| 摘要 |
A device (220) implements a method (600) of controlling dimming of a light emitting diode (LED) light source (230) by: receiving a phase-cut dimming signal (105) produced from an AC line voltage (15), ascertaining the peak voltage level (109) of the AC line voltage (15); ascertaining the present value of a phase-cut duty cycle of the phase-cut dimming signal, employing the peak voltage level of the AC line voltage to ascertain the maximum phase-cut duty cycle for the phase-cut dimming signal, ascertaining the phase-cut angle (107) of the phase-cut dimming signal from the present value of the phase-cut duty cycle of the phase-cut dimming signal and the maximum phase-cut duty cycle for the phase-cut dimming signal; and controlling the dimming of the LED light source in response to the phase-cut angle. |
