53 results about "Precision rectifier" patented technology

A power supply including an inverter receiving a DC input signal from a DC input source (11). The inverter is comprised of two half bridges (S1 A, S2A and S1B, S2B). Each inverter is driven by a signal source (13A, 13B), which outputs an AC signal. The output from each inverter is input to a first stage harmonic filter. The power supply includes an output circuit that includes first and second rectifiers (D1, D2) arranged about a point so that if the inverter attempts to drive the point beyond a predetermined first and second voltage, the respective rectifier conducts in order to return at least one of power and current to the DC input source. The output from the first harmonic filter (L1A, C1; L1B, C1) is output to a second harmonic filter (L2, C2) and is then output from the power supply.

A power converter generates direct voltage and includes a phase-shifted PWM bridge with first and second controllable switches connected as a half-bridge with a first tap, for generating AC at the first tap. An output transformer includes a primary winding coupled to the first tap. A full-wave rectifier is connected to a secondary winding of the output transformer. A filter is coupled to the full-wave rectifier for producing filtered output direct voltage. Resonances create surges which may undesirably result in energy loss. A second transformer includes a primary winding coupled to receive the resonant surges and a secondary winding at which transformed surges appear. A second rectifier is coupled to the secondary winding of the second transformer, for rectifying the surges. The energy of the surges is returned or coupled to the source or load. In one embodiment, the full-wave rectifier is a bridge rectifier.

In a switching power supply apparatus, a resonant capacitor and an inductor are connected in series between a primary winding in a transformer and a second switching element. A first rectifier smoothing circuit including a diode and a capacitor rectifies and smoothes a voltage occurring at a first secondary winding in the transformer during an on period of a first switching element to extract a first output voltage. A second rectifier smoothing circuit including a diode and a capacitor rectifies and smoothes a voltage occurring at a second secondary winding in the transformer during an on period of the second switching element to extract a second output voltage. A control circuit controls an on time of the first switching element and an on time of the second switching element on the basis of the first output voltage and the second output voltage.

A circuit for a power amplifier includes a main amplifier stage having an operational amplifier (110), a buffer NPN transistor (126) and an NPN transistor (127) connected in a totem pole configuration, and a buffer PNP transistor (133) and a PNP transistor connected in a totem pole configuration. The transistors regulate the voltage to the components directly connected to the operational amplifier (110 ). A sampling resistor (137) located between a speaker (140) and an output of the power amplifier measures the current. The sampling resistor (137) is inside a negative feedback loop so that an output resistance will be near zero. A protection circuit includes a high common mode rejection difference amplifier that level shifts the sampling resistor voltage to a ground reference voltage. A precision rectifier full wave rectifies the current signal so that the current signal can he compared to a maximum current. If the instantaneous a circuit for a power amplifier includes a main amplifier stage having an operational amplifier, a buffer NPN transistor and an NPN transistor connected in a totem pole configuration, and a buffer PNP transistor and a PNP transistor connected in a totem pole configuration. The transistors regulate the voltage to the components directly connected to the operational amplifier. A sampling resistor located between a speaker and an output of the power amplifier measures the current. The sampling resistor is inside a negative feedback loop so that an output resistance will be near zero. A protection circuit includes a high common mode rejection difference amplifier that level shifts the sampling resistor voltage to a ground reference voltage. A precision rectifier full wave rectifies the current signal so that the current signal can be compared to a maximum current. If the instantaneous current exceeds the maximum current, the protection circuit turns off both the positive and negative power supplies.

A moisture sensing apparatus includes an oscillator for supplying an AC signal to a driven ring of a sensor having a pad inside the ring, and a ground plate around the ring. An amplifier forms part of a temperature-compensated, precision rectifier, and is connected to the pad. A first diode connected to the output of the amplifier in a feedback loop of the amplifier, where the amplifier nullifies temperature variation effects upon the diode, and supplies a rectified signal which is a function of moisture content of material in contact with the sensor. A second diodes is connected between the amplifier output and other input of the amplifier. The sensor has a rounded configuration to avoid electrostatic field fringing effects, and a passive impedance with both resistive and capacitive members is connected in parallel with the sensor to provide a functional baseline for the rectified signal.

An alternator comprises: an output rectifier converting AC voltage produced in an output armature winding into DC and supplying the DC electric power to a rechargeable battery and a current consumer; an excitation rectifier which is electrically separated from the output rectifier to convert AC voltage produced in an excitation armature winding into DC; and a power generation control unit. The power generation control unit compares the output voltage of the output rectifier or the terminal voltage of the battery with a predetermined reference voltage and controls current supplied to an excitation winding to which the DC voltage outputted from the excitation rectifier is applied, based on the comparison result.

A power supply for a guitar amplifier and the guitar amplifier and method of operating the guitar amplifier. The power supply includes an alternating current power input having a secondary winding and a filament winding, an output and a first vacuum tube rectifier coupled between the secondary winding of the power input and the output for rectifying the alternating current at the power input. At least a second rectifier is provided which is selectively couplable in parallel with the first vacuum tube rectifier. The at least one second rectifier can be a vacuum tube rectifier with each of the first and second rectifiers having a cathode continually energized by the filament winding, a solid state rectifier or both. The output amplifier has an output transformer having a primary winding with a center tap and with a first pair of vacuum tube amplifiers having their cathodes being coupled together and their plates coupled to the primary winding on opposite sides of the center tap. At least a second pair of vacuum tube amplifiers is provided having their cathodes coupled together and their plates being coupled to the primary winding on opposite sides of the center tap. A selector switch selectively causes at least one pair of the first pair of vacuum tube amplifiers and the at least a second pair of vacuum tube amplifiers to be operational and concurrently causes at least a selected one of the first vacuum tube rectifier and the at least a second rectifier to be operational corresponding to the selected at least one pair of vacuum tube amplifiers and the at least a second pair of vacuum tube amplifiers selected.

The invention relates to a generator accident reinforced excitation circuit, wherein the secondary side of an excitation transformer is a duplex winding which is respectively connected with a first rectifier and a second rectifier; the first rectifier is connected with a first diode and a rotor winding in series; the second rectifier is connected with a second diode and the rotor winding in series; one end of the rotor winding is connected with the anode of the first diode, and the other end of the rotor winding is connected with the cathode of the second diode; and a thyristor switch is connected between the cathode of the first diode and the anode of the second diode. By the structure innovation of the excitation main circuit, the invention completely optimizes the function features of the system, improves the parameter performance under an normal operation condition, achieves the purposes of high safety of 99.99%, high efficiency, energy saving, consumption reduction, and the like during long-term operation of an excitation system, reduces the cost of high-parameter excitation configuration, is favorable for safe operation for a long term, and ensures sufficient supply of accident reinforced excitation to generators.

An excursion limiter (10) broadly comprises a voltage controlled filter (40) to suppress an audio signal according to a selected threshold at a selected frequency using a control voltage. The voltage controlled filter (40) preferably produces an inversion signal at the frequency, amplifies the inversion signal according to the control voltage to produce a suppression signal, and combines the audio signal with the suppression signal, thus suppressing the audio signal at the frequency and creating a resultant signal. A control voltage generator (42) preferably generates the control voltage using a frequency compensation filter (58), a full-wave rectifier (60), a precision half-wave rectifier (61) and a non-linear compensator (62). The frequency compensation filter (58) isolates an initial component which is rectified by the full-wave rectifier (60), shifted, and rectified again at the precision rectifier (61) before being essentially flattened in a non-linear manner by the non-linear compensator (62).

An urban rail transit medium-voltage inverter type renewable energy utilization device includes a first rectifier transformer, a first rectifier connected with the first rectifier transformer, a second rectifier transformer and a second rectifier connected with the second rectifier transformer. The urban rail transit medium-voltage inverter type renewable energy utilization device also includes a feedback transformer, an inverter connected with the feedback transformer and a medium-voltage switch connected with the inverter. According to the invention, the device facilitates the recovery of renewable braking energy, requires no configuration of a resistance device, can solve the problems of high resistor heat productivity, large noise and the like, and has remarkable energy-saving effects.

The invention discloses an instantaneous overcurrent protection circuit of a medium-high voltage variable-frequency speed regulating device and a frequency converter. The circuit comprises a current sampling circuit, a voltage following circuit, a precision rectifier circuit, an inverting amplifier circuit, a hysteresis comparison circuit and a reverse output circuit, wherein an input end of the current sampling circuit is connected with an A phase and a C phase of an output end of the variable-frequency speed regulating device; the input end of the voltage following circuit is connected with the output end of the current sampling circuit; the input end of the precision filter circuit is connected with the output end of the voltage following circuit; the input end of the inverting amplifier circuit is connected with the output end of the precision rectifier circuit; the input end of the hysteresis comparison circuit is connected with the output end of the inverting amplifier circuit; and the input end of the reverse output circuit is connected with the output end of the hysteresis comparison circuit. The frequency converter comprises a master control chip and an overcurrent protection circuit; the master control chip stops power output of the medium-high voltage variable-frequency speed regulating device according to the an overcurrent protection signal output by the overcurrent protection circuit and cuts off high voltage input.

The present invention discloses a VSM-based two-level traction rectifier control strategy. By a mechanical model simulating a synchronous machine, the frequency of an input voltage of a rectifier is controlled, and by controlling the torque of a virtual machine, the rectifier is controlled to output the active power and a voltage at a DC side. By an electromagnetic model simulating the synchronousmachine, the amplitude of an input voltage of a traction rectifier and the reactive power outputted by a traction network are controlled, and by adding the voltage and frequency supporting links, therectifier can participate in the voltage and frequency adjustment of the traction network. According to the present invention, the traction rectifier can have the outer characteristics of the synchronous machine and has a certain damping characteristic, and by the oscillation of a damping system, an electric locomotive can participate in the voltage and frequency adjustment of the traction network actively while satisfying the own operation status, thereby enhancing the stability of a traction system, and playing an important part in the control of the traction rectifier.

A power supply for a guitar amplifier and the guitar amplifier and method of operating the guitar amplifier. The power supply includes an alternating current power input having a secondary winding and a filament winding, an output and a first vacuum tube rectifier coupled between the secondary winding of the power input and the output for rectifying the alternating current at the power input. At least a second rectifier is provided which is selectively couplable in parallel with the first vacuum tube rectifier. The at least one second rectifier can be a vacuum tube rectifier with each of the first and second rectifiers having a cathode continually energized by the filament winding, a solid state rectifier or both. The output amplifier has an output transformer having a primary winding with a center tap and with a first pair of vacuum tube amplifiers having their cathodes being coupled together and their plates coupled to the primary winding on opposite sides of the center tap. At least a second pair of vacuum tube amplifiers is provided having their cathodes coupled together and their plates being coupled to the primary winding on opposite sides of the center tap. A selector switch selectively causes at least one pair of the first pair of vacuum tube amplifiers and the at least a second pair of vacuum tube amplifiers to be operational and concurrently causes at least a selected one of the first vacuum tube rectifier and the at least a second rectifier to be operational corresponding to the selected at least one pair of vacuum tube amplifiers and the at least a second pair of vacuum tube amplifiers selected.

Provided is a power supply apparatus in AV equipment. The apparatus is coupled to an AC input and comprises a first power circuit comprising a first rectifier coupled to the AC input for generating a rectified DC, a predetermined power supply unit, a first power supply unit being in parallel with the predetermined power supply unit and coupled to a grounded first load, and a switch coupled to both the power supply units; and a second power circuit being in parallel with the first power circuit and comprising a second rectifier coupled to the AC input for generating a rectified DC, and a second power supply unit coupled to a grounded second load. Both the first and second loads are activated by the first and second power supply units for prohibiting fluctuation voltage occurred on the second load from transmitting to and interfering with the first load.

This straight tube LED illumination lamp includes the following: an LED element; a first plug having an input-output terminal and an empty terminal; a second plug having an input-output terminal and an empty terminal; a first rectifier that is connected to the input-output terminal of the first plug and the empty terminal of the second plug in order to convert alternating current to direct current; a second rectifier that is connected to the input-output terminal of the second plug and the empty terminal of the first plug in order to convert alternating current to direct current; and a bypass circuit through which current is flown back from either the first or second rectifier to the other rectifier. The bypass circuit has a current-limiting resistor to prevent the first and second rectifiers from being damaged.

The present invention provides a method for diagnosing a traction rectifier IGBT (Insulated Gate Bipolar Transistor) open-circuit fault in the CRH3 high-speed train, and belongs to the field of rectifier fault diagnosis. The method for improving the spectral kurtosis is used; the algorithm for improving the spectral kurtosis is simple, and the sudden change of energy in the signal and the corresponding frequency position can be detected; the degrees of the sudden change in the improvement of the spectral kurtosis under different faults are different; and when an open-circuit fault of a single-tube or a double-tube occurs, by using the method provided by the present invention, the fault occurrence can be quickly diagnosed, and the position of the fault tube can be precisely positioned. Themethod provided by the present invention is used for rectifier IGBT open-circuit fault diagnosis, fault occurrence can be quickly and accurately detected, and the fault type can be distinguished; andthe algorithm involved is simple, and without a large amount of data for training and testing, precise positioning of all fault types of the single-tube and double-tube of the rectifier IGBT can be realized.

The invention discloses a traction rectifier transformer isolation grounding system. The traction rectifier transformer isolation grounding system comprises a three-pole traction rectifier transformerisolation grounding system arranged at a three-phase power input terminal of a traction rectifier transformer, and a six-pole traction rectifier transformer isolation grounding system arranged at a six-phase power output terminal of the traction rectifier transformer. According to the traction rectifier transformer isolation grounding system, a rotating shaft of an isolating switch and the rotating shaft of a grounding switch are driven to rotate through an electric operating mechanism box to achieve opening and closing of the isolating switch and the grounding switch, thereby achieving powertransmission and power outage of an input end power supply and an output end power supply of the traction rectifier transformer and connection and removal of circuit protection ground wires of the input end power supply and the output end power supply to ensure the electric safety of equipment and the life safety of the personnel; and meanwhile, real-time communication can also be achieved through a digital communication technology and a remote control center, a ''remote control'' function can be completed and the real-time state of the traction rectifier transformer isolation grounding system can be transmitted to a central control room for real-time monitoring.

The invention provides a bias power supply device and an electron beam current adjusting method therefor, and relates to the technical field of bias power supplies of electron beam processing equipment. The device comprises a power frequency rectifier and filter circuit, a first inverter, rectifier and filter circuit, a second inverter circuit, a resonant converter circuit, a biasing transformer and a second rectifier and filter circuit, wherein the biasing transformer comprises a primary winding magnetic core and a secondary winding magnetic core, which are separated from each other; a primary winding of the biasing transformer is wound on the primary winding magnetic core; a secondary winding is wound on the secondary winding magnetic core; an input end of the power frequency rectifier and filter circuit is connected with an three-phase AC; the power frequency rectifier and filter circuit, the first inverter, rectifier and filter circuit, the second inverter circuit, the resonant converter circuit and two ends of the primary winding of the biasing transformer are sequentially connected with one another; two ends of the secondary winding of the biasing transformer are connected with the second rectifier and filter circuit; a negative output end of the second rectifier and filter circuit is connected with an electronic gun grid; a positive output end is connected with a negative terminal of a high-voltage power supply; and a positive terminal of the high-voltage power supply is grounded.

The invention discloses a bidirectional DC / DC power conversion device comprises a first inverter / rectifier unit, an LLC resonant unit, a second rectifier / inverter unit and a controller. The first inverter / rectifier unit, the LLC resonant unit and the second rectifier / inverter unit are connected. The controller is connected with the control end of the first inverter / rectifier unit and the control end of the second rectifier / inverter unit. The controller is used for respectively controlling the first inverter / rectifier unit and the second rectifier / inverter unit, so that the DC / DC power conversion device is controlled to perform the forward or reverse conversion on the electric power. The ZVS conduction can be realized. The buck-boost ratio of direct-current power conversion can be improved.The technical problems that a low-voltage large current is difficult to design, the power conversion efficiency is low, the size is large, the cost is high and the like are solved.

The invention discloses a metro traction power supply device with the over-voltage suppression function, a bilateral power supply direct current traction power supply circuit is formed by connecting four uplink and downlink traction feeders of an alternating current circuit breaker DL, a traction rectifier transformer T, a rectifier unit R, a direct current circuit breaker DS and a manual switch M, and the metro traction power supply device is characterized in that voltage suppression units used for avoiding current mutation of the power supply system and further suppressing the production of over-voltage are arranged on an uplink contact net line and a downlink contact net line of a dead zone. The metro traction power supply device can lead the current in the traction of the circulation of the power supply system to be transferred from a train to a capacitor during the process that a metro (light rail) runs from a live zone to the dead zone in the traction working condition or the regenerative brake working condition, and the energy stored by an inductor of a circuit of the power supply system can be released through a passage formed by the capacitor, thereby avoiding the production of the current mutation in the power supply system, eliminating the production of the over-voltage and solving the problem of over-voltage breakdown of the train produced through the dead zone.

An electric drive system for a vehicle includes a first generator in communication with a first engine, a second generator in communication with a second engine, a first rectifier and a second rectifier. Each generator has a main winding, each main winding being independently excitable and generating an alternating current (AC) output. A main AC output of the main winding of the first generator is in communication with the first rectifier, and a main AC output of the main winding of the second generator is in communication with the second rectifier. When in drive mode, the first engine drives the first generator and the second engine drives the second generator, and the first and second generators supply power to a plurality of inverters coupled to the first and second rectifiers, the plurality of inverts supplying power to a plurality of electric wheel motors.

Provided is a switching power supply device capable of effectively improving power supply efficiency with a small number of parts. The switching power supply device includes: a switching circuits (S1 to S4) for converting DC input power into AC power, a transformer (T) having a primary winding to which the AC power is supplied, first rectifiers (D21, D22) for rectifying the AC power induced by the secondary winding of the transformer into DC power, second rectifiers (D31, D32) having anodes connected to cathodes of the first rectifiers, and a capacitor (C) connected between the cathodes of second rectifiers and a predetermined potential node and functioning as an auxiliary power source of a predetermined load (F). Surge generated at the cathodes of the first rectifiers (D21, D22) of the secondary side during switching is supplied to the capacitor (C) via the second rectifiers (D31, D32). The load (F) uses power charged in the capacitor as an operation power source.

The invention discloses a power supply circuit and a TV set. The power supply circuit comprises a transformer, a first secondary winding of the transformer is connected with a first rectifier, and a second secondary winding is connected with a second rectifier; a first output end of the first rectifier is connected with a positive electrode of a first capacitor, a connection node is a high voltage output end, and a second output end of the is connected with, a negative electrode of the first capacitor, a first end of a first sampling resistor and a first input end of an overcurrent protection circuit are connected with each other; a first output end of the second rectifier, the positive electrode of a second capacitor, a second end of the first sampling resistor and a reference input end of the overcurrent protection circuit are connected with each other, the connection node is a low voltage output end, the second output end of the second rectifier, the first end of a second sampling resistor and the second input end of the overcurrent protection circuit are connected with each other, and the second end of the second sampling resistor and the negative electrode of the second capacitor are grounded. The technical scheme provided by the invention can optimize the cross adjustment efficiency of voltages output from two paths of the power supply circuit and improve the reliability of the power supply circuit.