CONTROL CIRCUIT FOR LIGHT-EMITTING ELEMENT

摘要

PROBLEM TO BE SOLVED: To increase the power factor of a control circuit controlling light emission of a light-emitting element.

SOLUTION: The control circuit includes: a rectification part 30 for full-wave rectifying an AC power source; a switching element 36 for switching current flowing through the light-emitting element for receiving a voltage which has been rectified by the rectification part 30; a voltage divider circuit 42 for dividing the voltage which has been full-wave rectified by the rectification part 30 to obtain a reference voltage Vref; a comparator 40 comparing a comparative voltage Vcmpaccording to a current flowing through the light-emitting element with the reference voltage Vref; and a control part 38 controlling switching of the switching element 36 according to a result of comparison by the comparator 40.

COPYRIGHT: (C)2011,JPO&INPIT