Metal vapour discharge lamp.

摘要

A metal vapour discharge lamp, a starter connected in parallel a discharge tube (11), combines a coiled non-fusible metal wire (12) which is wound on or laid along the outer wall of the discharge tube (11) and a non-linear capacitor (15) which is series connected to the non-fusible metal wire (12). As a result the discharge lamp can be assuredly and stably lit wth a small size ballast. Furthermore, passage of large current through the starter can be prevented even if the incandescent tube leaks. Furthermore, if the evacuated outer envelope (16) leaks or is broken, the circuit of the starter can be opened in that the non-fusible metal wire (12), which is heated by the discharge tube (11) oxidises and thereby becomes incandescent and breaks.