Patent ID: 9723665
Date: 2017-08-01
CPC Classifications: H02M,H05B,Y02B

Claim:
1. A lighting apparatus which supplies a current to a solid-state light-emitting device, the lighting apparatus comprising: an AC/DC converter which converts an AC voltage to a first DC voltage by rectifying and smoothing the AC voltage; a DC/DC converter which converts the first DC voltage to a second DC voltage to be applied to the solid-state light-emitting device; and a detection circuit which detects at least one of the AC voltage and the first DC voltage, wherein the DC/DC converter includes a switching element, and a control circuit that performs a control of repeatedly turning on and off the switching element in a boundary conduction mode, and the control circuit performs the control under which an ON time is kept from exceeding an upper limit that is previously determined, and raises the upper limit when the at least one of the AC voltage and the first DC voltage detected by the detection circuit falls below a predetermined value, the ON time being a period of time during which switching element is kept ON, the detection circuit includes a rectifier which converts the AC voltage to a DC voltage by rectifying and smoothing the AC voltage, and the control circuit raises the upper limit when the DC voltage output from the rectifier falls below the predetermined value.