Abstract: In the present disclosure, the multi-level AC/DC conversion circuit and the multi-level DC/DC conversion circuit calculate the duty ratio of synchronous rectification switch according to the input voltage, the output voltage, the interval time of turning on the main switch, the switching cycle and the duty ratio of main switch, thereby eliminating the need for additional zero-current detecting function or zero-crossing detection circuit in conventional AC/DC conversion circuits. Accordingly, for the multi-level AC/DC conversion circuit and the multi-level DC/DC conversion circuit of the present disclosure, the cost is reduced, and the reliability is enhanced.

Abstract: A multi-level conversion circuit and a control method for flying capacitor voltage thereof are provided. In the multi-level conversion circuit, each flying capacitor is connected between a common connection node of the lower switches connected therewith and a common connection node of the upper switches connected therewith. The control method includes steps of: (a) determining the main switch and synchronous rectification switch of the lower and upper switches; (b) acquiring an adjustment value corresponding to each flying capacitor; (c) adjusting a duty ratio of the main switch according to the adjustment value corresponding to the flying capacitor connected therewith; and (d) when the multi-level conversion circuit working in a CCM, increasing a phase-shift angle between the main switches by an angle to make a peak value or a valley value of an inductor current remain unchanged before and after adjusting the duty ratio.

Abstract: A multi-level conversion circuit and a control method for flying capacitor voltage thereof are provided. In the multi-level conversion circuit, each flying capacitor is connected between a common connection node of the lower switches connected therewith and a common connection node of the upper switches connected therewith. When the conversion circuit works in a DCM, the control method includes steps of: (a) determining the main switch and synchronous rectification switch of the lower and upper switches; (b) acquiring an adjustment value corresponding to each flying capacitor; and (c) adjusting a duty ratio of the main switch according to the adjustment value corresponding to the flying capacitor connected therewith, wherein the adjustment trend of the duty ratio under D<(N?2)/(N?1) is opposite to that under (N?2)/(N?1)<D?1, and D is the duty ratio before the adjustment.

Abstract: Provided are an interaction method and apparatus in a live streaming room, a device, and a storage medium. The method comprises: in response to a trigger operation for a preset drawing entry on a live streaming room page, jumping to a graphic drawing page from the live streaming room page, a drawing trajectory set for a preset object being displayed on the graphical drawing page; when a drawing stroke on the graphic drawing page is received, matching the drawing stroke with the drawing trajectory; and if it is determined that the drawing stroke is successfully matched with the drawing trajectory, displaying prompt information about successful participation in a preset activity, the preset activity and the preset drawing entry having a correspondence.

Abstract: A photovoltaic module, including a laminate including a solder strip; and a junction box arranged on a surface of the laminate and including a plate connected to the solder strip by laser soldering. The plate has a first region and a second region, in which a region covered by the solder strip on the plate is the first region, and a region not covered by the solder strip on the plate is the second region. A soldering seam formed by laser soldering includes a first soldering seam and a second soldering seam. The first soldering seam is located in the first region, and the first soldering seam extends through the solder strip into the plate along a thickness direction of the laminate. The second soldering seam is located in the second region, and the second soldering seam extends directly into the plate along the thickness direction of the laminate.

Abstract: Embodiments of the present disclosure relates to a photovoltaic module and a method for producing the photovoltaic module. The photovoltaic module includes a photovoltaic laminate and a junction box. The photovoltaic laminate includes a plurality of solar cells, at least one solder strip, a rear plate and a wiring member. The at least one solder strip is electrically connected with the wiring member. The junction box includes a bonding pad. The wiring member passes through an opening defined on the rear plate and abuts the bonding pad, and the wiring member is connected with the bonding pad by laser welding. A plurality of weld seams are formed in a welding region. Each weld seam extends from the wiring member towards interior of the bonding pad, and an extension depth of each weld seam in the bonding pad is not greater than 80% of a thickness of the bonding pad.

Abstract: The local light filling can be performed on a point in a photographed image. Alternatively, by adjusting an inner width of the flash chamber, the illumination field of view of the flash matches the focal length of the optical system to which the flash is applied, thereby implementing light concentration at a telephoto end and light scattering at a wide-angle end.

Abstract: The local light filling can be performed on a point in a photographed image. Alternatively, by adjusting an inner width of the flash chamber, the illumination field of view of the flash matches the focal length of the optical system to which the flash is applied, thereby implementing light concentration at a telephoto end and light scattering at a wide-angle end.