53 results about "Precision rectifier" patented technology

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.

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 power converter that interfaces a motor requiring variable voltage / frequency to a supply network providing a nominally fixed voltage / frequency includes a first rectifier / inverter connected to a stator and a second rectifier / inverter. Both rectifier / inverters are interconnected by a dc link and include switching devices. A filter is connected between the second rectifier / inverter and the network. A first controller for the first rectifier / inverter uses a dc link voltage demand signal indicative of a desired dc link voltage to control the switching devices of the first rectifier / inverter. A second controller for the second rectifier / inverter uses a power demand signal indicative of the level of power to be transferred to the dc link from the network through the second rectifier / inverter, and a voltage demand signal indicative of the voltage to be achieved at network terminals of the filter to control the switching devices of the second rectifier / inverter.

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).

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.

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.

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.

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.

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 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 present disclosure discloses a converter system, which at least includes the first and second back-to-back converters. The first back-to-back converter includes a first rectifier module and a first inverter module. The first rectifier module is used to convert a first AC voltage to a first DC voltage. The first inverter module is used to convert the first DC voltage to a second AC voltage. The second back-to-back converter includes a second rectifier module and a second inverter module. The second rectifier module is used to convert the first AC voltage to a second DC voltage. The second inverter module is used to convert the second DC voltage to the second AC voltage. The converter system can suppress the circular current through the synchronous operation of the first and second rectifiers or the synchronous operation of the first and second inverters.

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.