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: 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: 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: 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 LED driver with a silicon-controlled dimmer, can include: a supplementary current generating circuit configured to generate a supplementary current to ensure that an input current of the LED driver meets conduction requirements of the silicon-controlled dimmer; and where the supplementary current is determined in accordance with a drive current flowing through an LED load and a holding current of the silicon-controlled dimmer.

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: A power supply circuit can include: a constant current control circuit configured to receive a first voltage and a first current from a power supply, and to generate a second voltage and a second current that are substantially constant; a shunt circuit, where when the second current is greater than the output current, the shunt current circuit is configured to shunt the second current, and when the second current is less than or equal to the output current, the shunt circuit stops operating; and an energy storage circuit, where when the second current is greater than the output current, the energy storage circuit is configured to store energy, and when the second current is less than or equal to the output current, the energy storage circuit is configured to release energy and provide power for the load together with the constant current control circuit.

Abstract: A dimming signal conversion method can include: converting a dimming voltage to a PWM signal; adjusting a corresponding relationship between the dimming voltage and a duty cycle of the PWM signal according to brightness requirements of a LED light source; and generating a drive current of an LED driver based on the corresponding relationship.

Abstract: Techniques are presented herein for engagement and disengagement of Transport Layer Security proxy services with encrypted handshaking. In one embodiment, a first initial message of a first encrypted handshaking procedure for a first secure communication session between a first device and a second device is intercepted at a proxy device. The first initial message includes first key exchange information for encrypting the first encrypted handshaking procedure. A copy of the first initial message is stored at the proxy device. A second initial message of a second encrypted handshaking procedure for a second secure communication session between the proxy device and the second device is sent from the proxy device to the second device. The second initial message includes second key exchange information for encrypting the second encrypted handshaking procedure. The proxy device determines, based on the second encrypted handshaking procedure, whether to remain engaged or to disengage.

Abstract: An extended service-function chain (SFC) proxy is hosted on a network node and connected to a service path formed by one or more network nodes hosting a chain of service-functions applied to packets traversing the service path. The packets each include a service header having a service path identifier and a service index. A packet of a traffic flow destined for a service-function is received from the service path and sent to the service-function. An indication to offload the traffic flow is received from the service-function. The indication is stored in a flow table having entries each identifying a respective traffic flow. A subsequent packet of the traffic flow is received from the service path. The flow table is searched for the indication to offload the traffic flow. Upon finding the indication, the service-function is bypassed, and the subsequent packet is forwarded along the service path.

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 being configured to draw a bleeder current from the DC bus; and a controller configured to adjust the bleeder current to decrease in accordance with a first current sampling signal that represents a drive current flowing through an LED load after the silicon-controlled dimmer transitions from an off state to an on state. A method of controlling an LED driver can include: drawing a bleeder current from a DC bus of the LED driver; and controlling the bleeder current in accordance with a first current sampling signal representing a drive current flowing through an LED load to decrease after the silicon-controlled dimmer transitions from an off state to an on state.

Abstract: An LED drive circuit with a SCR dimmer, a circuit module and a control method therefor are provided. In each cycle of the alternating current, the bleeding current during a time period for turning on the SCR dimmer is distinguished from the bleeding current in a time period from an instant at which the SCR dimmer is turned on to an instant at which the LED load is lit. The bleeder circuit is controlled to perform bleeding at the first current during the time period for turning on the SCR dimmer, and then perform bleeding at the second current which is less than the first current from the instant at which the SCR dimmer is turned on, so that an average bleeding current of the bleeder circuit in each cycle can be reduced, the bleed loss can be reduced, and the efficiency of the LED drive circuit can be improved.

Abstract: An apparatus can include: a bleeder circuit coupled to a DC bus of an LED driver having a silicon-controlled dimmer; the bleeder circuit being configured to control a voltage of the DC bus to vary in a predetermined manner by drawing a bleed current through a bleed path when in a first mode, and to cut off the bleed path when in a second mode; and a controller configured to control the bleeder circuit to be in the first mode before the silicon-controlled dimmer is turned on.

Abstract: A system and method for multifunction device security includes determining when a device administrator's login credentials may have been compromised by violations of a device security policy. Approved device security settings corresponding to a multifunction peripheral are stored in memory and sent to the multifunction peripheral via the network interface. Current device security settings data are received from the multifunction peripheral via the network interface. The current device settings are tested relative to the approved device security settings. Violations determined from the testing trigger sending of a violation notification data to the multifunction peripheral via the network. Notification is received when violations exceed a threshold level and a reset of device administrator login credentials is commenced.

Abstract: Disclosed are a nicotinic acid or isonicotinic acid compound and a use thereof. The compound is the compound shown in Formula I, or a pharmaceutically acceptable salt, ester or solvate thereof. Efficacy tests demonstrate that the nicotinic acid compound can inhibit botulinum toxin endopeptidase activity in vitro, and has a significant protective effect on mice poisoned with botulinum toxin. On this basis, the compound may be used to prepare a drug preventing and/or treating botulinum toxin exposure and/or poisoning.

Abstract: An apparatus can include: a bleeder circuit coupled to a DC bus of an LED driver having a silicon-controlled dimmer, where the bleeder circuit is controlled to discharge a current of the DC bus; a controller configured to control the bleeder circuit to discharge the DC bus at a first current after detecting a transition in a voltage of the DC bus; and the controller being configured to control the bleeder circuit to discharge the DC bus at a second current until the DC bus voltage rises to a predetermined load driving voltage, where the second current is less than the first current.

Abstract: A method of controlling an LED driver can include: generating a first comparison signal using a first reference voltage, the first comparison signal having a duty cycle in accordance with an alternating current input voltage generated by a transformer of the LED driver, and representing an operation frequency of an input source; generating a conversion voltage signal by an averaging operation of the first comparison signal with a time constant that is greater than a switching period of an electronic transformer; generating a second comparison signal by comparing the conversion voltage signal against a second reference voltage; and determining whether the transformer is the electronic transformer or a power frequency transformer based on the second comparison signal.

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: 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: A handshake procedure to establish a first connection between a client and a server is monitored at an intermediate network device. A request message sent to the server from the client is received at the intermediate network device. The request message includes parameters defining a manner of receiving information from the server. The parameters defining the manner of receiving information from the server are modified to produce modified parameters. A redirect message is sent from the intermediate network device to the client to induce or cause the client to establish a second connection with the server based upon the modified parameters, wherein the redirect message contains the modified parameters.