Abstract: The present invention discloses a method and an apparatus for controlling a flyback converter, the flyback converter including a main switch, a transformer and an auxiliary switch. The method includes: obtaining a first voltage signal and a second voltage signal, the first voltage signal representing an input voltage of the flyback converter, and the second voltage signal representing an output voltage of the flyback converter; controlling turn-on of the auxiliary switch, wherein the turn-on time period of the auxiliary switch is determined according to the first voltage signal and the second voltage signal; and turning on the main switch at ZVS condition, wherein the main switch is turned on at the time delayed for a duration of a dead time after turning off of the auxiliary switch.

Abstract: A flyback converter includes: a transformer, including a primary winding and a secondary winding; a primary side switch electrically coupled to the primary winding; a feedback circuit, configured to detect an output voltage of a load and output a feedback voltage signal; a current detecting circuit, configured to sample current flowing through the primary side switch and output a current signal; and a control circuit, coupled to the feedback circuit and the current detecting circuit and configured to respectively receive the feedback voltage signal and the current signal, and output a switch control signal to the primary side switch; and wherein the control circuit configured to control a switching frequency of the primary side switch to increase with increase of an output power, and an increasing speed of the switching frequency to decrease with the increase of the output power.

Abstract: The present invention discloses a transmission control method, apparatus and system, so as to effectively utilize network link resources. The method of the present invention includes: acquiring link status information about a network; determining recommended values of TCP transmission parameters according to the link status information; and performing TCP transmission according to the determined recommended values of the parameters. The present invention can enable TCP transmission status to reflect network congestion status more real, prevent a congestion misjudgment from occurring, and improve a utilization ratio of link resources in a network.

Abstract: A control device, which is applied to a flyback converter including an auxiliary switch, includes: an on-time setter, configured to set an on-time threshold according to a reference value and an output voltage of the flyback converter; and an on-time controller, configured to output a control signal to turn on the auxiliary switch, and turn off the auxiliary switch when on-time of the auxiliary switch reaches the on-time threshold. According to the present disclosure, it is able to achieve zero voltage switching of a primary-side switch of the flyback converter with variable outputs.

Abstract: A control device applied to a flyback converter including an auxiliary switch includes: an output voltage integrator, configured to integrate an output voltage of the flyback converter to obtain an amplitude of a negative magnetizing current of the flyback converter; and a comparator controller, configured to compare the obtained amplitude of the negative magnetizing current with a reference value, and turn off the auxiliary switch according to a comparison result. According to the present disclosure, it is able to achieve zero voltage switching of a primary-side switch of the flyback converter with variable outputs.

Abstract: A control device applied to a flyback converter including an auxiliary switch includes: a current detector configured to detect an amplitude of a current of the flyback converter to obtain an amplitude of a negative magnetizing current of the flyback converter; and a comparator controller configured to compare the amplitude of the negative magnetizing current obtained by the current detector with a reference value, and turn off the auxiliary switch according to a comparison result. According to the present disclosure, it is able to achieve zero-voltage switching of a primary-side switch of the flyback converter with variable outputs.

Abstract: A flyback power converter includes a hybrid clamp circuit and a corresponding power management unit that substantially optimizes the performance of the flyback power converter in its entire line and load ranges. The clamp circuit, which is connected in parallel to a primary winding of the flyback transformer, includes a parallel combination of a capacitor and resistor that is connected in series with a parallel combination of a switch and a diode. By sensing the operating conditions, the power management circuit configures the clamp circuit either as a passive clamp or as an active clamp. In the passive-clamp configuration, the switch is kept turned off. In the active-clamp configuration, the switch operates with pulse-width modulation (PWM) which enables ZVS turn-on of the main switch.

Abstract: A PCB planar transformer, comprising: at least one primary winding layer, each formed with a primary winding therein, wherein wire traces constituting the primary winding have a first horizontal width; at least one secondary winding layer, each formed with a secondary winding therein, wherein wire traces constituting the secondary winding have a second horizontal width; and at least one shielding layer, each located between the primary winding layer and the adjacent secondary winding layer, wherein the shielding layer is formed with a conductor therein, and the conductor in the shielding layer has a third horizontal width, wherein at least one of the first horizontal and the second horizontal width is smaller than the third horizontal width of the conductor in the shielding layer.

Abstract: A control device applied to a flyback converter including an auxiliary switch includes: a current detector configured to detect an amplitude of a current of the flyback converter to obtain an amplitude of a negative magnetizing current of the flyback converter; and a comparator controller configured to compare the amplitude of the negative magnetizing current obtained by the current detector with a reference value, and turn off the auxiliary switch according to a comparison result. According to the present disclosure, it is able to achieve zero-voltage switching of a primary-side switch of the flyback converter with variable outputs.

Abstract: A control device applied to a flyback converter including an auxiliary switch includes: an output voltage integrator, configured to integrate an output voltage of the flyback converter to obtain an amplitude of a negative magnetizing current of the flyback converter; and a comparator controller, configured to compare the obtained amplitude of the negative magnetizing current with a reference value, and turn off the auxiliary switch according to a comparison result. According to the present disclosure, it is able to achieve zero voltage switching of a primary-side switch of the flyback converter with variable outputs.

Abstract: A control device, which is applied to a flyback converter including an auxiliary switch, includes: an on-time setter, configured to set an on-time threshold according to a reference value and an output voltage of the flyback converter; and an on-time controller, configured to output a control signal to turn on the auxiliary switch, and turn off the auxiliary switch when on-time of the auxiliary switch reaches the on-time threshold. According to the present disclosure, it is able to achieve zero voltage switching of a primary-side switch of the flyback converter with variable outputs.

Abstract: A flyback power converter includes a hybrid clamp circuit and a corresponding power management unit that substantially optimizes the performance of the flyback power converter in its entire line and load ranges. The clamp circuit, which is connected in parallel to a primary winding of the flyback transformer, includes a parallel combination of a capacitor and resistor that is connected in series with a parallel combination of a switch and a diode. By sensing the operating conditions, the power management circuit configures the clamp circuit either as a passive clamp or as an active clamp. In the passive-clamp configuration, the switch is kept turned off. In the active-clamp configuration, the switch operates with pulse-width modulation (PWM) which enables ZVS turn-on of the main switch.

Abstract: The present disclosure discloses a PCB winding transformer and a coil board thereof. The PCB winding transformer comprises a coil board and a magnetic core. The coil board includes a primary coil and a secondary coil. The primary coil and the secondary coil are wound around a magnetic core column of the magnetic core. At least two via holes which correspond to the primary coil and the secondary coil respectively are disposed in the coil board. In the primary coil and the secondary coil, the via hole corresponding to the coil with less turns is disposed between an inner side of the coil with more turns and the magnetic core column.

Abstract: The present invention discloses a control method and a control apparatus for a Flyback circuit. The Flyback circuit includes a primary switch, a secondary rectifier unit, a transformer and an output capacitor. The secondary rectifier unit includes a first terminal and a second terminal, which are electrically connected to the transformer and the output capacitor, respectively. In the control method for a Flyback circuit, after the secondary rectifier unit is controlled to be turned on once or twice according to the input voltage and/or output power of the Flyback, the primary switch is turned on to achieve the zero-voltage-switching. According to the invention, the zero-voltage-switching (ZVS) of the primary switch can be achieved under the entire input voltage range and the entire load range without adding additional power devices.

Abstract: The present invention discloses a control method and a control apparatus for a Flyback circuit. The Flyback circuit includes a primary switch, a secondary rectifier unit, a transformer and an output capacitor. The secondary rectifier unit includes a first terminal and a second terminal, which are electrically connected to the transformer and the output capacitor, respectively. In the control method for a Flyback circuit, after the secondary rectifier unit is controlled to be turned on once or twice according to the input voltage and/or output power of the Flyback, the primary switch is turned on to achieve the zero-voltage-switching. According to the invention, the zero-voltage-switching (ZVS) of the primary switch can be achieved under the entire input voltage range and the entire load range without adding additional power devices.

Abstract: A peer enrollment method, a route updating method, a communication system, and relevant devices to improve security of a peer-to-peer (P2P) network. The peer enrollment method includes: receiving an enrollment request from a peer, where the enrollment request carries identity information of the peer; verifying the identity information of the peer, and if the verification succeeds, obtaining peer location information of the peer and generating a peer credential according to the peer location information; and sending the peer credential carrying the peer location information to the peer so that the peer joins the P2P network according to the peer credential. Embodiments of the present application further provide a route updating method, a communication system, and relevant devices. Embodiments of the present application may improve security of the P2P network effectively.

Abstract: A peer enrollment method, a route updating method, a communication system, and relevant devices to improve security of a peer-to-peer (P2P) network. The peer enrollment method includes: receiving an enrollment request from a peer, where the enrollment request carries identity information of the peer; verifying the identity information of the peer, and if the verification succeeds, obtaining peer location information of the peer and generating a peer credential according to the peer location information; and sending the peer credential carrying the peer location information to the peer so that the peer joins the P2P network according to the peer credential. Embodiments of the present application further provide a route updating method, a communication system, and relevant devices. Embodiments of the present application may improve security of the P2P network effectively.

Abstract: The present disclosure provides a discovery method, a device and a system for an application layer traffic optimization server, which relate to communication field, so as to reduce the cross-domain traffic and meet the network optimization demand of a network ISP as an internet access point. The method for an application layer traffic optimization server, related to a terminal side, comprising: obtaining a domain name of a proxy server for a terminal data layer to access internet; obtaining, according to a query name constructed using the domain name of the proxy server, an address of an application layer traffic optimization ALTO server related to the proxy server from a domain name server DNS; and communicating with the ALTO server according to the address of the ALTO server. Embodiments of the present disclosure are mainly applied to the communication between the terminal and the ALTO server.

Abstract: A switching power supply includes: a rectifying unit; a Bulk capacitor; a converter; a monitoring circuit; a control circuit, controlling discharging of the Bulk capacitor, being configured to perform controls such that the voltage across the Bulk capacitor maintains the peak value after the Bulk capacitor having been charged to a peak value of AC voltage, and to perform controls such that the Bulk capacitor discharges from a peak value when the instantaneous absolute value of the AC voltage is smaller than or equal to the preset voltage. A method for controlling a voltage of a Bulk capacitor in the switching power supply includes detecting an instantaneous absolute value of the AC voltage; comparing the detected instantaneous absolute value of the AC voltage with a preset voltage; and controlling discharging and charging state of the Bulk capacitor according to comparison results.

Abstract: A packet processing method and an apparatus are provided. A first SFC proxy of a first SF entity splits a first packet to obtain a first original packet and a first SFC header, and the first SFC proxy sends the first SFC header to a second SFF. The first SF entity processes the first original packet to obtain a second original packet, and sends the second original packet to a service classifier. The service classifier sends, to the second SFF, a second packet that is obtained after the service classifier adds a second SFC header to the second original packet. The second SFF changes the second SFC header in the second packet into the first SFC header. In this way, a first packet carrying a first SFC header can be transmitted in a network architecture in which a legacy SF exists, so that the legacy SF becomes compatible.