Ballast for a discharge lamp used in motor vehicle headlamps

摘要

The discharge lamp (L) ballast has a control (20) which defines a short detection period after excitation of the lamp, a lamp life detector (30) which detects the end of the life of the lamp, sending a signal when the lamp extinguishes during during the detection period. A supervisor (40) emits an activation signal after the detection period is finished to ensure the lamp is activated.