987 results about "Flyback diode" patented technology

In an IGBT with a built-in freewheeling diode, a thickness (D) of a polished wafer is equal to 200 μm or smaller, and each of respective thicknesses (T8) and (T9) of an N⁺-type cathode layer (8) and a P⁺-type collector layer (9) is equal to 2 μm or smaller. Further, a total width of the N⁺-type cathode layer (8) and the P⁺-type collector layer (9) which extends along a width direction (X) is in a range from 50 μm to 200 μm. In this case, an interface (IF2) between a collector electrode (10) and the P⁺-type collector layer (9) occupies 30-80% of an interface (IF) between the collector electrode (10) and the P⁺-type collector layer (9) plus the N⁺-type cathode layer (8).

A semiconductor device includes a vertical IGBT and a vertical free-wheeling diode in a semiconductor substrate. A plurality of base regions is disposed at a first-surface side portion of the semiconductor substrate, and a plurality of collector regions and a plurality of cathode regions are alternately disposed in a second-surface side portion of the semiconductor substrate. The base regions include a plurality of regions where channels are provided when the vertical IGBT is in an operating state. The first-side portion of the semiconductor substrate include a plurality of IGBT regions each located between adjacent two of the channels, including one of the base regions electrically coupled with an emitter electrode, and being opposed to one of the cathode regions. The IGBT regions include a plurality of narrow regions and a plurality of wide regions.

An illumination system includes a power supply having a boost converter operating in the discontinuous conduction mode, a flyback converter operating in the critical conduction mode, and a switch coupled to the flyback converter. Several light emitting diodes receive power from the power supply. The boost converter may include a boost inductor (L_B) and a boost diode (D_B), constructed to perform the boost power factor correction (PFC) function. The flyback converter may includes a flyback inductor (L_FB) and a flyback diode (D_FB) and the power supply may be constructed to turn on the switch around the point where the current flowing in the flyback inductor reaches zero value.

A circuit device includes at least one switching element and a free wheeling diode connected in parallel to the switching element. The free wheeling diode is made up of a Schottky barrier diode using a semiconductor material having a band gap larger than silicon as its base material and also a silicon PiN diode, which are connected in parallel. The Schottky barrier diode and the silicon PiN diode are provided in the form of separate chips. A circuit system is also provided wherein a diode having a Schottky junction of a compound semiconductor as a rectification element built therein is combined, and a relationship, R²>4L/C, with impedance R (resistance), L (inductance), and C (capacitance) determined by a closed circuit between a power source and a positive or negative terminal when the current of the diode becomes zero during recovery operation, is satisfied.

An inverter circuit (120) is configured so as to perform synchronous rectification by six switching elements (130). The switching element (130) is formed of an unipolar device (SiC MOSFET in this case) using a wideband gap semiconductor. The inverter circuit (120) uses the body diode (131) of SiC MOSFET (130) as a freewheeling diode during synchronous rectification.

The invention relates to a transcranial magnetic field stimulator with a plurality of stimulating coils which comprises a high voltage charging power supply, a current-limiting resistance, an energy dumped capacitor, a reverse current reflowing diode, a thyristor switch, stimulating coils and a microcomputer controller. The stimulator is characterized in that: a stimulating unit comprises a thyristor switch, a stimulating coil and an energy dumped capacitor; N parallel connected stimulating units are connected to the current-limiting resistance and the high voltage charging power supply end; N stimulating units shared use an energy dumped capacitor; the microcomputer controller ends are respectively connected with the triggering ends of the thyristor switch in every stimulating unit; N is more than or equal to 2. A magnetic field stimulator of the invention can substitute a plurality of magnetic field stimulators in using, realizes the in-turn stimulation of a plurality of stimulating coils, and ensures a plurality of parts to get continuous stimulation from the program control. If the number of the energy dumped capacitor is increased, a plurality of coils not only can be stimulated in time sharing, but also achieving synchronous stimulation and couple stimulation.

A current sense and feedback circuit is provided for a non-isolated Buck power converter to maintain constant current load regulation. The Buck converter may have a high side power switch and may include an input port, a switcher unit including a switch and a controller, an inductor coupled to the output, and a freewheeling diode for circulating the inductor current when the switch is open. The simplified current sense and feedback circuit of the power converter may include a current sense resistor module coupled to the freewheeling diode to provide a sense signal to the controller. The controller may also be coupled to the output of the power converter to sense an over voltage condition. The simplified current sense and feedback circuit may provide output regulation while maintaining a low component count, small size, and low loss that makes the power converter suitable for use in compact design applications.

The invention discloses an electromobile range extender and a control method. The electromobile range extender consists of an engine, an engine ECU (Electronic Control Unit), an electronic throttle valve controller, a direct current starter, an engine speed sensor, an alternating current permanent magnet synchronous motor, a three-phase full-control rectifier, filter capacitors, voltage sampling resistors, a current sensor, a freewheeling diode and a three-phase full-control rectifying voltage regulation phase-shift trigger, wherein the engine is started by the starter and then drags the alternating current permanent magnet synchronous motor to generate electricity and output the three-phase alternating current voltage to the thyristor three-phase full-control rectifier; after the direct current pulsating voltage output by the rectifier is filtered by the two filter capacitors connected in series, the three-phase full-control rectifying voltage regulation phase-shift trigger acquires the output voltage and current of the range extender to obtain the output power, and adjusts a conduction angle according to the power to realize closed-loop control of the power; and the electronic throttle valve controller acquires the engine speed, adjusts the throttle valve opening, and realizes the closed-loop control of the engine speed. The electromobile range extender and the control method have the advantages of low cost and high control precision.

The invention provides a light-emitting diode (LED) switch constant-current driving circuit. The LED switch constant-current driving circuit comprises a voltage input module, an energy storage inductor, a freewheel diode, an LED module serving a load, a power tube for draining current and constant current, a detection module for detecting an input voltage phase state, a dimming control module connected to the detection module, an error amplifier connected to the dimming control module, a valley bottom detection circuit for detecting power tube drain voltage, a pulse width modulation circuit connected to the error amplifier and the valley bottom detection circuit, a control circuit for controlling the power tube according to detection voltage and PWM signals and a driving circuit of the power tube, wherein according to the dimming control module, input reference voltage Vref2 of the error amplifier and dimming control signals Vdimo are generated jointly through the detection voltage and reference voltage Vref1; the error amplifier enables the Vref2 to be compared with sampling voltage; and the pulse width modulation circuit is used for generating the PWM signals. According to the LED switch constant-current driving circuit, an electrolytic capacitor is not needed, an electronic transformer and a silicon controlled dimmer are compatible, the unique power tube in multiplexing simultaneously gives consideration to the draining current and the constant current, and the cost is effectively reduced.

The invention discloses a passive and nondestructive clamping single-phase high-gain converter, which comprises a coupling inductor. The first end of a first winding of the coupling inductor is connected with the anode of a power supply; the second end of the first winding is connected with the drain electrode of a power switch tube and the anode of a clamping diode; the cathode of the clamping diode is connected with the first end of a clamping capacitor; the source electrode of the power switch tube is connected with the cathode of the power supply; one end of a second winding of the coupling inductor is connected with the anode of a fly-wheel diode and the cathode of the clamping diode; the second end of the second winding is connected with the first end of a double-voltage capacitor; the second end of the double-voltage capacitor is connected with the cathode of the fly-wheel diode; the first end of the second winding of the coupling inductor and the first end of the first winding of the coupling inductor serve as same name ends of the coupling inductor; the anode of an output diode is connected with the cathode of the fly-wheel diode; the cathode of the output diode is connected with the first end of an output capacitor; and the second end of the output capacitor is connected with the cathode of the power supply.

A power semiconductor module (1) includes a first MOS transistor (16) connected to a positive side power supply terminal via a first conductor pattern (11), a first free wheeling diode (17) connected to the positive side power supply terminal via a second conductor pattern (12), a second MOS transistor (18) connected to a negative side power supply terminal via a third conductor pattern (13), and a second free wheeling diode (19) connected to the negative side power supply terminal via a fourth conductor pattern (14). These semiconductor elements (16-19) are connected to a load side output terminal via a common fifth conductor pattern (15). The semiconductor element (16, 17) connected to the positive side power supply terminal and the semiconductor element (18, 19) connected to the negative side power supply terminal are arranged alternately, substantially linearly.

A freewheeling DC/DC step-down converter includes a high-side MOSFET, an inductor and an output capacitor connected between the input voltage and ground. A freewheeling clamp, which includes a freewheeling MOSFET and diode, is connected across the inductor. When the high-side MOSFET is turned off, a current circulates through the inductor and freewheeling clamp rather than to ground, improving the efficiency of the converter. The converter has softer diode recovery and less voltage overshoot and noise than conventional Buck converters and features unique benefits during light-load conditions.

A method is specified for controlling a multiphase motor that is commutated by an inverter-side bridge circuit, in the course of which a particularly precise and technically simple detection of a control-relevant variable of a considered motor phase, in particular of a motor phase current and/or a back EMF voltage and/or a variable derived therefrom, takes place. It is provided here to determine the control-relevant variable with the aid of the current state of a freewheeling diode that is disposed in a phase half bridge, assigned to the respective motor phase, of the bridge circuit, the current state being detected during an on time in which a power switch, connected in parallel with the freewheeling diode, of the phase half bridge exhibits a conducting state, and a power switch connected in series with the freewheeling diode exhibits a blocking state.

The invention relates to a low and medium power high frequency DC-DC converter suitable for high-voltage input, which is based on the fundamental principle that: series capacitors are connected to a high-voltage direct current input, each capacitor serves as an input of the high-frequency forward DC-DC converter, and the outputs of the high-frequency forward DC-DC converter share a filter inductor, a freewheeling diode and an output filter capacitor; voltage feedback is acquired by sampling the output voltage of the high-frequency forward DC-DC converter, and a given reference voltage is compared with the voltage feedback so as to obtain a voltage loop output, namely a main output, by voltage regulation and calculation; and then, high-frequency forward DC-DC converter driving signals which are equational and alternate in phase are acquired to realized the control over a main circuit. The DC-DC converter has the advantages that: a low-voltage switching element is used under high voltage direct current input; the topology is simple; the cost is low; and the output has excellent dynamic and static performance.

A device and method of commutation control for an isolated boost converter provides a unique commutation logic to limit voltage spikes by utilizing switches on the secondary side to minimize a mismatch between current in the inductor and current in the leakage inductance of the transformer when commutation takes places. To minimize this mismatch, the current in the leakage inductance is preset at a certain level that approaches the current in the inductor prior to the commutation, thus significantly reducing the power rating for a clamp circuit and enabling use of a simple passive clamp circuit. In addition, through unique timing of the turn-on of the secondary switches, soft switching conditions are created that eliminate turn-on losses and the reverse recovery problems of free-wheeling diodes.

The invention discloses an online loss calculation method for a modular multilevel converter (MMC), and belongs to the field of power transmission and distribution. The method comprises the following steps of: 1) calculating the conduction loss of two insulated gate bipolar transistors (LGBT) and two flywheel diodes in each sub-module (SM); 2) calculating the switching loss of the two IGBTs and the reverse recovery loss of the two flywheel diodes in each SM; and 3) calculating related loss by using a loss calculation module. The method has the advantages that: 1, the complexity of manual measurement and calculation is effectively avoided when the MMC has a great number of modules, workload is greatly reduced, and the method is fast and convenient; 2, the online calculation of the loss of the MMC is realized, and the method is wide in application range, and can be applied to the loss calculation of an MMC system in any operating state; and 3, modular packaging is facilitated, a floor area is saved, the utilization rate of resources is increased, and the output of a platform comprises various kinds of loss and loss ratios, so that the method is direct and clear, and staff can conveniently observe the running state of the system at any time.

A system is employed to provide a substantially constant intensity light source via functional circuitry, the functional circuitry comprises a switching power supply. At least one signal is part of a matrix of LEDs connected in series and parallel and configured for redundancy. A monitoring circuit comprises a current sense circuit, wherein the current sense circuit includes an amplifier and at least one resistor in series with the amplifier. The current sense circuit includes a power converter circuit that senses a current of a flyback diode, recovers a dc component of a waveform via a low pass filter, and provides feedback control of the at least one signal.