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Difference between revisions of "Philips Master TL-D 90 Graphica"
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Philips Master TL-D 90 Graphica (view source)
Revision as of 00:38, 9 October 2021
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== History == | == History == | ||
Flourescent lamps were an evolution of clear mercury vapour lamps. Development followed two avenues to increase efficiency, low pressure mercury vapour discharge and high pressure mercury discharge. High pressure mercury discharge created more useful light but the same deficit of no red and orange light was present so the light was still unsatisfactory. Low pressure mercury discharge is very efficient but not in outputting visible light, it is on UV-light emission. This UV-light is useless if it cannot be converted to visible light. | |||
Flourescent powders were developed to convert UV-light into visible light. Some of these powders were capable of emitting light at some wavelengths, making specific colours to be cast around but they had to be quite ressistant to UV-light and efficient. This meant that some time passed until the advent of halophosphate based colours that made possible the first daylight T12 flourescent lamps, around late 1930s. This was a major achievement as such lamps had the capability of directly competing with incandescent lamps and offer better efficiency and longer life. | |||
Subsequent developments improved lamp life and created a wide variety of flourescent powders that cast white light with different colour appearances from warm and neutral to cold and daylight. Higher and lower power lamps were created and standardization established. The preferred lamp gear turned from incandescent ballasting or mixed light to magnetic or reactive ballasts, which improved system efficiency. In the late 1970s, following requirements for higher energy efficiency due to the world oil crisis of 1973, there were major advances in technology. | |||
The advent of high efficiency tri-band or tri-phosphorous lamps was the most important landmark. Successful development of flourescent powders that had peak UV to visible light conversion at blue, red, and green colours with peaks near the ideal wavelengths made it possible to release lamps with specific colour appearances. This high energy in light conversion was complemented by changes in the lamps gas's fill from argon to Krypton, reducing thermal losses with a slight increase in operating voltage and starting voltage. This was the market releases of the the highly successful T8 lamp, or TL-D lamp that dominated since the early 90s. Of course, up until this time there were improvements in cathodes design and electron emmissive coatings as well as other performance enhancing solutions but the release of the TL-D lamp was the most important moment. | |||
Production of specialist lamps started in the 1950s with coloured lamps but also expanded to include De Luxe and specific lamps that would cater for many purposes. De Luxe lamps were an improvement of standard lamps in terms of colour reproction but was less efficient and had shorter service life due to coatings that were less stable in time than standard lamps. The advent of the tri-band TL-D flourescent lamp opened up the possibility of using part of its development to release new De Luxe lamps by combining such phosphorus coatings with previously developed ones. The result was a more stable, higher efficiency De Luxe lamp. Graphica lamps were a slight adaptation of previously developed phosphorus to TL-D lamps and their gas's fill and some experimentation in improving other aspects of operation to achieve better performance. | |||
== Manufacturing specificities == | == Manufacturing specificities == | ||