Discharge lamp arrangement esp. for motor vehicle headlamp - includes relay circuit for both main-beam and dipped headlamps, safeguarding supply circuit against unloaded operation

摘要

A combination of connection terminals (CN1, CN2) and signal lines (SG1, SG2) provides a check on whether or not the cables (CB1, CB2) feeding the electrodes of the two discharge lamps (HV1, HV2) are connected to the power supply circuit (10). The control circuits (11, 13) of the dipped and main-beam lamps respectively are activated to switch off the power using a two-contact relay (Ry) if the check finds the headlamp cable connection to be broken or irregular. ADVANTAGE - Damage by overvoltage to power supply circuit in absence of any connection to lamp cables is prevented.