Abstract: An LED control circuit, comprising: an isolated DC-DC circuit having a first current loop and a voltage loop, said circuit being used for outputting a stable direct current voltage; and a buck circuit having a control unit; wherein the control unit is used for controlling the buck circuit to output constant current, so as to supply power to an LED load, and also used for controlling the buck circuit to not operate when the direct current voltage is less than a preset voltage, and controlling the buck circuit to operate when the direct current voltage is greater than or equal to the preset voltage.

Abstract: An LED drive circuit, comprising: a Flyback circuit that has a current-limiting mode and a constant-voltage mode, a non-isolated DC-DC circuit, and a control circuit. The control circuit is used to detect the output voltage of the Flyback circuit, and, when the output voltage of the Flyback circuit is greater than or equal to a first preset voltage value, control the Flyback circuit to operate in the constant-voltage mode; the control circuit is further used to detect the switch transistor current or output current of the Flyback circuit, and, when the output current of the Flyback circuit is greater than a first preset current value, control the Flyback circuit to operate in the current-limiting mode.

Abstract: An LED control circuit, comprising: an isolated DC-DC circuit having a first current loop and a voltage loop, said circuit being used for outputting a stable direct current voltage; and a buck circuit having a control unit; wherein the control unit is used for controlling the buck circuit to output constant current, so as to supply power to an LED load, and also used for controlling the buck circuit to not operate when the direct current voltage is less than a preset voltage, and controlling the buck circuit to operate when the direct current voltage is greater than or equal to the preset voltage.

Abstract: An LED drive circuit, comprising: a Flyback circuit that has a current-limiting mode and a constant-voltage mode, a non-isolated DC-DC circuit, and a control circuit. The control circuit is used to detect the output voltage of the Flyback circuit, and, when the output voltage of the Flyback circuit is greater than or equal to a first preset voltage value, control the Flyback circuit to operate in the constant-voltage mode; the control circuit is further used to detect the switch transistor current or output current of the Flyback circuit, and, when the output current of the Flyback circuit is greater than a first preset current value, control the Flyback circuit to operate in the current-limiting mode.

Abstract: An integrated magnetic device includes a bobbin having a through hole. A center column magnetic core groove is arranged in the middle of the bobbin to divide the bobbin into a first bobbin and a second bobbin, the center column magnetic core groove is inserted with a center column magnetic core, the first bobbin and the second bobbin are both provided with a side magnetic core for forming a closed loop with the center column magnetic core, the side magnetic core includes a center column inserted in the through hole, a first winding groove for winding a magnetic device winding of a Boost circuit is provided between side walls of the first bobbin, and a second winding groove for winding a magnetic device winding of an LLC circuit is provided between side walls of the second bobbin.

Abstract: A resonant converter includes a resonant current truncating unit, a resonant current processing unit and a driving control unit. The resonant current truncating unit is connected in series in a current loop of a resonance circuit and is configured to periodically truncate to acquire a sampling interval and acquire a sampling signal characterizing a resonant current in the sampling interval. The resonant current processing unit is configured to perform an averaging process on the sampling signal to acquire a feedback signal. The driving control unit is configured to control a switching state of the main switch of the primary circuit based on the feedback signal, to make the resonant converter output a stable current.

Abstract: A resonant converter includes a resonant current truncating unit, a resonant current processing unit and a driving control unit. The resonant current truncating unit is connected in series in a current loop of a resonance circuit and is configured to periodically truncate to acquire a sampling interval and acquire a sampling signal characterizing a resonant current in the sampling interval. The resonant current processing unit is configured to perform an averaging process on the sampling signal to acquire a feedback signal. The driving control unit is configured to control a switching state of the main switch of the primary circuit based on the feedback signal, to make the resonant converter output a stable current.

Abstract: A control circuit in a power factor correction (PFC) circuit includes: a multiplier, used for multiplying a voltage sampling signal by a feedback signal, and outputting a first signal; and a waveform generating module, used for generating a second signal related to a filter capacitor connected in parallel to an input end and/or an output end of a rectifier bridge. A control signal for controlling a state of a main switch transistor is generated by using the first signal, the second signal, and a current sampling signal of the main switch transistor in the PFC circuit.

Abstract: Disclosed is a constant current drive for an LED light source, including a main power supply loop and at least one backup power supply loop. The main power supply loop at least includes a power conversion circuit. The power conversion circuit outputs a constant current to an LED light source. The backup power supply loop at least includes a power conversion backup circuit. The power conversion backup circuit outputs a constant current to the LED light source. When the power conversion circuit and the power conversion backup circuit operate normally, any one thereof operates in a nominal state or a derating state, and the output ends thereof are connected in parallel and then supply power to the LED light source simultaneously. When any one of the power conversion circuit and the power conversion backup circuit is invalid, the invalid circuit will not affect the normal operation of the remaining circuit.

Abstract: An auxiliary power supply circuit of a two wire dimmer, comprising: an auxiliary source capacitor (20) and a cutoff switch (30) constituting a series branch, a chopper switch (10) parallel-connected to the series branch, and a control device (40) connected to the chopper switch (10) and to the cutoff switch (30). The control device (40) measures an auxiliary source voltage and receives a chopper voltage control signal (Vg), and outputs signals (V1 and V2), on the basis of the result of a comparison between the auxiliary source voltage and a preset voltage and of the state of the chopper voltage control signal (Vg), to control the on and off of the chopper switch (10) and of the cutoff switch (30) for controlling the charging of the auxiliary source capacitor (20). The auxiliary power supply circuit has low losses, high efficiency, and is not limited by minimum chopper angle, and has low electromagnetic interference.

Abstract: A control circuit in a power factor correction (PFC) circuit includes: a multiplier, used for multiplying a voltage sampling signal by a feedback signal, and outputting a first signal; and a waveform generating module, used for generating a second signal related to a filter capacitor connected in parallel to an input end and/or an output end of a rectifier bridge. A control signal for controlling a state of a main switch transistor is generated by using the first signal, the second signal, and a current sampling signal of the main switch transistor in the PFC circuit.

Abstract: Disclosed is a constant current drive for an LED light source, including a main power supply loop and at least one backup power supply loop. The main power supply loop at least includes a power conversion circuit. The power conversion circuit outputs a constant current to an LED light source. The backup power supply loop at least includes a power conversion backup circuit. The power conversion backup circuit outputs a constant current to the LED light source. When the power conversion circuit and the power conversion backup circuit operate normally, any one thereof operates in a nominal state or a derating state, and the output ends thereof are connected in parallel and then supply power to the LED light source simultaneously. When any one of the power conversion circuit and the power conversion backup circuit is invalid, the invalid circuit will not affect the normal operation of the remaining circuit.

Abstract: An auxiliary power supply circuit of a two wire dimmer, comprising: an auxiliary source capacitor (20) and a cutoff switch (30) constituting a series branch, a chopper switch (10) parallel-connected to the series branch, and a control device (40) connected to the chopper switch (10) and to the cutoff switch (30). The control device (40) measures an auxiliary source voltage and receives a chopper voltage control signal (Vg), and outputs signals (V1 and V2), on the basis of the result of a comparison between the auxiliary source voltage and a preset voltage and of the state of the chopper voltage control signal (Vg), to control the on and off of the chopper switch (10) and of the cutoff switch (30) for controlling the charging of the auxiliary source capacitor (20). The auxiliary power supply circuit has low losses, high efficiency, and is not limited by minimum chopper angle, and has low electromagnetic interference.

Abstract: A current-driven synchronous rectifying drive circuit designed for a T-type voltage doubler rectifier with an energy feedback circuit including a clamp and energy feedback circuit, a high frequency transformer, a current transducer, an energy storage capacitor, an output capacitor, a first and a second synchronous rectifier, and a first drive circuit connected to the first synchronous rectifier and a second drive circuit connected to the second synchronous rectifier.

Abstract: A current-driven synchronous rectifying drive circuit designed for a T-type voltage doubler rectifier with an energy feedback circuit including a clamp and energy feedback circuit, a high frequency transformer, a current transducer, an energy storage capacitor, an output capacitor, a first and a second synchronous rectifier, and a first drive circuit connected to the first synchronous rectifier and a second drive circuit connected to the second synchronous rectifier.