QL Electrodeless Induction Lamp System

Launched in 1991 to coincide with the 100th Anniversary of the company, Philips' QL was the worlds first commercial induction lighting system.  It offers an exceptionally long service lifetime of 100,000 hours owing to the fact that no filament or electrodes are used in the design.  The QL system is comprised of three principal elements; the light generating discharge vessel, an antenna to couple power into the lamp, and an HF generator to drive the antenna.

The discharge vessel consists of a hollow soft glass bulb, containing a tubular re-entrant portion at the centre such that the antenna can be inserted into the lamp but is not in contact with the lamp's internal atmosphere.  The re-entrant is coated with an electron emissive material, while the inside of the bulb is coated with a triphosphor fluorescent powder and anti-blackening agents.  A thin electrically conductive coating on the outer surface serves as a shield to prevent radiation of HF signals outside the bulb.  The internal atmosphere is a neon-argon mixture and because of the high operating temperature, special amalgams are necessary.  One is attached to the re-entrant, while the other resides in one of the two exhaust tubes in the base.

The antenna consists of a short coil of stranded wire built up around a plastic-sheathed metal heat pipe, a component having an exceptionally high thermal conductivity.  The lower end of this is terminated in a metal plate which must be attached to a heat sink in the luminaire.  Good thermal contact at this point is crucial to ensure that the discharge vessel operates at a low temperature to keep the light generation efficiency high.  The antenna is driven by an HF generator at 2.65MHz for good coupling efficiency.
Manufacturer: Philips Lighting
Lamp Power: 85 Watts
Supply Current: 0.345 Amps
Supply Voltage: 180-265 Volts
Operating Frequency: 2.65 Megahertz
Cap: Special click-fit
Bulb Finish: Colour 840 Phosphor Soda-Lime
Bulb Type: P-110
Overall Length: 180.5 mm
Mass: 200 grams
Atmosphere: Ar-Kr-Ne | Hg-amalgam
Luminous Flux: 6,000 lm @ 100 hours 4,200 lm @ 60,000 hrs
Luminous Efficacy: 71 lm/W @ 100 hours 49 lm/W @ 12,000 hrs
Colour Temperature & CRI: CCT: 4000K CRI: Ra 80+
Chromaticity Co-ordinates: CCx: 0.390 CCy: 0.390
Burning Position: Universal
Rated Life: 100,000 hours (to 50% lumen depreciation)
Warm Up / Re-strike Time: 30 seconds Instantaneous
Factory: Turnhout, Belgium
Date of Manufacture: April 1992
Original / Present Value:
References: 1) Philips Lamp Catalogue 2001/2002.