Patent ID: 7064494

Claim:
A discharge lamp operating apparatus comprising: a DC power circuit portion for outputting a DC voltage; an inverter circuit including a switching element provided with a control terminal for converting an output form the DC power circuit portion to an AC voltage; a control terminal driving circuit for controlling the switching element provided with a control terminal to be on or off; and a resonant load circuit including a discharge lamp, a first inductor and a first capacitor, wherein the control terminal driving circuit comprises: a drive winding mutually coupled to the first inductor; a first series connection of a second inductor and a second capacitor; a second series connection of voltage clamp elements and an impedance element; a first parallel connection of the first series connection and the drive winding; and a second parallel connection of the second series connection and the second capacitor, and the control terminal driving circuit controls the switching element provided with a control terminal to be on or off by a voltage generated at the drive winding, wherein series connection of the clamp elements and the impedance element operably suppresses variations in the resonance frequency of the control terminal driving circuit.