Patent ID: 8872437
Filing Date: 2014-10-28
Classification: H05B,Y02B

Abstract:
1. A lighting apparatus comprising: a switching regulator configured to supply a direct current to a DC light source; and a control circuit configured to control said switching regulator in order to supply a direct current having a magnitude corresponding to a dimming ratio to the DC light source, wherein said switching regulator includes a switching element, and said control circuit is configured to adjust a switching frequency and on-duration of said switching element in accordance with the dimming ratio, and said control circuit is configured to, when the dimming ratio falls within a first dimming range, adjust the switching frequency to a frequency associated with the first dimming range and adjust the on-duration to duration associated with the dimming ratio in a range of the on-duration associated with the first dimming range, and said control circuit is configured to, when the dimming ratio falls within a second dimming range different from the first dimming range, adjust the on-duration to duration associated with the second dimming range and adjust the switching frequency to a frequency associated with the dimming ratio in a range of the switching frequency associated with the second dimming range.