Lampholders for low-voltage halogen lamps

With the exception of the B15d bases, the low-voltage sector is dominated by pin bases, which are fitted with a variety of different pin distances and diameters. Apart from classic lampholders that ensure both the electrical contact and the correct positioning of the lamp, connection elements are also available. These components are solely responsible for establishing electrical contact and are used in cases where, for instance, the regulations demand that the lamp be attached to its reflector (e.g. cold-light reflector lamps with GZ4 and GX5.3 bases). Extremely high temperatures are also generated during the operation of low-voltage halogen lamps as a result of the tungsten-halogen cycle and the high lamp currents. In addition, the respective luminaires are often of very compact design, which leads to heat accumulation and thus high internal temperatures. The materials the lampholder is made of thus play a vital role for the luminaire´s operating safety and the lamp´s service life. In addition to tried-and-tested materials - ceramics for casings and mica for covers - ever more frequent use is being made of highly heat-resistant plastics like LCP [liquid crystal polymer], (e.g. G4, GU4, GX5.3, GU5.3 and GY6.35 lampholders) and PPS [polyphenylenesulphide] (G4 lampholders). Plastic lampholders provide clear advantages: narrow tolerances, no material fractures, low weight and clip-attachment options.

The type of contact also plays an important role. Conventional contacts are only attached to one side of the lamp pin. In contrast, additional contact points - known as multipoint contacts - lead to a reduction of current density at the point of transition from the lamp pins to the lampholder contact and with that to a decrease in temperature. These contacts provide the further advantage of ensuring superior heat dissipation from the lamp pins to the conductor, where it can be radiated. The temperature advantage of multipoint contacts in defined conditions (including welded-on conductors) can amount to as much as 100 °C. In extremely rare cases, due to the high internal pressure in the bulb, it is possible for the lamp to shatter. For reasons of fire prevention (high temperature of the glass bulb), the lamp´s components must be prevented from falling out. Enclosed luminaires meet these requirements. Open luminaires, however, may only be operated using lamps with enclosed bulbs or low-pressure lamps. Lamps of this kind are suitably marked with pictograms on the lamp´s packaging and in the lamp manufacturer´s documentation. Lamps marked with pictogram no. 1 are suitable for use with open luminaires, whereas those marked with pictogram no. 2 may only be used in enclosed luminaires.
Lampholders for low-voltage halogen lamps are equipped with mounted cables or with plug-type connectors. In addition to the various lampholders contained in the catalogue, further lampholder models with various cable lengths and of various qualities as well as lampholders with plugconnected cables can be made available on request.