| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a control circuit for light-emitting device which controls to reduce variations in electric currents running through a light-emitting device when an amplitude of a voltage rectified by a rectification circuit varies. <P>SOLUTION: A reference voltage generation circuit 20 detects a rectification voltage Vrc subjected to full-wave rectification, generates a first voltage V1 and on the other hand, converts the rectification voltage into DC to generate a second voltage V2. A subtraction circuit or a division circuit generates a voltage corresponding to a difference between the first voltage V1 and the second voltage V2 as a reference voltage Vref. Thus, by variations in an input voltage Vin of AC supplied from an AC power supply, variations in an amplitude of the reference voltage Vref can be suppressed when an amplitude of the rectification voltage Vrc varies. <P>COPYRIGHT: (C)2013,JPO&INPIT |
