Showing papers on "Flyback converter published in 1969"
Patent•
14 Oct 1969
TL;DR: In this paper, a DC converter for transforming a DC voltage to an AC voltage of high frequency and including one or several switching means to effect this operation is described. But the authors focus on the use of premagnetization means for magnetizing the transformer core to increase the efficiency of the converter.
Abstract: The invention relates to a DC converter for transforming a DC voltage to an AC voltage of high frequency and including one or several switching means to effect this operation. The invention is specifically related to the use of premagnetization means for magnetizing the transformer core in order to increase the efficiency of the converter. This is effected by premagnetizing the core into saturation with a magnetic field which is opposite to the field generated by the current through the corresponding switching means. The transformer core will consequently operate in its saturated state from the point when the switching means is rendered conductive and the current through said switching means is increasing up to a certain value above which the core will operate in its nonsaturated state. This arrangement will provide a converter operating with substantially rectangular waveforms of the current supplied to the load, which means that the switching means can operate just below their maximum permissible current when energy is transferred from the current source to the load. The switching means will thus be utilized at a maximum thereby improving the efficiency of the converter.
13 citations
Patent•
02 May 1969TL;DR: A starting system for a SYNCHRONOUSL-COMCOM-UNIT is described in this article, where a BRIDGE RECTIFIER is connected and operated as an AC regulator to provide a VARIABLE REDUCED VOLTAGE to the synCHRONOUS CONDENSER.
Abstract: A STARTING SYSTEM FOR A SYNCHRONOUSLY COMMUTATED POWER CONVERSION UNIT. DURING START-UP A BRIDGE RECTIFIER IS CONNECTED AND OPERATED AS AN AC REGULATOR TO PROVIDE A VARIABLE REDUCED VOLTAGE TO THE SYNCHRONOUS CONDENSER. AFTER START-UP THE BRIDGE RECRIFIER IS RECONNECTED AS A PHASE DELAY RECTIFIER.
11 citations
Patent•
09 Oct 1969
TL;DR: In this paper, a static converter connecting an AC network with a DC line has a control system in which an AC control function voltage is derived from the AC network, while a DC regulator voltage was derived from a regulator.
Abstract: A static converter connecting an AC network with a DC line has a control system in which an AC control function voltage is derived from the AC network, while a DC regulator voltage is derived from a regulator. The control system further comprises a first arrangement for deriving the actual time between subsequent following control pulses for the valves of the converter and a second arrangement for deriving a desired value for said time corresponding to the relation between the period time of the AC network and number of pulses of the converter. The difference between said actual time and its desired value is stored in a memory circuit for each valve and as a correction magnitude taken together with the control function voltage and the regulator voltage.
11 citations
Patent•
12 May 1969
TL;DR: In this article, a static DC to DC converter with an output converter stage comprising a full-wave bridge with an SCR in each of two adjacent legs of the bridge is controlled by a variable phase synchronous pulse generator.
Abstract: A static DC to DC converter having an output converter stage comprising a full-wave bridge with an SCR in each of two adjacent legs of the bridge. The firing times of the SCR''s are controlled by a variable phase synchronous pulse generator controlled by an operational amplifier having one input connected to a reference voltage source and another input connected to feedback means across the converter''s output so that the converter''s output voltage is regulated. Means are provided for delaying, during start-up, the application of voltage to the pulse generator to prevent heavy current surges through the SCR''s. An overshoot voltage clipper is connected across the output of the operational amplifier.
6 citations
Patent•
04 Aug 1969
TL;DR: In this paper, a static converter with a delay angle control device, a control amplifier for controlling the delay angle, and an arrangement for blocking the converter is presented. But the converter does not have the ability to control the output of the blocking device over a switch delaying circuit.
Abstract: In a static converter which includes a delay angle control device, a control amplifier for controlling the delay angle control device, and an arrangement for blocking the converter. In order to provide for rapid starting of the converter a limiting member for limiting the delay angle of the converter so as to limit the direct voltage of the converter is controlled by the output signal of the blocking device over a switch delaying circuit. A transient order device is also connected to the input side of the control amplifier to increase the input signal of the amplifier and the transient order device is actuated by the blocking means for the DC transmission line connected to the converter. An under-voltage sensitive device actuated by the voltage in an AC network connected to the converter is connected in parallel to the blocking device, and the two parallel devices are connected to the limiting member and the transient order device by an OR gate.
4 citations
TL;DR: The proposed time-to-digital converter is a parallel unit to the ADC, and could be used in computer controlled multicounter experiments to time control and adjustment experiments.
4 citations
Patent•
20 Jun 1969TL;DR: In this paper, a power converter system utilizing a control converter operated during both the positive and negative current half cycles of the output voltage to initiate firing pulses for a power converter which can be operated in either a noncirculating current mode or a circulating current mode is described.
Abstract: A converter system utilizing a control converter operated during both the positive and negative current half cycles of the output voltage to initiate firing pulses for a power converter which can be operated in either a noncirculating current mode or a circulating current mode.
3 citations
Patent•
22 Jan 1969
TL;DR: In this paper, an improved high-speed AC to DC converters has been presented, which has a response time superior to that of existing AC-to-DC converters.
Abstract: AN IMPROVED HIGH-SPEED AC TO DC CONVERTER IS DISCLOSED WHICH HAS A RESPONSE TIME SUPERIOR TO THAT OF EXISTING CONVERTERS. THAT IS, THE DC OUTPUT OF THE CONVERTER REACHES ITS STEADY STATE VALUE IN A SHORTER TIME PERIOD THAN IS POSSIBLE WITH EXISTING AC TO DC CONVERTERS. THE IMPROVEMENT IN RESPONSE TIME IS ACHIEVED BY A UNIQUE CIRCUIT ARRANGEMENT INCLUDING A PLURALITY OF OPERATIONAL AMPLIFIERS. BY MEANS OF THE UNIQUE ARRANGEMENT, A COMPARATIVELY LARGE VOLTAGE PROPORTIONAL TO THE INPUT VOLTAGE IS ADDED TO THE DC OUTPUT INITIALLY AND UNTIL THE DC OUTPUT REACHES ITS STEADY STATE VALUE. THE LARGE VOLTAGE ALLOWS A CAPACITOR IN FILTER CIRCUIT TO CHARGE MORE RAPIDLY THEREBY SIGNIFICANTLY DECREASING THE TIME REQUIRED FOR THE DC OUTPUT VOLTAGE TO REACH A STEADY STATE VALUE. FURTHERMORE, THE CONVERTER OF THE PRESENT INVENTION FEATURES INCREASED ACCURACY AND PRECISION.
Patent•
11 Sep 1969
TL;DR: In this paper, a method and apparatus for testing an A-to-D converter by applying to the AtoD converter a DC test signal whose amplitude is varied and which is modulated by an AC signal is presented.
Abstract: A method and apparatus for testing an A-to-D converter by applying to the A-to-D converter a DC test signal whose amplitude is varied and which is modulated by an AC signal. The output digital data from the A-to-D converter is applied to a D-to-A converter and then displayed for monitoring the distortions of the A-to-D converter.
Patent•
03 Jun 1969TL;DR: In this paper, a converter arrangement is provided which can be set to operate both as an inverter and as a rectifier and wherein the converter elements are constituted by thyristors which are liable to damage by sharply rising voltages thereon brought about by overcurrent conditions when the converter is operating as a Rectifier.
Abstract: A converter arrangement is provided which can be set to operate both as an inverter and as a rectifier and wherein the converter elements are constituted by thyristors which are liable to damage by sharply rising voltages thereon brought about by overcurrent conditions when the converter is operating as a rectifier. To protect the converter elements against damage in such event, means are provided for changing over the operating mode of the converter from rectifier to inverter operation and to also cut off the converter operation completely after a predetermined time delay if the overcurrent condition persists.