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LED light bulbs - some questions before buying

Surely someone needs to invent a bulb holder that is such a design that small fingers can’t go in and complete the circuit? I remember my first 240v shock as a kid doing just this - I’m amazed that it’s still possible.
 
Rug Doc said:
I remember my first 240v shock as a kid doing just this
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me too :eek: bedside light fixture, where the lamp had gone, and i thought it would be a good idea to take the dead lamp out and stick my finger in the holder
 
clivem2 said:
not only the bulb.
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The bulb is just the outer glass envelope - in tradtional GLS, bulb-shaped. The thing that screws in and produces light is a lamp.

There are NO lamp factories left in the UK at all, except odd-ball niche things unless the very small SLi unit making short (150-450mm long) fluorescents is still running, which I VERY much doubt. The last lamp glass factoy was DEMA/SLi/GTE near Sheffield, that closed several years ago and has been cleared and built on.

Traditional ordinary GLS are still available but are presumably made in the very far back-end of beyond using a goat in a treadmill to generate a vacuum in them, as they last not very long at all.
 
gintonic said:
me too :eek: beside light fixture, where the bulb had gone, and i thought it would be a good idea to take the dead lamp out and stick my finger in the holder
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Any educated young man knows it’s essential to try ones finger in a newly available hole.
 
Things could be worse. I am pretty certain that the US uses even-numbered ES threads, the rest of the world uses odd-numbered, if not, it is the other way around.
An E24 cap will fit in an E25 holder, just, but may stick and gall, or drop out unexpectedly.
 
Vinny said:
Things could be worse. I am pretty certain that the US uses even-numbered ES threads, the rest of the world uses odd-numbered, if not, it is the other way around.
An E24 cap will fit in an E25 holder, just, but may stick and gall, or drop out unexpectedly.
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Probably an approximation of 1" for the Americans, they haven't learnt from the Mars Climate Orbiter fiasco.
 
Vinny said:
The bulb is just the outer glass envelope - in tradtional GLS, bulb-shaped. The thing that screws in and produces light is a lamp.

There are NO lamp factories left in the UK at all, except odd-ball niche things unless the very small SLi unit making short (150-450mm long) fluorescents is still running, which I VERY much doubt. The last lamp glass factoy was DEMA/SLi/GTE near Sheffield, that closed several years ago and has been cleared and built on.

Traditional ordinary GLS are still available but are presumably made in the very far back-end of beyond using a goat in a treadmill to generate a vacuum in them, as they last not very long at all.
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Well ok...I have a lamp on my desk, it's an anglepoise lamp. What do I call the anglepoise if not a lamp? I'm sure there's a "correct" answer but in normal (non-technical) English it's a lamp. I could call it a desk lamp I suppose but I doubt that's technically correct either.

It's a lamp which lights because it's held within a lamp-holder and a metal support structure connected to mains voltage wired to reach the lamp's contacts.

I got there...
 
gintonic said:
me too :eek: beside light fixture, where the bulb had gone, and i thought it would be a good idea to take the dead lamp out and stick my finger in the holder
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Me, I got the exposed conductors of a flex, held on to live and neutral and switched the socket on with my toe, to see what it would feel like. I remember a moment of flying through the air before hitting the wall.

I used to test LED bulbs for compatibility with a major lighting equipment distributors dimmer equipment ((UK -) iLight) with the early generation of LED bulbs. They certainly are different from purely resistive (Tungsten) bulbs. What was acceptable with resistive loads (and their inherent thermal inertia) just didn’t work any more. Zero crossing drift became a significant problem. Add to that that they are an electronic device. Power electronics tend to get a bit dodgy with very low voltages. Some early LED bulbs worked fine between 3-230V, but below 3V became capacitors. When the AC went to about below -3V there was a surge of current that either tripped the current limit or stressed any silicon in the line.

I tested a lot of different manufacturers bulbs. When it came to dimming there was a lot of variation in their performance. Some work fine if you use the correct type of dimmer others can either be distracting or destroy the control.
 
TalYWaun said:
Me, I got the exposed conductors of a flex, held on to live and neutral and switched the socket on with my toe, to see what it would feel like. I remember a moment of flying through the air before hitting the wall.
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school friend of mine, used to go up to his loft, where for some unknown reason there was exposed and live remains of a pendant lamp fitting.

He used to get great joy from the resultant blue sparks generated when he whacked the live remains of the pendant fitting with a metal bar.....
 
TalYWaun said:
I used to test LED bulbs for compatibility with a major lighting equipment distributors dimmer equipment ((UK -) iLight) with the early generation of LED bulbs. They certainly are different from purely resistive (Tungsten) bulbs. What was acceptable with resistive loads (and their inherent thermal inertia) just didn’t work any more. Zero crossing drift became a significant problem. Add to that that they are an electronic device. Power electronics tend to get a bit dodgy with very low voltages. Some early LED bulbs worked fine between 3-230V, but below 3V became capacitors. When the AC went to about below -3V there was a surge of current that either tripped the current limit or stressed any silicon in the line.
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Not really at all surprising as incandescent lamps are just bits of wire in a glass enclosure.

All the rest, you are supplying mains to some running gear and that gear varies enormously from manufacturer to manufacturer, lamp design to lamp design. In the case of discaharge lamps, including fluorescents, the gear supplies around 90V, at the lamp terminals (once it has struck).
The V drop on LEDs is? It is around 1.5 to 3.5V depending on lots of things, not least colour, but the gear supplying that varies hugely.
 
Arkless Electronics said:
So what the hell is going on with BC (bayonet cap) light bulbs? It was always very rare to find a main ceiling light bulb that was anything else in the UK but when I look at the lightbulb section in local supermarkets I now can't find any at all! It's looking like I'll have to change the sockets in several of my light fittings next time a new bulb is needed.... and yet I have never seen or heard any mention of BC being phased out...
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I noticed this recently when an elderly relative asked me to change a bulb for them. She didn't have the right type so I popped to the nearby shops, the third shop I tried, a 'Home Bargains' or some such came good after Morrisons and Wilkos failed, but it was still more for a two pack of BC22 100w-equivalent warm white LED, than for the four pack of the equivalent ES27 in there!
 
gintonic said:
school friend of mine, used to go up to his loft, where for some unknown reason there was exposed and live remains of a pendant lamp fitting.

He used to get great joy from the resultant blue sparks generated when he whacked the live remains of the pendant fitting with a metal bar.....
Click to expand...

I did a very silly thing with fitting a light in the loft of an ex... this was in filament bulb days and as there was no light and I had to do some work up there I had a look for what was around and found a ceiling mount type bulb holder... with no pendent flex.... that 'll do... so I mounted holder and normal light switch to beams and wired up with twin and earth etc. Only weeks later did it occur to me that it was rigidly fitted at head height and if someone had accidentally nutted it they would have smashed the bulb and got the red hot LIVE ends of the prongs that once connected to the filament right in the forehead! The need to carry out work in loft now passed it became a "round tuit" job and we split up not long after.... and she moved house a couple of years later...OOPS
 
Arkless Electronics said:
I did a very silly thing with fitting a light in the loft of an ex... this was in filament bulb days and as there was no light and I had to do some work up there I had a look for what was around and found a ceiling mount type bulb holder... with no pendent flex.... that 'll do... so I mounted holder and normal light switch to beams and wired up with twin and earth etc. Only weeks later did it occur to me that it was rigidly fitted at head height and if someone had accidentally nutted it they would have smashed the bulb and got the red hot LIVE ends of the prongs that once connected to the filament right in the forehead! The need to carry out work in loft now passed it became a "round tuit" job and we split up not long after.... and she moved house a couple of years later...OOPS
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There was a film like that, where Michael Caine bumps off his wife "accidentally on purpose." Mind you, she had it coming.....
 
I am about to take delivery of a whole load of bulbs and fittings - all Calex from Holland.
I think I have pretty much the final lot available of the E40 'Eclipse / Elipse' and some 30 or 40 of the other XXL sizes, (my favourite being the colosseum) Then back to the normal E27 (so actually both odd and even numbers in the UK/EU) for yet more of their old type bulbs.
I also use the new Philips colour master in GU10, and find it nigh on impossible to tell the difference between them and halogen, apart from the heat output difference.
 
Vinny said:
The bulb is just the outer glass envelope - in tradtional GLS, bulb-shaped. The thing that screws in and produces light is a lamp.
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Only for tradesmen. For the rest of the world the bulb is the thing that screws into a lamp. Such as a table lamp, lava lamp, etc. Like a theory, which has different meanings depending on whether you are a scientist or a normal person.
 
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