PL*S Twin-Tube Compact Fluorescent
The Philips PL*S family was the first line of compact fluorescent lamps designed for non-retrofit applications, the founding idea upon which virtually all present compact fluorescent lamps are based. It was developed simply as a compact alternative to miniature TL fluorescent lamps commonly found in domestic applications, for instance underneath cupboards and to illuminate small areas built into furniture.

But with the compact shape and integrated starter-switch it was hoped that a new generation of luminaires would be conceived around it, being small enough to break into the applications where previously, only a GLS incandescent lamp would have been suitable. The PL*S lamps deliver a similar light output and colour quality to that of GLS products, but on average last eight times longer and use only a quarter of the electricity. The ratings of 5W, 7W, 9W and 11W correspond roughly with the light output of 25W, 40W, 60W and 75W lamps. A 13W version is offered for the American market.

A simple push-fit G23 2-pin lamp cap is common throughout the range, and within the square plastic portion is housed a standard glow-bottle starter and radio interference supression capacitor. This is to simplify wiring of the luminaire to minimise its size and complexity, and also to ensure that a fresh starter is fitted with each lamp change.

The inclusion of the capacitor in parallel with the starter precludes these lamps from being operated on DC circuits, high frequency ballasts, or emergency lighting systems. For these applications, a starterless lamp employing a 4-pin cap was offered some years later.
Manufacturer: Philips Lighting
Lamp Power: 9 Watts
Lamp Current: 0.17 Amps
Lamp Voltage: 60 Volts
Cap Type: G23
Bulb Finish: Triphosphor 827 Colour 82
Bulb Type: T-13 T-12 in eighths/inch
Overall Length: 145 mm 5¾ inches
Width: 27 x 13 mm 1 1/16 x ½ inch
Discharge Length:
Electrodes: Triple Coil Tungsten Triple Carbonate Emitter
Atmosphere: Ar,Kr | Hg
Luminous Flux: 600 lm @ 100 hrs 540 lm @ 2000 hrs
Luminous Efficacy: 66.7 lm/W @ 100 hrs 60.0 lm/W @ 2000 hrs
Colour Temperature & CRI: CCT: 2700K CRI: Ra 81
Chromaticity Co-ordinates: CCx: 0.460 CCy: 0.414
Burning Position: Universal
Rated Lifetime: 8,000 hours Rated to 50% survival
Warm-up / Re-strike Time: 2 minutes Instant
Factory: Juarez Mexico
Date of Manufacture: August 1989 Date Code H9
Original / Present Value: £3.41 (1988) £6.12 (2005)
 
References: 1) Philips UK Lamp Catalogue 1989/90.
2) Philips UK Price List 1988.