Proper light bulbs returning?

[Tim Streater]

But it shouldn't just be the bakelite, Shirley? That covers up a brass bit that you actually plug the lamp into.

[Tim Watts]

Up, down and sideways over 40 years, 4 houses.

My thinking too. BC for regular, and GU10 for spots. We have a couple of SES table lamps but the damn things are nearly impossible to avoid.

Yes. In engineering speak, "Low Voltage" means less than 1000VAC or 1500VDC between conductors or 600VAC/900VDC to earth (IIRC). So they invented "Extra Low Voltage" to stand for what normal people call low voltage

Good for certain installation zones which is why I have one (shower). I would also use it for soffit lighting if I had any as that's the one other place it's likely to get a good soaking.

I'm using a few 2D commercial fittings (simple, white, round, not too big) for the kids bedrooms and the hall. The bedroom deployment is a separate circuit to give a good strong daylight effect over a desk as both rooms are north facing.

I figure an all white fitting with a white diffuser will tend to go unnoticed against a white ceiling - I'll see how right I am - but I'm not too bothered as this is a clear "function over form" scenario. Their "main" lighting is chrome, dimmable, and SWMBO approved.

It's occured to me that for a few places I said I wanted downlighters with LEDs for nightlighting or to sort out dark corners, I don't necessarily need true downlighters. I actually don't really like them anyway - I've just got programmed into defaulting to them because everyone else does.

So I'm off to look for a very small discrete inexpensive fitting now and see what gives.

Sockets are so much easier: "what colour dear?", "white's OK", "then I'll use brand as they seem good..."

Cheers

Tim

>

[Tim Watts]

[Lieutenant Scott]

On Sun, 04 Mar 2012 17:48:41 -0000, Tim Watts wro= te:

Must be bloody good light fittings then - brass? The plastic ones go br= ittle if they have a 100W in them.

They seem to be making LEDs in all fittings now anyway - not in supermar= kets so much, but on ebay and mail order companies.

Oh.... I shoulda known that, having done engineering in my degree :-)

Unless you put the light IN the shower cubicle, I don't see it necessary= to be quite that careful.

I love really bright light, much easier to see and easier to think what = you're doing! Before LEDs I got some "biobulb" CFLs which made a proper= white light instead of the weak yellow crap you get from most CFLs. Tr= ouble is they lasted only 6 months, and in fact 2 of the 10 caught fire = (well smoked). Not sure if they would have caught fire if I hadn't been= there to switch them off.

ROFL!!! "SWMBO approved" - that should be on documentation along with t= he electrical safety approvals.

I like brass coloured fittings where possible. I think chrome looks che= aper. I suppose I associate brass with gold and chrome with silver. A = silver medal is only 2nd place :-)

For corners I have compact ceiling mounted spots, which I aim into the c= orners of the room.

WHITE? UGH. I have brass. I managed to get a pack of 10 double brass = sockets for =A320 on ebay, brand new in packets. B&Q wanted =A312 EACH!=

[ARWadsworth]

IKEA........

[Andrew Gabriel]

A thin tungsten wire is about as resistant to thermal shock as anything you can think of. No other parts of a filament lamp normally contribute to standard lamp failures, even in lamps which are flashed on and off all their life.*

In any case, folks who operate lamps which are flashed all their life have plenty of data to show life is related to the total "on" time, and not the number of times switched, so it's kind of pointless to speculate on the mechanism behind a failure method that doesn't exist.

*Again, I'm excluding halogen lamps here, which have other possible failure modes.

[Andrew Gabriel]

I have built my own LED soffit lights, because: a) the lamps would be difficult to change, requiring access to neighbours' gardens to foot the ladder (as I did for fitting, but that's a one-off). I'm running 3W LEDs at 2W on substantial heatsinks, so should get much longer than the rated life (I'm not expecting to ever change them). b) The small LED light source enabled me to use optics to direct the light precisely along the path, without spilling/wasting it where it's not wanted (e.g. into neighbour's windows). c) Much cheaper than buying any of comperable quality, even if I could find some which generated the right beam pattern.

If they ever got water into them, they would be destroyed - that wasn't a reason I used LEDs.

I have also recently designed/built an outdoor LED lamp for someone else's garden, which generates a very specific light pattern to light up a path at night. The motivation for this was to avoid putting mains wiring around the garden (it runs off 24V). The unit is a conventional PIR lantern bought from B&Q, gutted and fitted with multiple LEDs and optics to direct the beam, and internal copper mountings to conduct the heat to the aluminium case and hold the LEDs at precisely the right angles to generate the required light pattern. The location is right next to a road junction, and another factor was to avoid any dazzle outside the garden - the precise control of light which can be achieved with small light source LEDs means the light source is invisible from the road. A neighbour described it as ghostly, because you can see a brightly lit path when it's on, but the quantity of light required to do that doesn't seem to come from the lantern, which means I'm not wasting the light dazzling peoples' eyes. It's working very well, and I will shortly be designing another one for a different location and lighting pattern.

When designing fittings, I try to consider which ones are likely to still be around in 10-20 years time. I like and have used 2D lamps in a number of designs, but they don't meet the efficiency standards required by the EU. However, it looks like manufacturers are now addressing this with modifications to some of the 2D power ratings, but other ratings will probably go away.

Well I don't. Downlighters do have their place, but when I see them being used to provide general lighting, I just see "cheap and nasty", poor lighting design, and no imagination.

[dennis]

From the lighting industry federation web site

"Q. Is a GLS lamp life affected by switching rate?

A. Life is tested with one switching per 12 hours. One switching per hour reduces life about 1%."

If you design a lamp that flashes all the time you either under run the lamp or you use soft start circuits. This extends the life a lot. You may or may not have noticed that traffic lights use soft start to improve lamp life.

Well you wouldn't want a halogen lamp to run below its minimum envelope temp or it would blacken.

[Andrew Gabriel]

Rapid sell a selection, and CPC a few. Mostly I have bought them from trade lighting shows (or got free samples in some cases).

Farnell were advertising heavily at the last one I went to, but I haven't yet got around to looking at what they have. Thermal management (heatsink, and heat conduction) is even more critical. Rapid stopped selling the heatsinks I often use, so I will have to find another source shortly. The other way, as above, is to conduct the heat away to the luminare casing, particularly if it's aluminium or copper. I tend to make copper strips to do this out of copper pipe hammered flat. I did use some copper bus bar offcuts too, but buying it new is much more expensive than using copper pipe.

16W and 28W look safe - GE have produced wattmizer versions. 10W and 21W don't look like they have a future, and I have used both of these. I wouldn't use 10W nowadays in new designs as that's right in ideal LED terratory now. Getting same light output as a 21W lamp in the same space and keeping it cool enough for LEDs is still quite a challenge. (28W would be easier as the lamp is bigger, and so will the fitting be - indeed LED versions of former 2D lights already exist in the larger sizes.)

[<me9]

Which is rather thin and bends quite easily allowing the bulb to fall.__

[PeterC]

My impression of Prolite is that they're intrisically fakes.

I saw advice, years ago, to use only the well-known brands and those included GE - oh well...

[Andrew May]

It is because of the cost compared to traditional bulbs which are less than a pound each. Would you accept the same argument for other consumer goods? If a TV is expected to last seven years and some last fifteen would be be upset if the one you bought only lasted six months? What about a new car?

[Adam Funk]

,

[Andrew Gabriel]

Years ago, the well-known brands used to design and manufacture their own products. I get the impression they just go shopping in China nowadays, and you get some good, and some bad products.

Philips was a good make, but around the time the CFL Genie came out, the quality seemed to drop rather noticably.

[Lieutenant Scott]

I saw it regularly with 100W bulbs.