Showing papers on "Flyback transformer published in 1973"

Electronic dust separator system

Abstract: A device for electronic collection of dust which includes an electrostatic separator and a high voltage transformer which, in conjunction with a pulse generator, supplies a pulse voltage to the separator. The output voltage of the pulse generator is superimposed on the output voltage of the transformer to cause the voltage at the electrostatic separator to exceed the spark over limit, once each cycle of the transformer output.

Current transformer with active load termination

Abstract: A current transformer and transresistance amplifier are combined; the secondary winding of the current transformer being connected to the input of the transresistance amplifier and being virtually short-circuited because of the very low input impedance of the transresistance amplifier. The transresistance amplifier, nevertheless, supplies an output voltage which is proportional to current in the primary winding of the current transformer. An output voltage is developed from the current in the secondary winding. An important advantage, among others, of the subject combination is that a current transformer having considerably lower volt-ampere capacity may be employed. A current transformer employed alone for the same purpose would have to have a much larger volt-ampere capacity.

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.

Line time base in television receiver

Abstract: A line time base in a television receiver including a symmetrical limiter for cutting off the line flyback pulses from which the reference signal for the synchronizing circuit is derived. As a result a slice is obtained whose duration and amplitude is constant and independent of the load on the EHT generator.

High dc voltage generating circuit

Abstract: A high DC voltage generating circuit is provided with an impedance element connecting a switching element with the primary winding of a fly-back transformer, and a capacitive element is connected to the primary winding of the fly-back transformer to form a resonance circuit therewith, so that the fly-back transformer delivers, as its output, a sinusoidal high voltage which is subjected to a voltage doubler rectification to provide a high DC voltage with improved regulation.

Apparatus for outdoor lighting, especially for traffic signs

Abstract: An outdoor lighting fixture having a high discharge lamp which requires a relatively high feeding voltage. The fixture is supplied with mains voltage by a cable located in the ground. A first transformer located below the ground is used to step-down the high voltage from the mains. The resulting low voltage is transmitted to a second transformer which steps-up the voltage to that required by the lamp. This second transformer is located adjacent to and is connected to the lamp.

Constant-voltage power supply

Abstract: In a power supply circuit useful for a horizontal deflection circuit in a television receiver, there is provided a voltage-controlled semiconductor element, for example, such as silicon controlled rectifier, in order to stabilize effectively the output power voltage. The silicon controlled rectifier is switched between its OFF and ON states in response to two kinds of pulses: flyback pulses occurring within the television receiver and newly produced control pulses having relative phases with respect to the phase of the flyback pulses which relative phases differ depending upon variations in the input power voltage. Current flow through the silicon controlled rectifier charges a capacitor connected thereto which in turn provides the stabilized output voltage to the horizontal deflection circuit.

Compensated transformer circuit

Abstract: A circuit for reducing or eliminating the effect of the magnetizing inductance of a transformer on voice-frequency signals coupled through that transformer. Circuitry is provided to generate voltages and currents which simulate the presence of a negative inductance and to couple those voltages and currents to a transformer in cancelling relationship to the magnetizing inductance thereof. Circuitry is also provided to reduce or eliminate the effect of the equivalent shunt resistance of the transformer and thereby render the transformer virtually free of core losses. Finally, circuitry is provided to linearize the nonlinear magnetization characteristics of non-linear cores and thereby substantially reduce the distortion of signals coupled through the transformer.

Broad band balanced modulator

Abstract: A broad band balanced modulator with a signal input side and a signal output side comprising first transformer means on the signal input side including an unbalanced-to-balanced transformer, second transformer means on the signal output side including a balanced-to-balanced transformer having a balanced coil with a center tap, rectifier means for connecting the output of said first transformer means to the input of said second transformer means, a local oscillator connected between ground and said center tap, and the size of the unbalanced-to-balanced transformer of signal input side being larger than that of said second transformer means.

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.

Ferroresonant transformer battery charger circuit

Abstract: A battery charger circuit comprises a ferroresonant transformer. A first rectifier circuit connected between the transformer and a battery provides a first rate of voltage. A second rectifier circuit connected in ''''piggy-back'''' with the first rectifier circuit between the transformer and the battery provides a second rate of voltage.

Phase correction for horizontal oscillator in cmos form

Abstract: A horizontal oscillator system in CMOS form, for use in a television receiver, comprising an oscillator connected to a divider-buffer stage and a phase comparator; the output of the divider-buffer stage is applied to the horizontal drive circuitry of the television receiver and the flyback signal produced by the horizontal drive circuitry is coupled back to the phase comparator, which includes a positive-logic channel and a negative-logic channel terminating in a complementary pair of MOS-FET''s. The phase comparator compares the flyback signal with a horizontal synchronizing pulse derived from the sync separator of the television receiver, and develops a control voltage varying in amplitude in response to changes in phase of the flyback signal and the horizontal sync pulse. The control voltage is applied to the oscillator so as to control the operating frequency and thereby maintain the oscillator frequency in synchronism with the horizontal sync pulse.

Pulse transmitter for transmission line

Abstract: A pulse transmitter is coupled to the transmission line through a pulse transformer, and at the end of a produced pulse, there occurs in the transformer a reverse voltage peak due to the fact that the magnetizing transformer current does not instantaneously vary when switched. The magnetizing current decreases and must be nulled before the generation of the next pulse. According to the invention, the reverse peak is utilized for accelerating such a magnetic current decrease, by diminishing the transformer damping.

Current transformer terminated by active load elements for providing phase-inverted signals

Abstract: The secondary winding of a current transformer is terminated in a virtual short-circuit condition by a pair of active load elements, such as transresistance amplifiers, which provide, for example, a pair of phase-inverted output voltages proportional to current in the primary winding of the current transformer.

Method and apparatus for generating electrical voltage of amplitude varying with time

Abstract: Voltage generators in which the primary winding of a superconductive transformer is excited by momentary connection to a source of direct current and is further energized responsively to voltage induced in the secondary winding by cyclic changing of primary winding current, for compensating losses internal to the transformer and associated circuitry. Control of such further energization and maintenance of transformer winding current below the current level at which the transformer windings are rendered normal are effected by superconductive current-interrupting devices.

Field deflection circuit

Abstract: A field deflection circuit in which the deflection coil is connected to a direct voltage source during the flyback period so as to reverse the polarity of the deflection current. For this purpose the deflection coil is connected through a switch controllable connected to the direct voltage source, which switch is controlled by the difference between a voltage proportional to the steep-edged sawtooth input signal and a voltage proportional to the deflection current. This difference is considerable during the flyback period and is utilized for switching on the controllable switch; it becomes zero as soon as the deflection current has reached its required value at which the switch is switched off again. It is thus achieved that the polarity reversal is always terminated when the required value is reached, even when the direct voltage fluctuates and also when the inductive load is changed.

High voltage generator

Abstract: A high voltage generator is provided in which a rectifier is connected with the same polarity to each end of the secondary winding of a transformer, e.g., a flyback transformer in such a manner that the other end of one of the rectifiers is connected to a reference potential point and a high DC voltage is produced at the other end of the other rectifier, and moreover, if desired, a moderately high DC voltage is derived from a neutral point for the alternating current which is formed in the secondary winding.

Protective system for mobile electric power apparatus

Abstract: In a mobile electric power apparatus, such as a mining machine to which high voltage ac power is supplied from a remote substation through a flexible cable, the frame of the machine is grounded at the substation through a ground conductor in the cable. Integrity of the ground conductor is continuously monitored by means of a low voltage dc current derived from the power circuit at the machine end through a potential transformer having a wye-connected primary. The potential transformer supplies a rectifier through a zig-zag autotransformer. A neutral-to-neutral connection between the zig-zag transformer and the potential transformer primary enables balanced return of monitor current through the power conductors.

High voltage generator for x-ray diagnosis apparatus

Abstract: A high voltage generator for X-ray diagnosis apparatus includes a high voltage transformer with at least one primary winding connected to an alternating current net and at least one secondary winding feeding the X-ray tube as well as means adjusting the high voltage by changing the primary alternating voltage. These means are connected to a rectifier bridge located in the primary circuit of the high voltage transformer. The invention is particularly characterized in that these means are formed by a variable resistance connected to the outlet of the rectifier.

Voltage-limited deflection system for a television receiver

Abstract: A voltage-limited deflection transformer includes a tuning capacitance integrally formed therein. A portion of the transformer winding is in the form of two strips of insulated metallic foil arranged on the core such that the foil strips form the electrodes of the capacitance required to tune the transformer. An open circuit occurring in one foil results in no DC to the transformer whereas an open circuit in the other foil substantially disables the transformer. A short circuit in the foil capacitor detunes the transformer and lowers its output voltage.

Bonneville Power Administration Transformer Short Circuit Test Results - Comparison of Winding Inspection With Diagnostic Methods

Abstract: This paper summarizes Bonneville Power Administration's transformer short circuit test experience of three-phase units rated 115-kv Delta to 12.47-kv Wye; reviews BPA's diagnostic and low voltage impulse test results, and correlates them with factory inspection of damaged units. Special emphasis is on the low voltage impulse method of evaluating transformer damage.

Horizontal linearity correction circuit

Abstract: A cathode ray tube deflection circuit having a flyback transformer coupled to a potential source and via a parallel coupled horizontal output stage and a horizontal deflection yoke to a potential reference level with a damper stage coupled to the junction of the transformer means, output stage, and deflection yoke includes a linearity correction circuit wherein a winding of the transformer means coupled to a potential reference level is also coupled to a series connected switching means and series resonant circuit connected to the potential reference level and to the damper stages whereby the rate of change of current flow through a deflection yoke is altered to enhance linearity of the trace period of a cathode ray tube.

Regulated high voltage power supply circuit

Abstract: This invention contemplates a regulated high voltage power supply circuit for a high voltage generator circuit of a television receiver set wherein a high voltage controlling saturable reaction is connected in series to an output winding of a flyback transformer and the inductance of the saturable reactor is varied dependent on variations in beam current, whereby the anode voltage of a cathode ray tube is regulated against the variations in beam current.

Ground fault interrupter apparatus with means protecting against a grounded neutral condition

Abstract: Ground fault interrupter apparatus of the differential transformer type is provided with an additional output transformer, the primary of which is connected between a line conductor and the neutral conductor of an A.C. system with a current limiting resistor adjacent the primary winding. The secondary of the output transformer is the neutral conductor. THe saturation properties of the core of the output transformer are such that during each half cycle a voltage pulse is induced in the secondary. The voltage pulse is of no consequence in the system during normal conditions but if a grounded neutral condition exists a current is produced in the neutral conductor unbalancing the differential transformer and interrupting operation.

Resonant energy recovery type crt deflection circuit

Abstract: A winding coupled to the input choke of a resonant energy recovery type deflection circuit with a disconnect diode in series with the choke enables use of a power supply voltage for the circuit which is much lower than what has heretofore been required due to the need to maintain sweep current and flyback voltage at acceptable levels. Another embodiment includes a transductor and a difference amplifier to regulate the deflection circuit yoke capacitor voltage so that raster size remains constant. The circuit is thereby immune to component and power supply voltage variations. Both embodiments utilize mostly elements which are substantially non-dissipative.

Low frequency filtered power supply

Abstract: In a television receiver having a source of signals at a horizontal scan frequency and a cathode ray tube, a power supply means includes a flyback transformer coupled to the signal source, a voltage multiplier means coupling the transformer to the cathode ray tube, and a low frequency filtering means coupling the transformer to circuit ground whereby low frequency filtering is provided for relatively low value of beam current of the cathode ray tube and undesired bending of a scan raster is inhibited.

High voltage regulator

Abstract: A horizontal flyback transformer in a television receiver includes a driving choke winding coupled to a horizontal drive stage. A regulating winding is wound on the same core leg as the driving choke winding. A high voltage winding and a primary winding for driving a horizontal deflection yoke coil are wound on an opposite core leg. To regulate the high voltage developed by the high voltage winding, the regulating winding is coupled to a variable loading circuit controlled by current through a resistor in series with the driving choke winding. Each core leg includes an air gap selected to cause the leakage inductance between the primary winding and the driving choke winding to be equal to the inductance of the primary winding.

Horizontal deflection circuit

Abstract: A solid-state horizontal deflection circuit including a high voltage applying circuit for a television receiver or the like in which a gate-controlled switching device is used for applying a deflection current to a horizontal deflection coil to perform horizontal beam scanning and another semiconductor switching device is used for applying a pulse voltage to a flyback transformer to produce a high voltage supplied to a cathode ray tube, and further a couple of diodes connected in series are provided in connection with the above two switching devices. Both switching devices are turned on in response to a horizontal driving signal supplied to at least one of them and turned off by the recovery current of the series-connected diodes.

High voltage generating device

Abstract: A high voltage generating device used to obtain a high voltage supplied to the television receiver picture tube anode, comprising a high voltage coil generating an a-c voltage and having an output terminal connected to one end of a rectifier means whose other end is connected to a high voltage lead line, wherein the high voltage coil and rectifier are molded together with a resin. Thus, it can be readily manufactured and will be small in size, light in weight and excellent in insulation character. This invention relates to high voltage generating devices used to obtain d-c high voltage supplied to the anode of television receiver picture tubes. In the usual d-c high voltage generating means, an a-c voltage is first generated and stepped up through a transformer, and the a-c high voltage generated in the high voltage coil of the transformer is rectified through a rectifying means to thereby obtain a d-c high voltage. For example, in the television receiver a d-c high voltage of about 10 to 30 KV is supplied to the anode of the picture tube. This voltage is obtained from flyback pulses generated from the horizontal deflection circuit by stepping up these pulses through the flyback transformer and rectifying the transformer output through a rectifying means. However, such high voltage generating means should use special parts for the stepping-up means and rectifying means because extremely high voltage is involved. Also, the insulation factor is very significant. Therefore, considerably large space is inevitably occupied. In order to solve the above problems, it has been proposed to use solid-state rectifiers such as silicon rectifiers which are small in size but nevertheless have excellent breakdown voltage characteristic and excellent reliability. Also, in television receivers it has been proposed to have the high voltage resonate at harmonic frequency to obtain improved operational efficiency. In case of using solid rectifier means, however, it is necessary to ensure a considerably large space surrounding the rectifier, so that support means of a considerably large size is required to hold the rectifier sufficiently spaced from other parts. It has further been proposed to construct a multi-stage rectification block by combining a plurality of rectifying elements and a plurality of capacitors. In this case, the entire block is accommodated in a casing, and resin is charged into the casing to produce a molding which is subsequently attached to a chassis frame and connected to the high voltage coil. Again in this case, a considerably large space is necessary due to the plurality of capacitors. An object of the invention is to provide a high voltage generating device, which can overcome the afore-mentioned drawbacks inherent in the prior-art high voltage generating device, and which is small in size, excellent in insulation character and capable of being readily manufactured.