Showing papers on "Boost converter published in 1977"

A new optimum topology switching DC-to-DC converter

Abstract: A novel switching dc-to-dc converter is presented, which has the same general conversion property (increase or decrease of the input dc voltage) as does the conventional buck-boost converter, and which offers through its new optimum topology higher efficiency, lower output voltage ripple, reduced EMI, smaller size and weight, and excellent dynamics response. One of its most significant advantages is that both input and output current are not pulsating but are continuous (essentially dc with small superimposed switching current ripple), this resulting in a close approximation to the ideal physically nonrealizable dc-to-dc transformer. The converter retains the simplest possible structure with the minimum number of components which, when interconnected in its optimum topology, yield the maximum performance. The new converter is extensively experimentally verified, and both the steady state (dc) and the dynamic (ac) theoretical model are correlated well with theexperimental data. both theoretical and experimental comparisons with the conventional buck-boost converter, to which an input filter has been added, demonstrate the significant advantages of the new optimum topology switching dc-to-dc converter.

High voltage single-ended DC-DC converter

Abstract: A new energy transfer system is evaluated for application in a 130 watt, l800 volt dc to dc converter. The single-ended half-wave transformer-coupled converter provides high efficiency (82%) with a low component count in the power train, resulting in a 25% cost reduction relative to a push-pull pulse-width controlled converter.

Spark plug igniter comprising a dc-dc converter

Abstract: A spark plug igniter with an auxiliary power source, in which the auxiliary power source is a DC-DC converter including a feedback loop. A high voltage induced in a secondary winding of an ignition coil and a DC voltage generated by the converter are additionally supplied in the same polarity to a spark discharge gap. The feedback loop of the DC-DC converter comprises a feedback winding, a rectifier connected to the feedback winding through a reactance element, and means for connecting the DC output of the rectifier in series to the DC power source of the converter in the same polarity.

A 2.5 KV high-reliability TWT power supply: Design techniques for high efficiency and low ripple

Abstract: A power supply designed to operate a high-efficiency, ten-watt TWT used as the power amplifier in a communications satellite is described. The electrical environment in which the power supply must operate and the required functional outputs are defined. Emphasis is placed on efficiency and regulation of the high-voltage converter. Operation is outlined by use of a functional block diagram and description of the primary power-handling circuits. Command, monitoring, and fault control, while vital to the proper operation of the amplifier, are not topics of this paper. The high-voltage converter achieves primary regulation through pulse-width modulation. The basic relationships which control its design, and the base drive circuit used to modulate the pulse width are described. An energyrecovery system using a two-winding inductor is employed in conjunction with the buck-mode converter. The principal sources of dissipation in the supply, contained in the highvoltage converter, are described. Relationships governing the dissipative loss in each are developed, and solved by use of a computer program. The results are presented in terms of graphs showing the effect on overall loss of varying critical parameters. Control of ripple, both externally imposed and internally developed, is a primary consideration of the power supply design. Its accomplishment is described in terms of the primary regulator, supplemental regulation by means of a linear regulator, and filtering at both input and output. Results of the design effort are summarized by a presentation of operational characteristics, and a brief description of the packaging.

DC to DC converter with regulated input impedance

Abstract: A converter designed to be powered by a constant current and variable voltage source such as a coaxial cable of variable length includes regulation circuitry to regulate the input voltage of the converter. In particular, the switching device of a single-ended converter is pulse width modulated to regulate the input impedance and hence the input voltage of the converter to permit its efficient operation at varying cable lengths.

New DC-DC converters with an energy storage reactor

Abstract: New DC-DC power converters with an energy storage reactor are presented. In the conventional converter circuits of an energy storage reactor, there is an extraordinary increase of the output voltage due to the excess magnetic energy, when the reactor current becomes discontinuous for the light-load. This phenomenon can be removed by making use of a dummy load or a reactor of sufficiently large inductance. However, the use of the dummy load makes the efficiency poorer and the size as well as the weight becomes larger if the inductance of the reactor is increased. In the converter circuits presented, the excess magnetic energy, which is stored in the reactor and undissipated in the load circuit, can be recovered to the input power source through the additional transistor and diode. With these converter circuits, the dummy load can be removed for any load condition and further the inductance of the reactor can be made smaller.

Series induction/parallel inverter power stage and power staging method for DC-DC power converter

Abstract: An improved series inductor/parallel inverter power stage and power stagingethod for a transistor controlled DC-DC power converter in which the integrating capacitance is located in the output of the power stage transformer and the series inductor has a secondary winding connected across this capacitance for transferring stored energy from the inductor primary directly to the transformer output rather than through the transformer, and current flow through the transformer primary is controlled by two parallel, alternately conducting pulse-width-modulated transistors in a manner such that only a single transistor is located in the main current flow path at any given time. The improved power stage is characterized by reduced power dissipation and peak voltage stresses on the transistors, increased simplicity, and improved reliability. A DC-DC power converter having at least two improved power stages of the invention arranged in parallel and adjusted for conduction of preset fractions of the total power in phased relation.

Power confidence system

Abstract: A data processing system includes as part of its power circuits, a number of converter circuits, each coupled to a different one of the power supply units which are to provide different voltages for distribution and use throughout the system. Each of the power supply circuits furnish a 24 volt dc power confidence signal to a central ac power input entry panel which applies the power confidence signals to the converter circuits. Each converter circuit includes an optically coupled isolator circuit which converts the 24 volt dc signal to a noise free low voltage logic level suitable for utilization by the low level high speed logic circuits included within the system. The output noise free low voltages provided by the converter circuits are in turn applied to a corresponding number of confidence input lines of a system interface unit which includes a plurality of ports, each port connected to a different module within the data processing system. The states of the low voltage logical level signals are stored in a status register. When the operating system determines that a unit is inoperative due to a power supply unit failure, it can logically disconnect the port having a module having the failure. Additionally, one of the converter circuits provides a second output signal which is used to enable the clock circuits during system power up only after the system has been placed in a known state.

Power converter control system

Abstract: A power converter control system for use with a power converter of the type which comprises a plurality of cascade-connected converter units of which at least one converter unit is subjected to continuous control of its conduction phase angle and the remaining converter units are subjected to on-off control of their conductivity is arranged to include a master controller for instructing the number of the converter units to be rendered operative, a reversible counter operative to change its content in response to a phase controlling command applied to the continuously controlled converter unit indicating a maximum or minimum conduction phase angle or delayed phase angle in conduction, a unit change control unit for producing unit changing operation signals to be applied to the respective converter units for controlling the operation of the same, by using one of the binary bits derived from the counter without modification and decoding the remaining bits, and a comparing and identifying circuit which compares the content of the reversible counter with the output of the master controller and causing the reversible counter to operate in response to the aforementioned phase control command until the content of the same becomes identical to the output of the master controller.

Protected aircraft power and phase converter

Abstract: A compact power and phase converter is adapted to utilize the single-phase and direct current power outputs of a conventional aircraft power supply, converting such outputs into stable three-phase power on wye-connected, grounded neutral distribution lines. An automatic current limiter provides overload protection for the converter when excessive output current is demanded.

Static Leonard system

Abstract: The disclosed Leonard type elevator system comprises a reversible converter for controllably driving a DC motor, and an AC voltage detector and a DC voltage detector connected to the AC and DC sides of the converter respectively for detecting the voltages developed on the respective sides of the converter. When a difference in detected voltage between the two detectors exceeds a predetermined magnitude due to a decrease in the AC source voltage, a comparator produces an output serving to disconnect the DC motor from the converter. Also the comparator may produce such an output when the converter receives regenerative power from the DC motor.

The Venerable Converter: A New Approach to Power Processing

Abstract: A regulating dc-to-dc converter is described which utilizes a new circuit configuration to achieve several desirable features including higher efficiency, a single circuit for regulation and conversion, minimized output filter requirements, and simplified control system applications. The dc operating characteristics are derived and the efficiency of the new converter is shown to compare favorably with the conventional boost regulator. An ac model is derived and a comparison is made between analytical and experimental results.

Aircraft power and phase converter

Abstract: A compact power and phase converter is adapted to utilize the single-phase and direct current power outputs of a conventional aircraft power supply, converting such outputs into stable three-phase power on wye-connected, grounded neutral distribution lines. An automatic current limiter provides overload protection for the converter when excessive output current is demanded.

Thyristor control method for thyristor AC-DC converter

Abstract: In an AC-DC converter for converting an AC power by a six-phase, half-wave or three-phase, full-wave back-to-back or anti-parallel connection thyristor bridge to a DC power for input to a load, while the current to the load is small, the converter is actuated as a converter of a three-phase, half-wave back-to-back connection bridge, thereby to enable an alternate supply of negative and positive currents to the load. Letting the output by the AC-DC converting operation of the three-phase, half-wave back-to-back connection bridge and the output by the other converting operation be identified as main and auxiliary outputs, respectively, as the load current increases, the auxiliary output is also supplied to the load.

Voltage boost circuit for telephone systems

Abstract: In a voltage boost circuit, for telephone systems where reverse battery supervision is employed, optically coupled semiconductor devices are used to control both the polarity and the charge on a nonpolar capacitor. This capacitor is powered from a DC to DC converter and the capacitor serves the dual functions of a rectifier filter capacitor and a voice frequency (VF) bypass capacitor. The voltage boost circuit charges the capcitor so that it aids the central office battery, thus extending the normal operating range of the central office. Whenever the current in the loop drops below a predetermined threshold level, the voltage boost is removed by a rapid discharge of the aformentioned capacitor. When the loop is closed, the capacitor is quickly chared to the full boost voltage with a polarity so as to aid, or increase, the current in the loop.

Continuity testing device for conducting connection - has low voltage source and stepping up converter with Zener diode in parallel with output

Abstract: The device has a supply voltage source. There are two test terminals, and there is a current limiting resistor and a signalling device which delivers a signal when the connection is not broken. The supply voltage source (1) produces a low output voltage. It is followed by a converter (3) which steps up the test voltage. There is a non-linear component, esp. a Zener diode (8). It forms with the current limiting resistor (7) a voltage divider. The non-linear component (8) is connected in parallel with the converter (3) output terminals (4, 5).

Electrostatic direct energy converter performance and cost scaling laws

Abstract: This study is concerned with electrostatic type direct energy converters for direct recovery of a large fraction of the plasma ion energy from fusion reactors. Simplified equations are presented for each of the important loss mechanisms in both single-stage direct converters and multistage ''Venetian Blind'' type direct converters. These equations can be used to estimate the efficiency and electric power output of the direct converter subsystem. Scaling relations for the cost of each major component in the direct converter subsystem are also given; these include the vacuum tank, direct converter modules, the DC power conditioning equipment, cryogenic vacuum pumping system and the thermal bottoming plant. The performance and cost scaling laws have been developed primarily for use in overall fusion power plant systems codes. However, to illustrate their utility, cost-effectiveness studies of two specific reference direct converter designs are presented in terms of the specific capital costs (i.e., the capital cost per unit electric power produced) for the Direct Converter Subsystem alone. Some examples of design improvements which can significantly reduce the specific capital costs of the Direct Converter Subsystem are also given.

A Frequency to Voltage Converter for Use as a Speed Transducer

Abstract: In this paper a frequency-to-voltage converter is proposed for use as a speed transducer over a 100:1 range. It aims to keep to a minimum the number of pulses per revolution of the opto-electrical transducer required whilst also minimising the output voltage ripple content and giving an adequate speed of response. It operates on the basis of a phase-locked loop giving a modulation of constant mark-space ratio over the frequency range. Mathematical models of the converter are derived to analyse and predict its dynamic performance and the behaviour of a prototype practical circuit is examined.

Transistor oscillator power converter

Abstract: The converter includes a transistor, a transformer having a ferromagnetic core, tuning capacity, and rectification of high frequency oscillations which occur in the converter for producing a voltage for an electrical load different in magnitude from the voltage of an electrical energy source from which the converter takes power. Load voltage and electrical energy source voltage may be direct current voltages or changing voltages. The converter operates to maintain the voltage across the load at a constant value independent of the resistance of the electrical load. The oscillations occur only when transistor bias current is provided, for example by bias current conduction through the load, in which case negligible power is taken from the electrical energy source by the converter when the load is disconnected. High frequency of oscillations in the converter provides certain advantages.

Electronic DC battery charger - has boost circuit and control circuit and sensors to detect battery voltage and temp. to indicate state of charge

Abstract: A, battery charger receives d.c. power from an external source through a power connector. Switch means receives the power from the power connector and supplies it to a boost circuit which is removably and conductively connected to a battery. A control circuit is connected to receive a battery voltage signal from the battery and a battery temp. signal from a sensor positioned to detect battery temp. The control circuit determines the state of charge of the battery from the voltage and temp. signals. The control circuit supplies (1) switching signals to the switch means to cause the switch to be conductive, and (2) boosting signals to the boost circuit to cause the boost circuit to charge the battery in accordance with a pre-selected charging program related to the state of charge of the battery.

A modular approach to the design of high-power DC-DC converters

Abstract: Ripple current in the power filter capacitors of a DC-DC converter can be reduced with a multiphase power switching circuit. Ripple current reduction is easier to achieve in the output filter capacitor than in the input filter capacitor because a low-impedance interconnect is required to take advantage of the possible reduction in the input. Noise and reparability requirements may demand the use of a relatively high-impedance interconnect among the input capacitors. Reparability of a converter is improved if components that can cause each other to fail are contained in the same module. Reliability of a power switching module is improved if it contains a current limit based on an extension of the power transistor off-time. Testing is simplified if the number of interconnects between modules is minimized.

Microwave input circuit with parametric down converter

Abstract: A microwave input circuit including a parametric upper sideband down converter for receiving an input signal whose frequency is not much different from the intermediate frequency produced at the output of the down converter. The down converter may be either of the series type or of the parallel type and has its signal input directly connected to a microwave antenna and terminated by the real antenna resistance (Rg) or the real antenna conductance (Gg), respectively, at the input signal frequency (fs1). The parametric down converter comprises a cascade connection of a parametric down converter stage and a parametric up converter stage with both of said stages being of the series type or of the parallel type. The down converter stage is terminated at its image frequency (fsp) with a real resistance (Rsp) or a real conductance (Gsp), respectively, and satisfies the following relationship for a series type down converter: ##EQU1## WHERE Rs1 is the series resistance of the reactance diode in the down converter stage, or the following relationship for a parallel type down converter: ##EQU2## where GD1 is the conductance loss of the reactance diode in the down converter stage, due to Rs1.