Abstract: A high-frequency isolation alternating/direct current conversion circuit and a control method thereof are disclosed. The conversion circuit includes an alternating current source, a direct current source, a resonant capacitor, a high-voltage energy-storage filter, a high-frequency inverter bridge, a drive circuit, a resonant inductor, a high-frequency isolation transformer, a direct current side synchronous switch, a control circuit, and the like. The conversion circuit is made to be switched between two working modes, a rectification mode and an inversion mode by using a preset direct current source reference voltage as a reference, according to an external voltage reference, and by using different turn-on working modes of the high-frequency inverter bridge.

Abstract: A high-frequency isolation alternating/direct current conversion circuit and a control method thereof are disclosed. The conversion circuit includes an alternating current source, a direct current source, a resonant capacitor, a high-voltage energy-storage filter, a high-frequency inverter bridge, a drive circuit, a resonant inductor, a high-frequency isolation transformer, a direct current side synchronous switch, a control circuit, and the like. The conversion circuit is made to be switched between two working modes, a rectification mode and an inversion mode by using a preset direct current source reference voltage as a reference, according to an external voltage reference, and by using different turn-on working modes of the high-frequency inverter bridge.

Abstract: An AC-DC conversion circuit includes an input rectifier circuit, a primary side input filtering capacitor, a primary side inverter circuit, a drive circuit, an isolation transformer, a secondary side rectifier circuit, a secondary side capacitors, and a control circuit connected between the secondary side output filtering capacitor and the drive circuit, where the drive circuit is connected to the primary side inverter circuit. The primary side inverter circuit and the primary side input filtering capacitor form a loop, so as to form a clamping resonant circuit. Inverter switching transistors operate in a zero voltage switching (ZVS) state. The secondary side rectifier circuit has two operation modes including a forward operation mode and a flyback operation mode. Each of the first and the second inverter switching transistors in the primary side inverter circuit is used as an inverter switching transistor or a clamping switching transistor according to an operation period.

Abstract: An AC-DC conversion circuit includes an input rectifier circuit, a primary side input filtering capacitor, a primary side inverter circuit, a drive circuit, an isolation transformer, a secondary side rectifier circuit, a secondary side capacitors, and a control circuit connected between the secondary side output filtering capacitor and the drive circuit, where the drive circuit is connected to the primary side inverter circuit. The primary side inverter circuit and the primary side input filtering capacitor form a loop, so as to form a clamping resonant circuit. Inverter switching transistors operate in a zero voltage switching (ZVS) state. The secondary side rectifier circuit has two operation modes including a forward operation mode and a flyback operation mode. Each of the first and the second inverter switching transistors in the primary side inverter circuit is used as an inverter switching transistor or a clamping switching transistor according to an operation period.

Abstract: A proactive worm containment (PWC) solution for enterprises uses a sustained faster-than-normal outgoing connection rate to determine if a host is infected. Two novel white detection techniques are used to reduce false positives, including a vulnerability time window lemma to avoid false initial containment, and a relaxation analysis to uncontain (or unblock) those mistakenly contained (or blocked) hosts, if there are any. The system integrates seamlessly with existing signature-based or filter-based worm scan filtering solutions. Nevertheless, the invention is signature free and does not rely on worm signatures. Nor is it protocol specific, as the approach performs containment consistently over a large range of worm scan rates. It is not sensitive to worm scan rate and, being a network-level approach deployed on a host, the system requires no changes to the host's OS, applications, or hardware.

Abstract: A pre-stage boost device, comprising: a selector switch (130); a power factor inductor (140), a common boost circuit (150), a rectifier circuit (160), and a filter circuit (170). The common boost circuit includes: connected in series a first switch (Q1), a second switch (Q2) and a third switch (Q3). The rectifier circuit includes two rectifier diodes (D5, D6). The filter circuit includes connected in series two capacitors (C1, C2). Maximum multiplexing of the main power components under the battery mode and the commercial power mode is achieved by this invention, the cost to performance ratio is also improved.

Abstract: A proactive worm containment (PWC) solution for enterprises uses a sustained faster-than-normal outgoing connection rate to determine if a host is infected. Two novel white detection techniques are used to reduce false positives, including a vulnerability time window lemma to avoid false initial containment, and a relaxation analysis to uncontain (or unblock) those mistakenly contained (or blocked) hosts, if there are any. The system integrates seamlessly with existing signature-based or filter-based worm scan filtering solutions. Nevertheless, the invention is signature free and does not rely on worm signatures. Nor is it protocol specific, as the approach performs containment consistently over a large range of worm scan rates. It is not sensitive to worm scan rate and, being a network-level approach deployed on a host, the system requires no changes to the host's OS, applications, or hardware.