Patent ID: 7432660
Filing Date: 2008-10-07
Classification: H05B,Y02B

Abstract:
1. An electronic ballast for igniting and powering at least one gas discharge lamp, said electronic ballast comprising: an AC/DC converter circuit for receiving an AC voltage and converting said AC voltage into a DC voltage; an integrated circuit for controlling said ballast; an inverter circuit for receiving said DC power and producing an output AC voltage; end of lamp life circuitry for detecting a positive or negative DC rectification current exceeding a predetermined threshold being produced by an installed gas discharge lamp and turning off said integrated circuit if such predetermined threshold is exceeded; a multiple striking circuit for performing a predetermined number of striking attempts to ignite an installed lamp; re-ignition circuitry connected to the inverter circuit for automatically attempting to ignite a new lamp that has been installed in said ballasts; and wherein said end of lamp life circuitry further detects excess symmetric lamp voltages and shuts down said integrated circuit if such excess symmetric lamp voltages are detected for more than a predetermined amount of time.