High pressure discharge lamp apparatus

Abstract

In a high pressure discharge lamp apparatus comprising a discharge tube and a current limiting device connected in series, an over-current protecting semiconductor switching device such as a triac (TC) is further connected in series to said discharge tube, the triac (TC) being controlled of its firing angle responding to an output of a current detection circuit which detects a change of the lamp current through a change of the lamp voltage, and a pulse generator is further connected in parallel to the discharge tube and gives reignition pulse thereto at least during the zero-current period in each cycle of the lamp current.

Dependencies are inferred from the claim text.