An inverter circuit for ballasting a gas discharge lamp having a delay
circuit designed to delay regenerative control of the inverter switches
until a d.c. bus has attained steady-state operating d.c. voltage. The
inverter circuit includes a drive control circuit for inducing an a.c.
load current. The inverter circuit includes first and second complementary
switches serially connected between the bus and a reference bus. The
switches are connected together at a common node through which the a.c.
load current flows. A driving inductor is connected at one end to the
common node and operatively connected at the remaining end to a control
node. A load circuit includes a resonant inductor connected at one end to
the common node, with the resonant inductor mutually coupled to the
driving inductor. A resonant capacitor is serially connected between the
remaining end of the resonant inductor and the reference bus. The gas
discharge lamp is serially connected with a d.c. blocking capacitor across
the resonant capacitor. A delay circuit, comprising a serially connected
resistor and capacitor is connected across the drive control circuit.
