Patent ID: 7247998
Filing Date: 2007-07-24
Classification: H05B

Abstract:
1. An end-of-life sensor apparatus for an electronic ballast having a direct current power supply including a direct current choke, the direct current power supply coupled to an inverter adapted to power a luminous lamp, the sensor comprising: an end-of-life sensor directly connected to the direct current choke, and adapted to detect an end-of-life lamp condition and generate an end-of-life signal, the end-of-life sensor including a peak detection circuit and a repetitive pulse monitoring circuit, the peak detection circuit coupled to the direct current choke and adapted to detect changes in the voltage level across the direct current choke and generate peak pulses, the repetitive pulse monitoring circuit adapted to receive the peak pulses, detect an end-of-life lamp condition, and generate the end-of-life signal; and an inverter control circuit electrically adapted to receive the end-of life signal and coupled to the inverter, the inverter control circuit adapted to change the operation of the inverter when the end-of-life signal is received.