Showing papers on "Flyback converter published in 1971"

Pulse-width modulated dc to dc converter with zero percent duty cycle capability

Abstract: A pulse-width modulated DC to DC converter is enabled to operate into short circuits and limit the current output by having the capability of operating at zero percent duty cycle. The regulation feedback loop utilizes a light-emitting diode and phototransistor optical arrangement to permit isolation between the input and output sides of the converter. The light emitting diode is responsive to voltage monitoring and current monitoring circuitry on the output side of the converter. The converter operates in a crossover mode in which the regulation switches from voltage regulation to current regulation or vice versa as load conditions change.

Dc to dc converter with voltage regulation feedback loop achieving isolation between input and output by time domain techniques

Abstract: A DC to DC converter includes a digital type voltage regulation control circuit which permits complete isolation between the input and output circuits. The regulation signals comprise timing pulses coupled by a pulse transformer from voltage monitoring circuitry on the output side of the converter to switching control circuitry on the input side of the converter. The rectifier of the converter utilizes synchronous rectifying transistors driven by a proportional base drive arrangement which utilizes the regenerative action of a current transformer to transform the collector current of the transistor into a base drive current. This proportional base drive arrangement includes a third stored charge sweep-out winding and a diode to permit high frequency operation of the converter rectifier with low voltage high current saturation transistors.

Dual voltage system

Abstract: Two 12-volt batteries are connected in series across the output of a 24-volt charging system, and a DC to DC converter is connected between the output of the charging system and a junction between the batteries. To maintain equal voltages across both batteries, the voltage at the junction is compared with a reference voltage by a voltage regulator that is operatively connected with a DC to DC converter to maintain a regulated output therefrom to the junction.

Dual voltage charging system

Abstract: First and second batteries are connected in series between the terminals of a vehicle starting motor. The DC output terminals of a DC generator are connected across the first battery and also across a voltage sensitive switch and the oscillator transformer input stage of a DC to DC converter. The rectifier output stage of the DC to DC converter is combined with a voltage regulator that is connected across a second battery. The voltage sensitive switch renders the input stage of the converter operative when the output of the the generator is greater than a first predetermined voltage and inoperative below. The voltage regulator maintains a second predetermined voltage across the second battery by rendering the output stage of the converter operative to charge the second battery when the voltage thereon is below the second voltage and inoperative above.

Dc to dc converter with voltage regulation through pulse width modulation by control of the distribution of flux variations in a dual core transformer

Abstract: A DC to DC converter regulates its voltage output by controlling the distribution of flux variations in a dual core transformer included in the converter''s inverter circuit. The inverter output is coupled to a rectifier and the output load, via one core of the transformer. A voltage regulation control circuit includes the other core of the transformer and pulse width modulates the inverter output by controlling the flux variations in the two cores of the transformer. The second core included in the voltage regulation control circuit advantageously permits complete isolation between the input and output circuits of the converter.

Direct current to direct current chopper inverter

Abstract: Circuitry for converting direct current at one voltage level to direct current at another voltage level by the use of alternately fired transistor switches or the like feeding into a transformer, and incorporating flyback transformer means to prevent large current spikes and dissipated energy when the ON times of the transistors overlap, when the transistor switches are driven with pulses of unequal widths, or when the transformer primary turns on either side of a center tap are unequal. The basic concept of the invention is to connect a winding of an inductive energy storing flyback transformer in series with one or more chopper switches so that when the switch or switches are closed, the switch current is limited by the presence of the energy storing flyback transformer. When the switches are open, the stored energy of the flyback transformer is allowed to transfer current to a load through a diode.

The Separately Excited DC Traction Motor Applied to DC and Single-Phase AC Rapid Transit Systems and Electrified Railroads, Part II---Application

Abstract: The introduction of power thyristors and rectifiers in dc-dc chopper and ac-dc converter circuits allows the replacement of the traditional dc series motor by the separately excited dc motor This paper will consider the characteristics and the application of separately excited dc motors operating from either a dc input with a dc chopper using dynamic braking, or from a single-phase ac input with an ac-dc converter using regenerative braking, part I deals with the separately excited dc traction motor itself, while part II deals with its applications

Application Factors for Thyristor Converter DC Motor Drives

Abstract: Many papers in the decade of the 1960's have covered the basic principles of the dc converter in most aspects of design for 12-, 6-, and 3/6-pulse configurations. The problems discovered in applying these systems are dealt with, and the governing design parameters are identified. Specifically treated are the subjects of safety, isolation, noise immunity, line pollution, and performance. Examples of how hardware design is influenced by these considerations on a regenerative system in the 5?500 hp range are included. The parameter of economics is an important common factor to all application studies, hence this is considered in the conclusions.

Flyback transformer device

Abstract: A flyback transformer device wherein a flyback transformer and diode are accommodated in a hermetically sealed metal container which is filled with insulating oil whose amount of charge resulting from corona discharge is less than a predetermined value.

High voltage electric network

Abstract: A high voltage electric network has an AC part and a DC part and a converter station connecting the parts. An arrangement is provided for controlling the converter station to maintain a predetermined power exchange between the two parts of the network and to dampen oscillations arising in the AC part. The AC part has two portions as seen from the connection point of the converter station. The converter station is connected to the AC part by an inductive member which has an intermediate output connected to the portion of the AC part of lower impedance while one end of the inductive member is connected to the converter and the other end portion of the AC part.

Switch-type d.c. to d.c. converter

Abstract: A transistor coupled to a nonsaturating transformer is provided with a capacitive feedback path to form a D.C. to D.C. converter.