Switch on otherwise there will be a bangBallasts are used in the operation of gas discharge lamps to reduce the discharge current which, if it rises unchecked, destroys the lamp used or causes the fuse to trip. As with energy-saving lamps, a ballast can be integrated into the lamp or added to the luminaire as an additional element. Only in the case of the integrated version is it possible to connect the lamp directly to the mains supply.
In general, there are two different types of ballasts: electronic ballasts and magnetic ballasts. In contrast to electronic ballasts, magnetic ballasts require a so-called starter. Depending on the losses caused by this starter, magnetic ballasts are divided into conventional ballasts, low-loss ballasts or ultra-low-loss ballasts.
Magnetic ballasts, which are constructed as conventional ballasts, consist of a choke, which usually contains an iron core wound with copper wire. Due to the ohmic resistance of the copper as well as the remagnetization and eddy current losses in the core, heat development and power losses of around ten to twenty percent of the lamp output occur. Conventional ballasts used in fluorescent lamps also require a starter. This starter switches the incandescent cathodes directly into the electric circuit when they are started for preheating. Conventional ballasts are very reliable. They usually function for decades without malfunctions and without having to be replaced.