Patent ID: 8994284
Filing Date: 2015-03-31
Classification: H05B

Abstract:
1. A high intensity discharge lamp control circuit, comprising: a first winding and a second winding, both of the first winding and the second winding being coupled with a series-connected inductor of a high intensity discharge lamp; a current zero point detector having a first input terminal, a second input terminal and an output terminal, the first input terminal and the second input terminal of the current zero point detector being connected with a different-name end of the first winding and a same-name end of the second winding, respectively, the current zero point detector being used for detecting an inductor current zero crossing signal of the high intensity discharge lamp; an inductor current signal generator having a first input terminal, a second input terminal, a third input terminal and an output terminal, the first input terminal and the second input terminal of the inductor current signal generator being connected with the different-name end of the first winding and the same-name end of the second winding, respectively, the third input terminal of the inductor current signal generator receives a signal related to the inductor current zero crossing signal to generate an inductor current signal in the circuit; a modulator having a first input terminal, a second input terminal and an output terminal, the first input terminal and the second input terminal of the modulator being connected with the output terminal of the current zero point detector and the output terminal of the inductor current signal generator, respectively, the output terminal of the modulator being connected so as to output a modulation signal; and a driving circuit having a first input terminal, a second input terminal, a third input terminal and an output terminal, for driving switches in the high intensity discharge lamp control circuit, the first input terminal of the driving circuit being connected with the output terminal of the modulator to receive the modulation signal outputted by modulator, the second input terminal and the third input terminal of the driving circuit being connected with a first external signal and a second external signal, respectively, the output terminal of the driving circuit being connected to the high intensity discharge lamp through an inverter circuit for controlling the inductor current to operate in a critical continuous inductor current mode.