Showing papers on "Flyback transformer published in 1976"
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09 Feb 1976
TL;DR: In this paper, a transformer assembly comprising a core structure having an open space, primary and secondary coil units mounted either in parallel or in concentric relationship on the core structure, and a unitary insulating envelope of heat-resistant dielectric material such as silicon rubber, is presented.
Abstract: A transformer assembly comprising a core structure having an open space, primary and secondary coil units mounted either in parallel or in concentric relationship on the core structure, and a unitary insulating envelope of heat-resistant dielectric material such as silicon rubber, the insulating envelope a portion encapsulating the windings of the primary and secondary coil units and a portion occupying that area of the above mentioned open space which is subject to production of a corona discharge due to the high voltage to be developed in the secondary coil unit. The insulating envelope is formed by injecting the dielectric material of fluid state into a mould to which the subassembly of the core structure and coil units is fitted in part of in its entirety except for terminal elements. A partial vacuum is established in the mould so that the insulating envelope produced is void-free. The transformer is useful especially as a flyback transformer for use in a horizontal deflection circuit of a television receiver.
31 citations
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14 Jun 1976
TL;DR: In this article, a step-up DC converter suitable for construction as an integrated circuit chip provides a separate rectangular wave oscillator using a silicon transistor and a power amplifier driven thereby which supplies current to the primary winding of a two-winding stepup transformer matched to the constant duty cycle of the oscillator.
Abstract: A step-up DC converter suitable for construction as an integrated circuit chip provides a separate rectangular wave oscillator using a silicon transistor and a power amplifier driven thereby which supplies current to the primary winding of a two-winding step-up transformer matched to the constant duty cycle of the oscillator thereby simplifying construction of the transformer and permitting the oscillator and power amplifier voltage step-up transformer functions to be individually optimized for overall high efficiency operation. A hysteresis switching voltage comparator senses the rectified value of the high voltage output from the transformer relative to a stable reference voltage and switches both the oscillator and the amplifier to their standby current condition when a predetermined high output voltage level is obtained and switches both oscillator and amplifier into conduction when the output voltage falls to a predetermined level. A second comparator operates an LED indicator when the output voltage is above a certain level.
29 citations
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24 Sep 1976TL;DR: In this paper, a power transistor switch is employed to selectively connect the transformer primary across a DC source of power to provide energy storage when the switch is closed and to provide power transfer when it is open, by way of transformer flyback.
Abstract: A multiple output switching regulator power supply operates as a self-oscillating circuit with a light weight ferrite core transformer and a sense winding used exclusively for voltage regulation purposes. A power transistor switch is employed to selectively connect the transformer primary across a DC source of power to provide energy storage when the switch is closed and to provide energy transfer when the switch is open, by way of transformer flyback. The power transistor switch is controlled by a feedback circuit which includes a current sink connected to selectively divert current away from the base of the power transistor switch and a timing circuit for controlling the operation of the current sink. A capacitor, connected across the sense winding is monitored by a high gain voltage comparison circuit which activates the timing circuit in dependence on the voltage variation on the capacitor.
28 citations
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01 Oct 1976TL;DR: Based on the principle of the regulating transformer booster, a new voltage regulator is described which selects parts of the supply-voltage waveform by means of phase-controlled thyristor switches and thus provides fast and variable voltage boost.
Abstract: Based on the principle of the regulating transformer booster, a new voltage regulator is described which selects parts of the supply-voltage waveform by means of phase-controlled thyristor switches and thus provides fast and variable voltage boost. Two different types of control are investigated and their performance is analysed with different types of load. Various experiments are done to substantiate the analytical investigation.
26 citations
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30 Aug 1976TL;DR: A ferroresonant transformer includes a transformer core, primary and secondary windings, and a secondary core section of the transformer core is formed at least in part of a first magnetic material which saturates at a relatively small magnetizing force as mentioned in this paper.
Abstract: A ferroresonant transformer includes a transformer core, primary and secondary windings A secondary core section of the transformer core is formed at least in part of a first magnetic material which saturates at a relatively small magnetizing force The remainder of the transformer core is formed of a second magnetic material which saturates at a magnetizing force greater than that of the first magnetic material The transformer also includes a ferroresonant capacitor which is responsive to the magnetic flux generated by current in the primary winding for generating a magnetic flux for saturating the secondary core
23 citations
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14 Apr 1976TL;DR: In this article, a television receiver protection system providing X-ray protection to the viewer responds to rectified horizontal flyback pulses supplied to the gate electrode of a silicon controlled rectifier through a zener diode.
Abstract: A television receiver protection system providing X-ray protection to the viewer responds to rectified horizontal flyback pulses supplied to the gate electrode of a silicon controlled rectifier through a zener diode to trigger the silicon controlled rectifier into conduction when the high voltage level from the flyback transformer of the receiver becomes abnormally high. The silicon controlled rectifier is connected across the power supply for the horizontal oscillator, so that the horizontal oscillator is rendered inoperative when the silicon controlled rectifier becomes conductive.
19 citations
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18 Oct 1976
TL;DR: In this paper, an electric power converting apparatus utilized to convert the power of a storage battery into an AC voltage, step up the AC voltage by use of a step up transformer, and rectify the secondary voltage of the transformer to directly operate a DC driving motor of a car or an AC motor through an inverter is provided.
Abstract: In an electric power converting apparatus utilized to convert the power of a storage battery into an AC voltage, step up the AC voltage by use of a step up transformer and rectify the secondary voltage of the transformer to directly operate a DC driving motor of a car or an AC motor through an inverter, a rectifier and an inverter are provided to energize the secondary of the transformer from a commercial source and another rectifier is provided on the primary side of the transformer to charge the storage battery.
15 citations
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07 Oct 1976TL;DR: In this article, a flyback transformer is connected to a resonant capacitor and is driven by a switching device synchronized with horizontal scanning pulses so that flyback pulses are produced during the normal retrace intervals in the horizontal deflection.
Abstract: Apparatus is provided for preventing the generation of an excessively high voltage by the high voltage circuit of a CRT device, such as a television receiver, thereby avoiding the danger of producing injurious X-ray radiation and further minimizing the potential fire hazard attributed to such an excessively high voltage. A flyback transformer is connected to a resonant capacitor and is driven by a switching device synchronized with horizontal scanning pulses so that flyback pulses are produced during the normal retrace intervals in the horizontal deflection. A relatively low voltage power supply is coupled to the switching device to apply an operating voltage thereto. A first detecting circuit is coupled to the flyback transformer for detecting a high frequency component included in the flyback pulses in the event of a malfunction of the resonant capacitor, such as a disconnection of that capacitor, which high frequency component causes an excessively high voltage to be produced by the high voltage circuit. A second detecting circuit is coupled to the flyback transformer for detecting a high flyback pulse level that is produced when the operating voltage applied by the low voltage power supply exceeds a predetermined level. In the event that the first detecting circuit detects the presence of a high frequency component or the second detecting circuit detects a high flyback pulse level, a switch is actuated to control the CRT deflection circuit, thereby reducing the level of the flyback pulses, and thus the level of the high voltage produced by the high voltage circuit.
14 citations
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8 citations
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03 Dec 1976TL;DR: In this paper, a high voltage generator suitable for use in a television receiver set was proposed, where a frequency dependent attenuation circuit is connected to a primary winding of a flyback transformer, which generates a high-voltage to be supplied to a CRT whereby a regulation for high voltage is improved.
Abstract: A high voltage generator suitable for use in a television receiver set wherein a frequency dependent attenuation circuit is connected to a primary winding of a flyback transformer which generates a high voltage to be supplied to a CRT whereby a regulation for a high voltage is improved
7 citations
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28 May 1976
TL;DR: In this paper, a switching transistor is provided to disable the deflection coil when rendered conductive, and a negative bias voltage is derived from the juncture between the first and second capacitors.
Abstract: A horizontal deflection circuit of a television receiver comprises series-connected first and second capacitors resonated with the deflection coil to provide an oscillating current during the retrace period of horizontal scanning. A switching transistor is provided to disable the deflection coil when rendered conductive. A negative bias voltage is derived from the juncture between the first and second capacitors. A positive bias voltage is derived from the flyback transformer and applied to the base of the transistor together with the negative bias voltage. Under the normal condition of the circuit, the resultant voltage at the base of transistor holds it under the blocking state. Should the first capacitor become faulty, the transistor is biased into the conducting state by the positive potential to disable the circuit.
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24 Nov 1976
TL;DR: In this paper, a push-pull current transformer is used to produce an output voltage generated based upon an input direct voltage and a given desired voltage, where a series connection comprises a longitudinal regulating member, an inductor and a push pull current transformer which produces the output voltage.
Abstract: A circuit for the production of an output voltage generated based upon an input direct voltage and a given desired voltage. A series connection comprises a longitudinal regulating member, an inductor and a push-pull current transformer which produces the output voltage. The input direct voltage is fed to the push-pull current transformer. The push-pull current transformer includes a push-pull transformer having push-pull primary winding and a secondary winding. In addition, the push-pull current transformer includes switching transistors which are switched on and off in push-pull by a control circuit. The control circuit delivers a suitable cyclical changing control signal to the switching transistors. Circuitry is provided for minimizing if not eliminating spikes in the current occurring during a switching of the switching transistors. As a result, the switching transistors remain free from excessive voltages which can damage same.
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19 Aug 1976TL;DR: In this paper, a compact impedance transformer increases the magnitude of a voltage pulse applied to an X-ray generator using a variable impedance spiral delay line is used to achieve voltage doubling.
Abstract: A compact impedance transformer increases the magnitude of a voltage pulse applied to an X-ray generator A transmission line transformer is implemented using a variable impedance spiral delay line to achieve voltage doubling
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22 Nov 1976
TL;DR: In this article, a magnetically coupled two transistor multivibrator for use with power supplies is presented, where an auxiliary transformer having its secondary winding in series with the transistor base drive circuits is employed.
Abstract: A magnetically coupled two transistor multivibrator for use with power supplies. In addition to the usual collector driven output transformer, an auxiliary transformer having its secondary winding in series with the transistor base drive circuits is employed. The auxiliary transformer has primary windings powered by emitter current. Provision is also made for feedback from the main output transformer so that the secondary base drive windings can be powered from either emitter or collector currents. Electronic means are employed to isolate the output transformer from the base drive transformer upon the occurrence of a short circuit in the load, thus permitting the emitter windings to take over the function of supplying feedback and maintaining oscillations.
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08 Jul 1976
TL;DR: In this paper, an electrical load in series with a source of AC power is connected across the anodes of a triac with the secondary of a transformer being connected between the triac gate and one of the triAC anodes.
Abstract: An electrical load in series with a source of AC power is connected across the anodes of a triac with the secondary of a transformer being connected between the triac gate and one of the triac anodes. An electronic switch controls current flow in the primary of the transformer such that a negative voltage is supplied at the gate of the triac during conduction by the primary until saturation of the transformer occurs. After saturation, the electronic switch opens the transformer primary initiating a flyback period during which the triac gate potential rings positive and a consistent peak positive current is supplied to the triac gate from the secondary of the transformer. A half-wave rectifier circuit and transistor may be substituted for the triac for DC load control, or a pair of these transistor circuits may be connected in series to provide AC load control.
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08 Oct 1976
TL;DR: In this article, color signals are time compressed and are transmitted after being inserted in horizontal flyback periods, and the color signal is transmitted after the insertion of a single color node.
Abstract: PURPOSE:Color signals are time compressed and are transmitted after being inserted in horizontal flyback periods.
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16 Aug 1976
TL;DR: An electric amplifying arrangement for supplying current to an inductive load in response to an input signal of saw-tooth waveform, e.g. a deflection amplifier for a cathode ray tube, was proposed in this article.
Abstract: An electric amplifying arrangement for supplying current to an inductive load in response to an input signal of saw-tooth waveform, e.g. a deflection amplifier for a cathode ray tube, wherein during the ramp portion of the input voltage a linear relation is maintained between variation in the load current and the input signal (i.e. Class A operation occurs) and, during flyback, energy recovery is provided, thereby providing higher efficiency than is obtained with known Class A saw-tooth amplifiers.
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08 Jun 1976TL;DR: A novel saturated time-delay transformer is connected in series with the dc load and detects and limits overcurrent until the fault has been corrected or the power source removed.
Abstract: A novel saturated time-delay transformer is connected in series with the dc load. The transformer detects and limits overcurrent until the fault has been corrected or the power source removed. This transformer design can be used at any voltage level however, the paper describes it in conjunction with high voltage (HV) circuits. Some design details for such a transformer are given.
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22 Apr 1976
TL;DR: In this paper, a one-kick multi-vibrator with a RC element defining the pulse duration is connected between the timing generator and the d.c. voltage transformer, in such a way that as the input and charge reversing voltages increase the pulse length of the voltage transformer decreases.
Abstract: Between the timing generator and the d.c. voltage transformer there is connected a one-kick multi-vibrator with a RC element defining the pulse duration. At each pulse of the timing generator the RC element is excited. The pulse duration defining the "on" period of the d.c. voltage transformer is also influenced by the charge reversing voltage dependent on the input voltage. This is done in such a way that as the input and charge reversing voltages increase the pulse duration of the d.c. voltage transformer decreases. The one-kick multi-vibrator consists of two gates, the first acting as an inverter and the second as a NOR gate.
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TL;DR: In this article, an analysis of the behavior of single-phase transformer coupled loads controlled by an ac switch is presented, where the current and load voltage equations are derived taking into account the principal parameters of the transformer, and it is shown that the extinction angle is a function of the ratio of the inductances, an equivalent time constant, and the triggering angle.
Abstract: An analysis of the behavior of single-phase transformer coupled loads controlled by an ac switch is presented. The current and load voltage equations are derived taking into account the principal parameters of the transformer, and it is shown that the extinction angle is a function of the ratio of the inductances, an equivalent time constant, and the triggering angle. Through the suggested analysis more exact results are obtained than compared to the conventional analysis.
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07 Oct 1976TL;DR: In this article, the primary transformer current is monitored by threshold level switches coupled to solid stage control circuits, which operate the protection loops which prevent damage to the drive system if the pick-up contacts start to lift off the conductors e.g. at high speed.
Abstract: The electric traction vehicle with overhead power supply has a current monitoring system in the high voltage input side of the transformer. The primary transformer current operates on threshold level switches which are coupled to solid stage control circuits. These operate the protection loops which prevent damage to the drive system if the pick-up contacts start to lift off the conductors e.g. at high speed. The system is more responsive than relay protection in the secondary circuits of the transformer.
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TL;DR: In this article, the performance of a television camera using a pyroelectric Vidicon has been improved by the use of flyback gas pedestal generation and a low relative-permittivity target material.
Abstract: The performance of a television camera using a pyroelectric Vidicon has been improved by the use of flyback gas pedestal generation and a low-relative-permittivity target material.
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02 Nov 1976
TL;DR: In this article, a transformer control device based on the magnetization principle is proposed, which includes a voltage comparator unit, intermediate amplifiers and power amplifiers, as well as an additional intermediate amplifier and the connection of the inputs of the intermediate amplifier in series opposition makes it possible to separately magnetize each yoke of the transformer.
Abstract: The proposed transformer control device is based on the magnetization principle and includes a voltage comparator unit, intermediate amplifiers and power amplifiers The introduction of an additional intermediate amplifier and the connection of the inputs of the intermediate amplifiers in series opposition makes it possible to separately magnetize each yoke of the transformer The separate magnetization of the transformer yokes instead of their differential magnetization substantially reduces the no-load current of the transformer, brings down the mean power required to control the magnetization of the yokes in the continuous voltage adjustment range, and thus raises the transformer's efficiency