According to the disclosed embodiment of the invention, a circuit and
method for stabilizing an operating characteristic of a compact
fluorescent lamp driven by a ballast circuit having an operating
frequency controlled by a component value, may comprise a first circuit
connected to said ballast circuit for applying the component value
thereto; and a second circuit connected to the ballast circuit for
changing the component value so as to stabilize the operating
characteristic. The operating characteristic may be power, current,
voltage or crest factor for example. The second circuit changes the
component value in response to a bus voltage of the ballast circuit and
includes a switching device such as a transistor responsive to the bus
voltage. In the disclosed embodiment the component value is a resistance,
the first circuit comprises a first resistor, the second circuit
comprises a second resistor, and the switching device selectively
connects the second resistor to said ballast circuit in response to the
bus voltage exceeding a predetermined threshold.