Author Topic: What filament (Read 12596 times)

debook · « **on:** November 17, 2003, 05:58:00 am »

Can anyone offer suggestions on the carbon filaments shown here from a c1900 German catalogue?
First is a spiral and the second two separate wavy filaments.

[This message has been edited by debook (edited November 17, 2003).]

[This message has been edited by debook (edited November 17, 2003).]

Chris W. Millinship · « **Reply #1 on:** November 17, 2003, 06:25:00 am »

The left-hand one looks like a variation of the Sterioptican filament, as seen on American heat/projector lamps like this one:

Used in conjunction with projector lenses like those in Magic Lanterns, to provide a tight, round, intense spot of light. Also used in theraputic heat lamps because the ~250 watt filaments put out a lot of heat.

Please excuse the poor images, they`re my old stock photos taken with a video camera a couple years ago. This lamp is currently in storage, otherwise I`d re-photograph it now.

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Visit the Bulb Museum!
e-mail: curator(at)bulbmuseum(dot)net.

debook · « **Reply #2 on:** November 17, 2003, 05:23:00 pm »

Thanks for that Chris. The filament in the engraving is also very thick and considering the high candlepower 32 NK 250V it seems very short. I presume NK is the German equivalent of CP?

As to the quality of your images! Very good considering it is a video camera.

Stan · « **Reply #3 on:** November 18, 2003, 06:42:00 am »

Hi, people,

I have also few bulbs with very interesting filaments. Stan
http://www.bulbcollector.com/photos/stan1.jpg
http://www.bulbcollector.com/photos/stan2.jpg
http://www.bulbcollector.com/photos/stan3.jpg
http://www.bulbcollector.com/photos/stan4.jpg

[This message has been edited by tim (edited November 18, 2003).]

Tim · « **Reply #4 on:** November 18, 2003, 09:38:00 am »

Regarding the illustration above in the first message, can anyone tell me what the numbers refer to that are etched on the bulbs? Notice the "29" & "41". I have several European bulbs with similar numbers etched on the glass. They don't seem like candle power or voltage ratings but maybe I'm wrong. Just curious...

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Tim
Kilokat's Antique Light Bulb Site
Mountain Dew Collectibles, Volume I

debook · « **Reply #5 on:** November 18, 2003, 09:48:00 am »

Tim,

The numbers in the etchings are merely part of the illustration and not etched on. However, I know the numbers you refer to and these are 'Series' or batch numbers. Some wrappers warn that if using lamps in series to ensure that they have the same series number.

Mónico González · « **Reply #6 on:** November 18, 2003, 12:43:00 pm »

I may add that the "NK" etching refers to "Neue Kerze" (New Candle) a flux unit that differs slightly from "HK" (Hefner candles) and IK (International Candle) and of course CP.
I have a conversion sheet in somewhere, so when I will find it, I will post the conversion ratio between all these luminous flux units.

Best regards,
M. Gonz?lez.
http://mis-bombillas.webcindario.com

debook · « **Reply #7 on:** November 18, 2003, 05:03:00 pm »

The comparison table will be interesting - look forward to it. It would be nice to know which countries used what units.

Meanwhile, I added another 21 images to the VVG catalogue pages today. 199 to go...

Including a bizarre sideways filament #99 and two more with the wavy filament #58 & #71

debook · « **Reply #8 on:** November 18, 2003, 05:06:00 pm »

Stan,

Do you have another angle of your third picture, I cannot see the filament well, do you know it's purpose?

Frank

Mónico González · « **Reply #9 on:** November 18, 2003, 07:04:00 pm »

Hi Frank
I've linked your great site from mine yet!
Thanks for have linked the mine from your too.

Also, your pictures are very nice and interesting Stan.

Best regards
M. Gonz?lez.

[This message has been edited by M?nico Gonz?lez (edited November 18, 2003).]

Stan · « **Reply #10 on:** November 22, 2003, 04:20:00 am »

Do you have another angle of your third picture, I cannot see the filament well, do you know it's purpose?

Frank[/B][/QUOTE]

Do you think picture with lamp number D 952? If yes, it is: NARVA 25.5650/56 1000W/110V. This lamp was used in capital (Praha) planetarium, in great Zeiss stellar projector. I found it and get from director perhaps 20-25 years ago. Sorry, I was not able find instantly the datas. The filament is spiralised in the same distance around central glass rod, that the light must be homogenous. Last picture with number D 1263 was made by GEC Ltd Osram England, 2250W/100V G38. Was made probably to lighthouse.

James · « **Reply #11 on:** November 27, 2003, 07:58:00 pm »

Hi Stan,

Your last lamp is the GEC Aero-Beacon lamp, was in production until about 1988. It mainly has military airfield applications. In later years the filament design was changed, and made use of two flat grid filaments. Looking down on them they were arranged at right angles to each other in a + shape, called the Cruciform filament. Its very popular for British lighthouse lamps, I'll post a photo of one later this week.

James.