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SL*18 Compact Fluorescent with Integral Ballast |
The lamp consists of a 12mm fluorescent tube folded into three large U-bends to form four parallel sections, enclosing a wirewound magnetic ballast, and with a glowbottle starter and thermal fuse being integrated in the base. A prismatic glass jar refracts the light uniformly, and earned the SL its nickname as the jampot lamp - resembling the latter in both shape and weight! A crucial development that made this lamp feasible was the invention by Louis Vrenken of the rare earth phosphors having an aluminate host lattice, in place of the usual silicates or tungstates. These new materials slowed the rate of lumen depreciation, a degradation process that had always been very fast in tubes of such narrow diameter with traditional phosphors.
Compact fluorescent technology progressed a long way during the following four decades, but never achieved the low cost, convenience and simplicity of the incandescent lamp. Although the SL lamp featured here is technologically a great milestone, it is easy to see why it was slow to penetrate the market. Most notable is its great weight - owing to the conventional magnetic ballast inside, the mass of the lamp is more than half a kilogram and this was prone to make many table and standard lamps top heavy and unstable. The large dimensions precluded installation in some luminaires, the run-up time of three minutesproved unacceptable, and the light had a pronounced 50Hz flicker.
| Manufacturer: | NV Philips Gloeilampenfabrieken | |
| Lamp Power: | 18 Watts | |
| Lamp Current: | 0.180 Amps | |
| Lamp Voltage: | 220 Volts | |
| Cap Type: | E27s/27 | Ni plated brass + vitrite |
| Bulb Type: | T-72 | |
| Bulb Finish: | Prismatic Moulded | Soda-lime glass |
| Electrodes: | Triple coiled tungsten | Triple carbonate emitter |
| Atmosphere: | Inner: Ar|Hg Amalgam | Outer: Air |
| Luminous Flux: | 900 lumens | @ 100h hours |
| Luminous Efficacy: | 50.0 lm/W | @ 100h hours |
| Colour Temperature & CRI: | CCT: 2700K | CRI: Ra=80 |
| Chromaticity Co-ordinates: | CCx: 0.462 | CCy: 0.412 |
| Rated Lifetime: | 5,000 hours | to 70% survival |
| Warm-up & Re-strike time: | 3 minutes | Instant re-strike |
| Burning Position: | Universal | |
| Overall Length: | 168 mm | 65/8 inches |
| Light Centre Length: | ||
| Mass: | 560 grams | |
| Factory: | Terneuzen | The Netherlands |
| Date of Manufacture: | March 1982 | Date Code: C2 |
| Original Value: | GB £5.00 (1983) | |
