131results about How to "Reduce surge voltage" patented technology

A light-emitting-diode drive circuit for driving n (where n is a natural number equal to or greater than two) light-emitting diodes (LED1 to LEDn) connected in series includes n′ (where n′ is any natural number equal to or greater than two but equal to or less than n; here, n′=n−1) lit-LED number control switches (SW1 to SWn−1). Here, there are n′ ways of turning on only one of the n′ lit-LED number control switches (SW1 to SWn−1) and there are, as corresponding to those n′ ways, n′ ways of lighting different numbers of light-emitting diodes among the n light-emitting diodes (LED1 to LEDn) connected in series.

A capacitor module in which the structure of a connecting portion is highly resistant against vibration and has a low inductance. The capacitor module includes a plurality of capacitors and a laminate made up of a first wide conductor and a second wide conductor joined in a layered form with an insulation sheet interposed between the first and second wide conductors. The laminate comprises a first flat portion including the plurality of capacitors which are supported thereon and electrically connected thereto, a second flat portion continuously extending from the first flat portion while being bent, and connecting portions formed at ends of the first flat portion and the second flat portion and electrically connected to the exterior.

This cathode for electrochemical reactor comprises a diffusion layer and a catalyst layer.It has bimetallic or multimetallic nanoparticles, dispersed in direct contact with the diffusion layer, at least one of the metals being chromium (Cr) wholly or partly in oxidized form.

An inverter controller is configured to control an inverter device. The inverter device is configured to generate a drive voltage of an AC load by a switching operation of a switching element that a reflux diode is connected to. The inverter controller is configured to perform a control of setting a switching speed of the switching element to be smaller on a lower level side of a magnitude of a current flowing in the AC load than on a higher level side of the magnitude of the current.

A power control unit which comprises a plurality of semiconductor elements including a plurality of high-potential side semiconductor elements and a plurality of low-potential side semiconductor elements, and each having a first face and a second face, a collector terminal or an emitter terminal provided on the first face, or an emitter terminal and a gate terminal provided on the first face; a plurality of bus bars electrically connected with at least one of the semiconductor elements, and forming a power module together with the semiconductor elements; a terminal block having signal lines and a resin mold which supports the signal lines; and an engaging portion provided on at least one of the bus bars, and engaging with a portion of the terminal block, and also supporting the terminal block, the signal lines directly connected with the gate electrodes through the engaging portion.

A capacitor module in which the structure of a connecting portion is highly resistant against vibration and has a low inductance. The capacitor module includes a plurality of capacitors and a laminate made up of a first wide conductor and a second wide conductor joined in a layered form with an insulation sheet interposed between the first and second wide conductors. The laminate comprises a first flat portion including the plurality of capacitors which are supported thereon and electrically connected thereto, a second flat portion continuously extending from the first flat portion while being bent, and connecting portions formed at ends of the first flat portion and the second flat portion and electrically connected to the exterior.

The invention discloses a high-power electromagnetic surveying transmitter system which comprises a generator set, a three-phase rectification bridge, a filter capacitor, an H type inversion bridge, a booster transformer, a single-phase rectification bridge, a transmitting bridge, an electrode, a temperature detection circuit, a first voltage detection circuit, a second voltage detection circuit, a first current detection circuit, a second current detection circuit, a first central processing unit, a second central processing unit and a transmitting control platform. Transmitting voltage parameter and transmitting current parameter are transferred through communication, and actual transmitting voltage and actual transmitting current are displayed in real time through parameter feedback; transmitting parameters of the transmitting control platform are received to control the transmitting of the transmitting bridge, and transmitting voltage and transmitting current signals are acquired and fed back to the transmitting control platform in real time; the PWM (pulse-width modulation) of the H type inversion bridge is realized to obtain stable and reliable transmitting signals; and the electrode is the signal transmitting port of the system. Thus, the accuracy and response speed of the transmitted waveform are improved.

The purpose of the present invention is to minimize switching losses of an inverter. An induction heating device includes: a plurality of induction heating coils (20) which are disposed adjacent with each other; a plurality of inverters (30), each of which has a capacitor (40) serially connected to each of the induction heating coils (20), and converts a DC voltage into a square wave voltage; and a control circuit (15) which controls so as to align the phase of coil currents flowing though the plurality of the induction heating coils (20), wherein the control circuit (15) controls the timing at which the square wave voltage transitions such that an instantaneous value of the square wave voltage is preserved in either the DC voltage or a turnover voltage, when the coil current zero crosses.

An output voltage controller for an AC vehicle generator is proposed. The output voltage controller can easily suppress variation in rectified output voltage due to a switching surge without using a slope generation circuit in a voltage adjustment circuit. An excitation circuit that excites a field coil 13 includes a circulation element 31, a semiconductor switch element 33, an inductor 35, and transient voltage absorption means 40. The circulation element 31 is connected in parallel to the field coil 13. The semiconductor switch element 33 is connected in series with the field coil 13 and turned on and off by a voltage adjustment circuit 60. The inductor 35 is connected in series with the field coil 13 and the semiconductor switch element 33. The transient voltage absorption means 40 absorbs a transient voltage generated in the inductor 35 in association with the switching of the semiconductor switch element 33 between ON and OFF.

A capacitor is connected between direct current voltage terminals, and inductance means is connected between one end of the capacitor and one of load terminals. In a case in which the direct current voltage exceeds a set value, voltage at both ends of the capacitor is shared by the first and second switching elements that are not electrically conductive; in a case in which the direct current voltage is below the set value, the first and second switching elements are electrically conductive on a periodic basis or as needed to output reversed-polarity voltage between load terminals; and in a case in which the first and second switching elements are turned off, voltage at both ends of the capacitor restricts voltage applied to both ends of the first and second switching elements, during a period in which the first and second feedback rectifier elements are electrically conductive.

A capacitor is connected between direct current voltage terminals, and inductance means is connected between one end of the capacitor and one of load terminals. In a case in which the direct current voltage exceeds a set value, voltage at both ends of the capacitor is shared by the first and second switching elements that are not electrically conductive; in a case in which the direct current voltage is below the set value, the first and second switching elements are electrically conductive on a periodic basis or as needed to output reversed-polarity voltage between load terminals; and in a case in which the first and second switching elements are turned off, voltage at both ends of the capacitor restricts voltage applied to both ends of the first and second switching elements, during a period in which the first and second feedback rectifier elements are electrically conductive.

A switching device includes a plurality of semiconductor switching elements coupled in series, a smoothing capacitor, and snubber circuit. Each of the semiconductor switching elements includes a free wheel diode. The smoothing capacitor is coupled in parallel with a direct current power source and the semiconductor switching elements. The smoothing capacitor smoothes an output of the direct current power source and supplies the smoothed output to the semiconductor switching elements. The snubber circuit is coupled between a first connecting point and a second connecting point in parallel with the semiconductor switching elements. An inductance of a first channel provided from the first connecting point to the second connecting point through the smoothing capacitor is equal to or more than 10 times as large as an inductance of a second channel including the semiconductor switching elements and the snubber circuit.

In an AC motor driving circuit from an AC power supply and a DC power supply, a matrix converter and a power conversion circuit are provided. The matrix converter is connected between an output of the AC power supply and an input of the AC motor. In the power conversion circuit, switches back-to-back connected to diodes, and bidirectional switches are series-connected, respectively. Connection junctions between the switches and the bidirectional switches are connected to the input phases of the AC motor, respectively. The other terminal of each switch is connected to one terminal of the DC power supply while the other terminal of each bidirectional switch is connected to the other terminal of the DC power supply. In this manner, the number of switches through which electric power passes at the time of operation is reduced so that loss can be reduced. Accordingly, power conversion efficiency can be improved.

The present invention provides a power module, power converter, and vehicular electric machine system capable of reducing inductance of a peripheral section of an output terminal in a power module, and additionally, reducing a surge voltage. A positive emitter conductor 3 connected to an emitter electrode of a positive power semiconductor element Mpu and an output terminal U are electrically interconnected by using a plurality of aluminum wires 7, a negative collector conductor 4 connected to a collector electrode of a negative power semiconductor element Mnu and the output terminal U are electrically interconnected by using a plurality of aluminum wires 9, and the positive emitter conductor 3 connected to the emitter electrode of the positive power semiconductor element Mpu and the negative collector conductor 4 connected to the collector electrode of the negative power semiconductor element Mnu are further electrically interconnected by using a plurality of aluminum wires 8.

The invention provides an RCD buffering circuit of a Z-source inverter and a Z-source inverter topology circuit comprising the buffering circuit, and relates to the buffering circuit of the Z-source inverter. The buffering circuit aims to solve the problems that direct-current link voltage of RC, RCD and RCD amplitude limiting type buffering circuits for the Z-source inverter generates a slope, the value of the direct-current link voltage is excessively high, and the loss is large. According to the RCD buffering circuit of the Z-source inverter and the Z-source inverter topology circuit comprising the buffering circuit, a non-inductive resistor and a switch device in a traditional RCD buffering circuit are connected in series and then connected with a fast recovery diode in parallel, and then the whole is connected with a non-inductive capacitor in series and then connected to a direct-current bus side of the Z-source inverter in parallel. The switch device additionally arranged is connected when the Z-source inverter is in a non-direct connection state, and disconnected when the Z-source inverter is in a direct connection state. The problems of the voltage distortion, the excessively high voltage value and the large direct connection loss generated when the traditional buffering circuit is applied to the Z-source inverter can be solved. The buffering circuit is suitable for the Z-source inverter medium and small in power.