So mercury-xenon short arc lamps have some use in industrial applications requiring such ultraviolet wavelengths. A ballast is required to limit the current flowing through the lamp and also to provide any necessary high voltage starting pulses. Some short arc lamps have only the two main electrodes. Others have a third electrode for applying the starting pulse. In most short arc lamp fixtures, current limiting is achieved with an inductor.
Some newer fixtures have electronic ballasts.
Since the voltage across the arc is typically low compared to the line voltage, an inductor ballast will allow nearly constant current to flow through the lamp even if the voltage across the arc changes due to aging or warmup. Some electronic ballasts provide more nearly constant power, and the lamp does not overheat as badly if the arc voltage rises due to aging electrodes. If the lamp has a starting electrode, the high voltage pulse may be obtained from simple, inexpensive circuitry. If a lamp with only two electrodes requires a high voltage pulse, then series triggering or pseusoseries triggering is required. In series triggering, the secondary of a transformer that generates the high voltage pulse is in series with the lamp.