Showing papers on "Forward 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.

True rms to dc converters

Abstract: An apparatus for converting a complex AC voltage wave to an equivalent DC value which is a measure of its true RMS value and which may then be read on an accurate indicating device such as a digital voltmeter, incorporating thermal converters and operational amplifiers in a temperature-compensated configuration The apparatus maintains a portion of an unknown AC voltage wave, which is thermally converted into a DC voltage, substantially equal to a DC reference voltage A portion of a DC output voltage is also maintained substantially equal to the DC reference voltage Since the proportioning means for the complex AC voltage wave and the DC output voltage is the same, the true RMS value of the complex AC voltage wave is equal to the DC output voltage

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.

Analog-to-digital converter analyzing system

Abstract: A system in which a variable and measurable analog signal, such as a voltage, is supplied to an A/D converter, which is being analyzed. Successive digital outputs, such as numbers, of the converter are determined and temporarily stored for comparison purposes. Based on the relative values of the successive numbers, the input voltage to the converter is varied, both in polarity and in magnitude, until a voltage is reached, which when applied to the converter there exists a 50 percent probability that the output number is one of two adjacent numbers. The voltage magnitude, or simply the voltage, is recorded to represent one indecision zone. Thereafter, the input voltage is varied to determine another indecision zone between a selected output number and another number, different therefrom by one.

Demand regulated dc to dc power supply

Abstract: A blocking oscillator dc to dc converter is used to supply voltage to a variable load. The load current is amplified and the amplified load current is integrated to provide a driving current which is a function of the load current. The driving current is supplied to the blocking oscillator to increase the frequency of the blocking oscillator as the load current increases.

Vehicular transmission pump drives

Abstract: The pump in an automatic transmission is drivingly connected by one-way clutches to be driven by either the transmission converter''s impeller or turbine, whichever is turning faster. The drive connection between the pump and the converter''s turbine is provided by a drive member which extends through the converter''s flow circuit and around the converter''s stator in the converter''s eye to connect to the turbine.

Dc to ac static power converter with short circuit protection

Abstract: DC voltage is coupled through an active voltage regulator to a voltage inverter to develop a precisely controlled AC output voltage. Feedback from the inverter output supplies requisite operating bias to the regulator only when the inverter develops an output voltage, thus rendering the regulator inoperative in the absence of an output voltage as on the occurrence of a short circuit at the load, thereby affording short circuit protection for the DC to AC converter.

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.

D.c. converter having control transistor in blocking oscillator feedback

Abstract: An apparatus for increasing an applied DC voltage level to a higher DC voltage level by utilizing a current feedback network to provide fast switching and control in the power transistors.

Converter station having parallel-connected static converters

Abstract: A converter station for high voltage direct current includes two substantially identical parallel converter branches provided with control systems therefore which limit the control angles of the converters of the branches upwards or downwards. A balancing arrangement is provided to assure equal current distribution between the two converter branches when they are forced so far in one direction that the limit value emitter for the converters of one of the converter branches becomes active. The balancing arrangement includes a device responsive to the difference between the current in the two branches to regulate the control system of the converter of the other branch. This arrangement may include cross connections between the limit value emitters to control converters of both converter branches.

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.