Abstract: The application discloses a preparation method for an aluminum alloy cavity casting filled with special-shaped foamed aluminum. The preparation method includes: preparing special-shaped foamed aluminum in a first mold by adopting a powder metallurgy foaming method; fixing the special-shaped foamed aluminum coated with the soldering flux in a second mold after the special-shaped foamed aluminum is coated with soldering flux; and casting by using molten aluminum alloy. According to the preparation method for the aluminum alloy cavity casting filled with the special-shaped foamed aluminum, the overall strength of the casting can be improved while the wall thickness of the casting is reduced to meet the requirement that the overall quality of the casting is not increased.

Abstract: A heater and a cigarette utensil are provided. The heater includes: a base body; an electrically conductive coating, including a first electrode and a second electrode formed to be spaced apart on a surface of the base body; and an electric heating coating formed on the surface of the base body. Each of the first electrode and the second electrode includes a first portion and a second portion. The first portion of the first electrode and the first portion of the second electrode are both at least partially covered by the electric heating coating to be located between the surface of the base body and the electric heating coating, and are electrically connected to the electric heating coating. The second portion of the first electrode and the second portion of the second electrode are both exposed from the surface of the base body.

Abstract: An isolated power converter can include: a primary side having a primary winding and a primary power transistor; a secondary side having a secondary winding and a secondary power transistor; a secondary control circuit configured to change a voltage across the secondary winding to change a voltage across the primary winding during a period when both the primary power transistor and the secondary power transistor are in a turn-off state; and a primary control circuit configured to control switching states of the primary power transistor, such that an output signal of the isolated power converter matches an output demand.

Abstract: A synchronous rectification control circuit for controlling a switching circuit comprising a synchronous rectifier switch, can include: a drive circuit configured to generate a drive signal to control switching states of the synchronous rectifier switch; and a voltage regulation circuit configured to control the drive circuit to adjust an amplitude of the drive signal to decrease to a preset threshold in an adjustment state when a drain-source voltage of the synchronous rectifier switch is greater than an adjustment threshold before the synchronous rectifier switch is turned off, where a time that the voltage regulation circuit is in the adjustment state is an adjustment time.

Abstract: The application discloses a preparation method for an aluminum alloy cavity casting filled with special-shaped foamed aluminum. The preparation method includes: preparing special-shaped foamed aluminum in a first mold by adopting a powder metallurgy foaming method; fixing the special-shaped foamed aluminum coated with the soldering flux in a second mold after the special-shaped foamed aluminum is coated with soldering flux; and casting by using molten aluminum alloy. According to the preparation method for the aluminum alloy cavity casting filled with the special-shaped foamed aluminum, the overall strength of the casting can be improved while the wall thickness of the casting is reduced to meet the requirement that the overall quality of the casting is not increased.

Abstract: A switching control circuit for a flyback converter having a main switch coupled to a primary winding of a transformer and a rectifier switch coupled to a secondary winding of the transformer, can include: a first voltage generating circuit configured to generate a first voltage sampling signal representing information of an input voltage; a synchronous rectification control circuit configured to adjust an on-time of the rectifier switch according to the first voltage sampling signal in order to adjust an absolute value of a negative current flowing through the secondary winding; and where the negative current is configured to discharge a parasitic capacitor of the main switch in order to reduce a drain-source voltage of the main switch.

Abstract: A synchronous rectification control circuit for controlling a switching circuit comprising a synchronous rectifier switch, can include: a drive circuit configured to generate a drive signal to control switching states of the synchronous rectifier switch; and a voltage regulation circuit configured to control the drive circuit to adjust an amplitude of the drive signal to decrease to a preset threshold in an adjustment state when a drain-source voltage of the synchronous rectifier switch is greater than an adjustment threshold before the synchronous rectifier switch is turned off, where a time that the voltage regulation circuit is in the adjustment state is an adjustment time.

Abstract: An isolated power converter can include: a primary side having a primary winding and a primary power transistor; a secondary side having a secondary winding and a secondary power transistor; a secondary control circuit configured to change a voltage across the secondary winding to change a voltage across the primary winding during a period when both the primary power transistor and the secondary power transistor are in a turn-off state; and a primary control circuit configured to control switching states of the primary power transistor, such that an output signal of the isolated power converter matches an output demand.

Abstract: A synchronous rectification control circuit for controlling a switching circuit comprising a synchronous rectifier switch, can include: a drive circuit configured to generate a drive signal to control switching states of the synchronous rectifier switch; and a voltage regulation circuit configured to control the drive circuit to adjust an amplitude of the drive signal to decrease to a preset threshold in an adjustment state when a drain-source voltage of the synchronous rectifier switch is greater than an adjustment threshold before the synchronous rectifier switch is turned off, where a time that the voltage regulation circuit is in the adjustment state is an adjustment time.

Abstract: A frequency control circuit, applied in a switching converter, can be configured to: regulate an off time of a power transistor of the switching converter in one switching cycle according to an on time of the power transistor, or regulate the on time of the power transistor in one switching cycle according to the off time of the power transistor; and maintain an operating frequency of the switching converter to be within a predetermined range.

Abstract: A switching control circuit for a flyback converter having a main switch coupled to a primary winding of a transformer and a rectifier switch coupled to a secondary winding of the transformer, can include: a first voltage generating circuit configured to generate a first voltage sampling signal representing information of an input voltage; a synchronous rectification control circuit configured to adjust an on-time of the rectifier switch according to the first voltage sampling signal in order to adjust an absolute value of a negative current flowing through the secondary winding; and where the negative current is configured to discharge a parasitic capacitor of the main switch in order to reduce a drain-source voltage of the main switch.

Abstract: A synchronous rectification control circuit for controlling a switching circuit comprising a synchronous rectifier switch, can include: a drive circuit configured to generate a drive signal to control switching states of the synchronous rectifier switch; and a voltage regulation circuit configured to control the drive circuit to adjust an amplitude of the drive signal to decrease to a preset threshold in an adjustment state when a drain-source voltage of the synchronous rectifier switch is greater than an adjustment threshold before the synchronous rectifier switch is turned off, where a time that the voltage regulation circuit is in the adjustment state is an adjustment time.

Abstract: A frequency control circuit, applied in a switching converter, can be configured to: regulate an off time of a power transistor of the switching converter in one switching cycle according to an on time of the power transistor, or regulate the on time of the power transistor in one switching cycle according to the off time of the power transistor; and maintain an operating frequency of the switching converter to be within a predetermined range.

Abstract: A frequency control circuit, applied in a switching converter, can be configured to: regulate an off time of a power transistor of the switching converter in one switching cycle according to an on time of the power transistor, or regulate the on time of the power transistor in one switching cycle according to the off time of the power transistor; and maintain an operating frequency of the switching converter to be within a predetermined range.

Abstract: A frequency control circuit, applied in a switching converter, can be configured to: regulate an off time of a power transistor of the switching converter in one switching cycle according to an on time of the power transistor, or regulate the on time of the power transistor in one switching cycle according to the off time of the power transistor; and maintain an operating frequency of the switching converter to be within a predetermined range.

Abstract: A flyback converter can include: a power switch controlled to be turned on/off to control a current through a primary side; a first primary winding coupled between an input terminal and a first terminal of the power switch, where a dotted terminal of the first primary winding is coupled to a first terminal of the power switch; a second primary winding coupled between a second terminal of the power switch and a primary grounding terminal, where a dotted terminal of the second primary winding is coupled to the primary grounding terminal; a secondary winding configured between the first and second primary windings in a radial direction of a magnetic core, where the first primary winding, the second primary winding, and the secondary winding are wound around the magnetic core; and a secondary rectifier and filter circuit coupled with the secondary winding, and configured to generate a stable current/voltage.

Abstract: The present application discloses a device for wireless charging circuit, comprising: a primary circuit box, which comprises at least one first switch unit; a secondary circuit box, which comprises at least one second switch unit; a transmission plate, which comprises a primary inductor of a transformer and a primary compensation capacitor, the primary inductor being coupled in series with the primary compensation capacitor; a receiving plate, which comprises a secondary inductor of the transformer; the transmission plate and the receiving plate are magnetically coupled with each other; the transmission plate is coupled with the primary circuit box; and the receiving plate is coupled with the secondary circuit box. The voltage between external terminals of transmission plate and the voltage between external terminals of receiving plate can satisfy the safety requirement.

Abstract: A flyback converter can include: a power switch controlled to be turned on/off to control a current through a primary side; a first primary winding coupled between an input terminal and a first terminal of the power switch, where a dotted terminal of the first primary winding is coupled to a first terminal of the power switch; a second primary winding coupled between a second terminal of the power switch and a primary grounding terminal, where a dotted terminal of the second primary winding is coupled to the primary grounding terminal; a secondary winding configured between the first and second primary windings in a radial direction of a magnetic core, where the first primary winding, the second primary winding, and the secondary winding are wound around the magnetic core; and a secondary rectifier and filter circuit coupled with the secondary winding, and configured to generate a stable current/voltage.

Abstract: Disclosed are an isolated power converter and a switching control signal using the same. In the isolated power converter, the positions of the power switch and the primary winding are exchanged, and the feedback voltage detection and secondary current zero-crossing detection are carried out in accordance with the voltage across the primary winding. Thus, primary side control can still be implemented without employment of an auxiliary winding.

Abstract: Disclosed are an isolated power converter and a switching control signal using the same. In the isolated power converter, the positions of the power switch and the primary winding are exchanged, and the feedback voltage detection and secondary current zero-crossing detection are carried out in accordance with the voltage across the primary winding. Thus, primary side control can still be implemented without employment of an auxiliary winding.