HIGH-PRESSURE GASEOUS DISCHARGE LAMP INCLUDING A STARTING ELECTRODE

摘要

Ignition of the arc between the main electrodes of a high-pressure gaseous discharge lamp is achieved by placing an integral thermionic starting electrode adjacent one of the main electrodes and then concurrently heating the starting electrode and applying a low-voltage starting voltage to the starting electrode and the adjacent main electrode. After the resulting auxiliary arc has heated the adjacent main electrode, the operating voltage is applied across the main electrodes and the starting voltage is terminated, thus causing the arc to shift from the thermionic electrode to the other main electrode. The starting electrode is heated electrically by connecting it to an external power source through a pair of leads sealed through the lamp envelope.