Patent ID: 9578699
Date: 2017-02-21
CPC Classifications: H05B,Y02B

Claim:
1. A control circuit configured to control electric power to a load based on a rectified drive signal, the rectified drive signal being a drive signal rectified by a rectifier, the drive signal being an alternating-current signal whose phase is controlled by a dimmer comprising a switching device, the control circuit comprising: a time period detection part configured to detect a time period in which an amplitude of the rectified drive signal is less than or equal to a predetermined level, wherein the time period detection part is configured to output a detection signal including a pulse having a pulse width that is based on a time period in which the amplitude of the rectified drive signal is greater than the predetermined level; and a dimmer current control part being configured so that a control current to the dimmer is greater than or equal to a holding current of the switching device during the time period.