Photo Gallery

Mid-1990s Philips SDW-R 50W PAR20

Following the successful introduction of the PAR20 Halogena around 1993, Philips developed metal halide and white sodium variants of the compact lamp in order to get similar benefits, i.e., small size and efficient control of light, in highly efficient lamps. The main challenge in designing PAR20 HID light sources consisted in fitting a double-ended burner in the small lamp, a rather difficult task given the need for the HID arctube to be protected from ambient air. To that end the burner was sealed in a compact double-ended quartz jacket since PAR20 lamps do not have a gastight construction. Because the length of the jacketed HID source exceeded that of halogen capsule used in the original Halogena PAR20, the HID version had to be fitted with a protruding front window made via a glass-pressing method.

The SDW-R 50W PAR20 shown here is the result of such development. While the lamp has the same wattage as the Halogena variant, its sodium burner produces 3.8-times more light at a lower color temperature (2500 vs. 2900 K). Because of this lamp configuration, heat is not evacuated as effectively as in the standard SDW-T. So, in order to keep the burner temperature within tolerances, its quartz jacket is filled with nitrogen so as to dissipate heat via thermal conduction and convection processes. In this case there is no getter used in the lamp.

The SDW PAR20 concept was not developed into a commercial product because its protruding front glass precludes an effective control of the projected light beam. The Halogena PAR20 relies on a lenticulated front window to homogenize its beam pattern, something which was of course not possible with the SDW variant. However, the development of the compact single-ended ceramic metal halide lamp in the first half of the 1990s solved the capsule length problem and this enabled Philips to release a proper metal-halide PAR20 lamp with a lenticulated front glass in 1995. Such design was not applied to SDW lamps because of the longer sodium burner which still caused a geometrical mismatch with this particular lamp platform.


Keywords: Lamps

Mid-1990s Philips SDW-R 50W PAR20


Following the successful introduction of the PAR20 Halogena around 1993, Philips developed metal halide and white sodium variants of the compact lamp in order to get similar benefits, i.e., small size and efficient control of light, in highly efficient lamps. The main challenge in designing PAR20 HID light sources consisted in fitting a double-ended burner in the small lamp, a rather difficult task given the need for the HID arctube to be protected from ambient air. To that end the burner was sealed in a compact double-ended quartz jacket since PAR20 lamps do not have a gastight construction. Because the length of the jacketed HID source exceeded that of halogen capsule used in the original Halogena PAR20, the HID version had to be fitted with a protruding front window made via a glass-pressing method.

The SDW-R 50W PAR20 shown here is the result of such development. While the lamp has the same wattage as the Halogena variant, its sodium burner produces 3.8-times more light at a lower color temperature (2500 vs. 2900 K). Because of this lamp configuration, heat is not evacuated as effectively as in the standard SDW-T. So, in order to keep the burner temperature within tolerances, its quartz jacket is filled with nitrogen so as to dissipate heat via thermal conduction and convection processes. In this case there is no getter used in the lamp.

The SDW PAR20 concept was not developed into a commercial product because its protruding front glass precludes an effective control of the projected light beam. The Halogena PAR20 relies on a lenticulated front window to homogenize its beam pattern, something which was of course not possible with the SDW variant. However, the development of the compact single-ended ceramic metal halide lamp in the first half of the 1990s solved the capsule length problem and this enabled Philips to release a proper metal-halide PAR20 lamp with a lenticulated front glass in 1995. Such design was not applied to SDW lamps because of the longer sodium burner which still caused a geometrical mismatch with this particular lamp platform.

DSC00829.JPG Philips_SON-ST_150W_-_BE_1981.jpg Philips_SDW-R_50W_-_NL_m1990s.jpg Tungsram_HgMI_25021D_-_HU_1978.jpg Osram_HQI-TS_70W21WDL_Plus_-_DE_1994.jpg
Lamp/Fixture Information
Manufacturer:Philips
Model Reference:SDW-R 50W PAR20
Lamp
Lamp Type:White sodium
Filament/Radiator Type:Thermal discharge in xenon, mercury, and sodium vapors
File information
Filename:Philips_SDW-R_50W_-_NL_m1990s.jpg
Album name:Max / Thermal discharge lamps
Keywords:Lamps
Filesize:426 KiB
Date added:Aug 09, 2024
Dimensions:1200 x 763 pixels
Displayed:9 times
DateTime Original:2017:03:05 17:34:38
Exposure Time:1/18 sec
FNumber:f/8
File Source:Digital Still Camera
Flash:No Flash
Focal length:34.3 mm
ISO:400
Model:X-T1
Software:Adobe Photoshop CS5 Windows
White Balance:1
URL:https://trad-lighting.net/gallery/displayimage.php?pid=175
Favorites:Add to Favorites

Comment 1 to 5 of 5
Page: 1

Sammi   [Aug 09, 2024 at 08:05 PM]
Another gem for us to see. Bulb Man
Ria   [Aug 09, 2024 at 08:12 PM]
Fascinating; there are so many lamps that never made it into production, engineering samples are always good to find Bulb Man
Sammi   [Aug 09, 2024 at 11:20 PM]
And quite a few have found their way here.! Very Happy Bulb Man
Max   [Aug 10, 2024 at 01:28 PM]
There are many more to come for sure Smile
Sammi   [Aug 10, 2024 at 01:46 PM]
Ooh... Surprised

Comment 1 to 5 of 5
Page: 1