LED, Fluorescent, Incandescent?

[genesplicer]

I already use a blended approach. lots of my lights are on dimmers, so I use incandescent in those. In most other places I have fluorescent, and I am currently working on banked LEDs in a few areas where they will be useful to us, such as above our workbenches. The difficulty lies in finding the proper blend of "white" LEDs to give us a decent imitation of natural light.

 

[TobiasTheViking]

American television on CRTs flickers at 60 Hz (30 Hz for fine details), which is fine most of the time, but European television (and film) runs at 50 Hz and drives me crazy, though the locals seem accustomed to it.

Trust me, some europeans (read me) have the same problem, my tv is a 100hz, i get a headache from looking at anything below 73, and i feel half blind(i can't really explain it, feels like the light is being sucked from my eyes) at less than 65.

 

[Olowkow]

We live near an airport and our lightbulbs go out constantly due to the vibration from planes taking off. A couple months ago we spent the extra money for two 8 packs of the compact flourescent bulbs, thinking they would last longer. They don't. They are all burned out already. Waiting for LED to improve I guess.

If it is true that your light bulbs go out due to "vibration from planes", you have loose connections. Do you check the incandescent bulbs with an ohmmeter, or the fluorescent ones in another socket to be sure they are bad?

There is no reason that planes taking off should burn out light bulbs, unless the vibrations are so severe that they weaken the filaments. If that is the case, I would check for structural damage to the house.

We have been using the fluorescent bulbs for many years with no failures.

 

[casebro]

Does 'SAD' treatment require full spectrum? I would think that like everything else, the human body probably uses a narrow range of light to do whatever it is that needs doing. One of the UVs probably, since incandescents make lots of IR. So, maybe cheaper bulbs would work as well? Any SAD studies re: wavelengths ?

And re: the flickering of 'industrial fluorescents', the newer ones use electronic ballasts, so probably flicker lots faster than the the ones that ran on a 60 hertz transformer. And so much more efficient, our local electric co. is replacing the old with the new for free. I guess the new ballasts don't get warm, plus the different bulb is more efficient.

 

[TjW]

I already switched to (mostly) led use except a few fixtures which still need to be replaced. The initial round of LED's I bought were rather crappy and ended up dimming significantly after a short period of time.

I've actually been working on building my own LED lighting system which is going to use an internal rectifier and capacitors to give some good smooth DC and then I'm using some solid state relays to control the brightness and color temperature by having several arrays of different led's.

If you're going to go to that much trouble, why not just use one (or three, if you want to do some sort of color balancing thing) of the LED controller chips available? They're essentially switching regulators that allow controlling the duty cycle.

 

[Dan O.]

Would a 42" LED monitor be a suitable treatment for SAD? The color balance can be easily adjusted as well as adding texture and motion. You would probably have to sit in front of the thing for several hours a day. For that, the content would need to be captivating.

For LED lighting, a switching power supply would be more efficient than a simple rectifier. Most power LEDs are driven by pulse circuits to get better light generating efficiency at higher currents but keep the heat down by limiting the duty cycle. I'm thinking the best solution will be dual conversion. A main AC/DC switching power supply driving a DC distribution bus and individual pulse controllers on each light for dimming/smart house controls and such.

 

[Soapy Sam]

i get a headache from looking at anything below 73, and i feel half blind(i can't really explain it, feels like the light is being sucked from my eyes) at less than 65.

You really have'nt realised yet?
The NWO illuminati are stealing your light and beaming it to a Bavarian Schloss.

Why did you think they call them "illuminati"?

 

[WildCat]

There are places where the CF bulbs won't work well. The biggest killers are heat, cold and bad power. Many enclosed fixtures will get too hot for the electronics in a CF bulb and they will burn out early. If it's too cold most CFs won't light.

I've had CF bulbs in my detached, non-heated garage for nearly 2 years now. Both still work, even a few weeks ago when it was 10 below zero Fahrenheit. Now, they weren't very bright initially then but they were adequate for the use.

I'd use CF bulbs more if they could be dimmed, is there an insurmountable technical issue that prevents this?

The halogen bulbs in my bathroom fixture over the medicine cabinet are still going strong after 1 year, I have it on a digital dimmer so I think that helps the life span.

 

[Dan O.]

There is a self dimming CF bulb where you turn it off momentarily to drop to a lower brightness. They also make CF bulbs that work with certain dimmers.

The problem with generic CF bulbs and dimmers is that the bulbs use a bridge rectifier and capacitor to convert the AC input to DC before going through a switching circuit to generate high voltage pulses for the gas tube. A standard dimmer operates by reducing the duty cycle if the AC waveform. Since the AC peak is still the same, the capacitor is charged to the same voltage but this happens over a much shorter time so the peak current goes way up. Heating in the wires is proportional to the square of the current so when you cut the duty cycle in half the peak current doubles which quadruples the peak heating resulting in a doubling of the average heating (ouch)! At some dimmer settings you can have peak currents of 5 to 10 times the full on setting. That can exceed the current rating of the wires and has been shown to cause fires.

A dim-able CF bulb would have a double switching power conversion (which should improve efficiency) and would then be able to detect the dimmer setting and adjust its own duty cycle to match the dimmer. A better long term solution would be a smart lamp with remote control for the lighting and a replaceable bulb without all the electronics.

Halogen bulbs have an interesting self repair property. They last longer than regular bulbs because they trap the metal vapor from the filament in the gas and keep it from plating the inside of the bulb (which is the primary cause of dimming in incandescent bulbs). When you turn the bulb off the metal vapor plates back onto the cooling filament.

 

[Olowkow]

Halogen bulbs have an interesting self repair property. They last longer than regular bulbs because they trap the metal vapor from the filament in the gas and keep it from plating the inside of the bulb (which is the primary cause of dimming in incandescent bulbs). When you turn the bulb off the metal vapor plates back onto the cooling filament.

Also, the halogen cycle depends upon having an envelope, quartz, that gets very hot. This is why they are generally quite small in size. If dimmed, the tungsten vapor will soon be deposited on the inside of the quartz and cause it to not only have less light output, but absorb heat irregularly causing failure, either of the filament or the socket/pins.

Halogen lamps should not be handled with bare fingers, as salt deposits on the quartz can cause hot spots.

 

[MattusMaximus]

Anyone ever seen this website?

One Billion Bulbs

Thoughts? Comments?

 

[Leicontis]

I'm very happy with the 1W LED in my 2-D-cell Mag-Lite - way brighter than the normal bulb, and likely a lot more durable, too.

As far as home lighting goes, I'm waiting to see what pops up with the OLEDs they're working on - from what I've heard, they're supposed to be cheaper and have better color balance than regular LEDs. That, and they can be made as flexible sheets - I expect we'll have a lot less glare and bright spots to worry about when we can make our entire ceiling glow!

 

[Graham Jackman]

There is a self dimming CF bulb where you turn it off momentarily to drop to a lower brightness. They also make CF bulbs that work with certain dimmers.

The problem with generic CF bulbs and dimmers is that the bulbs use a bridge rectifier and capacitor to convert the AC input to DC before going through a switching circuit to generate high voltage pulses for the gas tube. A standard dimmer operates by reducing the duty cycle if the AC waveform. Since the AC peak is still the same, the capacitor is charged to the same voltage but this happens over a much shorter time so the peak current goes way up. Heating in the wires is proportional to the square of the current so when you cut the duty cycle in half the peak current doubles which quadruples the peak heating resulting in a doubling of the average heating (ouch)! At some dimmer settings you can have peak currents of 5 to 10 times the full on setting. That can exceed the current rating of the wires and has been shown to cause fires.

A dim-able CF bulb would have a double switching power conversion (which should improve efficiency) and would then be able to detect the dimmer setting and adjust its own duty cycle to match the dimmer. A better long term solution would be a smart lamp with remote control for the lighting and a replaceable bulb without all the electronics.

Halogen bulbs have an interesting self repair property. They last longer than regular bulbs because they trap the metal vapor from the filament in the gas and keep it from plating the inside of the bulb (which is the primary cause of dimming in incandescent bulbs). When you turn the bulb off the metal vapor plates back onto the cooling filament.

That's not quite right. The halogen reacts with the tungsten evaporated from the filament to form more volatile tungsten halides. Weak spots in filaments have higher resistance and thus get hotter and it is at these points that the tungsten halide decomposes to deposit fresh tungsten metal. The idea being to deposit metal where it's most needed.

 

[Dan O.]

That's not quite right. The halogen reacts with the tungsten evaporated from the filament to form more volatile tungsten halides. Weak spots in filaments have higher resistance and thus get hotter and it is at these points that the tungsten halide decomposes to deposit fresh tungsten metal. The idea being to deposit metal where it's most needed.

You're right. I knew I should have looked it up instead of trying to post from memory.

 

[sugarb]

We have changed over to the fluorescent. I don't worry too much about broken bulbs. Actually, I can't recall ever breaking a light bulb (other than christmas lights that get smashed because I've been too lazy to put them up correctly). The thing that I'm finding most difficult is breaking the habit of turning the light switch off every time I leave the room, for just those quick trips in and out. I spent years conditioning housemates, instructing them that light switches go up AND down...and now I'm trying to adapt to this 15 minute thing. All that wasted harping...it is really quite tragic.

 

[mhaze]

http://www.superbrightleds.com/

 

[luchog]

Does 'SAD' treatment require full spectrum? I would think that like everything else, the human body probably uses a narrow range of light to do whatever it is that needs doing. One of the UVs probably, since incandescents make lots of IR. So, maybe cheaper bulbs would work as well? Any SAD studies re: wavelengths ?

The research is only just being done on specific wavelengths, but seems to indicate that the key frequencies are in the blue end of the spectrum; and doesn't extend into the UV, which is generally not recommended.

Incandescents have very little blue in them. Ordinary fluorescents are also similarly deficient in blue light, as they emit primarily in the green region of the spectrum. Colour-balanced CFLs also tend to be somewhat deficient, but better. Full-spectrum CFLs (the sort intended for plants and reef aquaria) are the best choice so far, as they have a sufficient intensity in the blue spectrum, and are relatively inexpensive. Full-spectrum Metal Halide have the best colour balance and light intensity, but are considerably more expensive than CFLs, and have a problem with heat generation.

Blue-white LEDs have been tried, but so far proven to be ineffective at treating SAD. The colour range is far too narrow, and the intensity is nowhere near high enough without spending several thousand dollars on enourmous banks of LEDs. By contrast, a good high-intensity full-spectrum CFL bank can be made for about one to two hundred dollars; and a good metal-halide system will run two to four hundred.

 

[luchog]

Would a 42" LED monitor be a suitable treatment for SAD? The color balance can be easily adjusted as well as adding texture and motion. You would probably have to sit in front of the thing for several hours a day. For that, the content would need to be captivating.

No, nowhere near suitable.

It's not just the colour temperature that's important. The light intensity is even more important. Most light systems intended to treat SAD have roughly the same light intensity as 2 or 3 450Watt incancescent floods. They're typcally made with a bank of 4-6 CFL tubes, or 2-5 high-intensity CFL "bulbs", running between 150 and 300 Watts, or a single 200-450Watt metal halide bulb. Even at it's brightest, your monitor wouldn't put out even the same light intensity as a single 50Watt CFL unit.

 

[XBoxWarrior]

I grow all my weed with Metal Halide for the vegetative state (nice and bright)...

and fruit them out with High Pressure Sodium (very warm and sunset like) ...

as far as the house goes, I use a mix of CF, and Incandescents.

But after reading this thread, I now realize that the "NWO Illuminati" is sucking my brains out through my laptop screen........I often wondered why my laptop was killing my vision?

My mycology basement lab doesn't require much lighting, so I just use a CF (or two) over the giant (48 gallon) Tupperware containers.

Gotta pay the bills.

 

[Graham Jackman]

No. No we can't.

Perhaps we could further occupy Soapy Sam by pointing out that these lamps are really phosphorescent, not fluorescent!http://www.internationalskeptics.com/forums/images/smilies/smile.gif