BS: Replacements for incandescent lights

Subject: BS: Replacements for incandescent lights
From: GUEST,The black belt caterpillar wrestler
Date: 01 Oct 07 - 07:29 AM

The Government(UK) has stated that incandescent light bulbs will be phased out in the next four years. What do you replace them with if you get migraine headaches from flourescent light bulbs/strips?
My wife does, so I expect that we will have to stock pile a lifetime's supply of filament bulbs before they disappear.

Also, can you get low energy bulbs in all the different sizes and shapes that are needed to fit in some of these odd light fittings?

And what about my 1970s "Astra lamp" that needs the heat as well as the light, also coal effect electric fires that do the same etc.?

I presume that this does not apply to vehicles?

Subject: RE: BS: Replacements for incandescent lights
From: GUEST,BobL
Date: 01 Oct 07 - 08:28 AM

Do low energy bulbs trouble her in the same way? The reason I ask is that ordinary mains-driven fluorescent tubes flicker 100 times per second (120 in America), fast enough not to be visible but still discomforting to the few who unfortunately are sensitive to it. Compact fluorescents on the other hand flicker several thousand times a second, if at all, so shouldn't have the same effect.

I shall stock up with tungsten filament bulbs myself though, as my home is copiously equipped with dimmer switches, and present-day low energy bulbs aren't compatible with them. My lounge is also lit by a set of rather fancy globes, which look at their best with clear rather than frosted bulbs.

Subject: RE: BS: Replacements for incandescent lights
From: Keith A of Hertford
Date: 01 Oct 07 - 08:43 AM

In UK, we usually have heating on when lights are in use.
The thermostat will simply replace all the heat expensively saved by the low energy lamp.

Subject: RE: BS: Replacements for incandescent lights
From: maeve
Date: 01 Oct 07 - 08:46 AM

All fluorescent lights give me violent migraines, as do strobe or very bright incandescent lights (glare). I have less trouble when my eyes are shielded from direct exposure; wearing sunglasses, or a hat with a brim, but have found nothing of the sort to completely forstall the migraine reaction.

The spiral compact bulbs are often shielded by a lamp shade, which may be helpful for most sufferers. There are some filters that are helpful for some people; none so far do me much good. Full spectrum/natural light types are usually less of a problem.

Fluorescents have been known to trigger headaches and behavioral problems for children, too, and many schools have replaced the lights with natural sunlight, area (incandescent) lighting, etc.

I would suggest that anyone who has trouble with the fluorescent lights may wish to experiment, and keep records as to your personal reaction to different kinds of lighting.

Regards,

maeve

Subject: RE: BS: Replacements for incandescent lights
From: Rapparee
Date: 01 Oct 07 - 09:08 AM

I think that this is something that hasn't yet been thought through.

How is the government going to dispose of the mercury? Each CF bulb contain a minute amount, and you can't just toss them into a landfill (a/k/a dump or tip). After they extract the mercury, how do they plan to dispose of THAT? You can't just dump it into the ocean.

We use CF bulbs here at home, and take them to the hazmat disposal site when they burn out.

Regular tubular fluorscent bulbs, by the way, do not contain mercury. At least the newer ones don't.

Now if we were all to be irradiated we wouldn't need lights....

Subject: RE: BS: Replacements for incandescent lights
From: Bee
Date: 01 Oct 07 - 09:44 AM

The compact fluorescent bulbs do heat up, just not as much as incandescents. The savings for me are in the long life of the bulbs. I was replacing my kitchen bulbs as often as once a month (dark kitchen, plus frequent power fluctuations, I think). The CF bulbs have been in place for two years.

Most lights have shades of some sort. Fluorescent tube lighting has bothered me in the past, but the CF bulbs don't seem to have any effect.

Subject: RE: BS: Replacements for incandescent lights
From: Grab
Date: 01 Oct 07 - 09:45 AM

What do you replace them with if you get migraine headaches from flourescent light bulbs/strips?

Hopefully LEDs, although they've yet to come into serious use in house lighting. Only a matter of time though, and maybe the idea of announcing this phase-out in advance is to try and kickstart that. Or there's halogens, which are not as good as LEDs/fluorescents but are still an improvement over regular incandescents.

As far as vehicles go, LEDs are already used in practically all new cars. Upper brakelights have been LED since they were first introduced, main brakelights are now mostly LED, and indicators are often LED too. The only thing yet to be LED-ised are headlights, and those are available now if you want them - or you can use halogen headlights. (Or gas-discharge if you're a Pimp-My-Ride type. ;-)

Graham.

Subject: RE: BS: Replacements for incandescent lights
From: Metchosin
Date: 01 Oct 07 - 10:53 AM

I'm a fan of LEDs too Grab. I made myself a white LED headlamp about five years ago, using the housing from an incandescent headlamp that I picked up in a thrift store. We also use LED lights to illuminate the countertops in the kitchen as a backup during power outages.

They have really come down in price in the past couple of years and a 5 LED puck light with batteries can now be purchased in Canada for under $5.00, but the white LED bulbs that can be retrofitted into incandescent circuits are still way too pricey to make any economic sense and they are still better suited to task lighting because they are so directional. If the price comes down, the first place I'd consider using them would be in the halogen track lighting in the office here. The halogens really pump out the heat in the summer.

I'm prone to migraines, but but like Bee, I have not found that the CF bulbs have caused me any problems. I rather like the light they produce. A far cry from the old overhead flickering flourescent lighting of bygone years. The light from the computer monitor probably bothers me more than CFs do.

What I do note though is that the compact CFs are less useful in situations where you only need the light briefly, such as storage rooms. They take a few minutes to come up to full brightness, by which time I've turned it off again. So I'll keep the incandescents in those situations until I'm no longer allowed to purchase and use them. Also the mini CFs won't fit into the overhead fixtures in our kitchen either, so when they ban incandescents here, we're going to have to spring for new fixtures and all the energy saving that that will entail.

Because we use electric heat, I'm not convinced CFs save us any money, particularly in the winter. Whether the heat for a room is coming from an incandescent bulb or a baseboard heater, makes no difference, its all cumulative. I probably could save more in power consumption by unplugging the cell phone charger and other charging devices, when not in use or turning off the computers at night.

Subject: RE: BS: Replacements for incandescent lights
From: EBarnacle
Date: 01 Oct 07 - 10:57 AM

I have been having discussions with my local sanitation department about disposing of flourescent bulbs of all sizes. The recycling people wont take it and the regular trash people just take anything that is in the bin. The answer I have been getting is that they are not equipped to deal with toxic waste and that the people in our area should take their flourescents to the once every three months recycling days. Somehow, I do not see that happening. As a result, mercury is getting into the waste stream. Also batteries of all descriptions.

Those of you suffering from headaches and similar problems from the bulbs should consider getting a complete neurological examination.

Subject: RE: BS: Replacements for incandescent lights
From: Greg B
Date: 01 Oct 07 - 12:21 PM

One issue with compact fluorescents, and probably LEDs of the future,
is that they can't be dimmed in the conventional manner, at least
not run-of-the-mill ones, with the inexpensive dimmers that
mount in the walls.

There do exist dim-able CFs, but they are many times more expensive
than standard ones, and not readily available in shops.

If you dim a bulb down to about half its usual brightness you
end up using less than half the power and also extend the life
of the bulb greatly.

So while energy-saving bulbs are great in many applications, it
is short-sighted to forcibly 'ban' incandescents. They have their
uses.

Subject: RE: BS: Replacements for incandescent lights
From: Rapparee
Date: 01 Oct 07 - 01:09 PM

When the oil runs out we'll all be watching TV by candlelight anyway....

Subject: RE: BS: Replacements for incandescent lights
From: GUEST,petr
Date: 01 Oct 07 - 01:14 PM

Mark Jaccard, a Professor of Environmental studies and energy economist,
here in Canada, did a study on cf bulbs - and being keen on doing his bit- switched over all his lights.

At the time the cf bulbs were quite a bit more pricey so he worked out that he would just about break even in several years. But he managed to break one getting out of the car (so much for breaking even)- then the kids knocked over a couple of lights, and then he found they gradually disappeared and his wife admitted she hated the lights from the bulbs and they ended up being mostly filed away in drawers.

The only problem with energy efficient appliances is that they are effective if people dont end up using more energy. ie. get a new fridge but put the old one in the basement and get a wine cooler or a water cooler. Big Screen tvs, more track lighting etc..

But they are planning to implement this in AUstralia and Canada too.

Subject: RE: BS: Replacements for incandescent lights
From: Greg B
Date: 01 Oct 07 - 01:30 PM

You also have to consider the waste in the switchover. I have
a cupboard full of disused incandescent bulbs. If I throw them
away, then I'm wasting the remaining life and the energy it
took to make them. If I give them to someone else, then that
person will burn up watts with them.

Watts to do?

Subject: RE: BS: Replacements for incandescent lights
From: pdq
Date: 01 Oct 07 - 01:56 PM

Yep. Watt's a mother to do?

BTW, some posts seem to imply that compact flourescent bulbs contain mercury and regular ones do not. This is not true. The basic principle of the flourescent light is that mercury will vaporize at low temperatures and conduct electricity through that vapor (to arc).

Considering that lighting is a small part of the average household's energy use, I believe the ban on incandescent light bulbs is a typical move by the Envionmentalists who feel they have the right to tell others what to do. A properly designed modern house can use electricity to power pumps, fan, lights and various appliances. The trick is to have heating (including water) and cooling done by solar and various heat exchange methods, not by gas. Certainly not by electricity.

Subject: RE: BS: Replacements for incandescent lights
From: GUEST,The black belt caterpillar wrestler
Date: 01 Oct 07 - 06:44 PM

Well as far as we can tell the latest low energy bulbs are much better from the migraine point of view, but the "colour temperature" of them is such that they are unpleasant until they have warmed up for a few minutes.

I still don't think there will be a low energy option for my Astra lamp (later marketed as laval lamps):)

Subject: RE: BS: Replacements for incandescent lights
From: Peace
Date: 01 Oct 07 - 08:12 PM

Was living in a place where electricity was outrageously expensive. Tried a few 'energy saver' bulbs. They did save energy. Also couldn't see a fu#kin' thing, but they saved energy.

Subject: RE: BS: Replacements for incandescent lights
From: McGrath of Harlow
Date: 01 Oct 07 - 08:31 PM

I have rather assumed that cheaper dimmer switch versions will have to come out before the old style bulbs can be eliminated.

What's happened in Australia in that direction?

Subject: RE: BS: Replacements for incandescent lights
From: sneeble
Date: 01 Oct 07 - 08:32 PM

Ironically I have two 6 ft fluorescent tubes hanging over a large fish tank. One is 8500 kelvin and the other is 4500 kelvin, the two are shielded because of the glare. The ambient light bouncing off the tank is enough to light up a large open plan lounge. All other lighting is pretty much redundant. We do have fluorescent tubing accent lighting throughout the house and I now fully understand the usefulness of pelmets. I too are irritated by CF bulbs and refuse to install them in my office, the refresh rate of my monitor and the refresh rate of the bulbs constantly clash, creating havoc on the brain and eyes.

Subject: RE: BS: Replacements for incandescent lights
From: open mike
Date: 01 Oct 07 - 09:00 PM

here are some sites for the lava lamp or lava lite
http://www.syddware.com/lavalamps/
http://www.lavaworld.com/

Subject: RE: BS: Replacements for incandescent lights
From: The Fooles Troupe
Date: 02 Oct 07 - 06:52 AM

"dim a bulb down to about half its usual brightness you
end up using less than half the power"

Actually the square law applies...



"I have rather assumed that cheaper dimmer switch versions will have to come out before the old style bulbs can be eliminated. What's happened in Australia in that direction?"

Dimmable CFLs are now available in the Supermarkets - not much more so that undimmable ones. Only in the standard BC/ES fittings though.

You can get a 'PAR38' equivalent CFL.

Trying to find odd shaped lights for fitting that depend on the bulb shape, or small size ones is difficult, and the very small physical sizes cannot be found at all.

~~~~~~
"Considering that lighting is a small part of the average household's energy use, I believe the ban on incandescent light bulbs is a typical move by the Envionmentalists who feel they have the right to tell others what to do."

Actually I can tell you EXACTLY what happened - and I'm NOT making this up - Little Fascist Johnny and his Mad Mates here in Oz started the stupidity - World First! Intended as a distraction from the refusal to ratify Kyoto! As well as pretending to have an 'environmental policy'!

A local Electronics Magazine did a big expose on all the serious flaws in the scheme - including the fact that CFLs take more energy and greenhouse gas to manufacture! A list of applications for which CFLs cannot work, include Theatre Lighting, hot and cold places - fridges, stoves etc, vibration, such as cars, etc. In 'industrial lighting situations' huge discharge lamps (2KW to 5KW each) are used. 500 watt halogen strips are used in a lot of 'domestic spotlight' type outdoor lighting - as well as small carparks! no CFL equivalents exist for these application - total replacement of fittings is needed.

Actually you can get LED plugins that fit into standard halogen downlight fittings - but they are still pricey - the do have the advantage of less heat as well - many house fires are caused by halogen downlight fittings - beside which you can't seal the room - you have to have ventilation thru many of these type fittings up to the ceiling!

Interesting the comments about migraines - must forward that to them!

Actually I have used them since the first Phillips huge sized ones appeared - about AUD$20 ea! When expired, the outer glass cases made wonderful tea light holders!

You CAN find different 'temperature ratings' - but one of the 'cheap chains' here brought in a massive quantity of 'blue' ones - didn't sell many! :-)

Actually halogens are normally very wasteful energy wise. for a single '50Watt' - you need about 62 watts - each light has a separate transformer (or switchmode converter) hidden in the ceiling!

I personally prefer reflected light rather than harsh downlighting - I have white ceilings.

But I do have 2 10W halogen 'garden fittings' that are positioned in my 'computer desk' - which is a 3 ft square cubicle built from bolt together shelves with some sheet metal. Directional and not too bright.

Subject: RE: BS: Replacements for incandescent lights
From: jacqui.c
Date: 02 Oct 07 - 07:59 AM

We're using a mix of both types of bulb right now. I've put the low energy bulbs where we use the lighting most of the time and where the light stays on for a while once it's switched on. The incandescents that we have left are used where the light might be on for just a minute or two as I have heard (true or not) that you can drastically shorten the life of the low energies by switching them on and off too fast and too often.

Subject: RE: BS: Replacements for incandescent lights
From: Bee
Date: 02 Oct 07 - 08:00 AM

I've never liked halogen indoor lights - too hot, too many fires started by them. I also found they don't make good task lighting if you are trying to do very delicate handwork that requires close eye work and concentration. They seem to cast innumerable minute shadows.

Subject: RE: BS: Replacements for incandescent lights
From: maeve
Date: 02 Oct 07 - 08:01 AM

Just as a matter of interest:

Electromagnetic radiation/ Full spectrum lighting    (Scroll down about 2/3 )

Kids & fluorescent lighting


maeve

Subject: RE: BS: Replacements for incandescent lights
From: Grab
Date: 02 Oct 07 - 12:25 PM

Greg, LEDs are the easiest thing in the world to dim. Any dimmer switch will work with LEDs - the worst that can happen is that the dimming "steps" aren't quite the same.

Graham.

Subject: RE: BS: Replacements for incandescent lights
From: Peace
Date: 02 Oct 07 - 12:54 PM

Here's hopin' . . . .

Subject: RE: BS: Replacements for incandescent lights
From: Kaleea
Date: 02 Oct 07 - 01:07 PM

Um, this may seem like a dumb question, but here goes: If the original Edison light bulbs are still working in museums, is it possible for someone to make light bubls in their own home/workshop & use them?
Nest dumb question: do the little light bulbs in the solar garden/yard type lights bother people, too? They seem to all use reflective stuff around them to increase the output of light, but very low watt bulbs.
Irony of life: the local power company is recommending that everybody run right out & buy the new powersaving bulbs (which made me immediately become suspicious), but the local gov't. is threatening to ban them. Funny thing is, the tv station I was watching tell about this (some months back) said nothing about the mercury.

Subject: RE: BS: Replacements for incandescent lights
From: McGrath of Harlow
Date: 02 Oct 07 - 01:26 PM

"Any dimmer switch will work with LEDs "

All the low energy bulbs I've seen have a notice on the box saying not suitable for using with dimmer switches, and I keep on finding stuff on teh web saying stuff like "Low energy lamps cannot normally be used with dimmer switches" - so I've never tried using them, in case something drastic happens.

So what's the truth?

Subject: RE: BS: Replacements for incandescent lights
From: Mr Red
Date: 02 Oct 07 - 01:37 PM

Flourescent strip lights have more than 50% modulation at 100 (120) Hz and fairly peaky. Tungsten is nearer 20 and pretty sinusoidal at that (the square of sine wave is "1+cos" which is still a sinewave).

The energy saving bulbs have their own higher frequency circuit but I am not sure what kind of electronics they use. As far as I can tell there is no hint of flicker in peripheral vision. Peripheral vision evolved to be fast and vague to watch for danger hence you see flicker more out of the corner of your eye.

Another factor that can have an effect (and effect by association) is the colour or more specifically the spectrum. Tungsten looks more yellow because the spectrum is biased in the red and infra-red region. Flouresents have specific lines at the colours of phosphor mix. And nature and cost dictate a lot of that.

There are dimmers and bulbs that can cope together but we are back to cost again.

Subject: RE: BS: Replacements for incandescent lights
From: McGrath of Harlow
Date: 02 Oct 07 - 01:50 PM

here are dimmers and bulbs that can cope together - that's what I'd heard. But "Any dimmer switch will work with LEDs" is a bit different.

Subject: RE: BS: Replacements for incandescent lights
From: Greg B
Date: 02 Oct 07 - 02:13 PM

McGrath, the 'standard' CFs won't work with dimmers.

Apparently LED bulbs will though I'm a bit dubious given
that LEDs are low-voltage devices and not real linear in their
response.

Here in the US the dimmable CF bulbs are still not available
readily at retail outlets.

I use 4 CF 60-watt equivalents in each of my bathrooms. I rather
like the fact they don't come up to full brightness for about
30 seconds. Less shock factor at night or first thing in the
morning. Lots of saving in those high-wattage rooms, too.

Subject: RE: BS: Replacements for incandescent lights
From: JohnInKansas
Date: 02 Oct 07 - 08:11 PM

Dimmable fluorescent lights were used beginning ca. 1970 in some places, most notably in a couple of airplanes for area lighting in the passenger compartment. These required a completely different kind of tube, however, and an external high frequency and high voltage power supply for each bulb. The high frequency was to make it easier to get the high voltage, and the essentially RF frequency could be modulated (PWM?) to change the current through the tubes/bulbs.

I haven't seen specs on how they're being built, but the guess is that the "modern" low energy bulbs use the same principles. The base contains a small frequency/voltage converter that's actually applying a couple of hundred(?) volts inside the tube, probably at some higher frequency like perhaps 400 Hz(?). The absence of a separate "starter" - required with old-fashioned long tube fluorescents - implies at least that something inside the bulb is working in much different manner.

When we moved into our current home, we found that the previous owners had "decorated with lighting" so that we needed 11 different kinds of bulbs to keep all the installed fixtures working. In two cases I've actually replaced fixtures to get rid of the more exotic kinds, and in most of the rest of the place I've just "uglified" things by using less fancy bulbs. With the exception of a set of yard lights, a couple of halogen floor lamps, and about four desk lamps (that will eventually get converted) I've been using the plug-in low power lamps everywhere that incandescent bulbs were installed for at least the last 4 or 5 years.

I could brag that replacing all the light bulbs saved us tremendous amounts on our electric bills, but I'd have to figure out how much of that was due to the hot tub breakdown. I had already calculated that the tub was costing us "more than $150/month" if we turned it on, so I wasn't too sorry when it became "unfixable."

We have found that the new bulbs do not give the impression of lighting things as well as the "equivalent" incandescent bulb, but since a "100W-equivalent" bulb only uses 47W actual, I've considered it safe to replace in 60W rated fixtures with "100W-equivalent" bulbs and with that conversion the apparent lighting is much the same, perhaps a little "softer," still with some reduction in power usage.

The new-style bulbs do last somewhat longer than incandescents, but the claims on the package are somewhat optimistic. I'm not sure that the savings on energy consumed and on bulb replacements would be much better than "break-even" if the new bulbs are bought singly at common retail outlets, but there is a definite $aving$ if bought in small bulk quantities at the bulk outlets (Sams/Costco) or in bulk packages at the lumber yard (Home Depot/Lowes).

Some of the replacement bulbs carry a warning that they should be used only in "base down" applications, although this warning doesn't appear on most newer kinds. There does seem to be a slight reduction in bulb life, at least for some, if used in "odd angle locations." This might be something to watch for on the packaging if buying a large bunch of them for general replacement.

John

Subject: RE: BS: Replacements for incandescent lights
From: Grab
Date: 02 Oct 07 - 09:36 PM

Since LED lights aren't generally available yet, the dimmer manufacturers are mostly justified in that statement! :-)

LEDs are low voltage devices, sure. So they'll use multiple LEDs in series to make the voltage up, or use a transformer to drop the voltage.

The behaviour of a LED-plus-resistor combination is that it does nothing at lower voltages, then it starts conducting and lighting. With the resistor in there, as the voltage rises above that break-point, the light level increases. That means there'll always be a portion of the sine-wave where the LEDs do nothing. When the steps in your dimmer coincide with this region, the dimmer won't have any effect, because the LEDs won't light anyway. But the steps in the dimmer which *do* coincide with the LED being on will dim the LED as normal. So as I said, the worst-case is that the dimmer steps aren't the same as before.

This is assuming they don't try anything fancy with the LEDs. It would be easily possible to make up a circuit which compensates for voltage fluctuations and so on by converting the AC to DC and regulating it- in that case, a dimmer wouldn't work. This circuit would be less efficient though and for no real gain, so I can't see this happening when LEDs get into mainstream use.

Graham.

Subject: RE: BS: Replacements for incandescent lights
From: Gurney
Date: 02 Oct 07 - 10:32 PM

I started work in a factory that was 5 years old. From 6 to 8 years from new we had to replace many of the strip lighting tubes.
Looked like a bell-shaped curve to me. I wonder how the new mini floros will last. They are not doing too well for me so far, some crapped out quite early, possibly because, like strip lighting, they don't much like being switched on and off too much.

Foolstroupe may have the best idea in uplighting, because distance seems to make a difference to me. I get headaches in my workshop, with strip-lighting just above my head, but not in a factory, where it is several metres up.

Subject: RE: BS: Replacements for incandescent lights
From: JohnInKansas
Date: 02 Oct 07 - 10:55 PM

Grab -

I haven't seen LED lighting that's other than as arrays of multiple individual LEDs - usually a fairly large number of individual emitters for reasonable amounts of light. I would suspect that the most practical way of providing a dimmable LED array would be via a square wave with the width of the "squares" varied (Pulse Width Modulation = PWM). Each element would turn on at each cycle of power, but the duration of each "on" would be varied. If done at sufficiently high frequency, flicker would be undetectable, and could be additionally reduced by using different sets of emitters out of phase with each other. Polyphase square wave PWM control modules should be available¹ from Radio Shack if you'd like to try it out.

¹ I will admit I haven't looked for one recently, but the control circuits are quite simple, and probably are available as integrated circuit modules.

John

Subject: RE: BS: Replacements for incandescent lights
From: mg
Date: 03 Oct 07 - 12:05 AM

Gee..how about sunlight..solar tubes etc. The devil herself might have invented flourescent lights, at least the older ones. They have so many health hazards associated with them. Sit in the dark before you sit under them, and protect children from them. It is like drinking sewage water from an electromagnetic standpoint. mg

Subject: RE: BS: Replacements for incandescent lights
From: San Francisco Bill
Date: 03 Oct 07 - 12:48 AM

Thank you all for this discussion. I had no idea that so many people were 'allergic' to CFL lights, but it seems like the older ones are at fault.

Some years ago, following a kitchen remodel, my wife (for the moment) insisted on 150 Watt bulbs for our 6 ceiling lights. They blew out our 600 W dimmers in short order - the math is not that difficult to do to explain why THAT happened.

I switched to 65 watt 'miser' bulbs, and nobody noticed - I even stopped having to replace dimmers! Once it was over, she started using the 150 watt bulbs, with the inevitable dimmer blow-outs.

To the point, you don't have to be a tree hugger to try to eliminate waste. I manage a vacation property at Lake Tahoe. I was shocked - so to say - when the summer electricity bill was over $400 a month!

The highest cost - by far and away - is, as a rental, when the maintenance man has to come out and replace a bulb, he charges $25 for the trip! Plus the cost of the bulb!

I just came back after replacing about 20 bulbs with CFLs. When I go back in November, I plan on replacing 20 more. Soon, the electric dryer and cooktop will be toast as well, as I plan to replace them with gas!

Subject: RE: BS: Replacements for incandescent lights
From: JohnInKansas
Date: 03 Oct 07 - 01:52 AM

One of the very real problems I've had with my ~60 year old house is that ceiling fixtures - whether loaded with rated size bulbs or with "something bigger" to get more light - eventually bake both the insulation on the wiring/wires and the ceiling panels (plaster board) to the point that any movement of the wire invites spectacular fireworks and interrupted circuits, and replacing a fixture quite often involves breaking out enough "fried and powdered" plaster board to get to something solid enough to start a patch from.

At least the new lower watt lamps (can) dump a little less heat into the fixture and surrounds, so that potentially things may last a little longer, and perhaps be a little safer from the structural/fire resistance standpoint.

Sixty or seventy years shouldn't be long enough for anything to show the wear and tear I've seen in some of the stuff around my place.

[Excuse me for a moment now. LiK seems to be having some sort of convulsive gigglefit.]

John

Subject: RE: BS: Replacements for incandescent lights
From: Grab
Date: 03 Oct 07 - 05:30 AM

That's what I was thinking too, John - a simple array of multiple LEDs is the only sensible way to do it. As for dimming, the problem with square-wave PWM is that you need to be starting with DC. But a dimmer switch is just doing PWM on the AC anyway, so the effect will be basically the same.

Graham.

Subject: RE: BS: Replacements for incandescent lights
From: GUEST,Keinstein
Date: 03 Oct 07 - 06:18 AM

Most dimmers don't do PWM on the AC, they do phase control. That means the AC doesn't turn on (if you're dimming) at the start of the cycle, but is delayed until some later point. This results in a horrible current waveform like ripsaw teeth.

Subject: RE: BS: Replacements for incandescent lights
From: JohnInKansas
Date: 03 Oct 07 - 01:10 PM

Keinstein - What you describe is exactly what PWM is. Pulses occur at regular intervals. The "width" of the pulse is controlled/varied to change the net power transmitted. If you do the math, almost any "signal conditioning" can be described as a "phase effect," "frequency effect," etc. (FM radio should properly be called Phase Modulation, since the signal is carried in the phase difference between the received signal and a reference frequency, according to some.) While the textbooks often illustrate the theory with square waves or sawteeth, that isn't what really happens in most real-world devices. Improperly designed or inappropriately applied, the simplest "peak clipping" devices, like those used for common incandescent light dimmers can generate lots of noise, but it's not really necessary with slightly more sophisticated components.

A problem commonly encountered with solid state switching devices, like LEDs, is that the do not tolerate being "sort of on" or "pretty much off." In the vicinity of the "on" switch point they carry large currents but still have significant resistance, so they heat up and go "POP!." In the vicinity of the "off" switch point, they have high resistance but still have significant current, so they heat up and go "BANG!."

Back in the olden times, much attention was devoted to designing effective "crowbar circuits" that would assure that when the device was switched on it would go instantly to "FULLY ON" and when it was switched off it would be instantly "FULLY OFF." Most solid state devices that resemble LEDs now usually contain additional components on the same chip to assist the flip between ON and OFF states, and to prevent dwell in the nether region between, but a clean drive signal that makes the transition quickly and cleanly is still important.

A "clipping circuit" of the kind Grab suggests, and that Keinstein describes, has a tendency to "soft switching" that is potentially destructive when used with solid state switching devices. A circuit of that kind would likely be used to detect when the actual drive voltage/current would switch on and off, but would likely be the "control" circuit to switch the actual bulb/tube voltage/current between two fairly stable ON and OFF states. To avoid flicker (and to minimize component size) the switching would likely be at a much higher frequency than is available from ordinary line sources.

If one still needed to solder a bunch of components together to convert AC line to DC, oscillate at higher frequency, transform to preferred voltages, and PWM the ultimate output to apply it to the bulb, questions of "complexity" would be of very real significance; but in today's world one just "buys a chip" and plugs it in. It's a lot like building a radio - since about 1950 or so.

A difficulty with the "compact fluorescent" replacement bulbs is that "on the inside" they don't operate off line voltage. The line voltage is converted inside the base to what is needed to light up the tube. A dimmer for bulbs of current design would need to be part of the conversion circuitry to be effective, so each bulb would need its own built-in-the-base dimmer knob.

The situation is similar for halogen bulbs/lamps, but for a different reason. The lamp must be operated at full power in order for the glass/silica tube to come to proper operating temperature. If the outer tube does not reach proper operating temperature the filament will self-destruct fairly rapidly. The tolerance on temperature is sufficient to allow halogen elements to be used in most "livable" environments, but they don't last as long in extremely cold areas as more common incandescents. If "visibly dimmed" they most likely would cool off too much to provide the "halogen effect" for which they're named.

John

Subject: RE: BS: Replacements for incandescent lights
From: McGrath of Harlow
Date: 03 Oct 07 - 01:41 PM

Gas gives much pleasanter lighting. I wish they'd kept on developing the technology to make it less inconvenient. I don't know how it measures on the eco-scale though.

Subject: RE: BS: Replacements for incandescent lights
From: GUEST,petr
Date: 03 Oct 07 - 05:06 PM

the question is - what to do about backyard patio heaters, or driveway de-icers etc..

the light bulb thing is a step toward higher efficiency but doesnt address higher energy use - we may encourage a higher efficiency refrigerator but its pointless if people put the old fridge in the basement - or get a wine cooler or water cooler etc..

Subject: RE: BS: Replacements for incandescent lights
From: JohnInKansas
Date: 03 Oct 07 - 11:54 PM

Reducing the amount of energy used, whether it's by using more efficient methods to do the same things, or omitting the frivolous energy hogs that advertising urges everyone to have.

I've chosen, in one instance, the removal of a power hog, by de-commissioning and attempting to remove the busted hot tub.

My primary observation from that effort is that it is extremely difficult and time consuming to cut up a heavy, structural, fiberglass object to get it through the door, after some

          F***G IDIOT

builds the room around it after installing the monster.

John

Subject: RE: BS: Replacements for incandescent lights
From: GUEST,Keinstein
Date: 04 Oct 07 - 07:33 AM

Quite right JiK, but the point I was trying to make is that it's the AC that's being controlled- so with LEDs or other lights that go instantly on/ off the dimmer will produce unpleasant flicker at 100/120Hz. With incandescents the thermal inertiaof the filaments is enough to mask this effect.

It's quite possible to make HF pwms that won't flicker, but in these days of costs pared down to nothing, they won't happen until the market's hand is forced.

Another thing that annoys me is the difficulty of comparing specs when some units are quoted in candelas, others in lux, others in lumens, others in watts/ square metre, and yet others (the incandescents) in just watts. These all measure different aspects- the consumer only needs four parameters: How much visible light it emits, what is its angle of illumination, what colour(s) is the light, and how much power it takes.

Subject: RE: BS: Replacements for incandescent lights
From: Mr Red
Date: 04 Oct 07 - 01:50 PM

The problem with LED lights when sold as 240 Volts is that they have some form of step-down, like a transformer and choke circuitry (magnetics). It is the magnetics that the dimmers don't like.

Flourescents have chokes, energy saving bulbs still have magentics - albeit at a higher freqency and gawd knows what on the 240v side to chop (techie term) the 50Hz.

They had banks of LED lights in the ceilidh tent at Shrewsbury FF and they were bright. I bet it saved on the power cable size though. And the weight in the roof.

Subject: RE: BS: Replacements for incandescent lights
From: GUEST,The black belt caterpillar wrestler
Date: 04 Oct 07 - 04:39 PM

Does a light that is more to the blue end of the spectrum give a false impression of being brighter?
I'm asking because I have one of those wind up LED lanterns that have a quite blue light that glares a lot but in contradiction doesn't seem to illuminate well.

I know that the human eye works best in the green part of the spectrum and is more efficient at detecting colour differences in that range.
Some evidence for saying we evolved in jungles rather than on the savanah?

Subject: RE: BS: Replacements for incandescent lights
From: folk1e
Date: 04 Oct 07 - 08:15 PM

I was taught that we see more "efficiently" at the yellow point of the spectrum. Fairly close to that of sunlight!
A choke is just a magnetic coil, the reason dimmers "don't like magnetics" is that with A.C. a magnetic coil will alter the phase angle and cause more power to be used with less effect. Our teacher (yes I still remember him) demonstrated a "dimmer" that used that effect. He called it Wattless power! He also showed us how to dim any normal 240v flourescent fitting!

Subject: RE: BS: Replacements for incandescent lights
From: mouldy
Date: 05 Oct 07 - 08:45 AM

Well just about all the lights in my house have been "energy savers" for years, and now they do small ones that actually fit the shades, my wall lights are too. That's made 240w go down to 42w. The range and style of the bulbs is improving all the time.
Because I'm on my own a lot I tend to just use a 20w bulb in the standard lamp next to my chair and remember to switch other lights off when not needed. However I have to confess that in having my bathroom modernised I have gone down the halogen light route from fluorescent tube lights, and I have a halogen reading lamp at the side of my bed. But I still have 2 fluorescent tubes in my kitchen.

Andrea

Subject: RE: BS: Replacements for incandescent lights
From: dick greenhaus
Date: 05 Oct 07 - 12:08 PM

One major problem with multiple-LED arrays is that, like old Xmas tree lights, they're series connected. If one goes, they all go.

Subject: RE: BS: Replacements for incandescent lights
From: Mr Red
Date: 06 Oct 07 - 03:57 AM

LED arrays - depends on the confiuration - one PSU and multiple outlets means parallel. And you can get those in DIY stores. And diodes can burn short so a series connected array may go brighter then go pop. If they are fed with AC pairs of diodes would be back to back so some light continues. Ya get wot ya pays for.

Eye - peaks at the yellow frequencies.

Magnetics - simple (ie cheap) dimmers use thyristors which switch on at varying angles to effect control of an average voltage. Magnetics don't like transients too much, and then as folk1e says the current is still positive when the voltage goes negative which electronics don't like too much. (similarly in the negative part of the cycle)