E27 LED lamp

[white exec]

Disappointing to discover the claimed ultra-long life of "mains" LED lamps is, apparently, often not what is advertised.
Had a series fail here, brand as per photos, with a rating on the package of 40,000h. That's a cool 22 years, at 5h per day. Really? No, they managed a couple of years, then pop...pop...pop and died.

Took one apart, just to see what was crammed into the small 'golfball' E27 package, and this was it:

I know electronics are cheap, but was surprised how much that double-sided board contained. A recycling nightmare!
A clutch of better quality similar has now been fitted in the kitchen.

[GiveMeABreak]

We've got LED G4 replacement Spots for the kitchen - have been gong for years without an issue - but had to go back to the Halogen numbers because the light was just 'nice, but dim'!

[myglaren]

We've got LED G4 replacement Spots for the kitchen - have been gong for years without an issue - but had to go back to the Halogen numbers because the light was just 'nice, but dim'!

I fitted four of these several years ago in my daughter's kitchen - six quid from China. I wasn't expecting much but the halogens were costing a fortune, only lasting days, a couple of weeks at most.

The light was better, softer so not all the harsh highlight as deep shadows so although they are no brighter, visibility is much improved.
Never a problem with them, still going sttrong - My daughter gets through light bulbs at a progigious rate - I am suspecting a fault on the consumer unit as the new oven I bought her a couple of weeks ago failed - it is just a standard 13A plug on it so tested it in another outlet and it was fine.
On testing the cooker socket there was only 190V and an indicated neutral fault.
Must fix it one day but not keen to drag the consumer unit out as she has solar cells that can be a pain to shut off safely. Worried about damaging the inverters

I have a load of E14 and E27's here and a few have failed but generally they do better than halogens and tungsten bulbs.

Had a sconce on the staircase that was on permanently - gloomy stairwell. Died when the fixed the boiler that it was wired in to
It had lasted several years.

Replaced recently with a similar one - they are only £8

I have heard that it is the driver that fails rather than the LEDs. Doesn't help much as replacing or repairing the driver isn't much fun.

[white exec]

230v halogen 'spots' are a disaster - a long, thin, delicate 230v filament.
The 12v MR16 version (which does need a transformer) will soldier on for years, decades even.

Mains-voltage filament lamps, especially the high wattage ones are not good news.
Remember (from the 70s and 80s) overhead projectors (OHPs) used to run on a 230v 650W halogen lamp (an A1/233). Cost about £6-10 each, and lasted 25h if you were lucky.

Then came the A1/223: 24v 250W. Small, short, stubby filament, bi-pin. Fraction of the heat, rugged, and actually brighter. Point source of light, so better focus through the optics. Cost was £1.10, and life 50h+, more if you under-ran them very slightly.

Soft-start transformers would extend life even further. In Education, converted thousands of OHPs across the world from the old lamp to the new, using Rank Tutor-2 slide projector parts (lampholder + transformer). Never looked back.

No-one today knows what an overhead projector is, of course.

Moral: Avoid mains-voltage halogen lamps.

[Gibbo2286]

230v halogen 'spots' are a disaster - a long, thin, delicate 230v filament.
The 12v MR16 version (which does need a transformer) will soldier on for years, decades even.

Mains-voltage filament lamps, especially the high wattage ones are not good news.
Remember (from the 70s and 80s) overhead projectors (OHPs) used to run on a 230v 650W halogen lamp (an A1/233). Cost about £6-10 each, and lasted 25h if you were lucky.

Then came the A1/223: 24v 250W. Small, short, stubby filament, bi-pin. Fraction of the heat, rugged, and actually brighter. Point source of light, so better focus through the optics. Cost was £1.10, and life 50h+, more if you under-ran them very slightly.

Soft-start transformers would extend life even further. In Education, converted thousands of OHPs across the world from the old lamp to the new, using Rank Tutor-2 slide projector parts (lampholder + transformer). Never looked back.

No-one today knows what an overhead projector is, of course.

Moral: Avoid mains-voltage halogen lamps.

You mean an epidiascope

[white exec]

You mean an epidiascope

No.

Left: Episcope Right: Epidiascope
An episcope is able to project an image from a flat printed sheet/book/map/drawing/flattish object.
A diascope is a slide projector, projecting a small transparent slide or still film, 35mm or otherwise.
An epidiascope is able to do both, having two lenses and optical systems.

An overhead projector (OHP) uses an A4 or 10x10" glass platen, on which is placed a sheet of film, printed or drawn with transparent inks, or opaque text (eg from a photocopier). It's lit from underneath, and the image is projected with the overhead mirror/lens.
A shallow dish placed on it, with water and small fish,** provides animated relief from OHP-transparency boredom*.

* This has now been replaced with PowerPoint boredom, delivered by laptop and digital/video projector.
** Alternatives include oil-water mixes, creepy-crawlies, ripple-tanks (ask the Physics teacher), popcorn (if very patient).

[Hell Razor5543]

And then you have projectors which can produce a wide image from close to the white surface;

https://www.projectorshop24.co.uk/en/ri ... aYQAvD_BwE

I will get more information (if anybody are interested), but the Ricoh websites are down for scheduled maintenance. I have to also admit that I work for Ricoh (although not in any of the production facilities).

[Gibbo2286]

The word came into my head straight away, when I was in my last year at school I spent the whole year as assistant (bottlewasher) to the science master in the lab, he had badgered the school into funding an epidiascope for the lab.