Abstract: A power supply converter can include: an AC-DC linear circuit configured to rectify an AC input voltage to generate a DC voltage, and to transfer the input energy to an output terminal thereof during at least part of a time interval when the DC voltage is greater than an output voltage thereof, in order to generate a first output voltage and a first output current; and a conversion circuit configured to convert the first output voltage to a second output voltage, and to convert the first output current to a second output current for a load.

Abstract: In one embodiment, a network security device is configured to monitor data traffic between a first device and a second device. The network security device may be configured to intercept a first initial message of a first encrypted handshaking procedure for a first secure communication session between the first device and the second device, the first initial message specifying a hostname that has been encrypted using first key information associated with the network security device, decrypt at least a portion of the first initial message using the first key information to determine the hostname, re-encrypt the hostname using second key information associated with the second device, and send, to the second device, a second initial message of a second encrypted handshaking procedure for a second secure communication session between the network security device and the second device, the second initial message specifying the hostname re-encrypted using the second key information.

Abstract: A current drive circuit applied in an LED drive circuit that is compatible with a triac dimmer and is configured to generate a direct current bus voltage includes: a current generation circuit configured to receive the direct current bus voltage, and to generate a drive current based on a PWM dimming signal, in order to drive an LED load; and an input current regulation circuit configured to generate a regulation signal based on a duty cycle of the PWM dimming signal, in order to control an operation state of the triac dimmer.

Abstract: A voltage converter can include: an input end configured to receive an input voltage; an output end configured to generate an output voltage; N switched capacitor circuits sequentially coupled in series between the input end and the output end, where N is a positive integer greater than or equal to 2; where each switched capacitor circuit comprises a switch circuit and a flying capacitor, and at least the flying capacitor of an i-th switched capacitor circuit is configured as an output capacitor of an (i?1)-th switched capacitor circuit, where i is a positive integer that is greater than or equal to 2 and less than or equal to N; and a first energy storage element coupled to the output end.

Abstract: An apparatus for an LED driver with a silicon-controlled dimmer, can include: a bleeder circuit coupled to a DC bus of the LED driver; and a controller configured to control the bleeder circuit to draw a bleeder current from the DC bus when a conduction angel of the silicon-controlled dimmer is less than an angle threshold, in order to maintain a conduction state of the silicon-controlled dimmer.

Abstract: Presented herein are methodologies for implementing application security. A method includes generating an extraction vector based on a plurality of application security rules to be enforced, transmitting the extraction vector to a first agent operating on a first network device and to a second agent operating on a second network device; receiving, separately, from the first agent and from the second agent, first metadata generated by the first agent and second metadata generated by the second agent by the agents applying the extraction vector to network traffic passing, respectively, through the first network device and the second network device. The first metadata includes a transaction ID assigned by the first agent, and the second metadata includes the same transaction ID. The method further includes correlating the first metadata with the second metadata based on the transaction ID to construct a transactional service graph for the network traffic.

Abstract: A leakage protection circuit can include: a pull-down current generation circuit coupled between output terminals of a rectifier circuit; and a control circuit configured to control the pull-down current generation circuit to generate a pull-down current during a predetermined time interval, and to determine whether leakage occurs in accordance with a voltage detection signal that is representative of an output voltage of the rectifier circuit.

Abstract: A control circuit for a switching converter having a main power switch and an auxiliary power switch, where the control circuit is configured to: charge and discharge a junction capacitor of the main power switch during a turn-off period of the main power switch; and adjust a conduction time of the auxiliary power switch according to a difference between the charged and discharged charge levels across the junction capacitor.

Abstract: A power converter can include: a rectifier circuit; a silicon controlled dimmer coupled between an AC input terminal and an input terminal of the rectifier circuit; and a bleeder circuit coupled to an output terminal of the rectifier circuit, and being configured to provide a bleeder current after the silicon controlled dimmer is turned off. A method of controlling a power converter, can include: generating a bleeder current flowing though output terminals of a rectifier circuit of the power converter after a silicon controlled dimmer is turned off; and where the silicon controlled dimmer coupled to the rectifier circuit receives an AC input voltage.

Abstract: In one embodiment, a network security device is configured to monitor data traffic between a first device and a second device. The network security device may be configured to intercept a first initial message of a first encrypted handshaking procedure for a first secure communication session between the first device and the second device, the first initial message specifying a hostname that has been encrypted using first key information associated with the network security device, decrypt at least a portion of the first initial message using the first key information to determine the hostname, re-encrypt the hostname using second key information associated with the second device, and send, to the second device, a second initial message of a second encrypted handshaking procedure for a second secure communication session between the network security device and the second device, the second initial message specifying the hostname re-encrypted using the second key information.

Abstract: An LED drive circuit can include: a transistor and an LED load coupled in series, and being configured to receive a direct current bus voltage, and to generate an input current; and a control circuit configured to generate a drive signal to control an operation state of the transistor to control a distribution range of the input current by controlling an amount of accumulated charge of the input current during a half power frequency period.

Abstract: An apparatus for an LED driver with a silicon-controlled dimmer, can include: a bleeder circuit coupled to a DC bus of the LED driver; and a controller configured to control the bleeder circuit to draw a bleeder current from the DC bus when a conduction angle of the silicon-controlled dimmer is less than an angle threshold, in order to maintain a conduction state of the silicon-controlled dimmer.

Abstract: A detection circuit configured to detect the presence of a TRIAC dimmer for an LED driver, can include: a sampling circuit configured to receive a DC bus voltage, and to generate a voltage sampling signal that characterizes the DC bus voltage; and a detector configured to determine whether the LED driver is provided with the TRIAC dimmer in accordance with a duration of the voltage sampling signal being continuously greater than a first reference voltage.

Abstract: An apparatus can include: a light-emitting diode (LED) drive circuit having a silicon-controlled rectifier dimmer; and a bus voltage adjustment circuit configured to adjust a direct current bus voltage to delay a turn-on time instant of the silicon-controlled rectifier dimmer when a conduction angle signal is greater than an angle threshold.

Abstract: An apparatus can include: a linear drive circuit configured to control a drive current flowing through an LED load; a control circuit configured to acquire a conduction angle signal of a silicon-controlled rectifier dimmer and control the linear drive circuit; and the control circuit being configured to control the drive current to be decreased to reduce a current ripple and to maintain the silicon-controlled rectifier dimmer in a turn-on state when the conduction angle signal is less than a predetermined value.

Abstract: The disclosure relates to chemical synthesis, and more particularly to a biphenyltetradentate phosphite compound and a preparation and application thereof.

Abstract: A method of reducing THD can include: acquiring a first average inductor current during a first conduction time of a main power transistor of a power converter in a switching cycle; acquiring a second average inductor current during a second conduction time and an off time of the main power transistor in the switching cycle; and adjusting the second conduction time of the main power transistor in accordance with a difference between the first and second average inductor currents, where the first and second conduction times are successive.

Abstract: A control circuit for a switching converter, where: the control circuit is configured to generate a switching control signal according to an output voltage of the switching converter to control a switching state of a power transistor in the switching converter, and to adjust an output current of the switching converter; and a change trend of a length of a switching period of the power transistor is opposite to a change trend of the output voltage.

Abstract: A spirally ascending/descending cryogenic storage apparatus, comprising a cryogenic storage tank, the temperature in the cryogenic storage tank being continuously maintained at a certain deep cryogenic range. A driving component and a rotating storage rack are provided within the cryogenic storage tank. Multiple shelf boxes can be stored in the circumferential direction of the rotating storage rack. The driving component can drive the rotating storage rack to spirally ascent or spirally descent in the cryogenic storage tank. An access opening is provided on the cryogenic storage tank. The multiple shelf boxes can rotate to a position corresponding to the access opening with the movement of the rotating storage rack. The cryogenic storage tank is a liquid nitrogen tank. Liquid nitrogen is provided at the bottom part within the liquid nitrogen tank.

Abstract: A liquid nitrogen tank includes a tank, a storage rack and a drive component. The tank includes a tank cover, a tank body, a vacuum cavity layer and a heat-insulating cavity layer. The tank cover is disposed to cover on the tank body. An access door is provided on the tank body. A storage cavity is provided in the tank body. The heat-insulating cavity layer is provided on a periphery of the storage cavity. The vacuum cavity layer is provided on a periphery of the heat-insulating cavity layer. The storage rack is provided in the storage cavity. A plurality of cryopreservation tube racks are stored in the storage rack. The drive component can drive the storage rack to rotate and move up and down in the storage cavity, and can drive the plurality of cryopreservation tube racks to move to a position corresponding to the access door.