New Philips miniature HF ballast
New Philips miniature HF ballast
Timed to coincide with the Hannover Light Fair launch of the European design competition for residential luminaires, Philips presented a new miniature electronic ballast that drives light sources up to 15 W. The ballast is very small and designed for residential luminaires.
The new Philips ballast appears to be a great step forward in residential lighting: Ballasts for residential luminaires offered on the market have been either too big, too expensive, or unavailable in lumen packages suited for use in homes (or under home-like conditions). There have been a few exceptions, such as an electronic ballast offered by the UK firm Triteco. (IAEEL Newsletter 4/94). However, the fact that one of the worldÕs largest lighting manufacturers is now moving into this market will hopefully stimulate interest in the technology among luminaire manufacturers and thus among ballast suppliers as well.
Philips has branded their new ballast Matchbox, in an apparent attempt to emphasize its compact size. The custom-built little "matchbox", (see photo). in which the ballast is placed in promotional materials, is actually slightly larger than a normal matchbox. Nevertheless, the ballast is very small and lightweight. The ballast comes in both a linear and a rectangular version. Both of these are offered with a plastic housing, but the ballast is also approved for use without housing. This gives luminaire manufacturers the freedom to design even more compact luminaires; however, for safety reasons, Philips cautions that such designs should be discussed with them first.
The rectangular version is only 70 mm long, 40 mm wide and 22 mm high (with the housing, including a bottom plate with screw mounts, it is 80 mm) The linear version is 132 mm long, 22 mm high, and 22 mm wide (144 mm long with bottom plate). Although referred to as a multi-lamp ballast, this does not necessarily mean that one ballast will power all fluorescent lamps up to 15 W. The low lamp-power version will drive both miniature linear and compact fluorescent lamps up to 8W, and the higher lamp-power version will drive lamps between 9 and 13 W. The multilamp function does, however, offer the end-user some freedom in selecting light output. Ballasts that drive only a single lamp type are generally regarded as a problem when designing luminaires for residential customers: Since most luminaires for dedicated fixtures offer only one lamp choice, the end-user has little freedom when it comes to selecting the light output level once the luminaire has been purchased.
Philips says that the ballast is not intended for applications with frequent switching. For an average switching frequency of three times per day, the ballast is rated at 25 000 hours. This is equivalent to a lifetime of about 10 years for luminaires that have long burning hours in homes. The ballast is approved for luminaires in outdoor settings. In cases where the light is on continuously during the dark hours, 25 000 hours would translate into a mean lifetime of only 6 years. However, in such cases switching is more infrequent, which should allow the ballast life to be extended beyond the rated 25 000 hours.
Although the power factor of the ballast is not great, it is typical for screw-based CFLs, varying between 0.53 and 0.63 depending on the lamp used with the ballast. Philips has not provided data on harmonics. (There is an ongoing debate as to whether harmonic distortion and a low power factor is a problem in residential lighting. Swedish field tests indicate that the typical power factor and harmonic distortion of CFLs is not a major problem, see IAEELNewsletter 3-4/97 and Right Light 4 Proceedings.
There is no information on pricing for OEMs, which will vary greatly anyway, depending on volumes and delivery conditions. However, Philips is promoting the ballast aggressively in conjunction with the European design competition, where the introduction of moderately priced luminaires is one of the goals. Thus, the ballast cannot be priced too high if it is to be used in large quantities by luminaire manufacturers.
Nils Borg