833 results about "Rectifier diodes" patented technology

Power factor correction apparatus, for a switching power supply fed by an array of rectifying diodes and consisting of at least an input inductor, a contact of which is connected in series with a contact of the array, and of a power switch connected between the other contact of the array and the other contact of the input inductor that comprises circuitry for identifying, in each cycle determined by the switching frequency of the power supply, whenever the instantaneous value of the current through the inductor reaches a minimal value; circuitry for switching the power switch to its conducting state in response to the minimal current through the inductor; circuitry for reflecting the current flowing through the inductor by a measurable or simulated parameter; and circuitry for providing indication, in each cycle, by using the parameter, the indication being related to the timing until the peak value of the current, that corresponds to a specific load, has been essentially reached, or to the time from the moment that the current reaches the minimal value until the timing, and for switching the power switch to its non-conducting state in response to the indication.

A primary-side flyback power converter supplies a constant voltage and a constant current output. To generate a well-regulated output voltage under varying load conditions, the power converter includes a PWM controller. The PWM controller generates a PWM signal to control a switching transistor in response to a flyback voltage detected from the first primary winding of the power supply transformer. To reduce power consumption, the flyback energy of the first primary winding is used as a DC power source for the PWM controller. The flyback voltage is sampled following a delay time to reduce interference from the inductance leakage of the transformer. To generate a more accurate DC output voltage, a bias current is pulled from the detection input to form a voltage drop across a detection resistor for compensating for the voltage drop of the output rectifying diode.

The present invention discloses a forward-flyback converter with active-clamp circuit. The secondary side of the proposed converter is of center-tapped configuration to integrate a forward circuit and a flyback circuit. The flyback sub-circuit operating continuous conduction mode is employed to directly transfer the reset energy of the transformer to the output load. The forward sub-circuit operating discontinuous conduction mode can correspondingly adjust the duty ratio with the output load change. Under the heavy load condition, the mechanism of active-clamp flyback sub-circuit can provide sufficient resonant current to facilitate the parasitic capacitance of the switches to be discharged to zero. Under the light load condition, the time interval in which the resonant current turns from negative into positive is prolonged to ensure zero voltage switching function. Meanwhile, the flyback sub-circuit wherein the rectifier diode is reverse biased is inactive in order to further reduce the power losses.

An illumination apparatus is configured simply in a reduced scale while a light emitting diode is used as a light emitting source for illumination. The illumination apparatus includes an LED driving block including an LED bridge circuit formed from a bridge connection of a plurality of diode series circuits each of which is formed from a series connection of a plurality of light emitting diodes and a rectifying diode. A load resistor is connected to a rectification output of the LED bridge circuit. When an AC voltage is input to the LED driving block, the LED bridge circuit rectifies the AC voltage, and the resulting rectification current is used as driving current to drive the light emitting diodes to emit light.

The invention provides gallium nitride material devices, structures and methods of forming the same. The devices include a gallium nitride material formed over a substrate, such as silicon. Exemplary devices include light emitting devices (e.g., LED's, lasers), light detecting devices (such as detectors and sensors), power rectifier diodes and FETs (e.g., HFETs), amongst others.

A switching power supply device has a configuration in which a series combination of a first switching circuit and an input power source is connected in series with a series combination of a primary winding of a transformer and an inductor, a series combination of a second switching circuit and a capacitor is connected in parallel to the series combination of the primary winding of the transformer and the inductor, and the secondary winding of the transformer is provided with a rectifying smoothing circuit including a rectifying element. The first switching circuit is made up of a parallel connection circuit including a first switching element, a first diode, and a first capacitor. The second switching circuit is made up of a parallel connection circuit including a second switching element, a second diode, and a second capacitor. A switching controlling circuit is provided adapted to turn the first and second switching elements on and off alternately, with a period of time when both switching elements are off is interposed, and a capacitor is connected in parallel to the rectifying diode in the rectifying smoothing circuit.

A controller for providing a constant output current control signal in a switched mode power supply (SMPS) includes a conduction time compensation circuit that is configured to produce a compensated conduction time interval signal that includes compensation for a ringing waveform of a feedback signal. The compensated signal reflects more accurately the actual conductive time of a rectifying diode in a secondary winding of the switched mode power supply. In one embodiment, the compensated conduction time interval signal is used to generate a fixed ratio between the conduction time and the non-conduction time of the rectifying diode. In another embodiment, the controller also provides a constant voltage control signal.

In the DC/DC converter, a switching part has first and second switches serially connected from a power supply to a ground. The first and second switches switch on/off in response to first and second switching signals having a fixed frequency. The first switching signal has a phase level that does not overlap a corresponding phase level of the second switching signal. A transformer transforms a voltage applied to a first winding into a second winding in response to switching operation of the switching part, and resonates by an inductor and a capacitor of the first winding. Also, a rectifier includes a rectifying diode for rectifying the voltage from the transformer into a direct voltage. A feedback circuit detects the voltage outputted via the rectifier. Additionally, a controller controls pulse width of the first and second switching signals in a PWM mode according to the voltage detected by the feedback circuit.

An LED driving circuit of a backlight unit includes a switch connected between an input of direct voltage and a ground to switch the direct voltage according to a switching pulse; a rectifying diode connected between a connecting node and one terminal of the LED array to rectify driving voltage supplied according to switching operation of the switch; a smoothing capacitor having one terminal connected to a cathode of the rectifying diode and the other terminal connected to a ground; a voltage detecting resistor connected between the other terminal of the LED array connected to the ground and the other end of the smoothing capacitor to detect voltage from the current flowing to the ground; and a PWM controlling part for controlling on/off status of the switching according to the switching pulse, wherein the switching pulse has a duty ratio determined according to a preset internal reference voltage and the voltage detected by the voltage detecting resistor. The driving current of can be controlled at a constant current and thus be stabilized.

The zero voltage switch (ZVS) method for the synchronous rectifiers and inverter. The ZVS method for synchronous rectifier, in which the rectifier diode is replaced by a bi-directional-current one directional-voltage blocking capability switch, by allowing and terminating current flow in a reverse direction, achieves zero voltage turn-on on both inverter and rectifier switches. The ZVS method of the present invention includes: increasing an inductor current to a current upper limit with a first switch module active; decreasing the inductor current with the first switch module open and a second switch module passive; decreasing the inductor current with a second switch module active; turning the second switch module open when the inductor current turns negative; increasing the inductor current from a current lower limit with the first switch module passive; and increasing the inductor current with the first switch module active with zero voltage.

The invention relates to LED replacement lamp suitable for operation with a high frequency fluorescent lamp ballast, comprising—a LED load (LS) comprising a series arrangement of LEDs,—a first lamp end circuit comprising—a first lamp pin (LP1) and a second lamp pin (LP2) for connection to a first lamp connection terminal comprised in the high frequency fluorescent lamp ballast,—a first rectifier (D1-D4; D1,D2) equipped with at least one input terminal coupled to the second lamp pin and with first and second output terminals coupled to respective ends of the LED load, the first rectifier comprising at least two diodes, one of which is shunted by a first capacitor (C1),—a second lamp end circuit comprising—a third lamp pin (LP3) and a fourth lamp pin (LP4) for connection to a second lamp connection terminal comprised in the high frequency fluorescent lamp ballast,—a second rectifier (D5-D8, D5, D6) equipped with at least one input terminal coupled to the fourth lamp pin and with first and second output terminals coupled to respective ends of the LED load, the second rectifier comprising at least two diodes, one of which is shunted by a second capacitor (C2), wherein the first capacitor and the second capacitor form a series arrangement coupled between the second lamp pin and the fourth lamp pin.

A brushless generator with permanent-magnet multi-pole rotor disks and stator winding disks in their axial magnetic field includes integral electronics to efficiently generate regulated DC current and voltage from mechanical input power over a broad speed range. All power for the electronics is provided by rectifier diodes from its stator windings. Differential amplifiers provide stator voltage feedback signals. Its power rating is scalable, depending on the number of its disks. Having no iron cores and no gears, it incurs no cogging torque, and no gear friction. Integral power control electronics includes high-frequency pulse-width-modulated boost regulation, which provides regulated current at requisite voltage over its broad speed range. A main wind-powered embodiment to produce DC power for a constant voltage DC load over a broad speed range includes signal processing so output power varies according to the third power of speed. Combined boost-regulation, zero cogging torque, and no gearing, enable a wide speed range, for better power quality and higher wind energy yields.

A bi-directional transient voltage suppression (“TVS”) device (101) includes a semiconductor die (201) that has a first avalanche diode (103) in series with a first rectifier diode (104) connected cathode to cathode, electrically coupled in an anti-parallel configuration with a second avalanche diode (105) in series with a second rectifier diode (106) also connected cathode to cathode. All the diodes of the TVS device are on a single semiconductor substrate (301). The die has a low resistivity buried diffused layer (303) having a first conductivity type disposed between a semiconductor substrate (301) having the opposite conductivity type and a high resistivity epitaxial layer (305) having the first conductivity type. The buried diffused layer shunts most of a transient current away from a portion of the epitaxial layer between the first avalanche diode and the first rectifier diode, thereby reducing the clamping voltage relative to the breakdown voltage. The TVS device is packaged as a flip chip (202) that has four solder bump pads (211-214). The abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims pursuant to 37 C.F.R. §1.72(b).

An active voltage drop control-type pulse power generator includes power stages, a power inverter, a power loop, a control inverter, a control loop, and a compensation unit. The power stages include power cells connected in series. Each power cell includes a switch and a capacitor connected in series, a driver for driving the switch, a bypass diode connected to both ends of the switch, and a rectifying diode connected to both ends of the capacitor. The power inverter charges the capacitor via the power loop and the rectifying diode inside each power cell. The control inverter provides a control signal for the switch via the control loop and the driver inside each power cell. The compensation unit is connected to one of the power cells and generates a compensation voltage for compensating for a voltage drop at a load according to a voltage detected in real-time from the power cell.

A switching power supply unit for providing an output voltage that is controlled such that a first detection voltage detected on the basis of the output voltage becomes equal to a first reference voltage. The peak voltage at the node of a serially connected coil and a switch of the switching power supply unit is detected and used as a second detection voltage for over-voltage protection. Thus, over-voltage protection of the switching power supply unit is secured with no additional terminal on the switching control IC for over-voltage protection even if such components as a feedback circuit and a rectifying diode of the power supply unit become open.

Single-phase to three-phase converter comprising a rectifier stage, a DC link and an inverter stage, wherein the rectifier comprises a filter choke, one controllable switch for power factor correction, rectifying diodes arranged in a diode bridge configuration having input terminals and output terminals, the controllable switch being connected to the output terminals of the diode bridge, an upper blocking diode arranged between the positive output terminal of the diode bridge and the positive input of the DC link and a lower blocking diode arranged between the negative output terminal of the diode bridge and the negative input of the DC link, the DC link comprises a capacitor bank connected between the DC link, which capacitor bank has a center point. The inverter stage comprises three phase outputs, two of which are formed with a series connections of controllable switches arranged between the DC link for switching either positive voltage or negative voltage of the DC link to the phase outputs, and one phase output is formed of the voltage of the center point of the capacitor bank, and in that the center point of the capacitor bank is configured to be optionally connected to the neutral line of the single-phase AC input by using a connection switch element providing thereby doubled voltage to the DC link.

The hybrid three-level harmonic dc converter comprises an input voltage-dividing capacitor (1), a three-level bridge arm (2) with voltage stress half of the input value, two-level bridge arm (3), a harmonic network (4), an isolation transformer (5), and a rectification filter circuit (6). Wherein, it applies dual shift-phase control strategy, all switch tubes can realize zero-voltage operation in full load range. This invention reduces both ripple of input current and filter output,, and can work in very broad input voltage range.

RFID tag designs and sensors are disclosed that include a dispersive antenna and exhibit greater detection ranges relative to conventional designs. The designs include, for example a transponder having including a rectifier, a radio-frequency identification (RFID) circuit for receiving and responding to interrogation signals, and a frequency dispersion element for receiving a multi-phase input signal and creating a pulse therefrom for input to the rectifier. Frequency-dispersive elements (e.g., antennas) and compatible interrogation waveforms can be used so that the rectifying diodes receive high peak voltage levels relative to the average voltage levels.

The invention relates to a single-circuit output flyback converter controlled in a current mode. The single-circuit output flyback converter comprises an alternating current input source, wherein the alternating current input source inputs direct current to a first buffer circuit through an input filter capacitor after passing through a rectifier bridge circuit; the first buffer circuit is connected in parallel to a primary winding of a transformer, the primary winding is connected with the drain electrode of a switching tube, and a secondary winding is respectively connected with an output rectifier diode and the input end of a first absorption circuit and is connected to a control chip through a chip power supply circuit; the output end of the output rectifier diode is connected to a three-terminal voltage-stabilizing circuit through an output filter capacitor after being connected in parallel with the output end of the first absorption circuit; a second buffer circuit is connected in parallel between the source electrode and the drain electrode of the switching tube, and the grid electrode and the source electrode are respectively connected with the control chip through a sampling resistor; the compensation end of the control chip is connected with the output end of an isolating circuit, the input end of the insolating circuit is connected in parallel with the output filter capacitor, and the other input end of the isolating circuit is connected with the three-terminal voltage-stabilizing circuit which outputs voltage-stabilizing direct current; and a second absorption circuit is arranged in the three-terminal voltage-stabilizing circuit.

This invention LLC serial resonance DC/DC converter includes a bleeder capacitor, an inverter composed of four serial switches, a resonance circuit, a clamp, an isolation transformer, a commutating circuit and a filter, capable of realizing large input/output voltage regulation sphere with small frequency variable sphere by LLC resonance circuit with dual intrinsic resonance frequency, at the same time, the switch is effectively clamped by a pair of clamp diodes, so that each switch voltage stress is half of the input voltage and ZVS is realized in all sphere without any additional circuit, the commutation diode works at the ZCS state.

The invention discloses a rectifier diode temperature compensation circuit in a flyback converter, which mainly solves the problem that as the temperature rises, the forward voltage drop of the secondary side rectifier diode of the primary side feedback flyback converter is decreased to cause the increase of the output voltage of the flyback converter. The circuit comprises a temperature monitoring module, a temperature compensation module and an overtemperature protection module; the temperature monitoring module monitors the change of temperature, and respectively outputs two routes of current changing along with the temperature to the temperature compensation module and the overtemperature protection module; the temperature compensation module adds the generated compensation value intothe feedback voltage of the flyback converter, and outputs the compensated feedback voltage; and the overtemperature protection module carries out overtemperature protection by way of current comparison. The circuit not only can compensate the change of the forward voltage drop of the secondary side rectifier diode of the flyback converter as the temperature changes, but also can provide overtemperature protection for the flyback converter, moreover, the circuit structure is simple, and the circuit can be used in the designs of AC/DC (alternating current-to-direct current) conversion controller chips adopting the primary side feedback control technology.

The invention relates to an induction excitation type mixed excitation brushless synchronous motor which structurally comprises a stator and a rotor. The stator comprises a stator core, an armature stator winding and a stator excitation winding, wherein the armature stator winding and the stator excitation winding are arranged in a stator groove. The rotor comprises a rotor core, permanent magnets, a plurality of rotor excitation windings, rectifier diodes and a rotary shaft, wherein the plurality of rotor excitation windings are independent from one another and short-circuited through the diodes respectively. The permanent magnets are arranged on the rotor, and the number of the permanent magnets can be determined as various forms according to an excitation requirement. When direct current is led into the stator excitation winding, constant magnetic fields are built in air gaps. When the rotary shaft rotates at the synchronous speed, excitation current of pulse vibration is inducted on the rotor windings, the size of air gap magnetic fields is changed, and output voltage of the motor is controlled by changing current intensity in the stator excitation winding. The induction excitation type mixed excitation brushless synchronous motor has the advantage of being free of brush slip ring, requiring no exciters, being simple in structure and achieving brushless excitation of the rotor excitation mixed excitation motor.

The invention discloses an active clamping forward-flyback converter, which is provided with a primary side clamping resonant circuit comprising a series branch consisting of a clamping switching tube and a primary side clamping capacitor, wherein the series branch is connected with an original-level winding of the primary side of an isolation transformer in parallel or is connected in serial between a start end of the original-level winding of the primary side of the isolation transformer and a negative terminal of a direct current power supply; and a contravariant switching tube works in a ZVS state, and a secondary rectification circuit is one of a forward-flyback working rectification loop and a flyback working rectification loop. The active clamping forward-flyback converter can enter two different operation modes to achieve a large adjustment range of input and output voltages, reduce reverse steady-state voltages and reverse recovery resonance voltage spikes of a primary side switching tube and a secondary rectifier diode and the voltage stress and the switching loss of the primary side switching tube, and improve the efficiency. The active clamping forward-flyback converter is particularly suitable to be widely applied in the occasions with a very wide input voltage fluctuation range and a wide and high output voltage, in which semiconductors cannot withstand high voltages.

A rectifier hub and associated cooling method provide increased cooling efficiency for rotating rectifier diodes in a dry cavity generator. The rectifier hub has an inner and an outer circumferential surface and includes at least one pair of flow passages, and at least one flow channel. Each pair of flow passages extends between the hub inner and outer circumferential surfaces, and each flow channel is formed in the hub outer circumferential surface and couples the pair of flow passages in fluid communication with one another. This configuration allows a cooling medium to flow directly across the rectifier hub and cool the rectifier diodes mounted within drive cavities formed in the hub.

The invention relates to the field of switching converters, and particularly relates to a flyback active clamp-type switching converter control circuit and a control method thereof. The active clamp flyback circuit of the invention can realize reduced frequency and ZVS, and comprises a main power circuit, a clamp circuit, and an output rectification filter circuit, wherein a transformer and a main switching tube are connected to form the main power circuit; a clamp switching tube and a clamp capacitor and a clamp diode are connected to form the clamp circuit; and an output rectification diode and an output capacitor are connected to form the output rectification filter circuit. In comparison with the prior art, reduced frequency in light load can be realized, and the control scheme is flexible; switching loss in no load and loss of a transformer winding and switching tube inner resistance caused by a current effective value are little, no-load power consumption is greatly reduced, and the light-load efficiency is improved.

The invention discloses a super-wide output voltage range charger based on LLC topology and a control method. The super-wide output voltage range charger comprises an LLC resonant converter and a control circuit. The LLC resonant converter comprises a switch network composed of an MOSFET full-bridge conversion circuit, the input end of the switch network is connected with the input end of a power source, the output end of the switch network is connected with the input end of a resonant network, the output end of the resonant network is connected with a leakage inductor of a transformer, and a secondary side coil of the transformer is connected with a rectifying and filtering network; the control circuit comprises a control unit, the control unit controls MOS tubes of the MOSFET full-bridge conversion circuit to be connected or disconnected according to received signals at the input end and the output end of the LLC resonant converter, and therefore the LLC resonant converter can achieve no-voltage connection of a primary side switch tube and no-current disconnection of a secondary side rectifying diode within a full voltage range. The super-wide output voltage range charger is wide in output voltage, free of limitation of the input voltage range of a charged object and capable of charging various new energy electric vehicles.

The invention discloses a totem-pole bridgeless power factor correction circuit which comprises a switching tube series branch and a rectifier diode series branch, and also comprises two series diodes and two parallel diodes, wherein the switching tube series branch is provided with a first switching tube and a second switching tube, the rectifier diode series branch is provided with a first rectifier diode and a second rectifier diode, the two series diodes are respectively serially connected between the first switching tube and a negative busbar and between the second switching tube and a positive busbar, the two parallel diodes are respectively connected in parallel between a common terminal of the first switching tube and the positive busbar and between the common terminal of the second switching tube and the negative busbar, wherein reverse recovery time of the parallel diodes corresponding to the first switching tube is less than that of the first switching tube, and reverse recovery time of the parallel diodes corresponding to the second switching tube is less than that of the second switching tube. Because reverse recovery characteristics of the parallel diodes are better, a reverse recovery current is smaller without damaging the totem-pole bridgeless power factor correction (PFC) circuit working in a CCM (Coincident-Current Memory) mode.

The invention discloses a sectional type switch reluctance motor, belonging to the field of magnetic circuit components. The sectional type switch reluctance motor comprises a main shaft, at least two sections of stators, at least two sections of rotors and magnetic isolating plates arranged on the main shaft, wherein each section of the stators and each section of the rotors are respectively provided with magnetic isolating plates, and each section of the stators and each section of the rotors are uniformly distributed around 360 degrees in the axial direction respectively. Stator poles of each phase of each section of the stators are respectively connected in series and are connected with a one-way guide circuit; the one-way guide circuit comprises four rectifier diodes, energy storage capacitors, main control thyristor switches and guide thyristor switches which are connected in series two by two; series circuits of each stator pole are mutually connected in parallel; one ends of the series circuits are respectively connected with the main control thyristor switches and guide thyristor switches; and the middles of two series circuits of the rectifier diodes are respectively connected with two output ends of the alternative current. By utilizing the sectional type switch reluctance motor, output torque pulse can be effectively reduced, and by guiding the induced current among the sections, the energy consumption efficiency of a system is improved, the impact of the induced current to the components is reduced, and the service life of the system is prolonged.

A current-regulating driver circuit for a light emitting diode (LED) maintains energization drive to and thereby illumination provided by the LED at a prescribed, substantially constant value, over a relatively wide range of input (AC or DC) voltage. First and second input nodes are coupled to a source of AC or DC voltage and to a load, powered by the source of AC or DC voltage. An input rectifying diode is coupled to the first input node. A controlled current flow element is coupled in a first current flow path between the input rectifying diode and the LED and is controllably operative to supply current for illuminating the LED. A controlled current regulation circuit that includes a sense resistor coupled in series with the LED is coupled with the controlled current flow element between the first and second nodes, and is operative to regulate current supplied over the first current flow path by the controlled current flow element to the LED, and thereby accommodate variations in the value of the source of AC or DC voltage.

A switching power supply device includes a first series circuit of first and second switching elements connected in parallel with a DC power supply. An isolation transformer has primary and secondary windings and first and second auxiliary windings, a first layer including the primary windings between a second layer of the two auxiliary windings, and a third layer of the secondary windings. A capacitor in series with the primary windings defines a second series circuit in parallel with the second switching element. A rectifying and smoothing circuit includes a rectifying diode and a smoothing capacitor, connected to the secondary windings. First and second control circuits turn on and off the first and second switching elements based on voltages generated in the two auxiliary windings, to obtain a DC output from the rectifying and smoothing circuit, enabling an adequate auxiliary windings voltage and stable switching operation including stable zero-voltage turn-on.