Showing papers on "Buck converter published in 1983"
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16 Sep 1983TL;DR: In this paper, a buck regulator or impedance converter is described for operating a current limited power supply such as a photovoltaic array at or near its maximum power point, which is achieved at the compliance voltage which is an almost constant voltage, and means for sensing the voltage at the input of the regulator and using this sensed voltage to control a logic circuit which, in turn, controls the duty cycle of a switching transistor.
Abstract: A buck regulator or impedance converter is disclosed for operating a current limited power supply such as a photovoltaic array at or near its maximum power point. The maximum power point for such a supply is achieved at the compliance voltage which is an almost constant voltage. Means are provided for sensing the voltage at the input of the regulator and for using this sensed voltage to control a logic circuit which, in turn, controls the duty cycle of a switching transistor. The output from the switching transistor is coupled to an LC filter and from there to the load. The logic circuitry, responsive to the sensed voltage, controls the duty cycle of the switching transistor in such a manner as to maintain the input voltage approximately constant and thus to maintain the power supply at or near its peak power operating point.
138 citations
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25 Jul 1983
TL;DR: In this paper, an electrostatic precipitator system powered by a primary power source, the power supply has a converter and a high voltage device, which can be coupled to the primary source for producing a converter voltage with a different frequency content.
Abstract: In an electrostatic precipitator system powered by a primary power source, the power supply has a converter and a high voltage device. The converter can be coupled to the primary power source for producing a converter voltage with a different frequency content. The high voltage device is driven by the converter, producing from its converted voltage a high voltage. This high voltage is influenced by the different frequency content, having at least one frequency component at a predetermined low frequency which is sized to promote efficient precipitation.
63 citations
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TL;DR: In this paper, a nonlinear discrete-time dynamic model for the series resonant dc-dc converter is derived using approximations appropriate to most power converters, and compared with a laboratory converter for a large transient event.
Abstract: A simple nonlinear discrete-time dynamic model for the series resonant dc-dc converter is derived using approximations appropriate to most power converters. This model is useful for the dynamic simulation of a series resonant converter using only a desktop calculator. The model is compared with a laboratory converter for a large transient event.
46 citations
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06 Jun 1983TL;DR: In this article, a control circuit adapted to control the start-up trajectory of a DC-to-DC converter as a continuous function of the input voltage applied to it by the current-limited source is presented.
Abstract: The start-up trajectory of the operating point of a DC-to-DC converter normally includes a high current locus which must be traversed to reach the steady-state operating point. In the case of a converter powered by a current-limited source, such as a power supply system where one converter powers a plurality of subsequent converters, the subsequent converters may be unable to turn on due to inadequate current drive. By using a control circuit adapted to control the start-up trajectory of a DC-to-DC converter as a continuous function of the input voltage applied to it by the current-limited source, the start-up characteristics are constrained to be compatible to both source and load permitting the converter to proceed to its steady-state operating point.
28 citations
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TL;DR: In this paper, a capacitive water-level sensor using PTFE-insulated wire and a capacitance to frequency converter is described, where the converter draws only 150 mu A from a 5 V supply and is insensitive to supply voltage variations.
Abstract: A capacitive water-level sensor using PTFE-insulated wire and a capacitance to frequency converter is described. Construction is simple, yet overall linearity is 0.1%. Temperature drift of the sensor is -0.05%K-1 and that of the converter is <0.01%K-1. Long-term stability of the sensor appears excellent. The converter draws only 150 mu A from a 5 V supply and is insensitive to supply voltage variations.
26 citations
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23 Sep 1983
TL;DR: In this article, a converter drive circuit is activated when a shutter operation or the completion of a film winding operation, thereby driving a converter for oscillation, and the converter charges a main discharge capacitor to a given voltage, and when the given voltage is reached, the converter drive is deactivated, thereby ceasing the oscillation of the converter.
Abstract: A power supply unit for electronic flash includes a converter drive circuit which is activated when a main switch is turned on or in response to the completion of a shutter operation or the completion of a film winding operation, thereby driving a converter for oscillation. The converter charges a main discharge capacitor to a given voltage, and when the given voltage is reached, the converter drive circuit is deactivated, thereby automatically ceasing the oscillation of the converter.
24 citations
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13 Jul 1983TL;DR: In this article, a floating battery feed circuit (10) comprising a switchingmode, flyback power converter (200) where a capacitor (C3) connected to a converter transformer winding (201) develops a relatively low voltage used to energize the converter control circuitry (100).
Abstract: A floating battery feed circuit (10) comprising a switching-mode, flyback power converter (200) wherein a capacitor (C3) connected to a converter transformer winding (201) develops a relatively low voltage used to energize the converter control circuitry (100). The converter control circuitry prevents the operation of the battery feed circuit unless the voltage developed by the capacitor is above a predetermined magnitude. The power converter advantageously operates in only a constant-power mode regardless of loop impedance.
14 citations
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17 Jun 1983TL;DR: In this paper, a PWM converter is operated with a lagging power factor, and the apparent phase of the power supply voltage E is shifted depending upon the difference between a d-c voltage detected across both terminals of the capacitor and a set voltage, with the shifted voltage as a reference.
Abstract: The input terminals of a PWM converter are connected to the a-c power supply via a reactor. A capacitor C as well as a load 11 are connected to the d-c output terminals of the PWM converter. An apparent phase of the power supply voltage E is shifted depending upon the difference between a d-c voltage detected across both terminals of the capacitor and a set voltage, and a control signal for the PWM converter is prepared, with the shifted voltage as a reference. When the detected voltage is greater than the set voltage, the PWM converter is so controlled as to be operated with a lagging power factor, and the a-c voltage at the input terminals of the PWM converter becomes smaller than the power supply voltage. Accordingly, the d-c voltage can be maintained at a value smaller than the set voltage.
9 citations
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06 Jun 1983TL;DR: In this paper, an exact stability analysis of the buck regulator system is presented and the eigenvalues of the system can be brought back into the unit circle and the sys-tem thus stabilized with the addition of the feedforward loop.
Abstract: The interaction between the input filter and the regulator often causes serious degradation of performance. The reduction in loop gain due to input filter interaction can result in system instability. An exact stability analysis of the buck regulator system is presented. The input filter parameter values are varied and system instability is predicted for the case without feedforward. The eigenvalues of the system can be brought back into the unit circle and the sys tem thus stabilized with the addition of the feedforward loop. Measurements made for the cases with and without feedforward confirm the analytical prediction.
6 citations
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26 Jul 1983
TL;DR: In this paper, single-speed, three-phase motors are started and run by a static phase converter which comprises a timing circuit, adjustable for a starting interval, and a switching device which configures a plurality of capacitors, with respect to motor windings, so that a starting capacitance and a running capacitance are connected during a starting mode for a high torque condition, and, thereafter, the run capacitance is connected for running the motor.
Abstract: Single-speed, three-phase motors and two-speed, three-phase motors are started and run by a static phase converter which comprises a timing circuit, adjustable for a starting interval, and a switching device which configures a plurality of capacitors, with respect to motor windings, so that a starting capacitance and a running capacitance are connected during a starting mode for a high-torque condition, and, thereafter, the run capacitance is connected for running the motor.
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TL;DR: In this article, a small-scale Superconducting Magnetic Energy Storage (SMES) unit was constructed using small magnets and a high-voltage converter, and the characteristics of this unit were examined.
Abstract: A small-scale Superconducting Magnetic Energy Storage(SMES) unit was constructed using small magnets and a high-voltage converter, and the characteristics of this unit were examined. The high output voltage of the converter makes it possible for even a small magnet to charge and discharge large power. Moreover, converter control provides adequate protection during quenching. AC and DC filters can be eliminated from the converter system, and ripple voltage does not harm the superconducting magnet. These features demonstrated the potential of an SMES unit as a power system stabilizer and a peak load power supply.
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24 Mar 1983
TL;DR: In this article, a single-ended DC converter using the forward converter principle and having a current transformer and a flyback converter inductor, whose primary windings are connected in series, is described.
Abstract: The invention relates to a single-ended DC converter using the forward converter principle and having a current transformer and a flyback converter inductor, whose primary windings are connected in series. The transformation ratios of the current transformer and the flyback converter inductor are selected to be of equal magnitude. The rectifier elements on the secondary side are connected to the secondary windings of the current transformer and of the flyback converter inductor, and to one another, in such a manner that a continuous load current flows.
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24 Nov 1983
TL;DR: In this paper, a pneumatic-electric transducer was used to store an output voltage of a DC-DC converter with high service life at power failure by using a piezoelectric element flapper.
Abstract: PURPOSE: To obtain a pulse pneumatic pressure converter storing an output pneumatic pressure even at power failure with high service life by using a piezoelectric flapper for a pneumatic-electric transducer, dividing a power supply into two systems and backing up only the circuit relating to the piezoelectric element flapper. CONSTITUTION: An output voltage of a DC-DC converter 37 or a voltage of a battery 38 is inputted to a DC-DC converter 39, where the voltage is converted into around DC24V. the voltage V 2 is applied to an input electric circuit comprising an up-down counter 22, a D/A converter 23 and a comparator 24 or the like and a circuit element required minimum for holding an output pneumatic pressure such as a pneumatic-electric transducer 32 or the like. Since the voltage of the battery 38 is used as a backup power supply at power failure although no voltage is inputted to the converter 39 from the converter 37, the converter 39 generates the voltage V 2 . Thus, the piezoelectric element flapper 26 holds a potential corresponding to that at power failure and the output voltage is held to a value at power failure. COPYRIGHT: (C)1985,JPO&Japio
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10 Mar 1983
TL;DR: In this paper, a method for synchronisation of a converter synchronous motor to a supplying mains power supply via converter, in the case of which method the mains Power Supply and the motor are at approximately the same frequency, is described.
Abstract: The invention relates to a method for synchronisation of a converter synchronous motor to a supplying mains power supply via converter, in the case of which method the mains power supply and the motor are at approximately the same frequency. Pulses are derived from the mains power supply voltage via a trigger stage (12) and are compared with corresponding pulses from a three-phase (rotating field) detection system (4, 13) of the motor (3) in a logic device (11). If the phases are the same, the pulses which are derived from the mains power supply voltage are connected to the motor converter (5) in order to control the valves, and the pulses which are derived from the detection system are suppressed, the voltage in the DC intermediate circuit at the same time being set to a fixed value via the mains power supply converter (6), and a synchronising switch (18, 19) then being connected.
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11 Oct 1983TL;DR: In this paper, a high-speed bipolar logarithmic analog-to-digital (A/D) converter outputs signed binary numbers proportional to the signed binary number of a bipolar analog input signal.
Abstract: A high-speed bipolar logarithmic analog-to-digital (A/D) converter outputs signed binary number proportional to the logarithm of a bipolar analog input signal. A log converter is followed by a level shifting amplifier to center the output of the log converter on a temperature compensating reference. The reference voltage from the temperature compensating reference is used by a linear A/D converter to set the end points of the converter range. A code converter follows the A/D converter if a uniform absolute value coding is desired. Limiting the number of least significant bits (LSB) used to those representing the range of usable converter operation completes the device.
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08 Apr 1983
TL;DR: In this article, a current to frequency converter comprising a photocell, a voltage-to-frequency converter, an integrator in the feedback loop of the converter, the current source being connected to the summing junction of the converters, and a controlled circuit for attenuating the current injected from the converter to the summming junction to increase the frequency of output pulses is presented.
Abstract: A current to frequency converter comprising a current source, for example a photocell, a voltage to frequency converter, an integrator in the feedback loop of the converter, the current source being connected to the summing junction of the converter and integrator such that the frequency of output pulses from the converter is directly proportional to the magnitude of current injected from the converter to the summing junction, and a controlled circuit for attenuating the current injected from the converter to the summing junction to increase the frequency of output pulses. The controlled attenuating circuit includes a transistor switching arrangement for introducing increased resistance in the path for current injected from the converter to the summing junction in response to the presence of a control signal.