Light module for a motor vehicle headlamp and method and electrical circuit for operating same

摘要

A method operates a light source of a motor-vehicle headlight with direct current. The light source is actually designed for operation with alternating current. The light source comprises an inductive load and is arranged between bridge sections of an electrical H-bridge circuit having four semiconductor switches. During “alternating current” operation, the light source is supplied with the alternating current via the H-bridge circuit. Two of the semiconductor switches are arranged at a top and actuated via a respective bootstrap circuit.

主权项

1. A method for operating a light source of a motor-vehicle headlamp using direct current, wherein the light source was originally provided to be operated with alternating current, includes an inductive load, is arranged between branches of an electric H-bridge circuit with two high-side and two low-side closed semiconductor switches, and is applied with the alternating current in alternating current operation via the H-bridge circuit and each of the high-side switches arranged on top is controlled via a bootstrap circuit with a respective bootstrap capacitor, the method comprising steps of:
in direct current operation, periodically and temporarily disconnecting at least one of the switches for a recharging process; reconnecting the at least one of the switches at an end of the recharging process; and concluding the recharging process before current flowing via a branch of the H-bridge circuit reaches a value of about zero amps.