Showing papers on "Flyback converter published in 1973"

System oscillations from negative input resistance at power input port of switching-mode regulator, amplifier, DC/DC converter, or DC/DC inverter

Abstract: A switching regulator or a switching-mode amplifier, dc/dc converter, or dc/ac inverter can have a negative dynamic input resistance at the dc power input port. Frequently an LC decoupling filter is inserted in the dc power line between this equipment and the prime dc power source, to keep switching transients off the dc power buss. The negative input resistance of the equipment can exceed the positive output resistance of the LC filter and the power source. Then the system as a whole can oscillate. This oscillation can cause malfunction of the negative-resistance equipnent or of other types of equipment which may also be operated from the prime source. The conditions required for oscillation to take place are defined, and ways are shown to prevent the oscillation. The predicted oscillations have been observed experimentally.

Computer-Aided Design and Graphics Applied to the Study of Inductor-Energy -Storage Dc-to-Dc Electronic Power Converters

Abstract: A series of nine programs are developed for the design of the inductors of single-winding flyback converters. Three converter types are considered: voltage step-up, current step-up, and voltage step-up/current step-up. For each of the converter types, three pulse modulators are considered: constant frequency, constant transistor on-time, and constant transistor off-time. Computer-graphics displays are used to assist in evaluating characteristics of the various converter-modulator combinations.

Bias transformer for dual voltage input off-line converters

Abstract: In a dual voltage input AC to DC converter, the main DC voltage output is generated by a dual mode rectifier circuit, and an auxiliary AC voltage output is generated by a bias transformer circuit connected to the dual mode rectifier circuit. Though the AC to DC converter is capable of operating from dual input line voltages, both the main DC output voltage and the auxiliary AC output voltage remain constant and are independent of which one of the line voltages is input to the circuit.

Flyback transformer apparatus

Abstract: A flyback transformer apparatus is provided in which a flyback transformer is provided with a first and second secondary winding with one end of the first secondary winding connected to at least one first rectifier and a second rectifier connected between one end of the second secondary winding and the other end of the first secondary winding, a capacitor is connected to the second secondary winding, and a primary winding of the flyback transformer is inductively coupled with the high-voltage side winding portion of the first secondary winding, whereby the output impedance is reduced and a focusing voltage which does not give rise to defocusing is provided.

Converter control system with tapped transformer providing constant no-load secondary voltage

Abstract: A tapped transformer is inserted between an inverter connected to a DC transmission line and an AC system, the transformer being so controlled as to maintain a constant no-load secondary voltage. An inverter is so controlled that if DC current therein is below a rated value thereof, the DC voltage is maintained constant, whereas the extinction angle is maintained constant in the event of the DC current exceeding the rated value. It is further so controlled that in the event that a sudden change in the voltage in the AC system is detected, the extinction angle of the inverter is increased.

Dc signal translator with a variable amplitude oscillator

Abstract: A DC signal translator having an output DC isolated from the input comprises a variable amplitude oscillator generating an oscillating output signal having an amplitude directly related to the magnitude of the DC supply voltage for the oscillator. A DC isolating transformer is associated with the oscillator. A feedback rectifying circuit is coupled between the DC isolating transformer and the input of an amplifier so that the oscillator''s DC supply voltage, and hence, AC amplitude, is continuously adjusted so as to maintain a portion of the rectified DC feedback signal very nearly equal to the input signal. An output rectifying circuit which is matched with the feedback rectifying circuit is coupled to the isolating transformer so as to produce a DC output signal corresponding to the DC input signal while maintaining DC isolation between the input and the output of the DC signal translator.

Efficient dc/dc converter for a solid state fuze

Abstract: A DC/DC converter for transforming a high voltage to a lower voltage level for use in a solid state electrical time fuze. It comprises a constant charging network to charge a capacitor, which when charged, closes a switch in a series resonant circuit until a second switch closes forming a second resonant circuit.

Converter Transients Caused by Switching Type Surges on the DC Line

Abstract: A complete model of a typical H.V.D.C. converter station suitable for fast transient studies is used to irivestigate the effect of the converter termination on switching-type surges coming from the dc-line. The surge transfer to the converter side of the dc-reactor and the surge distribution within the converter plint are also investigated. Finally, a dynamic model is used to calculate the surge transfer stresses during current extinction followirng a switching surge.

High-efficiency converter and battery charger for an RTG power source

Abstract: Spacecraft power systems utilizing radioisotope thermoelectric generators CRTGs) as primary power sources present an uncommon set of require ments and limitations for interfacing dc-to-dc converters. A converter configuration is presented that complements these RTG characteristics. The circuit is a variation of the basic flyback regulator modified to provide input regulation. The converter has two isolated outputs. One output provides power directly to the spacecraft equipment, while the second is used for battery charging. Design problems addressed are noise generation in long cable lengths between the RTG source and the converter, regulation of the converter input to obtain maximum power transfer from the RTG to the equipment, and provision for two converter outputs while maintaining high efficiency with a simple design implementation. The design of a converter and battery charger used on the Viking Lander Capsule* is presented as an illustration.