Showing papers on "Precision rectifier published in 1987"

Analysis of a high-voltage merged p-i-n/Schottky (MPS) rectifier

Abstract: A new operating mode for the merged p-i-n/Schottky (MPS) rectifier structure is analyzed. It is shown that these devices exhibit superior forward-drop and turn-off-speed characteristics. As an example, for the same forward drop, the 400-V MPS rectifier is an order of magnitude faster in switching speed when compared to a p-i-n rectifier. In addition, for equal switching speed, the MPS rectifier has much lower forward drop and leakage current.

Wide-band precision rectification

Abstract: Operational-amplifier supply-current sensing is employed in the design of high-performance precision rectification. The designs presented in this paper compare favourably with conventional precision rectifier circuits both in linearity and bandwidth, and are constructed from low supply bias-current operational amplifiers and current mirrors. Application of this new rectifying technique in the design of precision peak-detector circuits is also described.

"The merged P-I-N Schottky (MPS) rectifier: A high-voltage, high-speed power diode"

Abstract: Experimental confirmation of the theoretically predicted superior characteristics of the MPS rectifier for high voltage, high frequency power switching applications has been obtained by the fabrication of devices with aluminum Schottky barriers. These devices exhibit a 6 to 8 fold smaller reverse recovery stored charge and operate at 1.5 to 3 times the forward current density when compared with the P-I-N rectifer. Typical applications are in motor drive and switch mode power supply circuits.

Method of making a rectifier and control module for an alternator

Abstract: A rectifier circuit and control regulator are assembled onto a single plate for integral installation within the housing of an alternator. The method includes fabricating the plate with insulating, masking and conducting layers so as to provide mounting areas for commonly oriented rectifier diodes and efficient cooling for the entire unit.

Peak detector and imaging system

Abstract: A circuit for detecting the positions and intensities of peaks in a digital input signal (which may be a digitized version of a signal from a CCD forming part of a three dimensional imaging device) employs a second derivative of the input signal for validating the presence of each input peak. Each validation signal enables an interpolation circuit that determines the position of a peak by finding the location of a zero crossing point of a first derivative of the input signal. Each validation signal also enables a maximum detector for measuring the intensity of each peak. The arrangement does not require resetting after each detection of a peak and is less sensitive than prior devices to noise or DC or low frequency components.

Circuit arrangement for generating a direct voltage from a sinusoidal input voltage

Abstract: A circuit arrangement for generating a direct voltage from a sinusoidal input voltage. A capacitor (2) is coupled to an output terminal (3) of a rectifier (1) which receiver the input voltage and is discharged via a first diode arrangement (5) and a load (10) which is connected to the output of the rectifier (1). A series circuit is connected in parallel with the first diode arrangement (5) and comprises a second diode arrangement (4), via which only the chage current of the capacitor (2) flows, and at least a parallel arrangement of a control circuit (9) and a smoothing capacitor (7).

Dimmable electronic transformer circuit

Abstract: To permit dimming of a halogen incandescant lamp, or set of lamps connected to an electronic transformer circuit which receives operating voltage from a power network, rectifies the current supply and chops the rectified power to provide high-frequency alternating voltage for transformation to low voltage of the incandesent lamp, a non-current compensated choke having an inductance of at least 50 mH is connected in series between the rectifier output terminals and the rectifier system terminals, an oscillation start acceleration circuit including a CR circuit is connected in parallel with the starting circuit for the alternately operating transistors and a pair of symmetry resistors (R6,R7) are connected in parallel to symmetry defining capacitors (C6,C7), connected across the rectifier output terminals and a mid-point (M) of the oscillation transistors. The arrangement permits soft starting of the transistors, even if a serially connected phase controlled dimmer circuit suddenly connects line voltage at peak value across the rectifier, while providing for continuous energy release, even if the dimmer control is turned beyond the 90° phase angle position and, for example, to 135° phase angle.

Modified multi-path detector

Abstract: In the receiver 1 shown in fig. 1 and comprising a multi-path detector 2, the detector 2 comprises a frequency noise peak detector 11, an AM-­detector 12 and a weighting circuit 29 connected to the detectors 11 and 12. When noise peaks and amplitude modulations occur in an antenna input signal selected by a diversity switch 4 on account of a control signal of the weighting circuit 29 one of the antennas 3-1 to 3-n is switched to. The switching is audible to an annoying degree and should be limited. By inserting a threshold arrangement (31, 32) in the detector 11, by means of a low-pass filter 31 and a rectifier circuit 32, an instantaneous threshold voltage is generated varying with the frequency swing of the modulating signal. When using this instantaneous threshold voltage it is achieved on the one hand that with a large swing, corresponding with a large amplitude of the modulating signal, switching is audible to a less annoying degree. On the other hand, at moments when the modulating signal has a small amplitude, switching may and can take place more frequently as it less audible because of the small amplitude of the modulating signal. Improved reliability on detecting multi-path distortion is achieved by also supplying the instantaneous threshold voltage to the AM-detector 12.

Device for the inductive heating of a workpiece by means of a plurality of inductors

Abstract: In devices for the inductive heating and keeping-warm of a workpiece by means of a plurality of inductors, a capacitor being connected in parallel with each inductor, both are fed by a power inverter, which is supplied from a common fully controllable rectifier. Each power inverter is connected via a smoothing choke in each case to the d.c. voltage output of the common rectifier and each power converter is controlled only by the assigned load oscillating circuit by voltage comparison between the actual voltage and the setpoint voltage, independently of the other power inverters and without influencing the other power inverters. The a.c. output voltage can be changed only in the case of one or a few of the power inverters by changing the respective inverter firing angle. For proportionally changing all the power inverter output voltages, this is achieved by changing the rectifier output voltage. It is expedient if the rectifier is in each case influenced in dependence on the coil with the smallest voltage.

Circuit arrangement for operating low-voltage halogen incandescent lamps

Abstract: not available for EP0264765Abstract of corresponding document: US4862041To permit dimming of a halogen incandescant lamp, or set of lamps connected to an electronic transformer circuit which receives operating voltage from a power network, rectifies the current supply and chops the rectified power to provide high-frequency alternating voltage for transformation to low voltage of the incandesent lamp, a non-current compensated choke having an inductance of at least 50 mH is connected in series between the rectifier output terminals and the rectifier system terminals, an oscillation start acceleration circuit including a CR circuit is connected in parallel with the starting circuit for the alternately operating transistors and a pair of symmetry resistors (R6,R7) are connected in parallel to symmetry defining capacitors (C6,C7), connected across the rectifier output terminals and a mid-point (M) of the oscillation transistors. The arrangement permits soft starting of the transistors, even if a serially connected phase controlled dimmer circuit suddenly connects line voltage at peak value across the rectifier, while providing for continuous energy release, even if the dimmer control is turned beyond the 90 DEG phase angle position and, for example, to 135 DEG phase angle.

Arc power source device

Abstract: PURPOSE: To prevent an arc power device against waveform distortion, by turning ON and OFF a switching element for charge and discharge control in a higher frequency than the power alternate current and by repeating the accumulation and discharging of energy with a reactor on the primary side. CONSTITUTION: An arc power source device is composed of a diode bridge rectifier 2 on the primary side, a smoothing circuit 3 on the primary side, switching elements 4∼5 for high frequency conversion, a switching control circuit 6, a transformer 7, a rectifier 8 on the secondary side, a smoothing circuit 9 on the secondary side, a current detector 10, a high-frequency high- voltage generation circuit 12, etc. It supplies direct current and high-frequency high voltage to a load 11 superposedly. There, a reactor 13, a transistor 14 and a current-limiting resistance 15 are provided. A drive circuit 17 of the above transistor 14 detects the voltage of the rectifier 2 and the voltage drop across both terminals of the resistance 15 and drives the transistor 14 with a control signal of a PWM waveform (in a higher frequency than the power alternate current). These consist of an active filter 18. The capacitor 3 is thereby so fully charged at all times that the current quantity is increased. COPYRIGHT: (C)1989,JPO&Japio

Control method and a circuit arrangement for a rectifier

Abstract: In the case of this rectifier, an electronically controllable switch (S1...S6) is connected in parallel with each diode (V1...V6). The switched-on phases of the electronically controllable switches are controlled in synchronism with the conducting phases of the associated line-commutated diodes. In consequence, the rectifier is conductive in a bidirectional manner for both current directions and is nevertheless of the line-commutated, uncontrolled type. The switching-on information items for the electronically controllable switches are derived from the currents of an auxiliary rectifier which is connected in parallel with the main rectifier to the AC voltage network. The bidirectional rectifier is preferably suitable for supplying a drive converter from an AC network, it being possible for the drive to drive and brake.

A high-power magnetically switched superconducting rectifier operating at 5 Hz

Abstract: Above a certain current level, the use of a superconducting rectifier as a cryogenic current source offers advantages compared to the use of a power supply at room temperature which requires large current feed-throughs into the cryostat. In some cases, the power of such a rectifier is immaterial, for example if it is to be used as a current supply for short test samples with low inductances. Usually, however, a rectifier is intended to energize large superconducting magnets, so the maximum power available becomes an important parameter since it determines the loading time. One method of increasing the power of a rectifier is to raise the operating frequency. In this respect, magnetically controlled switches with very fast switching times are preferable to thermally controlled ones. This paper reports on the design, as well as the experimental results of a magnetically switched full-wave superconducting rectifier. Once this rectifier is brought to its design frequency of 5 Hz, the average power delivered to the cryogenic load will be 500 W.

Gain control circuit

Abstract: A gain control circuit includes first and second clamping circuits each of which has a DC shift circuit and a comparator comprising the output of the DC shift circuit with a reference voltage and providing a feedback signal to the respective shift circuit. A peak detector is responsive to the output of the second clamping circuit and is connected with a comparator which outputs a gain control signal to a variable gain device or amplifier located between the clamp circuits and also to the comparators associated with the DC shift circuits for varying the follow-up speeds of the clamping circuits.

Voltage multiplying rectifier

Abstract: PURPOSE: To reduce loss and miniaturize a voltage multiplying rectifier, by employing MOSFETs in the voltage multiplying circuit. CONSTITUTION: A voltage multiplying rectifier consists of capacitors 2, 3, MOSFETs 5a∼6a, photo-transistors 9a, 10a, forming a photocoupler, light emission diodes 9b, 10b, resistors 13∼16, an operational amplifier 17 and the like and supplies electric power to a DC load 4. According to this constitution, the MOS FETs 5a, 6a, corresponding to the polarity of an AC power source 1, turn ON through the photocoupler. As a result, the capacitors 2, 3 are charged respectively through the MOSFETs, whereby a voltage about two times of a power source voltage is supplied to the DC load 4. Further, the ON-resistance of the MOSFETs 5a, 6a are about 1/10 of the same of a rectifying diode; therefore, generation of heat or the like may be reduced. COPYRIGHT: (C)1988,JPO&Japio

Device for limiting surge current

Abstract: A device for limiting surge current comprises a resistor (R₂) for limiting the surge, current which may arise in an incandescent lamp (L). The (R₂) is connected in series with the lamp (L) and a power source (D). A first controlled rectifier (SCR₂) has its main current path connected in parallel with the resistor (R₂). A second controlled rectifier (SCR₁) has its main current path connected to the gate of the first controlled rectifier. A delay circuit, for example, a RC-time constant circuit (R₅,C₂) has its output connected to the gate of the second controlled rectifier such that the power source supplies the lamp through the resistor (R₂) for a time period determined by the time constant of the delay circuit.

Noise preventing device for on-vehicle radio receiver

Abstract: PURPOSE:To keep desired sound quality by driving a switching device so that the n-th harmonic is made coincident with the tuning frequency of a receiving broadcast wave and using the means value signal of an AGC detection output to control the gain of an intermediate frequency amplifier stage thereby eliminating beat tone. CONSTITUTION:A DC motor 103 is provided to a vehicle mounted with a radio receiver and a control circuit 101 drives the motor 103 in a switching frequency whose n-th harmonic is coincident with the tuning frequency of the receiving broadcast wave. The output of an AGC detector 28 is inputted to a peak detector 27 and an upper limit peak voltage UPK and a lower peak voltage LPF from the detector 28 are obtained by an upper peak detector 27a and a lower peak detector 27b respectively. A level detector 26 receiving the voltages UPK, LPK obtains the means value of both the input signals, it is inputted to an AGC amplifier 22 as the mean voltage of the AGC voltage. Thus, the radio wave is received while eliminating the beat tone and keeping the desired sound quality in such way.

Single-ended down converter

Abstract: A controlled single-ended down converter comprises a transformer of d.c. separation of the input circuit and the output circuit, a switching element controlled in pulse width in the input circuit and a rectifier diode as well as a fly-wheel diode in the output circuit. During the conducting phase of the switching element, the transformer takes up magnetization energy. This energy is demagnetized through the barrier layer capacitance of the rectifier diode during the cut-off phase.

Peak value detecting circuit for inpulse voltage

Abstract: PURPOSE:To detect the peak value of an impulse voltage without reference to characteristics of a LED by discharging a charged CR circuit corresponding to the peak value of the impulse voltage and converting the discharging current into light by the LED. CONSTITUTION:The CR circuit 3 has a time constant larger than the duration time of an impulse input and discharges charges corresponding to the peak value of the impulse voltage inputted through a reverse current preventing diode D0. The LED 4 converts the discharging current of the circuit 3 into light and diodes D1 and D2 are connected in parallel to protect the LED from an overcurrent. The signal obtained through the light conversion of the LED 4 is transmitted to a photodetecting element PC through an optical fiber OF and converted into an electric signal The value of the output voltage of an element P and a threshold value set by a threshold setter S are compared with each other by a peak detector D to detect the peak value of the impulse voltage from the duration of the voltage when the voltage is larger than the threshold value.

Gain control circuits

Abstract: A gain control circuit includes first and second clamping circuits (1, 3) each of which has a DC shift circuit (6, 9) and a comparator (7, 10) comparing the output of the DC shift circuit (6, 9) with a reference voltage and providing a feedback signal to the respective DC shift circuit (6, 9). A peak detector (4) is responsive to the output of the second clamping circuit (3) and is connected with a comparator (5) which supplies a gain control signal to a variable gain amplifier (2) located between the clamp circuits (1, 3) and also to the comparators (7, 10) associated with the DC shift circuits (6, 9) for varying the follow-up speeds of the clamping circuits (1, 3).

Device for detecting excess-current in a direct-current generator with controlled rectifier

Abstract: The apparatus relates to an excess-current monitoring device in a direct-current generator having a controlled rectifier, and is particularly useful for electro-chemical machining. A reference signal is generated by a signal generator in accordance with the voltage drive of the rectifier and the mean current supplied to the load. The reference signal is supplied to a comparator which supplies a current-switch-off-signal when the value of the reference signal as compared to the instantaneous load current indicates excess mean load current. This enables optimum machining.

Full wave rectifier circuit

Abstract: A full wave rectifier is embodied in an integrated circuit and includes first and second field effect transistors (7, 11) of a common conductivity type. In a p-channel embodiment, the two FET source regions (5, 10) are formed by a common substrate region (18) coupled to ground and to one side of a DC load (13), the other side of which is coupled to a substrate contact region (19/21). The AC input is coupled between the commonly connected drain and gate electrodes of the field effect transistors (7, 11). The rectifier is suitable for use in a power source for CMOS, NMOS and PMOS circuits and is particularly applicable to power supplies implemented by inductive or capacitive coupling in smart cards or electronic keys.

Call signal recognition circuitry for telephone subscriber's appts. - has current sensor between rectifier and diode supplying detector sensing frequency

Abstract: The incoming call signal recognition circuit for a telephone line has a rectifier (14) allowing the rectified incoming call signal to be used to charge a storage capacitor (C) via a one-way current switch (24). A call signal detector (26) determines the frequency of the call signal from the rectifier output. A current detector (18) lies between the rectifier (14) and the switch (24) allowing a low-ohmic load (R1) to be coupled to the rectifier output when no current is being supplied to the capacitor (C). Pref. the current detector (18) and the switch (24) are simultaneously provided by a transistor with two collectors. USE/ADVANTAGE - Rapid response allowing switching in of loudspeaker propagating more pleasant sound, even a melody, than usual alarm-like bell.

Undersynchronous and oversynchronous current rectifier cascade and method for operating it.

Abstract: Undersynchronous and oversynchronous rectifier cascades having an asynchronous machine (5) with a slip-ring rotor, in which the slip power released when running undersynchronously as a motor or over- synchronously as a generator is fed back to the power supply network (1) via an invertor (36), are used for driving pumps, ventilators and compressors in the power range from 500 kW to 5 MW. in order that the undersynchronous and oversynchronous rectifier cascade can also be used as a generator in the undersynchronous region and as a motor in the oversynchronous region, the invertor (36) is operated with a DC intermediate circuit such that the intermediate circuit current (Id) disappears for a short period so that commutation of the valves of a rectifier (10) on the machine side is possible. In this way, the rotor current of the asynchronous machine (5) is predetermined by means of a coordinate converter (31), via a trigger pulse transmitter (23) on the machine side, in terms of its magnitude (Is) and phase angle ( phi ). A zero-current detector (26) is used to determine whether the intermediate circuit current (Id) is

Apparatus for detecting minute change in electric capacitance of measuring condenser

Abstract: PURPOSE:To perform detection wherein a control method is simple and a linear range is wide, by utilizing an S-shape characteristic obtained when the input of a tuning circuit, the output from a capacitor and the difference between peak detection outputs of said circuit and said capacitor are calculated. CONSTITUTION:The high-frequency voltage from a high-frequency oscillator 4 is applied to a tuning circuit A, wherein a capacitor 3 is connected to the LC circuit formed by connecting an inductance to a measuring capacitor 1 consisting of a pair of flat plates in which a specimen is inserted in series, through a resistor 5. When the output VA from a peak detector 6 performing the peak detection of the input voltage to the tuning circuit A and the output VB from a peak detector 7 performing the peak detection of the output from the capacitor 3 are inputted to a differential amplifier 8, the output V0 thereof draws an S-shape curve to input frequency f0. If the input frequency f0 is controlled so as to set the output V0 to zero when no specimen is inserted, voltage DELTAV0 is outputted simultaneously with the insertion of the specimen to detect yarn irregularity and the wt. variation of a fine yarn.

Optical receiving circuit

Abstract: PURPOSE:To extend the input signal range to form an optical receiving circuit which does not cause waveform distortion, by providing an amplitude detector which detects the output voltage amplitude of a main amplifier and an output control circuit which takes the output voltage of the amplitude detector as the control input to control the output bias potential of a preamplifier. CONSTITUTION:When the light is made incident on a photoelectric element 1, a photocurrent flowing to the photoelectric element 1 through a transistor TR 5 is generated and the TR 5 is operated by this current, and an output voltage Vop is generated in a TR 6 by this operation. The voltage Vop is amplified by a main amplifier 3 to become an output voltage Vom, and a peak detector 4 detects the peak value of the output voltage Vom, and the base current of a TR 7 is controlled by the detection output. A part of the current flowing through a resistance Rf by the output voltage Vop at this time is the base current of the TR 5, and another part of this current is a current I1 of the TR 7. When the current I1 flows, the bias potential of the output voltage Vop is raised by Rf.I1 if the internal resistance of the TR 7 is ignored.

Design of smoothing inductance for rectifier circuits

Abstract: A simple method to determine the value of smoothing inductance required in rectifier circuits is presented. The method is general and can be applied to a wide variety of power frequency and high frequency rectifier configurations. The application of this method reveals four distinct modes of operation in a three phase, three pulse, half-controlled, bridge rectifier configuration. The results indicate that the choice of inductance depends upon the peak-to-peak ripple current and the average DC output voltage. The accuracy of the analytical results are verified experimentally.

280A Switched Mode Charging Rectifier for Three-Phase Mains

Abstract: The large new digital telephone exchanges which are installed in Norway today require considerable amounts of power. This results in a large demand for 48V battery plants and charging rectifiers. This paper describes a 15kw switch-mode 48V charging rectifier for 3-phase mains. The rectifier can very easily be coupled from a 3-phase 230V AC mains to a 3-phase 415 AC mains. A single phase working mode is possible with reduced power output. The rectifier system also has the advantage that the mains current waveform is nearly sinus-shaped. The system has a strictly modular construction and comprises a cabinet, one control module and two rectifier modules. The rectifier unit is a secondary switch and can deliver 60V DC and 140A. Bipolar transistors are used for switching with a switching frequency of 25 khz. Both the rectifier units and the control unit have a strictly modular construction and can be replaced during normal service. Current sharing occurs between the rectifier units, and between several parallel-coupled rectifier systems, without using master/slave configurations.

DC-DC forward converter.

Abstract: not available for EP0249271Abstract of corresponding document: US4809149A controlled single-ended down converter comprises a transformer of d.c. separation of the input circuit and the output circuit, a switching element controlled in pulse width in the input circuit and a rectifier diode as well as a fly-wheel diode in the output circuit. During the conducting phase of the switching element, the transformer takes up magnetization energy. This energy is demagnetized through the barrier layer capacitance of the rectifier diode during the cut-off phase.