Abstract: An electronic ballast for igniting and maintaining a discharge arc in a discharge tube of a ceramic metal halide lamp wherein a resistance of the discharge tube varies with a temperature of the discharge tube during operation. It is desirable to energize the discharge tube with a substantially constant value to prevent changes in color of the light emitted by the discharge tube that result from changes to the power applied to the discharge tube. The ballast includes ballast circuitry having an inverter circuit driving an LC tank network coupled to the discharge tube. The LC tank network applies a time varying voltage to the discharge tube wherein a peak-to-peak magnitude of the time varying voltage applied by the LC tank network is determined by a frequency of oscillation of the inverter circuit.