Re-inventing the lightbulb

[ppppenguin]

A completely novel approach to high efficiency lighting.

http://www.sciencecodex.com/recycling_light-173105
http://www.telegraph.co.uk/news/science/...-LEDs.html

I wonder if this trick with incandescent filaments will outrun LEDs and CFLs in a few years time. Looks like it could be potentially inexpensive to make and inherently has excellent colour rendering.

This sort of back to the future idea has a parallel in electronics. We went from solid state devices (crystal and cats whisker) to new fangled valves and back to solid state with transistors.

[AlanBeckett]

It's on the BBC as well - http://www.bbc.co.uk/news/science-environment-35284112

Alan

[pamphonica]

As an aside, we went from not just cats whiskers but also FETs (first patented by Lilienfield in 1926) to "hollow state" and then back again! The only reason we couldn't have workable FETs (actually thin film MOSFETS) in the 20s was that Lilienfield could not get the silicon pure enough to get a usable "gain" in the device. It took 20+ years before the materials science caught up enough for practical transistors to emerge.
Jeremy

[ppppenguin]

My gues is that they will struggle with longevity. Conventional fluorescent and CFL should give 10000+ hours. LED should give 25000+ hours The don't always do so, mainly due to failures in the electronics. But this thing is a hot filament. If you want a decent colour temperature it's got to run at 2700K to 3000K which means an inherently limited life. I don't know if these special coatings prevent the tungsten evaporating, or whether they are compatible with the halogen cycle which redeposits the tungsten on the filament instead of the glass of the bulb.

It looks like it's a fairly thick filament which means low voltage. This inherently gives better efficiency and longer life. a 50W 12V MR16 halogen is more reliable and brighter than its 240V GU10 equivalent. GU10 halogens often have an appallingly short life, possibly due to fractionally high mains voltage. An old fashioned 230V 100W GLS bulb gives out about 1300lm, its 120V US equivalent is nearer 1600lm.

If you need the colour rendering and dimmability of conventional bulbs then the modern "direct replacement" 230V halogens are excellent. I have some 105W halogens whose bulb is the same size as a good old 100W GLS. The light output is close to an old 150W GLS and the colour is nicer too. They're on dimmers, rarely run at full whack and will probably last for long time. Maybe I'll treat myself to some trailing edge dimmers to get rid of the buzz.

This would do for my lounge. You've got to laugh at the bullet point: "Trailing edge technology"
http://www.screwfix.com/p/varilight-trai...w-va/80739

[Nick]

... Conventional fluorescent and CFL should give 10000+ hours. LED should give 25000+ hours The don't always do so, mainly due to failures in the electronics. ...

Towards the end of their manufacturing window, nixies were quoted with an MTBF of about 200,000 hours
That fell pretty exponentially if you over-drove them and totally relied on using Hg doping.

Not domestic white-light, but there you go

[Terry]

My gues is that they will struggle with longevity. Conventional fluorescent and CFL should give 10000+ hours. LED should give 25000+ hours The don't always do so, mainly due to failures in the electronics. But this thing is a hot filament. If you want a decent colour temperature it's got to run at 2700K to 3000K which means an inherently limited life.

An excellent idea but possibly a bit late in the day?

Apart from the longevity issue raised by Jeffrey, here's a longevity issue of a different sort ...

I wonder how long the traditional ES and bayonet cap holders will last with the decreasing use of incandescent bulbs?

Will new buildings use different fittings from day one, better suited for smaller, lighter LEDs? (Sorry about the pun!)

Rewired buildings would see the same fittings used, in the same way that, in previous times, 5A & 15A sockets were routinely replaced by 13A ones. As the market for ES and Bayonet types diminishes, the price differential caused will accelerate the change.

This new technology, if successful, is likely to take some time to develop. Is it possible that there won't be enough suitable fittings left by the time they become widely available?

CFLs are getting much better - the slow start up of early types seems to have been eliminated, judging by the performance of more modern replacements in our house and, no doubt, LED technology will continue to improve. After all, it isn't that long since LEDs were only available in red. Green followed quickly afterwards but blue was a longer time coming - followed, of course by white.

[ppppenguin]

I wonder how long the traditional ES and bayonet cap holders will last with the decreasing use of incandescent bulbs?

MR16 and GU10 are commonplace and a couple of others are too. With the very long life of LEDs we are seeing more fittings where the "bulb" can't be changed. Such as the downlights from TLC that I've used. The electronics will probably die before the LEDs. In the case of my TLC fittings the electronics is in a separate box, keeping it well away from the heat of the LEDs. As such it could probably be cracked open and fixed.

[Crackle]

I suppose as it is not April the 1st we can believe this "idea".

Mike

[Pat Pending]

As an aside, we went from not just cats whiskers but also FETs (first patented by Lilienfield in 1926)

I had to do a talk on J.E.Lilienfield a few years ago, and my research led me to some uncoroberated reports that he had managed to demostrate amplification and had built a broadcast reciever with protptypes of his device. Would I ever like that set in my collection!

Andy.

[ppppenguin]

There were various reports in the 1902s of "singing crystals", possibly from people trying 2 cats whiskers on a single crystal, accidentally making a point contact transistor.

Lilienfield is an enigmatic character. https://en.wikipedia.org/wiki/Julius_Edgar_Lilienfeld He certainly invented the idea of the FET but whether he made a workable device is another matter.