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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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Auer |
50CP |
| 'Osram' lamp with sintered metal filament |
| ~1908-10 |
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Pintsch |
25CP |
| 'Sirius' lamp with colloidal filament |
| ~1908-09 |
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Graetzin |
16CP |
| Sintered Tungsten with pasted filaments |
| ~1908-10 |
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Henrion |
16CP |
| 'Osmine' French Sintered Metal Filament |
| ~1909-10 |
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Osram |
25B |
| French Osram sintered tungsten lamp |
| ~1909-12 |
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Osram-GEC |
17W |
| GEC British Sintered tungsten filament |
| 1908 |
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Osram-GEC |
17W |
| German Auer lamp made for British GEC |
| 1910 |
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Ediswan |
17W |
| Royal Ediswan Tubular Sintered Tungsten |
| 1908 |
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GE |
40W |
| GE American Sintered Tungsten Filament |
| 1909 |
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Sunbeam |
100W |
| National Mazda Sintered Tungsten Filament |
| 1909 |
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Pope |
8 CP |
| Miniature low voltage sintered tungsten |
| ~1908-12 |
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| | Drawn Tungsten Filament |
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GE-National |
40W |
| Crinkled Filament and Eldred Glass-Metal Seals |
| 1912 |
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GE-Edison |
40W |
| Pasted Filament Clamps & Dumet Seals |
| c.1915 |
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GEC |
40W |
| Osram Drawn Tungsten "Angle" Type |
| 1911 |
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S.F. Auer |
30CP |
| O.R. Omnidirectional Radiation Spiral Filament |
| ~1910-15 |
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| | Coiled Tungsten Filament |
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GE-Edison |
500W |
| Mazda 'C' Early Style 500W Gasfilled |
| 1915 |
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Philips |
100W |
| Tungsten Gasfilled HalfWatt |
| 1919 |
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GEC |
60W |
| First Coiled-Coil Tungsten Filament GLS |
| 1934 |
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GEC |
100W |
| Swan Centenary GLS with Single Support Wire |
| 1979 |
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GEC |
100W |
| Experimental GLS with Plastic Cap |
| c.1980 |
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GE |
150W |
| Rough Service with Tuff-Skin coating |
| 1979 |
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| | Infrared Recylcing Coating |
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Duro-Test |
65W |
| Tungsten Gasfilled with IRC Coating |
| c. 1980 |
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