Discharge lamp lighting device, and lighting equipment and lighting system using the device

Abstract

A level shift IC () of a power supply/shutoff section () is operable, when a shutoff signal (Sa) is input from a timer circuit () for a time T during an ON state of a discharge lamp (), to turn off a MOSFET () so as to shut off power supply to a smoothing capacitor (). When a detection signal (Sb) of a capacitor voltage is lowered to a value less than a reference voltage Vrduring input of the shutoff signal (Sa), an output of a comparator () is changed from an H level to an L level in an inverted manner. In conjunction with this change, respective outputs of an auxiliary control circuit () and a NOT element (,) are changed from an L level to an H level in an inverted manner. As a result, a current flows from the NOT element () to an LED () through a resistor () to turn on the LED (). Thus, a life end of the smoothing capacitoris annunciated, and a main control circuit () is operable to suppress an output of an inverter main circuit ().