Patent ID: 8766558
Filing Date: 2014-07-01
Classification: H05B

Abstract:
1. A lighting circuit for lighting a semiconductor light source, the circuit comprising: a DC/DC converter configured to receive a DC first voltage and a DC second voltage different from the first voltage and generate a DC third voltage such that a difference between the third and second voltages is more than a difference between the first and second voltages; a first connector comprising a first terminal, wherein the third voltage is applied to the first terminal, wherein the first connector is configured to connect the first terminal and one end of the semiconductor light source; and a control circuit configured to control the DC/DC converter such that a value of current flowing between the DC/DC converter and the first terminal is set to a certain value, wherein the control circuit is configured to select only the first voltage as a voltage applied to the other end of the semiconductor light source, when a light emission voltage for emitting the semiconductor light source is less than an absolute value of the difference between the first and second voltages, and wherein the control circuit is configured to select the first voltage or the second voltage as the voltage applied to the other end of the semiconductor light source, when the light emission voltage is not less than the absolute value.