On Thursday, October 18, 2012 2:33:22 PM UTC+1, Andrew Gabriel wrote:
In article ,

Fred writes:

On Mon, 15 Oct 2012 12:33:46 +0000 (UTC),

(Andrew Gabriel) wrote:



The shape is a standard equi-thermal bulb (the shape you end

up with if you want the bulb to be similar temperature all

around the enclosed short arc tube, ignoring convection heating).



I used to be interested in different shaped light bulbs when I was

young. It's a shame I lost interest as I grew up. It must be an

interesting industry to work in.



I've never seen a BC high pressure sodium lamp, or BC on any

equi-thermal bulb, because a BC lampholder can only support

that weight and size of lamp when hanging cap-up. It was used

for some early mercury vapour lamps with more conventional

(GLS/pear-shaped) lamps, for use in cap-up fittings, including

self-ballasted ones with internal filament ballasts, but yours

has an external ballast (and no external ignitor, at least, you

didn't mention one).



I have had a closer look. There is something printed on the bulb but

all I can make out is "Phillips"; the rest is too faded to see. It

seems it is not a BC cap but actually has pins at right angles, a bit

like a car brake light. I've taken a photo for you to see. You may be

able to see a little of what is inside the glass, if that helps

identify it?



It's an obsolete mercury vapour lamp, probably 80W or 125W.

They were retro-fitted into filament lamp luminares in the 1950's

and 1960's. They came in two types, standard BC which is a direct

plug-in replacement for the filament lamp, as the lamp has a

built-in ballast in the form of a tungsten filament, and the

separately ballasted type you have there which required the

lampholder to be changed, to prevent the two types of lamp

getting mixed up (your one would explode if plugged into a

streetlamp with no ballast fitted).



As for an ignitor, I have no idea what one of those is so I don't know

if it has one. There seems to be a patch on the "ballast", if I am



Mercury vapour lamps don't need an ignitor.

(If it was high pressure sodium, it would have, some smaller

lamps have it inside the bulb, or it can be external).



using that word correctly, as if a label used to be there but it is

long gone, so I can't tell you more I'm afraid.



The capacitor label, not the best photo, sorry, says it includes a

resistor and a fuse.



The lamp:

http://tinypic.com/r/2ni0h1k/6

"luminare" actually (or sometimes lantern in the context of street lighting).

That looks like a 1950's one. There are streetlighting forums where

a collector would be able to tell you the make and model from your

picture.



The bulb:

http://tinypic.com/r/2qbgl6s/6

More properly called the "lamp", although the "bulb" is the outer glass

envelope of the "lamp".



and

http://tinypic.com/r/w9ean7/6



ballast:

http://tinypic.com/r/p9mhh/6



capacitor:

http://tinypic.com/r/ieqyyc/6

I can only read 0.0MFD, which doesn't make sense.

Datasheet values I have are 8MFD for 80W, and 13MFD for 125W, but

the capacitor value doesn't matter at all for correct operation,

only for power factor correction of the supply current drawn.



I don't know if any of those help at all?



Thanks.

ebay calls


NT