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Osram Colorstar DSX-T 80W |
Combined with a dedicated electronic driver capable of delivering two distinct waveforms to the lamp, its dischage could be made to opeate in different modes resulting in a colour temperature of either 2600K or 3000K. The DSX lamp was targetted primarily at applications such as shop window illumination where the colour temperature could be switched between a warm incandescent style and whiter halogen-like appearances to suit the products on display.
The DSX lamp is based on mercury-free high pressure sodium technology. By increasing the xenon gas pressure to very high levels the volt drop it contributes to the discharge is capable of replacing the electrical role performed by mercury in a conventional lamp. Ignition becomes more difficult at such high xenon pressures, and starting is facilitated by a coiled tungsten wire alongside the arc tube combined with an ignition pulse of 4kV from its dedicated driver, unusually high for a sodium lamp. Elimination of mercury means that the sodium ratio in the arc tube is constant over time, and combined with precise control of lamp power by the electronic driver, this lamp is unique among high pressure discharge sources in that there is no colour shift as it ages. A special pre-focus cap is employed to permit accurate beam control from reflector optics in display lighting. The lamp was not a commercial success and was discontinued after a few years. The colour shift of only 400K was too small to make a major market impact.
| Manufacturer: | Osram GmbH | |
| Lamp Power: | 77 Watts | |
| Lamp Voltage: | 33 Volts | |
| Lamp Current: | 2.3 Amperes | |
| Cap Type: | PG12-3 | Nickel Plated Brass |
| Bulb Type: | T-32 | T-10 in eighths/inch |
| Bulb Finish: | Clear | Borosilicate |
| Electrodes: | Backwound Tungsten | |
| Arc Length: | mm | inches |
| Atmosphere: | Na Xe | Outer: Hard Vacuum |
| Luminous Flux: | 4,500lm @ 100h | |
| Luminous Efficacy: | 58.4lm/W @ 100h | |
| Colour Temperature & CRI: | CCT: 2600/3000K | CRI: Ra 85 |
| Chromaticity Co-ordinates: | CCx: | CCy: |
| Rated Lifetime: | 7,500 hrs | |
| Warm-up & Re-strike Time: | 50 seconds | 80 seconds |
| Burning Position: | Universal | |
| Overall Length: | 149 mm | 5 7/8 inches |
| Light Centre Length: | 91 mm | 3 9/16 inches |
| Factory: | Spandau, Berlin | Germany |
| Date of Manufacture: | June 1998 | q868 |
| Original / Present Value: | GB £55.76 (1994) | GB £82.60 (2009) |