| 摘要 |
A ballast circuit for a gas discharge lamp includes a d.c.-to-a.c. converter circuit with circuitry for coupling to a load circuit, for inducing a.c. current therein. The converter circuit comprises a pair of switches serially connected between a bus conductor at a d.c. voltage and a reference conductor. The voltage between a reference node and a control node of each switch determines the conduction state of the associated switch. The respective reference nodes of the switches are connected together at a common node through which the a.c. current flows, and the respective control nodes of the switches are connected together. The load circuit has circuitry for connecting to a gas discharge lamp and comprises a piezoelectric transformer having a body and including a reference lead connected to one of the bus and reference conductors, an input lead coupled to the common node, and an output lead connected to the lamp. A circuit is provided for coupling to the control nodes a feedback signal representing current in the load circuit, for facilitating self-regenerative control of the switches.
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