Showing papers on "Boost converter published in 1976"

A Controllable Secondary Multikilowatt DC Current Source With Constant Maximum Power Factor in its Three-Phase Supply Line

Abstract: A type of industrial size dc converter for submegawatt applications is described and illustrated with the characteristics of a small scale 10 kW model. High conversion efficiency near 97 percent is maintained at full power and with an internal frequency of operation near 10 kHz. The system is characterized by the behavior of a true current source with inherent short circuit capability of its output terminals. All power is processed via a firmly controlled high Q series resonant circuit. Feasibility of power densities in excess of 1 kW/kg component weight is demonstrated. This high power density reflects itself in low quantities of material needed for construction of these systems. Operation of the dc converter as part of a rectifier-filter converter system, powered from a three-phase supply line is described. Test data demonstrate a high power factor PF?0.95 for all conditions of converter loading. Data obtained from a thyristor bridge-filter system are presented and subjected to comparative analysis.

Modeling of switching regulator power stages with & without zero-inductor-current dwell time

Abstract: State space techniques are employed to derive accurate models for buck, boost, and buck/boost converter power stages operating with and without zero-inductor-current dwell time. A generalized procedure is developed which treats the continuous-inductor-current mode without the dwell time as a special case of the discontinuous-current mode, when the dwell time vanishes. An abrupt change of system behavior including a reduction of the system order when the dwell time appears is shown both analytically experimentally.

Method and apparatus for conditioning of nickel-cadmium batteries

Abstract: A method and apparatus for reconditioning batteries utilizing a DC-DC converter. During a discharge of the batteries, each cell is monitored by the converter. When the voltage of a cell decreases to a predetermined level, a converter will assume the load of this cell and inhibit the voltage from reaching zero, thereby preventing voltage reversal of that cell.

Low-power monolithic COS/MOS dual-slope 11-bit A/D converter

Abstract: A single-chip, auto-zeroing, dual-polarity, single power supply A/D converter will be discussed, citing CMOS amplifier techniques used and performance results.

High speed digital switch

Abstract: A switching system for rapidly configuring transmission paths between comer equipments for high speed digital information in parallel form couples the input of a parallel-to-serial (P/S) converter to the output of each equipment providing information and the output of a serial-to-parallel (S/P) converter to the input of each equipment receiving information. A digital switch rapidly configures information transmission channels between its inputs and outputs in response to instructions from a configuration control. Each switch input is coupled to the output of a P/S converter, and each switch output is coupled through a switch output lead to the input of an S/P converter. A clock provides a periodic clock signal to each P/S converter through an adjustable delay control and to each S/P converter through a clock lead, wherein the electrical lengths of the switch output lead and clock lead coupled to the same S/P converter are equal. Each transmission path through the system is coupled between a P/S converter and an S/P converter which are synchronously operated.

The venable 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 ocnverter 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.

Efficient bidirectional power converter for portable data gathering apparatus

Abstract: Input and output switching transistors are alternatively activated to form a charging path and a discharging path for an inductor. The inductor periodically charges through the input transistor from an unregulated rechargeable battery, and discharges through the output transistor into an output capacitor. The output voltage taken across the output capacitor is regulated by negative feedback which varies the inductor charging period through the input transistor. The converter regulation is bidirectional. The voltage from the battery is initially greater than the regulated output voltage, but decreases to a value less than the output voltage as the battery discharges. When the battery is fully charged the converter regulates the battery voltage down to the output voltage. As the battery voltage drops through discharge, the converter regulates the lower battery voltage up to the output voltage. When the output voltage is not required by the data gathering apparatus, the output transistor is deactivated terminating the output voltage and establishing a residual standby mode in the power converter.

Speed Control of D. C. Motor Using Teyristor Dual Converter

Abstract: The paper describes the design, construction and testing of a closed-loop system for the speed control of a separately excited d.c. motor fed from a dual converter. The dual converter makes possible regenerative braking and reversal of direction of rotation. There is only one firing unit and the firing pulses are diverted to the appropriate converter by a master controller. There are three control loops: one for armature current control, one for adjusting the firing angle of the oncoming converter, and one for speed control.

Laser power supply

Abstract: A laser power supply includes a dc to dc converter which feeds a multiplier-rectifier circuit to provide a high dc voltage output. The converter includes a power transistor which is subject to a control of its on time to provide constant current regulation. A smooth regulation is provided by a proper timing of the turn off signal to the power transistor by sampling the emitter signal of a transistor which is included in a synthesized thyristor, the thyristor being operable to hog base current from the power transistor. The converter is coupled to the output multiplier-rectifier by a transformer which has a feedback winding connected in series with the base of the power transistor.

Unipolar wide-range current-to-frequency converter

Abstract: In a unipolar version of an analog-to-digital converter of low-level signals involving a self-zeroing current-to-frequency converter, which virtually eliminates the effects of voltage offsets at the input to the converter while avoiding large leakage currents, improved circuitry is provided in order to avoid paralysis of the converter which could be caused by small input currents or charges of polarity opposite to that of the normal signal current or by drifts in the converter input voltage which produce a negative-charge offset. The circuitry includes provision for the automatic introduction at the converter input of a relatively-large restoration current with the same polarity as the signal current, and this current can also be used for converter checking and calibration. One version of this circuitry involves exposing a junction diode at the converter input to light, causing it to act as a photodiode. One easily controlled source of such light may be a light-emitting diode conducting a suitable current placed in close proximity to the junction diode within the same enclosure. When the junction diode forms a part of a secondary feedback loop used during the discharge period of a primary capacitive feedback, then exposing it to light speeds up the secondary feedback, thereby reducing converter dead time. Other devices may be used for current introduction at the converter input, including a mechanical switch, but they are less preferable from the standpoint of leakage current, size and speed of response.

Regulation of a lightweight high efficiency capacitor diode voltage multiplier DC-DC converter

Abstract: A method for the regulation of a capacitor diode voltage multiplier dc-dc converter has been developed which has only minor penalties in weight and efficiency. An auxiliary inductor is used, which only handles a fraction of the total power, to control the output voltage through a pulse width modulation method in a buck boost circuit.

Efficient AC energy converter - has internal resistance of DC energy converter connected into AC circuit

Abstract: The ac energy converter has improved energy conversion efficiency compared with direct conversion systems such as thermocouples, thermionic valve diodes, photovoltaic cells, fuel cells, magnetohydrodynamic converters etc. To this end, the electrical internal resistance of a direct energy converter is connected into an a.c. circuit, and means are provided to ensure that the current flows through the internal resistance of the direct energy converter as rectified current, and that an impedance is provided in the a.c. circuit so as to limit the current. The impedance value is greater than the value or magnitude of the internal resistance of the direct energy converter, which is a laser diode.

Switching regulator with feedback system for regulating output current

Abstract: A switching regulator includes a chopper circuit and a DC-DC converter. A switching signal for use with the chopper circuit is derived from an inverter portion of the DC-DC converter so as not to use an external pulse oscillator. A DC voltage feeback circuit is provided from the output of the DC-DC converter to the chopper circuit so as to stabilize the DC output signal of the DC-DC converter.

Digital-to-analog converter having transient suppressor system

Abstract: A digital-to-analog converter having means to suppress the transient signals present at the output of the converter in response to a clock pulse synchronized with the transient signal. The clock pulse applies a forward bias to a pair of series-connected diodes which clamp the digital-to-analog converter output to ground. An integrator is connected to the converter output terminal to stabilize and filter the output signal while the terminal is clamped to ground.

Special power electronics topics

Abstract: Session 2 covers a broad spectrum of topics, ranging from circuit analysis methods through new circuit configurations to system applications, and also a component testing technique. In the first paper, Hayner et al. introduce a new pulse-width-modulated dc-to-dc boost converter, the Venable converter, in which current is fed continuously to the output capacitor, thereby alleviating the filtering requirements. In addition, the converter has high efficiency and transfer function properties that do not depend upon the duty ratio. Rostad et al, in the second paper,describe the application of the Venable converter to a series of satellite TWT power processors.

Power saving circuit for use with a converter circuit in a telephone switching installation

Abstract: Power saving means is shown for use with a converter circuit in a telephone switching installation. The converter circuit comprises an analog-to-digital converter and a digital-to-analog converter. The voltage supply for the converter circuit is switched on only upon the appearance of analog signals to be converted into digital signals or digital signals to be converted into analog signals.

Phase control oscillator

Abstract: PURPOSE:To realize a simple constitution by sharing the primary part of the analog-digital converter at the input side of the memory part and the digitalanalog converter at the output side

Computer control of a high frequency thyristor AC-AC converter

Abstract: The paper presents a direct data control method of an AC to AC thyristor converter for induction heating by a minicomputer. The details of the hardware of the interface between the converter and a minicomputer, and of the software for the following two purposes are described. (1) Programmed output power control by variations of thyristor1s switching function given by the computer, and by the ON/OFF control of capacitors under instructions of the computer. (2) To use this system for the purpose of data acquisition by the computer which is necessary for designing this converter, such as the worst case turn-off time margin of the thyristor, optimal switching function pattern for power control, max. and min. output power, stability, etc.