Abstract: A grafted polypropylene resin is prepared by a grafting reaction of a polar monomer capable of absorbing microwave so as to raise its temperature in a microwave field to more than 200° C. and a solid polypropylene resin using microwave irradiation without adding an initiator. The polar grafted polypropylene resin that does not contain initiator residues and does not have a significant reduction in molecular mass compared with a resin before grafting is obtained.

Abstract: A continuous operation method is employed for the microwave high-temperature pyrolysis of a solid material containing an organic matter. The method includes the steps of mixing a solid material containing an organic matter with a liquid organic medium; transferring the obtained mixture to a microwave field; and in the microwave field, continuously contacting the mixture with a strong wave absorption material in an inert atmosphere or in vacuum. The strong wave absorption material continuously generates a high temperature under a microwave such that the solid material containing an organic matter and the liquid organic medium are continuously pyrolyzed to implement a continuous operation.

Abstract: A method of controlling a power convertor to perform diming control for a light-emitting diode (LED) load, can include: adjusting a length of a switching period of the power converter in accordance with a dimming signal; and controlling the power converter to generate a drive current corresponding to the dimming signal.

Abstract: A method of controlling a power convertor to perform diming control for a light-emitting diode (LED) load, can include: adjusting a length of a switching period of the power converter in accordance with a dimming signal; and controlling the power converter to generate a drive current corresponding to the dimming signal.

Abstract: A method of controlling a power convertor to perform dimming control for a light-emitting diode (LED) load, can include: adjusting a length of a switching period of the power converter in accordance with a dimming signal; and controlling the power converter to generate a drive current corresponding to the dimming signal.

Abstract: A control circuit for a switching converter having a main power switch and an auxiliary power switch, where the control circuit is configured to: charge and discharge a junction capacitor of the main power switch during a turn-off period of the main power switch; and adjust a conduction time of the auxiliary power switch according to a difference between the charged and discharged charge levels across the junction capacitor.

Abstract: A control circuit for controlling a power stage circuit of a switching converter, where the power stage circuit includes a magnetic component and a power switch, can include: the control circuit being configured to determine a turn-on trough of a current cycle by determining whether a time signal corresponding to a lock-on trough of the current cycle is within a threshold range, thereby controlling the power switch to be turned on at the determined turn-on trough; and whereby an ordinal number of the lock-on trough of the current cycle is the same as an ordinal number of the turn-on trough of the last cycle.

Abstract: A control circuit for controlling a power stage circuit of a switching converter, where the power stage circuit includes a magnetic component and a power switch, can include: the control circuit being configured to determine a turn-on trough of a current cycle by determining whether a time signal corresponding to a lock-on trough of the current cycle is within a threshold range, thereby controlling the power switch to be turned on at the determined turn-on trough; and whereby an ordinal number of the lock-on trough of the current cycle is the same as an ordinal number of the turn-on trough of the last cycle.

Abstract: A method of controlling a power convertor to perform dimming control for a light-emitting diode (LED) load, can include: adjusting a length of a switching period of the power converter in accordance with a dimming signal; and controlling the power converter to generate a drive current corresponding to the dimming signal.

Abstract: A power supply circuit can include: a constant current control circuit configured to receive a first voltage and a first current from a power supply, and to generate a second voltage and a second current that are substantially constant; a shunt circuit, where when the second current is greater than the output current, the shunt current circuit is configured to shunt the second current, and when the second current is less than or equal to the output current, the shunt circuit stops operating; and an energy storage circuit, where when the second current is greater than the output current, the energy storage circuit is configured to store energy, and when the second current is less than or equal to the output current, the energy storage circuit is configured to release energy and provide power for the load together with the constant current control circuit.

Abstract: A power supply circuit can include: a constant current control circuit configured to receive a first voltage and a first current from a power supply, and to generate a second voltage and a second current that are substantially constant; a shunt circuit, where when the second current is greater than the output current, the shunt current circuit is configured to shunt the second current, and when the second current is less than or equal to the output current, the shunt circuit stops operating; and an energy storage circuit, where when the second current is greater than the output current, the energy storage circuit is configured to store energy, and when the second current is less than or equal to the output current, the energy storage circuit is configured to release energy and provide power for the load together with the constant current control circuit.

Abstract: A power supply circuit can include: a constant current control circuit configured to receive a first voltage and a first current from a power supply, and to generate a second voltage and a second current that are substantially constant; a shunt circuit, where when the second current is greater than the output current, the shunt current circuit is configured to shunt the second current, and when the second current is less than or equal to the output current, the shunt circuit stops operating; and an energy storage circuit, where when the second current is greater than the output current, the energy storage circuit is configured to store energy, and when the second current is less than or equal to the output current, the energy storage circuit is configured to release energy and provide power for the load together with the constant current control circuit.

Abstract: An LED driving circuit configured to drive an LED lamp having first and second loads, can include: a power converter; a dimmer configured to control the power converter to output a driving current to the LED lamp; and a current distribution circuit configured to adjust a proportion of current from the driving current that flows through each of the first and second loads of the LED lamp, in order to adjust the color temperature or the brightness of the LED lamp.

Abstract: A power supply circuit can include: a constant current control circuit configured to receive a first voltage and a first current from a power supply, and to generate a second voltage and a second current that are substantially constant; a shunt circuit, where when the second current is greater than the output current, the shunt current circuit is configured to shunt the second current, and when the second current is less than or equal to the output current, the shunt circuit stops operating; and an energy storage circuit, where when the second current is greater than the output current, the energy storage circuit is configured to store energy, and when the second current is less than or equal to the output current, the energy storage circuit is configured to release energy and provide power for the load together with the constant current control circuit.

Abstract: A multichannel constant current LED controlling circuit can include: (i) a control loop configured to generate a first control signal in accordance with a current feedback signal that represents a driving current flowing through an LED load, where the LED load comprises a plurality of LED strings coupled in series; (ii) a loop steady state network comprising a plurality of steady state holding components configured to hold a plurality of steady state control signals that correspond to a plurality of load states of the LED load, where when a state of the LED load varies, at least one of the steady state holding components is selected by the control loop to generate the first control signal; and (iii) a power switching transistor of a power stage circuit configured to generate a pseudo-constant output current to drive the LED load.

Abstract: An LED driving circuit configured to drive an LED lamp having first and second loads, can include: a power converter; a dimmer configured to control the power converter to output a driving current to the LED lamp; and a current distribution circuit configured to adjust a proportion of current from the driving current that flows through each of the first and second loads of the LED lamp, in order to adjust the color temperature or the brightness of the LED lamp.

Abstract: A method of filtering a ripple can include: (i) generating, by a sampling circuit, a sense voltage signal that represents an output current flowing through a load; (ii) generating, by a filter circuit, a filter voltage signal by filtering the sense voltage signal, where the filter circuit includes a switch capacitor circuit and a filter capacitor; and (iii) generating, by an error amplifying circuit, an error compensation signal by amplifying a difference between the sense voltage signal and the filter voltage signal, where the error compensation signal is configured to compensate and regulate the output current flowing through the load by controlling a power switch that is coupled to the load and the sampling circuit.

Abstract: An LED driving circuit for driving an LED load including N LED strings, where N is a positive integer no less than 2, can include: (i) a power converter having a power switch; (ii) a constant current control circuit that controls a switching operation of the power switch such that the power converter generates a driving current for the LED load; (iii) N control switches respectively coupled in series to the N LED strings; (iv) a PWM signal generator configured to generate N color tuning PWM signals; and (v) a color tuning control circuit configured to output N switching control signals according to the N color tuning PWM signals, to control switching operations of the N control switches, to regulate a ratio of a current through each LED string of the LED load to the driving current, and to regulate the color temperature of the LED load.

Abstract: A multichannel constant current LED controlling circuit can include: (i) a control loop configured to generate a first control signal in accordance with a current feedback signal that represents a driving current flowing through an LED load, where the LED load comprises a plurality of LED strings coupled in series; (ii) a loop steady state network comprising a plurality of steady state holding components configured to hold a plurality of steady state control signals that correspond to a plurality of load states of the LED load, where when a state of the LED load varies, at least one of the steady state holding components is selected by the control loop to generate the first control signal; and (iii) a power switching transistor of a power stage circuit configured to generate a pseudo-constant output current to drive the LED load.

Abstract: A multichannel constant current LED controlling circuit can include: (i) a control loop configured to generate a first control signal in accordance with a current feedback signal that represents a driving current flowing through an LED load, where the LED load comprises a plurality of LED strings coupled in series; (ii) a loop steady state network comprising a plurality of steady state holding components configured to hold a plurality of steady state control signals that correspond to a plurality of load states of the LED load, where when a state of the LED load varies, at least one of the steady state holding components is selected by the control loop to generate the first control signal; and (iii) a power switching transistor of a power stage circuit configured to generate a pseudo-constant output current to drive the LED load.