Metal vapor discharge lamp

摘要

A metal vapor discharge lamp comprises main electrodes and an auxiliary electrode in an arc tube to initiate the discharge between the main electrode and the auxiliary electrode at the initiation of the operation and then to result the discharge between the main electrodes by disconnection of the auxiliary electrode by a bimetallic switch means. A second bimetallic switch means which delays the operation from that of the first bimetal, is connected in series to the first bimetallic switch means so as to discharge in a circuit formed in an outer bulb to break a part of the circuit and to prevent a ballast from overheating.