Patent ID: 8378585

Claim:
A method of controlling an oscillator of a high frequency ballast igniting and operating a metal halide lamp having an operating power, an operating current and an operating frequency comprising: receiving power from an alternating current (AC) power supply; converting the received power to direct current (DC) power wherein the converted DC power is provided to a controller of the ballast; initializing the controller of the ballast in response to receiving the DC power at the controller; energizing a power supply loop of the oscillator via the controller, the power supply loop including the converted DC power, wherein the oscillator generates AC power from the converted DC power and provides the generated AC power to the lamp at a first frequency less than the operating frequency of the lamp and wherein a current applied to the lamp is greater than the operating current; monitoring a power of the power supply loop of the oscillator; when the monitored power is greater than a power threshold which is greater than the operating power of the lamp, energizing the power supply loop such that the oscillator generates AC power from the converted DC power and provides the generated AC power to the lamp at a second frequency greater than the first frequency; and thereafter, energizing the power supply loop to operate the lamp at the operating power, the operating current and the operating frequency.