Endura Electrodeless Induction Lamp

The Endura lamp pictured here was Osram's answer to the earlier QL product from Philips. Its technology was in fact developed by Sylvania, and inherited by Osram in 1993 when it bought the North American Sylvania business from GTE. In the USA and Canada where the Sylvania brand is retained, this same lamp is marketed as Sylvania Icetron.

The development engineers were keen to maintain as many of the advantages of the fluorescent lamp as possible in their creation, namely the long tubular shape which leads to high efficacy, better than is attainable with the Philips QL lamp whose discharge is too hot and too compact to allow maximum efficacy to be realised. Philips' design is however a much more compact lamp which makes luminaire design simpler and light extraction more efficient. Both lamps have their own advantages in different application areas.

Power is coupled into the Endura lamp via the primary windings of a transformer coil, split into two halves wired in parallel and with 18 turns around each ferrite core located at opposite ends of the lamp. The closed loop discharge tube forms the (single) secondary winding of the transformer, into which power is inductively coupled without electrodes.

For maximum efficacy it makes use of a wide-bore T17 tube (54mm diameter). Two amalgams are employed - the main amalgam residing in the long tip-off, and a run-up amalgam being located in the core of the discharge tube on a small stalk to provide fast warm-up. Because the main amalgam is located outside the lamp its temperature can be adjusted - a small 1W heater for instance keeps the mercury vaporised and provides instant light in cold environments.
Manufacturer: Osram Sylvania Inc.
Lamp Power: 100 Watts
System Current: 0.48 Amps
System Voltage: 180 to 264 Volts
Operating Frequency: 250 Kilohertz
Cap: Special 3-pin plug
Bulb Finish: Lumilux 830 Triphosphor
Bulb Type: TR-54
Dimensions: 313mm x 139mm x 72mm
Electrodes: None
Atmosphere: Krypton 0.2 torr
Luminous Flux: 8,000 lm (100 hours) 5,600 lm (60,000 hours)
Luminous Efficacy: 80 lm/W (100 hours) 56 lm/W (60,000 hours)
Colour Temperature & CRI: CCT: 3000K CRI: Ra 80+
Chromaticity Co-ordinates: CCx: CCy:
Burning Position: Any except with amalgam tip-off at highest point
Rated Life: 60,000 hours (to 70% lumens, limited by ballast life)
Warm Up / Re-strike Time: 30 secs to 90% lumens Instantaneous
Factory: Drummondville, Canada
Date of Manufacture: May 2002
Original / Present Value:
References: 1) Osram Endura Technical Handbook, September 2001.
2) Osram Lichtprogramm 2002/2003.