| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a semiconductor light source lighting circuit that implements improved electrical efficiency while accommodating a wide range of forward drop voltage. <P>SOLUTION: A semiconductor light source lighting circuit 100 includes: a DC/DC converter 6 for, in response to receiving a DC battery voltage V<SB POS="POST">bat</SB>and a ground potential different from each other, converting the battery voltage V<SB POS="POST">bat</SB>such that a difference thereof from the ground potential increases to generate a DC boost voltage V<SB POS="POST">boost</SB>; a three-terminal circuit side connector having a boost voltage output terminal BOOST to which the boost voltage V<SB POS="POST">boost</SB>is applied, and when engaged with an LED side connector, connected at the boost voltage output terminal BOOST with an anode side of an LED 4; and a control circuit 102 for controlling the DC/DC converter 6 such that an LED current becomes a desired value, and selecting the battery voltage V<SB POS="POST">bat</SB>as a voltage to be applied to a cathode side if a forward drop voltage is lower than the battery voltage V<SB POS="POST">bat</SB>and selecting the ground potential unless the battery voltage V<SB POS="POST">bat</SB>is selected. <P>COPYRIGHT: (C)2013,JPO&INPIT |
