 |
The French manufacturer Compagnie des Lampes was one of the early pioneers in the development of metal halide lamps, but only ever made high power versions of 400W to 2000W. Metal halide technology becomes progressively more difficult to master at lower powers, and the company sourced in such products from Philips, with whom it had a technical affiliation for many years.
The Mazda MAI-series employs the same chemistry as GE's original metal halides, being dosed with the iodides of sodium, indium and thallium plus lithium as an impurity from the quartz. The influence from Philips is evidenced by the unusual neon-argon filled arc tubes, and neon-nitrogen filled outer envelopes, which facilitates ignition at lower voltages. An attempt to limit sodium loss by the photoelectric effect has been made by sleeving the arc tube support frame in heavy-walled quartz tubing.
Cdl-Mazda produced two different 2000W lamps - type 'A' having a short arc and being intended for use on a low voltage single phase supply. This type 'B' was was intended for use across the terminals of a 3-phase electricity supply, and has a long arc which offers improved system efficacy and lamp life. The arc tube has been fabricated from three pieces of quartz, and the outer bulb employs a zirconium-aluminium hydrogen getter. The cap employs a porcelain insulator to better withstand the high ignition voltages under humid outdoor conditions, but is of an old-fashioned and electrically unsafe design in which the cap shell is also electrified. Following Philips' 1982 takeover of CdL-Mazda, lamp was phased out and replaced by Philips' own equivalent version. |