Abstract: A light driving circuit includes a first and second illuminant unit, a power conversion unit, a first and second switching unit, and a first control unit. The power conversion unit receives an input voltage and converts the input voltage into an output voltage. The first switching unit is coupled to the first illuminant unit. When the first switching unit is turned on, the first illuminant unit is driven by the output voltage to emit light and generate a first output current. The second switching unit is coupled to the second illuminant unit. When the second switching unit is turned on, the second illuminant unit is driven by the output voltage to emit light and generate a second output current. The first control unit controls the first switching unit and the second switching unit to be turned on/off according to the first output current and the second current, respectively.

Abstract: A light regulating apparatus includes a converter, a load circuit, and a controller. The converter is configured to output a load current signal according to a controlling signal. The load circuit is driven by the load current signal. The controller is configured to generate the control signal. The controller includes an error calculation unit, a regulation unit, a feed forward compensation unit, and an addition unit. The error calculation unit is configured to generate a first error signal according to a reference current signal and a feedback signal. The regulation unit is configured to generate a regulating signal according to the error signal. The feed forward compensation unit is configured to generate a feed forward compensation signal according to the reference current signal. The addition unit is configured to generate the control signal according to the regulation signal and the feed forward compensation signal.

Abstract: A control method for a power converter is provided. The power converter includes an inductor, and a switch selectively turned on according to a control signal. The control method includes determining an on-time and a falling time according to a voltage information or a current information of the power converter; determining a switching period of the control signal according to the on-time, the falling time, and a resonant period corresponding to the inductor and a parasitic capacitance of the switch; adjusting the switching period by comparing the switching period with a first threshold period and a second threshold period; generating the control signal having the switching period when the switching period is greater than the first threshold period and less than the second threshold period or when the switching period is greater than the second threshold period and the power converter operates at over 50% of a rated power.

Abstract: A control method for a power converter is provided. The power converter includes an inductor, and a switch selectively turned on according to a control signal. The control method includes determining an on-time and a falling time according to a voltage information or a current information of the power converter; determining a switching period of the control signal according to the on-time, the falling time, and a resonant period corresponding to the inductor and a parasitic capacitance of the switch; adjusting the switching period by comparing the switching period with a first threshold period and a second threshold period; generating the control signal having the switching period when the switching period is greater than the first threshold period and less than the second threshold period or when the switching period is greater than the second threshold period and the power converter operates at over 50% of a rated power.

Abstract: A light driving circuit includes a first and second illuminant unit, a power conversion unit, a first and second switching unit, and a first control unit. The power conversion unit receives an input voltage and converts the input voltage into an output voltage. The first switching unit is coupled to the first illuminant unit. When the first switching unit is turned on, the first illuminant unit is driven by the output voltage to emit light and generate a first output current. The second switching unit is coupled to the second illuminant unit. When the second switching unit is turned on, the second illuminant unit is driven by the output voltage to emit light and generate a second output current. The first control unit controls the first switching unit and the second switching unit to be turned on/off according to the first output current and the second current, respectively.

Abstract: A light regulating apparatus includes a converter, a load circuit, and a controller. The converter is configured to output a load current signal according to a controlling signal. The load circuit is driven by the load current signal. The controller is configured to generate the control signal. The controller includes an error calculation unit, a regulation unit, a feed forward compensation unit, and an addition unit. The error calculation unit is configured to generate a first error signal according to a reference current signal and a feedback signal. The regulation unit is configured to generate a regulating signal according to the error signal. The feed forward compensation unit is configured to generate a feed forward compensation signal according to the reference current signal. The addition unit is configured to generate the control signal according to the regulation signal and the feed forward compensation signal.