Abstract: An AC-DC converter can include: a rectifying circuit configured to convert an AC input voltage into a DC voltage, where at least one active switching device is included in one conductive rectifying loop of the rectifying circuit; a control circuit configured to control switching states of the active switching devices according to an output voltage of the AC-DC converter and the AC input voltage, in order to decrease an error between the DC voltage and the output voltage of the AC-DC converter; and a DC-DC converter configured to convert the DC voltage into the output voltage of the AC-DC converter.

Abstract: The present invention relates to the technical field of clothing, and more particularly to a protective headgear and a multifunctional casual protective clothing. The protective headgear consists of a headgear body, an inner headgear, a goggle, breathing valves and a headgear zipper. The multifunctional casual protective clothing includes a piece of clothing and a protective headgear. A collar zipper is arranged on the collar of the clothing, and the collar zipper is connected with the headgear zipper of the headgear. By adopting the protective headgear, the multifunctional casual protective clothing of the present invention can avoid and prevent viruses, dust, smog, wind and snow; and after the protective headgear is removed, it can be used as ordinary casual clothing, with various functions and easy use, the protective headgear is suitable for casual clothing such as a coat, sportswear, down jacket, sweater, overcoat, jacket or leather jacket.

Abstract: An AC-DC conversion circuit can include an adaptive rectifier configured to receive an AC input voltage with different ranges, where operation states of the adaptive rectifier are adjusted according to a range of the AC input voltage, in order to decrease a fluctuation range of a DC output voltage of the adaptive rectifier.

Abstract: Provided are a method and apparatus for measuring a geometric parameter of an object, and a terminal. The method includes: establishing a three-dimensional coordinate system based on a real environment, in accordance with a first depth image of the real environment photographed by a camera component; obtaining pose data of a terminal, obtaining a second depth image and a two-dimensional image of an object to be measured, and displaying the two-dimensional image on a display interface of the terminal; in response to a measurement point selection instruction, determining a coordinate in the three-dimensional coordinate system of a measurement point based on the pose data, the second depth image and the two-dimensional image, and determining a geometric parameter of the object to be measured based on the coordinate; and displaying, in the two-dimensional image, the geometric parameter of the object to be measured.

Abstract: An AC-DC power converter can include: a front-stage power circuit; a rear-stage power circuit configured to share one power switch as a main power switch with the front-stage power circuit, where the rear-stage power circuit is coupled to a load, and a first magnetic component of the front-stage power circuit and a second magnetic component of the rear-stage power circuit are not in one conductive loop from a positive terminal of a DC input voltage to a negative terminal of the DC input voltage; and an energy storage capacitor coupled to the front-stage power circuit and the rear-stage power circuit, where energy is transferred to the energy storage capacitor and the load when the first magnetic component is discharged.

Abstract: A control circuit for a switching converter, can include: a current compensation signal generating circuit configured to generate a current compensation signal based on a current sampling signal representing an inductor current; and a control signal generating circuit configured to adjust a current control parameter of a current control loop in the switching converter according to the current compensation signal, in order to increase power factor (PF) and reduce total harmonic distortion (THD).

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 primary feedback control circuit of a series resonant converter having a transformer, can include: an excitation current simulation circuit configured to sample an excitation voltage of the transformer, and to generate a first voltage representing an excitation current of the transformer; and a feedback control circuit configured to control on and off states of power switches of the series resonant converter in accordance with the first voltage and a second voltage representing a resonant current of the series resonant converter, where the first voltage is controlled to be equal to the second voltage when a secondary current of the transformer is zero.

Abstract: The disclosure relates to the field of digital pathology imaging technologies, in particular, to a digital pathology scanner for large-area microscopic imaging. The digital pathology scanner for large-area microscopic imaging includes a plurality of microscopic objectives and a plurality of digital image sensors; the microscopic objectives and the digital image sensors are equal in quantity and are fixed relatively in a one-to-one correspondence manner. The digital image sensors are sequentially distributed so as to form a sensor array. The sensor array enables images formed by the digital image sensors to be sequentially distributed without intervals in a second direction when moving in a first direction, wherein the first direction is perpendicular to the second direction.

Abstract: A rectifier circuit applied in an AC/AC power supply, the rectifier circuit including: a filter circuit configured to receive a DC pulsating voltage, and to generate a supply voltage, where the supply voltage follows the DC pulsating voltage during a first time interval of an operation cycle; and where during a second time interval of the operation cycle, a value of the supply voltage is greater than the value of the supply voltage at an end of the first time interval, in order to reduce a size of the filter circuit.

Abstract: An AC-DC power converter can include: a front-stage power circuit; a rear-stage power circuit configured to share one power switch as a main power switch with the front-stage power circuit, where the rear-stage power circuit is coupled to a load, and a first magnetic component of the front-stage power circuit and a second magnetic component of the rear-stage power circuit are not coupled in one conductive loop from a positive terminal of a DC input voltage to a negative terminal of the DC input voltage; and an energy storage capacitor coupled to the front-stage power circuit and the rear-stage power circuit, where a common node of the first and second magnetic components is directly coupled to the power switch.

Abstract: A method of controlling a synchronous rectifier circuit can include: adjusting a falling amplitude of a drive voltage of a synchronous rectifier switch in the synchronous rectifier circuit in a pull-down mode; adjusting a shielding time during which the synchronous rectifier switch is in a turn-off shielding mode and is not to be turned off; turning off the synchronous rectifier switch after a drain-source voltage of the synchronous rectifier switch reaches a turn-off threshold; and where the falling amplitude of the drive voltage in the pull-down mode and the shielding time for a current period are adjusted according to an operation state of the synchronous rectifier switch in a previous period.

Abstract: A method, apparatus and storage medium for controlling a navigation map. The method includes: acquiring navigation key points contained in a navigation route between a current position of a vehicle and a next maneuver point, upon detecting a scale display event; calculating an optimal scale of the navigation map, according to the navigation key points and a pixel size of a terminal screen; and navigating the navigation route according to the optimal scale. The method, apparatus and storage medium for controlling a navigation map provided by the embodiments of the present disclosure improve the guidance of the navigation map and reduce the risk of missing an intersection during driving.

Abstract: A switching power circuit for charging a battery can include: four switches extending between two ports of a low-frequency AC input voltage and an energy storage circuit, where the energy storage circuit and a primary winding of a transformer are coupled between first and second nodes, the first node is a common node of the first and second switches, and the second node is a common node of the third and fourth switches; a rectification circuit having an input terminal coupled to a secondary winding of the transformer; a DC-DC converter having an input terminal coupled to an output terminal of the rectification circuit, and generates a charging current; and a control circuit that adjusts the charging current by controlling an operation of the DC-DC converter according to a charging requirement, in order to make an average value of the charging current meet the charging requirement.

Abstract: A switching power supply circuit can include: a high-frequency switch network configured to generate a high-frequency AC signal by performing high-frequency chopping on a low-frequency AC input signal; a transformer configured to receive the high-frequency AC signal at a primary winding thereof, to perform a voltage conversion on the high-frequency AC signal, and to generate an output signal at a secondary winding of the transformer; and a rectifier module configured to generate a DC signal by rectifying the output signal at the secondary winding of the transformer.

Abstract: A control circuit for controlling a synchronous rectification switch of a resonant converter, where in a switching cycle, the control circuit is configured to: delay a first time period from a first moment; control the synchronous rectification switch to be turned on when a drain-source voltage of the synchronous rectification switch reaches a first threshold after the first time period; and where the first time period is generated based on an operating state of the synchronous rectification switch in a previous switching cycle.

Abstract: A control circuit for a switching converter having a main power switch and a freewheeling circuit, can be configured to: control the freewheeling circuit to be turned on in a first time interval after the main power switch is turned off; control the freewheeling circuit to be turned on in a second time interval after the first time interval, in order to reduce turn-on loss of the main power switch; and where the first time interval and the second time interval do not overlap each other in a switching cycle.

Abstract: A zero-voltage-switching control circuit for a switching power supply having a main power switch and a synchronous rectifier switch, is configured to: control the synchronous rectifier switch to be turned on for a first time period before the main power switch is turned on and after a current flowing through the synchronous rectifier switch is decreased to zero according to a switching operation of the main power switch in a previous switching period of the main power switch; and where a drain-source voltage of the main power switch is decreased when the main power switch is turned on, in order to reduce conduction loss.

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: The present disclosure provides a method for implementation of wireless relaying. The method is applied to a wireless relay device. The method comprises: a wireless relay device sends a probe request packet carrying a first detection code and device information of the wireless relay device; receive a probe response packet sent by a first wireless routing device, the probe response packet carrying an SSID and a password corresponding to the first wireless routing device; and send an authentication request packet to a second wireless routing device, the authentication request packet carrying the SSID and the password that is carried in the probe response packet sent by the second wireless routing device to the wireless relay device, and the second wireless routing device being one of the first wireless routing devices.