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

In article ,
Geoff Lane writes:
I'm confused as to the difference between GU10 bulbs

Mains - plugs in a bit like a fluorescent lamp starter.

and some GU5.3 bulbs I have.

LV (12V usually) - two pins 5.3mm apart.

They look the same and the specs in the screwfix catalogue are very similar.

Geoff Lane

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Andrew Gabriel wrote:

I'm confused as to the difference between GU10 bulbs

Mains - plugs in a bit like a fluorescent lamp starter.

Right, I thought I had seen some LV GU10s but obviously mistaken.

Are the pins then 10mm apart

and some GU5.3 bulbs I have.

LV (12V usually) - two pins 5.3mm 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

In article ,
Geoff Lane writes:
Andrew Gabriel wrote:

I'm confused as to the difference between GU10 bulbs

Mains - plugs in a bit like a fluorescent lamp starter.

Right, I thought I had seen some LV GU10s but obviously mistaken.

Are the pins then 10mm apart

Sorry, I don't have any in the house to measure.

and some GU5.3 bulbs I have.

BTW, it's G5.3, not GU5.3

LV (12V usually) - two pins 5.3mm 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.

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".

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Geoff Lane wrote:
Andrew Gabriel wrote:

I'm confused as to the difference between GU10 bulbs

Mains - plugs in a bit like a fluorescent lamp starter.

Right, I thought I had seen some LV GU10s but obviously mistaken.

Are the pins then 10mm apart

and some GU5.3 bulbs I have.

LV (12V usually) - two pins 5.3mm 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.

5.3mm is no more or less precise than 5.0 or 6.0

On 3 Feb, 22:41, (Andrew Gabriel) wrote:
In article ,
* * * * Geoff Lane writes:

Andrew Gabriel wrote:

I'm confused as to the difference between GU10 bulbs

Mains - plugs in a bit like a fluorescent lamp starter.

Right, I thought I had seen some LV GU10s but obviously mistaken.

Are the pins then 10mm apart

Sorry, I don't have any in the house to measure.

and some GU5.3 bulbs I have.

BTW, it's G5.3, not GU5.3

LV (12V usually) - two pins 5.3mm 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.

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".

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

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

Jason wrote:

5.3mm is no more or less precise than 5.0 or 6.0

Except one is quoting accuracy to a 1mm whereas the other is to 0.1mm

Geoff Lane

Andrew Gabriel wrote:

BTW, it's G5.3, not GU5.3

Two different manufacturer's boxes each show GU5.3

Geoff Lane

"Geoff Lane" wrote in message
...
Jason wrote:

5.3mm is no more or less precise than 5.0 or 6.0

Except one is quoting accuracy to a 1mm whereas the other is to 0.1mm

Geoff Lane

How is 5.3mm less accurate than 5.0mm in tolerance variations?

Adam

ARWadsworth wrote:

How is 5.3mm less accurate than 5.0mm in tolerance variations?

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

Andrew Gabriel wrote:
In article ,
Geoff Lane writes:
I'm confused as to the difference between GU10 bulbs

Mains - plugs in a bit like a fluorescent lamp starter.


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...