Inrush current to the lamp

Each ballast unit requires higher current strength to guarantee normal start and inrush current to the lamp. Inrush current is the term used to describe the extra power level given to the lamp. The input current during stationary operation is lower than the starting current. After the lamp receives an ignition impulse from the starter motor and the arc is established, the ballast unit uses its operating voltage to provide the inrush current necessary to enable the lamp to remain lit. The lamp quickly increases intensity from a dull shine to a stable state with high-intensity light. Just a few seconds after the arc is established in the lamp, the majority of the stabilized state has been reached. Shortly thereafter, the stabilized state reaches 100 percent. A high power level is required to enable the lamp to reach a stabilized state in a short period of time. The high power level means that the lamp complies with SAE's specification regarding light versus time.