Abstract: A synchronous rectifier comprises at least one rectification switch (102, 103), and a control circuit (104) for controlling the at least one rectification switch to allow unidirectional current flow only. The control circuit comprises at least one current sensor (105, 106) for sensing an alternating component of current of the at least one rectification switch, and at least one driver circuit (107, 108) for controlling the at least one rectification switch at least partly on the basis of the direction of the sensed alternating component. Using the alternating component for controlling the rectification switch removes a need to compare the current to any non-zero constant or adjustable threshold value, and thus challenges related to defining the threshold value can be avoided. The synchronous rectifier can be for example a part of a resonant converter.

Abstract: The present invention discloses a current regulator circuit capable of reducing current ripple and a method of reducing current ripple. A power supply circuit generates a load current which originally has a current ripple. The load current is supplied to a load circuit. The current regulator circuit includes a regulator switch coupled to the load circuit, a current sense circuit for sensing the load current, and a control circuit. The control circuit controls the regulator switch to regulate a peak of a current sense signal minus an average of the current sense signal to a non-negative first predetermined value, or regulate the peak minus a valley of the current sense signal to a non-negative second predetermined value.

Abstract: A power conversion device includes a first detection circuit that acquires input information about an AC voltage and/or an alternating current which are inputted to the power conversion device from an AC power supply, a rectifier circuit, an inverter circuit including a switch, and a control circuit that generates a pulse signal for the switch while the control circuit (A) determines, based on the input information, whether the rectifier circuit is in a state in which the rectifier circuit allows switching noise to propagate from the switch to the AC power supply and (B) changes a frequency of the pulse signal with time at least in a period in which the rectifier circuit is in the state.

Abstract: A control circuit for a switch mode power supply (SMPS) includes a power switch for coupling to a primary winding of the power supply and a startup resistor coupled to an external input voltage and to a control terminal of the power switch. The control circuit also includes a controller. During startup, the controller is configured to cause the power switch to amplify a startup current from an external input voltage through the startup resistor and provide a startup power to the controller. During normal operation, the controller is configured to provide a power switch control signal to turn on and off the power switch for controlling a current flow in the primary winding and regulating an output of the power supply. The controller is configured to provide a current signal for driving an NPN power switch and to provide a voltage signal for driving an NMOS power switch.

Abstract: A method of controlling a DC/AC converter (2) comprises the steps of (a) providing a desired AC side reference value (VAmp); (b) setting a reference correction value (VAmp,corr,1); (c) calculating an AC side reference signal (VAC,set,1) as a function of the desired AC side reference value (VAmp) and the reference correction value (VAmp,corr,1); (d) obtaining an actual AC side signal (VAC,Act,1); and (e) calculating a converter control signal (MAC,1) as a function of the AC side reference signal (VAC,Set,1) and the actual AC side signal (VAC,Act,1); wherein the setting of the reference correction value (VAmp,corr,1) is based on a relation of the desired AC side reference value (VAmp) and the actual AC side signal (VAC,Act,1).

Abstract: This invention is a method and system for reserving and controlling access to products and services at a remote location via a communications network. In one or more embodiment, a user uses a client computer to select desired products and services. The system returns a price offer for the packaged products and services. Upon acceptance of the price offer, the selection of products and services is forwarded to an operations center for the building of an event regarding the redemption of the products and services. The system allocates a time frame for the redemption of each of the products and services as well as determining the order of redemption, based on polling a plurality of users desiring the same products and services in an event. The information generated by the operation center is then forwarded to a location for the redemption of the products and services.

Abstract: A power supply apparatus (10) includes a voltage input side (102), a power switch circuit (104), a voltage output side (106), a pulse width modulation signal generating circuit (108) and a burst frequency detection circuit (110). According to a pulse width modulation signal (114), the pulse width modulation signal generating circuit (108) controls the power switch circuit (104), so that the power supply apparatus (10) enters a burst mode. The burst frequency detection circuit (110) detects a burst frequency of the power switch circuit (104). The burst frequency detection circuit (110) informs the pulse width modulation signal generating circuit (108) that the burst frequency is in an audio frequency range if the burst frequency is in the audio frequency range. The power supply apparatus (10) leaves from the burst mode to avoid audio noise.

Abstract: A converter performs full-wave rectification on a single-phase voltage, thus outputting a rectified voltage across DC power supply lines. An inverter receives the rectified voltage and then supplies a three-phase AC current to an inductive load. Between the DC power supply lines is connected a charge and discharge circuit. The charge and discharge circuit includes a buffer circuit and a boost circuit. The buffer circuit includes a series connection between a capacitor and a switch. The boost circuit, which may be configured by a boost chopper, includes a switch, a reactor and a diode. The charge and discharge circuit provides and receives part of pulsations of the power input to the converter between the DC power supply lines.

Abstract: The present invention provides a coordinated coil scheduling method of multiple production lines in cold rolling area in steel plant, comprising: acquiring the information about the candidate coils to be scheduled in each of the multiple production lines in cold rolling area; building a coordinated coil scheduling model of multiple lines; obtaining the initial coordinated coil schedule of multiple lines by using a heuristic algorithm; improving the initial coordinated coil schedule in real time; and sending the improved coordinated coil schedule to the ACS of each production line. In this method, besides different production technological requirements of each coil, the cohesion relationship of different production lines are taken into account to make material supply to each equipment reasonable, and the smooth production process of coils in each of the lines is guaranteed with the changeover minimized, such that the whole efficiency of the manufacturing process is improved.

Abstract: Slab matching method for multiple hot rolling lines comprises grouping the slabs and orders to obtain slab-order groups; based on a criterion of slab-order specification matching, determining a matching condition between the slab and the order within each of slab-order groups; quantitatively describing a mis-order slab matching problem; matching the mis-order slabs to the orders; quantitatively describing a slab re-matching problem; adjusting the matching relationships of all the slabs and the orders to form a final scheme of slab matching to be distributed to the multiple hot rolling lines to execute, and the slab matching method is completed. The present invention improves the utilization of the mis-order slabs while reducing the waste of energy caused by repeated steelmaking, reducing the consumption of the material and lowers the amount of left material and stored material and saves production cost and storage cost for the plant.

Abstract: A regulator circuit includes: a regulator part configured to generate a constant internal power supply voltage based on an external power supply voltage; a connection port configured to receive power from the regulator part and to be connected to a connection cable having a predetermined cable resistance, the connection cable is configured to electrically connect the connection port to an external device; a current detecting part configured to detect a power supply current when the connection cable is connected to the connection port; and a voltage compensation part configured to compensate a voltage corresponding to a voltage drop due to the cable resistance according to a current value detected by the current detecting part.

Abstract: A method for identifying a source of a job referral, the method including identifying a URL that the job applicant uses to access a web page with functionality to enable the job applicant to apply for the first job, identifying a first job message record using the URL, obtaining an original job message record for an original job message using the first job message record, determining a first sender of the original job message from the original job message record, determining that a second job message was sent to the job applicant for a second job at the company by a second sender, wherein the second job message was sent to the job applicant before the first job message and wherein the second job message was sent to the job applicant within a look-back period, and identifying the second sender as the source of the referral for the first job.

Abstract: A resonant power converter. An embodiment with a fullbridge converter is disclosed, controlled with feedback or feedforward technique. Switching schemes are either based on a sort of look up table or on measurement of current or voltage. Dead time may be adjusted. Timing may be such, that in the respective diagonal pairs of the converter, one switch is switched on for a different time (different pulse width) than the other. Use in a relative high power environment for about 20 KW in e.g. an X-Ray or Computer Tompgrapy System.

Abstract: A controller for a switched mode power converter includes limit-to-valley ratio circuitry, an on-time generator, and a drive circuit. The limit-to-valley ratio circuitry is coupled to generate a ratio signal in response to sensing a switch current of a switch that regulates an output of the switched mode power converter. The ratio signal is representative of a time ratio between a first length of time that the switch current is at or above a switch current limit and a second length of time that the switch current is at or below a switch current valley that is a portion of the switch current limit. The on-time generator is coupled to vary a switch on-time signal in response to receiving the ratio signal. The drive circuit is coupled to output a drive signal to a control terminal of the switch in response to receiving the switch on-time signal.

Abstract: According to an embodiment, a circuit comprising includes a first switching circuit coupled to a power supply input, a second switching circuit coupled to an output of the first switching circuit, a supply capacitor coupled to the second switching circuit, and a startup cell coupled to the power supply input and the supply capacitor. The startup cell is configured to electrically couple the power supply input to the supply capacitor when the second switching circuit is not actively switching. The startup cell is also configured to electrically decouple the power supply input from the supply capacitor when the second switching circuit is actively switching.

Abstract: A power control system includes a multi-phase power source, an ungrounded multi-phase load, a plurality of power switching circuits and a plurality of zero-crossing circuits. The multi-phase power source includes a plurality of phase power outputs. The plurality of power switching circuits are each connected to provide power from one of the plurality of phase power outputs to the ungrounded multiphase load. The plurality of zero-crossing circuits are connected to provide control signals to the plurality of power switching circuits. Each of the plurality of zero-crossing circuits are connected between one of the plurality of power phase outputs and an ungrounded reference.

Abstract: A method and device for switching an operation mode of a five-level inverter are provided. The method includes: determining a first three-level operation mode as a three-level operation mode to be switched to from a five-level operation mode in a case that a PV input voltage is higher than a bridge line-line voltage command value; switching, after the operation mode is switched to the first three-level operation mode, the operation mode from the first three-level operation mode to a second three-level operation mode, in a case that a junction temperature of a switching device operating in the first three-level operation mode exceeds a first preset value; and switching the operation mode from the second three-level operation mode to the first three-level operation mode in a case that the junction temperature of a switching device operating in the second three-level operation mode exceeds a second preset value.

Abstract: A series circuit of capacitors and a series circuit of semiconductor switches such as SiC-MOSFETs are connected in parallel to a direct current power source, and one end of a bidirectional switch formed of semiconductor switches, such as IGBTs, and diodes, such as SiC-SBDs (Silicon Carbide Schottky Barrier Diodes), is connected to a series connection point (an M point) of the capacitors, while the other end of the bidirectional switch is connected to a series connection point of the semiconductor switches, in a three-level inverter that outputs three voltage levels by operating the semiconductor switches so as to satisfy at least one of the condition that the peak value of an alternating current output voltage Vo is a value of 80% or more of the voltage of the capacitors and the condition that an output power factor is 0.8 or more.

Abstract: A self-excited push-pull converter, where between the bases of the push-pull converter's transistors (TR1, TR2) and the effective power suppler there is provided a constant current source (II), which provides a constant current to the bases of the transistors. With the working voltage increases, the circuit enters into an operating mode not based on the core-saturation working mode, because the transistors' base current is limited by the constant current source and consequently the transistors' collector current cannot increase.

Abstract: An electronic converter circuit system and a control method are disclosed. The electronic converter circuit system has a digital control platform, centered on a digital control chip, consisting of a hardware circuit and software, and built in with single-end, push-pull, half-bridge, full-bridge type control modes. By simple setting, the circuit system works in corresponding modes. The electronic converter circuit system mainly controls the field-effect tubes and IGBT. Control orders in the control process are output after comprehensive diagnosis of the modules by the software control platform. During conversion, the circuit works stably and has high conversion efficiency.