would also be nice but those aren't really sold more of a special item... Same with LEDs btw typically just color index 80.

 

[Blazkowicz]

so LED bulbs will be something to order over the web rather than pick up in a random store.

 

[Gubbi]

One problem though is it is printed quite small usually (as a 3-digit number, like 827, meaning color index 80, 2700 Kelvin) - instead relying on the much less informative "warm-white". The problem with "warm-white" is that this is anything from 2400-3300K or so and that's definitely quite a big difference (newer osram ccfl for instance are usually 2500K and I can't stand them). Better color index (927 instead of 827) would also be nice but those aren't really sold more of a special item... Same with LEDs btw typically just color index 80.

Yeah, talking about a colour temperature for non-black body spectrum light sources make little to no sense. Of course, sense have little to do with marketing: Warm-white, means yellow/orange tinted light, which physically indicates a cooler light source.

IMHO, We need a better one dimensional measure of emission spectrum quality. CRI is only sampled at eight frequencies. Why not simply give the auto-correlated coefficient between a light source's spectrum and the corresponding black body spectrum sampled near-continously (like, > 100 frequencies) in the visible range. I'd expect industry to oppose this since CFLs and LEDs would be exposed as the lousy light sources that they are.

Cheers

 

[mczak]

IMHO, We need a better one dimensional measure of emission spectrum quality. CRI is only sampled at eight frequencies. Why not simply give the auto-correlated coefficient between a light source's spectrum and the corresponding black body spectrum sampled near-continously (like, > 100 frequencies) in the visible range. I'd expect industry to oppose this since CFLs and LEDs would be exposed as the lousy light sources that they are.

Well a a cri of 80 already pretty much tells you it's lousy (it doesn't really hurt my eyes that much though). I'd wish though they wouldn't have reduced it to a single digit, you typically can't tell if the cri is 80 or 89... you might be able to hunt down datasheets for the cfls but that's not exactly practical if it isn't printed on the product itself.
I'm actually not sure sampling more frequencies would change all that much?
In any case I'd be happy if you could get ccfls with CRI > 90. I guess the coating they'd need is too complex, the few you can get (as some overpriced special items, not in usual stores) also have lower power efficiency as far as I can tell.

 

[Grall]

You people are just way too fussy. Why the hell would CF or LED lamps 'not hurt your eyes much'? Cripes...

A dagger poked through your eyeball, THAT hurts.