DISCHARGE LAMP LIGHTING DEVICE

PURPOSE: To prevent large stress from being applied to a device, regardless of power voltage, and provide a compact and inexpensive discharge lamp lighting device. CONSTITUTION: An AC power supply E feeds power to a discharge lamp La via a current limiting element L1, thereby lighting the lamp La. A series circuit made of an overcurrent detecting element CF1 to open upon the flow of overcurrent, and a temperature detecting element TF1 to open upon the rise of the over-temperature of the element L1 is provided between the power supply E and the element L1. Also, a diode D1 is connected to both ends of the element TF1 in parallel and overcurrent is supplied to the element CF1 prior to the occurrence of shortcircuit in the element TF1 after the opening thereof. The element CF1 is thereby opened. According to this construction, a device is protected against large stress, regardless of power voltage and at the same time, a compact and inexpensive discharge lamp lighting device can be provided.