Patent ID: 8698428
Filing Date: 2014-04-15
Classification: H05B

Abstract:
1. A ballast comprising: a rectifier to receive an alternating current (AC) voltage signal and produce a rectified voltage signal therefrom; a power factor correction circuit to receive the rectified voltage signal and provide a corrected voltage signal; an inverter circuit to receive the corrected voltage signal and provide an energizing signal that powers a first lamp and a second lamp; a first circuit to selectively reduce the current applied to the first lamp and the second lamp by the energizing signal; a second circuit to selectively prevent the second lamp from being energized by the energizing signal; and a control circuit to control the first circuit to selectively reduce current applied to the first lamp and the second lamp, and to control the second circuit to selectively prevent the energizing of the second lamp; wherein the first circuit comprises a capacitive device connected in series with the first lamp and a short circuit selectively connected in parallel with the capacitive device, and wherein the second circuit comprises a short circuit selectively connected in parallel with the second lamp.