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Incandescent - Tungsten Filament
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Updated 19-X-2021 |
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Although the tungsten filament lamp offered a higher efficacy than its tantalum predecessor from the outset, it was not able to immediately replace the former filament material. This was owing to the very brittle nature of the original tungsten filaments - which were made from powdered tungsten particles sintered together to produce a fine wire. The difficult manufacturing process led to high costs and filament breakages in service were commonplace.
The problem was not overcome until the 1910 development of drawn-tungsten wire, this ductile material being much more robust and eminently more suitable for lampmaking. From this point onwards, practically all of the former filament materials were abandoned.
A third development in tungsten lamps was the important change from vacuum to gas-filled designs, and the parallel change from straight wire to coiled filaments. This gave a further significant boost in lamp efficacy combined with a reduction in costs. Lamps of all three tungsten technologies are featured on this page. |
| | Squirted & Sintered Tungsten Filament |
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![](Images/IN Thumbnails/t IN WS Osram 225-50G90CL-E27.jpg) |
Auer |
50CP |
'Osram' lamp with sintered metal filament |
~1908-10 |
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![](Images/IN Thumbnails/t IN WS Pintsch 125-25S55CL-E27.jpg) |
Pintsch |
25CP |
'Sirius' lamp with colloidal filament |
~1908-09 |
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![](Images/IN Thumbnails/t IN WS Graetzin 25-18SA55CL-B22d.jpg) |
Graetzin |
16CP |
Sintered Tungsten with pasted filaments |
~1908-10 |
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![](Images/IN Thumbnails/t IN WS Osmine 110-16SA55CL-B22.jpg) |
Henrion |
16CP |
'Osmine' French Sintered Metal Filament |
~1909-10 |
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![](Images/IN Thumbnails/t IN WS Osram 125-25S60CL-B22d.jpg) |
Osram |
25B |
French Osram sintered tungsten lamp |
~1909-12 |
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![](Images/IN Thumbnails/t IN WS GEC 50-17G75CL-B22d.jpg) |
Osram-GEC |
17W |
GEC British Sintered tungsten filament |
1908 |
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![](Images/IN Thumbnails/t IN WS GEC 100-17SA55CL-B22d.jpg) |
Osram-GEC |
17W |
German Auer lamp made for British GEC |
1910 |
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![](Images/IN Thumbnails/t IN WS Ediswan 105-17T25CL-B15d.jpg) |
Ediswan |
17W |
Royal Ediswan Tubular Sintered Tungsten |
1908 |
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![](Images/IN Thumbnails/t IN WS GE 117-40SA19FC-E26.jpg) |
GE |
40W |
GE American Sintered Tungsten Filament |
1909 |
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![](Images/IN Thumbnails/t IN WS National-Sunbeam 110-100S30CL-E26.jpg) |
Sunbeam |
100W |
National Mazda Sintered Tungsten Filament |
1909 |
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![](Images/IN Thumbnails/t IN WS Pope 4-8G35CL-B15d.jpg) |
Pope |
8 CP |
Miniature low voltage sintered tungsten |
~1908-12 |
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| | Drawn Tungsten Filament |
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![](Images/IN Thumbnails/t IN WD National-Columbia 108-40S67CL-E27 Crinkled.jpg) |
GE-National |
40W |
Crinkled Filament and Eldred Glass-Metal Seals |
1912 |
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![](Images/IN Thumbnails/t IN WD GE 110-40S18-E26 Pasted Clamps.jpg) |
GE-Edison |
40W |
Pasted Filament Clamps & Dumet Seals |
c.1915 |
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![](Images/IN Thumbnails/t IN W GEC 240-40SA62CL-BC-S1.jpg) |
GEC |
40W |
Osram Drawn Tungsten "Angle" Type |
1911 |
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![](Images/IN Thumbnails/t IN WD Auer OR 30K 115V.jpg) |
S.F. Auer |
30CP |
O.R. Omnidirectional Radiation Spiral Filament |
~1910-15 |
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| | Coiled Tungsten Filament |
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![](Images/IN Thumbnails/t IN WC GE 112-500SA40CL-E39.jpg) |
GE-Edison |
500W |
Mazda 'C' Early Style 500W Gasfilled |
1915 |
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![](Images/IN Thumbnails/t IN WC Philips Halfwatt 100W.jpg) |
Philips |
100W |
Tungsten Gasfilled HalfWatt |
1919 |
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![](Images/IN Thumbnails/t IN WC GEC 240-60PS65CL-B22d CC.jpg) |
GEC |
60W |
First Coiled-Coil Tungsten Filament GLS |
1934 |
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![](Images/IN Thumbnails/t IN WC GEC 240-100PS60CL-BC Single Support.jpg) |
GEC |
100W |
Swan Centenary GLS with Single Support Wire |
1979 |
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![](Images/IN Thumbnails/t IN WC GEC 240-100PS60FR-BC Plastic.jpg) |
GEC |
100W |
Experimental GLS with Plastic Cap |
c.1980 |
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![](Images/IN Thumbnails/t IN WC GE 120-150A25TS-E26.jpg) |
GE |
150W |
Rough Service with Tuff-Skin coating |
1979 |
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| | Infrared Recylcing Coating |
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![](Images/IN Thumbnails/t IN WC DuroTest 120-65G30IRC-E26.jpg) |
Duro-Test |
65W |
Tungsten Gasfilled with IRC Coating |
c. 1980 |
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