Abstract: A control circuit for a resonant converter, that is configured to: adjust a conduction time of one power switch and a conduction time of one corresponding synchronous rectifier switch in the resonant converter in a resonant period detection mode; control a resonance current to cross zero twice during the conduction time of the synchronous rectifier switch; and obtain a resonant period of the resonant converter.

Abstract: A switching power supply circuit can include: an energy storage capacitor; a high-frequency switching network coupled to the energy storage capacitor, and being configured to receive a low-frequency AC input voltage, to charge the energy storage capacitor, to perform high-frequency chopping on the low-frequency AC input voltage and/or a voltage of the energy storage capacitor, and to generate a high-frequency AC signal; and a rectifier module coupled to the high-frequency switching network, and being configured to receive the high-frequency AC signal, to rectify the high-frequency AC signal, and to generate a DC signal.

Abstract: A driving circuit of a switch array for controlling one of a plurality of battery modules coupled in series, where: each battery module comprises a plurality of batteries coupled in series; the driving circuit is configured to generate corresponding driving signals to control corresponding switches in the switch array, such that one battery that is selected to be balanced, is coupled between positive and negative poles of a DC bus voltage; and a reference ground of the driving circuit is configured as the negative pole of the DC bus voltage.

Abstract: A control circuit for a resonant converter, that is configured to: adjust a conduction time of one power switch and a conduction time of one corresponding synchronous rectifier switch in the resonant converter in a resonant period detection mode; control a resonance current to cross zero twice during the conduction time of the synchronous rectifier switch; and obtain a resonant period of the resonant converter.

Abstract: A switching power supply circuit can include: an energy storage capacitor; a high-frequency switching network coupled to the energy storage capacitor, and being configured to receive a low-frequency AC input voltage, to charge the energy storage capacitor, to perform high-frequency chopping on the low-frequency AC input voltage and/or a voltage of the energy storage capacitor, and to generate a high-frequency AC signal; and a rectifier module coupled to the high-frequency switching network, and being configured to receive the high-frequency AC signal, to rectify the high-frequency AC signal, and to generate a DC signal.

Abstract: A driving circuit for driving a piezoelectric load, can include: an energy-storage capacitor; a first power stage circuit configured to convert an input voltage into a first voltage, and to store the first voltage in the energy-storage capacitor; a second power stage circuit configured to receive the first voltage to charge the piezoelectric load during a first operation interval of an operation period, such that a power supply voltage signal provided to the piezoelectric load in the first operation interval corresponds to a reference voltage in a first interval; and a discharging circuit configured to discharge the piezoelectric load during a second operation interval of the operation period, such that the power supply voltage signal in the second operation interval corresponds to the reference voltage in a second interval.

Abstract: A control circuit for a resonant converter, that is configured to: adjust a conduction time of one power switch and a conduction time of one corresponding synchronous rectifier switch in the resonant converter in a resonant period detection mode; control a resonance current to cross zero twice during the conduction time of the synchronous rectifier switch; and obtain a resonant period of the resonant converter.

Abstract: A multi-degree-of-freedom riding saddle including a support portion configured to be connected to a bicycle frame and two seat plates disposed respectively corresponding to two thighs on two sides of a rider. A linkage portion is between the two seat plates and the support portion. The linkage portion to control front ends of the two seat plates in a riding direction to rise and fall in an alternating reciprocation linkage mode and control a front end of one of the seat plates in the riding direction to push, during falling, the other seat plate to rise entirely. Through the foregoing arrangement, during riding, the two seat plates can not only achieve rising and falling of the front ends in the alternating reciprocation linkage mode, but also achieve entire rising and falling of the seat plates during the rising and falling of the front ends, thereby improving comfort and saving labor.

Abstract: A substrate delivery device and a delivery method thereof are described for improving the substrate delivery efficiency, reducing abrasion in substrate delivery, and improving manufacturing efficiency of a display panel. The substrate delivery device comprises a reciprocating aligning mechanism and a screen pickup mechanism. The reciprocating aligning mechanism has a bearing platform carrying the substrate, and a first driving mechanism driving the bearing platform to move so as to bring the carried substrate to a preset position. The screen pickup mechanism has a pickup arm picking up a substrate on the reciprocating aligning mechanism, and a second driving mechanism driving the pickup arm to move. The pickup arm is located in a direction perpendicular to the substrate on the reciprocating aligning mechanism. When the reciprocating aligning mechanism moves to the preset position, the second driving mechanism drives the pickup arm to pick up the substrate on the reciprocating aligning mechanism.

Abstract: In one embodiment, a method of controlling a switching power supply, can include: (i) generating a driving current signal that follows a waveform of a sense voltage signal, where the sense voltage signal is related to a current through a collector of a transistor that is configured as a power switch of the switching power supply, where the collector is coupled to an inductive element of the switching power supply; (ii) providing the driving current signal to a base of the transistor, where the transistor is in a saturated conduction state when a pulse-width modulation (PWM) signal is active; and (iii) releasing charge accumulated on the base when the PWM signal is inactive to turn off the transistor.

Abstract: In one embodiment, an undervoltage protection circuit for a switching power supply can include: (i) an undervoltage detection circuit that determines whether an input voltage of the switching power supply is in an undervoltage state; (ii) a selection circuit configured to select a first or a second control signal to be provided as a main control signal to a control circuit; (iii) the control circuit being configured, in response to the main control signal being the first control signal, to control a switching operation of a power transistor in the switching power supply such that an output voltage of the switching power supply is maintained as substantially stable; and (iv) the control circuit being configured, in response to the main control signal being the second control signal, to control the switching operation of the power transistor to reduce an input power of the switching power supply.

Abstract: In one embodiment, a power factor correction (PFC) circuit can include: (i) a rectifier bridge and a PFC converter coupled to an input capacitor; (ii) a harmonic wave compensation circuit configured to shift a phase of a DC input voltage provided from the rectifier bridge, where the harmonic wave compensation circuit comprises a phase of about ?45° when a corner frequency is about 50 Hz; and (iii) a PFC control circuit configured to control the PFC converter, where the PFC control circuit comprises a first sampling voltage, and the harmonic wave compensation circuit is configured to control a phase of the first sampling voltage to lag a phase of the DC input voltage by about 45°.

Abstract: In one embodiment, a method of detecting a voltage can include: (i) generating a first current according to a first voltage and a converting resistor; (ii) charging a detection capacitor by the first current during a first time period of a switching cycle of a switching power supply; (iii) charging the detection capacitor by a second current during a second time period of the switching cycle; (iv) detecting a voltage across the detection capacitor to obtain a detection voltage at an end time of the second time period, where the first time period includes a rising portion of a current flowing through the inductor, and the second time period includes a decreasing portion of the inductor current; and (v) determining a state of a present output voltage of the switching power supply according to the detection voltage.

Abstract: In one embodiment, a method of compensating for transmission voltage loss from a switching power supply, can include: (i) receiving a sampling signal that represents an output current of the switching power supply; (ii) delaying the sampling signal to generate a delayed sampling signal; (iii) converting the delayed sampling signal to generate a compensation signal; and (iv) regulating an output voltage of the switching power supply based on the compensation signal to compensate for the transmission voltage loss from the output voltage transmission to a load such that a voltage at the load is maintained as substantially consistent with an expected voltage at the load.

Abstract: In one embodiment, a method of controlling a switching power supply, can include: (i) generating a driving current signal that follows a waveform of a sense voltage signal, where the sense voltage signal is related to a current through a collector of a transistor that is configured as a power switch of the switching power supply, where the collector is coupled to an inductive element of the switching power supply; (ii) providing the driving current signal to a base of the transistor, where the transistor is in a saturated conduction state when a pulse-width modulation (PWM) signal is active; and (iii) releasing charge accumulated on the base when the PWM signal is inactive to turn off the transistor.

Abstract: In one embodiment, a method of controlling a switching power supply, can include: (i) generating a driving current signal that follows a waveform of a sense voltage signal, where the sense voltage signal is related to a current through a collector of a transistor that is configured as a power switch of the switching power supply, where the collector is coupled to an inductive element of the switching power supply; (ii) providing the driving current signal to a base of the transistor, where the transistor is in a saturated conduction state when a pulse-width modulation (PWM) signal is active; and (iii) releasing charge accumulated on the base when the PWM signal is inactive to turn off the transistor.

Abstract: In one embodiment, a method of detecting a voltage can include: (i) generating a first current according to a first voltage and a converting resistor; (ii) charging a detection capacitor by the first current during a first time period of a switching cycle of a switching power supply; (iii) charging the detection capacitor by a second current during a second time period of the switching cycle; (iv) detecting a voltage across the detection capacitor to obtain a detection voltage at an end time of the second time period, where the first time period includes a rising portion of a current flowing through the inductor, and the second time period includes a decreasing portion of the inductor current; and (v) determining a state of a present output voltage of the switching power supply according to the detection voltage.

Abstract: In one embodiment, an undervoltage protection circuit for a switching power supply can include: (i) an undervoltage detection circuit that determines whether an input voltage of the switching power supply is in an undervoltage state; (ii) a selection circuit configured to select a first or a second control signal to be provided as a main control signal to a control circuit; (iii) the control circuit being configured, in response to the main control signal being the first control signal, to control a switching operation of a power transistor in the switching power supply such that an output voltage of the switching power supply is maintained as substantially stable; and (iv) the control circuit being configured, in response to the main control signal being the second control signal, to control the switching operation of the power transistor to reduce an input power of the switching power supply.

Abstract: In one embodiment, a method of compensating for transmission voltage loss from a switching power supply, can include: (i) receiving a sampling signal that represents an output current of the switching power supply; (ii) delaying the sampling signal to generate a delayed sampling signal; (iii) converting the delayed sampling signal to generate a compensation signal; and (iv) regulating an output voltage of the switching power supply based on the compensation signal to compensate for the transmission voltage loss from the output voltage transmission to a load such that a voltage at the load is maintained as substantially consistent with an expected voltage at the load.

Abstract: In one embodiment, a power factor correction (PFC) circuit can include: (i) a rectifier bridge and a PFC converter coupled to an input capacitor; (ii) a harmonic wave compensation circuit configured to shift a phase of a DC input voltage provided from the rectifier bridge, where the harmonic wave compensation circuit comprises a phase of about ?45° when a corner frequency is about 50 Hz; and (iii) a PFC control circuit configured to control the PFC converter, where the PFC control circuit comprises a first sampling voltage, and the harmonic wave compensation circuit is configured to control a phase of the first sampling voltage to lag a phase of the DC input voltage by about 45°.