I'm confused as to the difference between GU10 bulbs and some GU5.3 bulbs I have.
They look the same and the specs in the screwfix catalogue are very similar.
Geoff Lane
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15 years ago
What are GU10 Bulbs
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- posted
15 years ago
Mains - plugs in a bit like a fluorescent lamp starter.
LV (12V usually) - two pins 5.3mm apart.
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- posted
15 years ago
Right, I thought I had seen some LV GU10s but obviously mistaken.
Are the pins then 10mm apart
That makes sense but how on earth did they arrive at 5.3mm, the pins hardly seem precision items and I'm sure 5 or 6mm would have fitted, maybe I am wrong.
Geoff Lane
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- posted
15 years ago
Sorry, I don't have any in the house to measure.
BTW, it's G5.3, not GU5.3
MR16 is exactly the same size and base as the earlier A1/259 250W projector lamp which had a G5.3 base. Probably invented by one of the projector manufacturers originally. I used to use them in a Bell and Howell 16mm projector, to show films in my university hall of residence every 2 weeks, many years ago.
G6.35 was another common one, which is more obvious in origin - 1/4".
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- posted
15 years ago
5.3mm is no more or less precise than 5.0 or 6.0
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- posted
15 years ago
The 16 in MR16 is lamp diameter in eights of an inch, so MR16 is a 2"
50mm lamp, MR11 is 11/8" 35mm.Guess imperial measures are to do with American National Standards Institute , ANSI setting most of the standards for lamps.
Adam
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- posted
15 years ago
Except one is quoting accuracy to a 1mm whereas the other is to 0.1mm
Geoff Lane
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15 years ago
Two different manufacturer's boxes each show GU5.3
Geoff Lane
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15 years ago
How is 5.3mm less accurate than 5.0mm in tolerance variations?
Adam
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- posted
15 years ago
Well, I may be wrong in my understanding but if something is quoted in
10ths of a millimeter scale then I would assume it to be more precise than something quoted in full millimeters.When I wondered about 5.3mm I was comparing it with 5mm or 6mm and not
5.0mm or 6.00mm which I would agree would be the same tolerance variation.Geoff Lane
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- posted
15 years ago
And if they are made by Osram, they will have an all-glass construction (no ceramic base) and be a complete pig to get out. What is likely to happen is that as you push them and attempt to twist, even using a suction cup or similar, the front facing piece of glass will detatch from the rest of the lamp, leaving sharp edges onto which you are already pushing hard with your fingers. Cue much blood and cursing.....
This happened (well not the blood as I had got wise to it) with 50% of the 28 that I removed in our new house...