I have a couple of light fittings which use reflector bulbs ,R40's I
think . I recall using a R50 in one of them years ago as that was all
I had and it didn't work . I know have another lamp which also takes
SES reflector bulbs and it won't work with the one bulb I have in the
house ....I gave the others away when I changed the kitchen light
recently . I do know the bulb works as I used it in a Lava Lamp and it
lights and it is a Philips Spotone 30 which Google tells me is an R50

Now what I want to know is what physical difference is there between
R40's and R50's that mean one works and one doesn't in these
fittings .Anyone know?
R40's seem not to be available now.

Usenet Nutter wrote:
I have a couple of light fittings which use reflector bulbs ,R40's I
think . I recall using a R50 in one of them years ago as that was all
I had and it didn't work . I know have another lamp which also takes
SES reflector bulbs and it won't work with the one bulb I have in the
house ....I gave the others away when I changed the kitchen light
recently . I do know the bulb works as I used it in a Lava Lamp and it
lights and it is a Philips Spotone 30 which Google tells me is an R50

Now what I want to know is what physical difference is there between
R40's and R50's that mean one works and one doesn't in these
fittings .Anyone know?
R40's seem not to be available now.

Well,

The R tells you it's a reflector lamp and the 40 tells you that the
diameter of the lamp is 40 eighths of an inch (i.e. 5"). Ditto R50,
except that the diameter is 6 1/4"

R40 tells you nothing about the voltage, wattage, beam angle, cap size
(ES, SES, etc), colour, frosting or anything else.

Assuming that the physical size of your R50 wasn't a problem, then
either your R50 was duff, or possibly, the fitting needed the tab for
the centre connection to the bulb to be cleaned or bent out a little.

HTH

On Sun, 08 Nov 2009 14:42:09 +0000, Dave Osborne
wrote:

Usenet Nutter wrote:
I have a couple of light fittings which use reflector bulbs ,R40's I
think . I recall using a R50 in one of them years ago as that was all
I had and it didn't work . I know have another lamp which also takes
SES reflector bulbs and it won't work with the one bulb I have in the
house ....I gave the others away when I changed the kitchen light
recently . I do know the bulb works as I used it in a Lava Lamp and it
lights and it is a Philips Spotone 30 which Google tells me is an R50

Now what I want to know is what physical difference is there between
R40's and R50's that mean one works and one doesn't in these
fittings .Anyone know?
R40's seem not to be available now.

Well,

The R tells you it's a reflector lamp and the 40 tells you that the
diameter of the lamp is 40 eighths of an inch (i.e. 5"). Ditto R50,
except that the diameter is 6 1/4"

R40 tells you nothing about the voltage, wattage, beam angle, cap size
(ES, SES, etc), colour, frosting or anything else.

Assuming that the physical size of your R50 wasn't a problem, then
either your R50 was duff, or possibly, the fitting needed the tab for
the centre connection to the bulb to be cleaned or bent out a little.

HTH

I think you mebbe got the first bit wrong ..or at least not correct
for what I have ....this one bulb have is 2" across the top which is
about 50mm This the Philips Spotone 30 which ,as I said ,Google says
is an R50 although I believe you do get similar lamps in much larger
sizes. This lamp does work as I said .It just doesn't work in the two
lights I have that takes this type of lamp( or mebbe only R40's)

HOWEVER

Your last suggestion was spoton ( or should that be Spotone) .It was
the contacts in the lampholders that were the problem ..a slight tweak
with a thin screwdriver and the job was done ...
thx very much Dave.:-)

Usenet Nutter wrote:
On Sun, 08 Nov 2009 14:42:09 +0000, Dave Osborne
wrote:

Usenet Nutter wrote:
I have a couple of light fittings which use reflector bulbs ,R40's I
think . I recall using a R50 in one of them years ago as that was all
I had and it didn't work . I know have another lamp which also takes
SES reflector bulbs and it won't work with the one bulb I have in the
house ....I gave the others away when I changed the kitchen light
recently . I do know the bulb works as I used it in a Lava Lamp and it
lights and it is a Philips Spotone 30 which Google tells me is an R50

Now what I want to know is what physical difference is there between
R40's and R50's that mean one works and one doesn't in these
fittings .Anyone know?
R40's seem not to be available now.
Well,

The R tells you it's a reflector lamp and the 40 tells you that the
diameter of the lamp is 40 eighths of an inch (i.e. 5"). Ditto R50,
except that the diameter is 6 1/4"

R40 tells you nothing about the voltage, wattage, beam angle, cap size
(ES, SES, etc), colour, frosting or anything else.

Assuming that the physical size of your R50 wasn't a problem, then
either your R50 was duff, or possibly, the fitting needed the tab for
the centre connection to the bulb to be cleaned or bent out a little.

HTH

I think you mebbe got the first bit wrong ..or at least not correct
for what I have ....this one bulb have is 2" across the top which is
about 50mm This the Philips Spotone 30 which ,as I said ,Google says
is an R50 although I believe you do get similar lamps in much larger
sizes. This lamp does work as I said .It just doesn't work in the two
lights I have that takes this type of lamp( or mebbe only R40's)

OK, the eighth-inch numbering system is conventional for some lamps
including R, RO, PAR, prefix, etc which are based on American patterns.

For others, the number is the nominal lamp diameter in mm. Sorry I
neglected to mention this.

I confess I didn't look up the Philips Spotone product which would have
brought the inconsistency to light.


HOWEVER

Your last suggestion was spoton ( or should that be Spotone) .It was
the contacts in the lampholders that were the problem ..a slight tweak
with a thin screwdriver and the job was done ...
thx very much Dave.:-)

Glad to be of service.