Abstract: A push-pull inverter is supplied from an inductively current-limited DC voltage source by way of a center-tap on a transformer having significant inductance. This transformer inductance is parallel-coupled with a capacitance means. The inverter is made to self-oscillate through positive feedback provided by way of a saturable current transformer. The inverter frequency is determined by the saturation time of this current transformer, which saturation time is designed to be somewhat longer than the half-cycle period of the natural resonance frequency of the transformer inductance combined with the capacitance means. By controlling the length of this saturation time, the magnitude of the current provided to the fluorescent lamp is controlled, thereby permitting control of the light output in response to changes in the magnitude of the power line voltage.

Abstract: The present invention provides a power converter and a method for converting power. The power converter comprises an inductor, a transformer, first and second switches, a diode, and a full bridge. The inductor comprises a first winding, a second winding, and a third winding, and is coupled to an input voltage. The transformer has a first primary winding coupled to the first winding of the inductor, a second primary winding coupled to the second winding of the inductor, and a third primary winding coupled to the third winding of the inductor. The first switch is coupled to the first primary winding of the transformer, and the second switch is coupled to the second primary winding of the transformer. The diode is coupled to the third primary winding of the transformer. The full bridge is coupled to a secondary winding of the transformer, and the output voltage emanates therefrom.

Abstract: A power supply (10) has a first transistor (20) coupled for switching a coil current (Il9) in response to a first control signal (VC1). A second transistor (30) has a body diode (32) for discharging the coil current to produce a power factor corrected signal (VPFC). A conduction channel (31) of the second transistor is responsive to a second control signal (VC3) for developing a second coil current (I61) from the power factor corrected signal to adjust an output signal of the power supply, where the second control signal commences a time interval (TD2) after the first control signal terminates.

Abstract: A voltage converter circuit with a self-oscillating half-bridge configuration has a first and a second input terminal, and a first and a second output terminal, and including: a first power switch coupled between the first input terminal and the first output terminal, a second power switch coupled between the first output terminal and the second input terminal, a first voltage sensor having a first and a second sensing terminals coupled between the first input terminal and a control terminal of the first power switch, and a second voltage sensor having a first and a second sensing terminals coupled between the first output terminal and a control terminal of the second power switch. Each voltage sensor detects a voltage variation supplied on its respective first sensing terminal and generates on the respective second sensing terminal an activation potential for the respective power switch.

Abstract: A conversion apparatus having transistors, comprising means for inverting a DC voltage in order to obtain an AC voltage, means for filtering the AC voltage, including at least one parallel inductor Lp, the device being capable of operating above a resonant frequency Fp. The conversion apparatus comprises means for predicting a zero crossing of the instantaneous current I1p in the parallel inductor Lp, and means for causing a transistor of the device to switch if a zero crossing of the current I1p is predicted.

Abstract: In a DC/DC converter for producing a DC voltage from a supplied DC voltage with a reversible direction of action, a transformer operating in push-pull on the primary and secondary sides, the respective center taps are connected to a first terminal for the respective DC voltage, and further winding terminals are each connected via a semiconductor switch to a second terminal for the respective DC voltage, the semiconductor switches being controlled synchronously in pairs.

Abstract: A power supply for achieving high output power levels at a high efficiency from a compact profile. The power supply includes a current regulator which receives a source voltage and outputs a signal having a constant current. The signal output from the regulator is provided to a center tap of a primary winding of a transformer. The ends of the primary winding of the transformer are connected to switches which are controlled by a switch driver. The transformer, switches and switch driver form a resonant oscillator. The switch driver is connected to a zero voltage level detector which detects when the voltage of the signal output from the current regulator reaches a zero level. When such a detection is made, the zero voltage level detector provides an enable signal to the switch driver to operate the switches in a push-pull mode. By operating the switches in a push-pull mode, the energy balance and resonance of the transformer can be maintained.

Abstract: An energy efficient gate drive technique for binary push-pull MOSFET switching systems having a common switch node with inductive and capacitive elements connected to this common switch node. These energy storage elements on the common switch node can be parasitic in nature or discrete components. This technique recycles otherwise lost PMOS gate drive energy through the switch node, as a storage element, to the NMOS output FET.

Abstract: A pseudo-push-pull DC:DC converter topology replaces one primary switching transistor with a high speed passively switched diode coupled between one end of a transformer first primary winding and ground. A second primary winding is coupled to ground via a solid state switch that is driven with a control circuit that outputs a single drive signal of slightly less than 50% duty cycle. The other ends of the first and the second transformer primaries are coupleable to a source of Vin. The topology includes a gapped transformer whose transformer core stores sufficient electromagnetic energy when the solid state switch is turned-on by the control circuit to drive a load coupled to the transformer secondary when the solid state switch is turned-off. When the solid state switch is turned-off by the control circuit, the diode self-biases on, coupling the first transformer primary winding between Vin and ground, as though a perfectly driven solid state switch were turned-on.

Abstract: Single, multistage, and distributed magnetic switched and tank resonant power conversion systems utilizing NSME. The NSME provide, superior protection to conducted lightning transients, superior thermal operating bandwidth, higher magnetizing efficiency, greater flux/power density potential and form factor flexibility when implemented with the disclosed circuit strategies. Output voltage is maintained substantially constant and ripple free in the presence of line and load variations by the action of various feedback strategies. These mechanisms combine to produce compensations by controlling the duration and/or frequency of a switch or switches. A novel function generator implementation supplies a signal, which is a function of magnetic flux tracking, AC line phasing, and output voltage feedback to provide output regulation, active ripple rejection, and power factor correction to the AC line. Efficient energy storage and transfer is achieved by the optimized application of NSME.

Abstract: In prior art, the operation of the switching transistors Q1 and Q2 is within a range of class-AB to class-B and they are not good at efficiency since it is difficult to change the operating point thereof. There is disclosed an innovative switching power circuit which is self-oscillated by a tertiary winding N3 so that each of the pair of switching elements Q1 and Q2 may be conducted alternately and thereby a current flowing from the centertap is switched so as to selectively flow alternately to one side of the primary winding N1 or to other side thereof to generate an AC voltage on a secondary winding N2, said switching power circuit characterized by that an operating point of the switching elements Q1, Q2 is changed from that in starting by using a DC voltage generated by a switching operation of the switching elements Q1, Q2 as an inverse bias power source for the switching elements Q1, Q2.

Abstract: Circuits for driving a switching transistor (T3) with a driver stage (T2, T4, T5, L1), as are used for example in horizontal deflection stages of television sets or computer monitors, are known in a wide variety of embodiments. The invention specifies a power-efficient and cost-effective circuit of this type which contains a comparator circuit (T1), which monitors the voltage (UC) across the current input of the switching transistor (T3) for the purpose of monitoring saturation by comparing the said voltage with a reference voltage (UR), thereby effecting regulation. The comparator circuit may be realized, e.g. by a simple transistor circuit (T1), the reference voltage (UR) being applied to the control input of the said transistor circuit, the current input of the said transistor circuit being connected to the drive signal (US) of the driver stage, and the current output of the said transistor circuit being connected to the voltage (UC) via the current input of the switching transistor (T3).

Abstract: A driver circuit includes a half-bridge output stage including two transistors with a common terminal for connection as the driver output to a coil of a DC motor. Two amplifiers drive the transistors in the push-pull operation and two capacitors are connected between the driver output and one input of a respective amplifier to form feedback loops for controlling the output slew-rate. Two current generators are selectively connected to an input of either of the amplifiers through respective pairs of switches. A commutation sequencer turns on and off the switches according to a commutation program. Comparators are connected to the drive output for detecting predetermined output voltage conditions and providing the commutation sequencer with signals for conditioning the commutation program as a function of the detected voltage conditions.

Abstract: The present invention relates to a circuit for obtaining a wide dimming ratio from a Royer inverter and, more particularly, to a circuit that allows a back light to have wide dimming ratio without having unwanted current spikes that would significantly reduce the life of the back light bulbs. The invention is directed to a DC-to-AC inverter circuit for obtaining a wide dimming ratio in a display back light. The DC-to-AC inverter circuit consists of a voltage source, a Royer inverter circuit and switch circuit to turn on the Royer inverter. The Royer inverter is configured to receive a DC pulse modulated (PWM) signal that is coupled a transformer to produce an output AC PWM signal that is sent to the display back light. The configuration creates an imbalance in the Royer circuit that in turn prevents current spikes that occur when rapidly turning on the Royer inverter.

Abstract: A single power supply circuit, including a push-pull input converter stage and a voltage-controlled latch circuit output stage isolated from each other by a transformer, provides both voltage gridding and biasing functions in, for example, an x-ray tube application. In the gridding mode, a first voltage level supplies the push-pull converter to provide an output voltage that is sufficiently high to trigger the voltage-controlled latch circuit and thereby provide grid control via a grid control electrode. In the biasing mode, a lower voltage level supplies the push-pull converter such that the output voltage is insufficient to trigger the voltage-controlled latch circuit. As a result, a resistive voltage divider provides a predetermined biasing voltage on a bias control electrode.

Abstract: Zero voltage switching isolated boost converters that provide high efficiency power conversion between input and output DC voltages. The boost converters includes a voltage amplifying stage including first and second switching transistors, an input coupled inductor, and an output transformer. The voltage amplifying stage amplifies the DC input voltage which is transformed by the output transformer to produce the DC output voltage. A zero voltage control input circuit is coupled to gates of the switching transistors and to the output of the voltage amplifying stage. The input circuit generates synchronization signals that synchronize rising edges of gate drive signals applied to the switching transistors with a resonant circuit. This is achieved by observing the state of gate and drain voltages of the switching transistors and detecting the moment when both drains are low, and both gates are not high.

Abstract: A four quadrant power conversion topology comprising a multi-winding inductor, four switches, and four diodes is disclosed. The four quadrant power conversion is utilized in a number of power conversion devices such as a power efficient non-linear power amplifier that comprises the 4Q power conversion topology of the present invention and a switch-control-signal generator coupled to the 4Q power conversion topology. The switch-control-signal generator generates switch activation signals for driving the four switches of the 4Q power conversion topology.

Abstract: An inverter has a direct voltage intermediate circuit having a positive (Udc+) and a negative (Udc-) voltage busbar, and an auxiliary voltage source (1) which generates auxiliary voltages (U1, U2, U3) referenced to the positive (Udc+) and the negative (Udc-) voltage busbar of the direct voltage intermediate circuit. The inverter also has for each phase an upper (2) and a lower (3) power semiconductor, connected in series between the positive and the negative voltage busbar. The point between the semiconductors forms the phase output (Uout) of the inverter. An upper (4) and lower (5) gate driver outputs (8,9) are connected to the control electrode (G) of the respective upper (2) and lower (3) power semiconductors which have a positive (6) and a negative (7) auxiliary voltage input and a zero potential point (Com) connected to the output electrode (E) of the power semiconductor to be controlled.

Abstract: A DC-DC voltage converter 40, which is adaptable to VHF operation, has a power oscillator 52 to which a filtered input DC voltage 50 is applied for conversion to an output DC voltage. The power oscillator includes a push-pull amplifier 58, 60 and an impedance transformation circuit 62 to which the amplifier is connected. The power oscillator also includes a rectifier circuit 64 which is connected to the impedance transformation circuit. A feedback circuit 68 controls the frequency of the oscillator to regulate the output DC voltage. The oscillator frequency depends on the impedance values of oscillator circuit components and the values of a plurality of oscillator component intrinsic parameters.

Abstract: An inverter for producing AC power from a DC source is disclosed. The inverter uses a transformer and switches to convert current from a battery or other DC source into AC power that can be used to power household appliances or other devices. The primary windings of the transformer are directly connected to a heat sink to which the switches are mounted with electrical connection between the transformer and switches being via the heat sink. The connection point on the heat sink for the primary windings of the transformer is spatially removed from the locations of the switches to facilitate heat dissipation at both locations. The primary windings of the transformer are formed from a tape or ribbon-like conductor having a cross-sectional area that allows the construction of a relatively compact transformer while also providing primary conductors of relatively large cross section.

Abstract: A DC link power converter apparatus including a first DC to DC converter, a DC to AC converter and a load balancing storage element. The first DC to DC converter has first and second DC ports and the DC to AC converter has a third DC port and has an AC port. The first DC port is connectable to a DC source and the second DC port is connected to the third DC port. The AC port is connectable to an AC load. The load balancing energy storage element is connected to the second DC port for decoupling the DC to DC converter from the DC to AC converter by supplying energy to the third DC port when a voltage at the second DC port is tending to decrease and for storing energy received from the second DC port when a voltage at the third port is tending to increase.

Abstract: A circuit used to convert a DC input to an AC output includes a pair of series circuits. Each of the series circuits is in parallel with the DC input and includes a switch and a transformer primary. A capacitor couples the two series circuits, and is attached to each series circuit at a node between the respective transformer primary and switch. A secondary on the transformer provides the AC output. Optionally, multiple transformers may be utilized. Similar topologies may be used for rectification instead of inversion.

Abstract: A switching regulator with its less ripples, less switching loss, and low noise, which is capable of being miniaturized with high efficiency is provided. PWM control signals outputted from a terminal T6 of a pulse width control circuit IC1 are inputted to delay circuits DLa and DLb, respectively. The PWM control signal inputted to the delay circuit DLa, only a rise of which is delayed by a resistor Ra and a capacitor Ca, is applied to a gate of FET Q2 via a wave shaping circuit IC2. On the other hand, the PWM control signal inputted to a delay circuit DLb, only a fall of which is delayed by the resistor Rb and the capacitor Cb, is inverted via a wave shaping circuit IC2 and is applied to a gate of FET Q1 as an inverted control signal. Therefore, FETs Q1 and Q2 are turned ON/OFF in a predetermined period, and a pause period where FETs Q1 and Q2 are turned OFF is only a delayed constant period.

Abstract: A current controlled voltage boost circuit for a high voltage converter. The voltage boost circuit includes a boost converter connected to receive an input voltage and a control signal, and output an increased output voltage to the high voltage converter as a function of a control signal. The circuit further includes a current sensing circuit providing an output voltage proportional to the sensed input current to the high voltage converter. The output voltage from the current sense circuit varies a reference voltage that is compared to the boost converter output voltage by an error amplifier. The error amplifier, in turn, outputs a control signal to the boost converter such that the control signal controls the boost converter output voltage as a function of the input current to the high voltage converter.

Abstract: A power terminal is connected to a DC power source. A differential amplifier has primary and secondary input terminals and an output terminal, and a device applies a reference voltage to the secondary input terminal of the differential amplifier. A phase inverter has an input terminal connected to the output terminal of the differential amplifier and has primary and secondary output terminals that output two output signals of opposite phase. A push-pull drive circuit has primary and secondary input terminals connected to the primary and secondary output terminals of the phase inverter, and has primary and secondary output terminals connected to a switching element that alternately turns on and off by being driven by the two output signals of opposite phase that are provided from the output terminals of the phase inverter.

Abstract: A line type modulator for modulating an RF power device in a medical linear accelerator is described. The modulator employs a low voltage DC power source and a flyback transformer. Current sensing circuitry senses current in the primary winding of the flyback transformer and generates a current sense signal indicative thereof. A solid-state switching stage is coupled between the DC power source and the flyback transformer which electrically connects and disconnects the DC power source and the primary winding in response to a control signal. Control circuitry coupled to the current sensing circuitry and the switching stage generates the control signal in response to the current sense signal. The anode of a charge diode assembly is coupled to the secondary winding of the flyback transformer. A delay element is coupled to the cathode of the charge diode assembly. A pulse forming network is coupled to the delay element and generates an energy pulse.

Abstract: A four quadrant flyback converter, employable as part of a ringing signal generator, includes: (1) a transformer having first and second primary windings of opposite polarity and a secondary winding, (2) first and second switches that alternatively couple the first and second windings, respectively, to a source of DC input power and (3) a bidirectional switch coupling the secondary winding to an output of the converter, the first, second and bidirectional switches switchable to provide a continuous waveform at the output.

Abstract: A circuit arrangement for multiple use of a transformer core, comprising a winding with center tap on the primary side and two separate windings on the secondary side, has a controlled switch in each feed line for the two primary windings which is preferably clocked with high frequency. A rectifier is connected to the first secondary winding in particular for forming a switching power supply, which is thus supplied with energy. An FET transistor is coupled to the second secondary winding, in particular for forming a driving pulse transmission, preferably via two Z-diodes with anti-serial connection, which transistor is thus supplied with driving pulses. The magnetic circuit for the transformer is actuated via switches which change polarities on the primary side of the transformer. The switch-on pulse duty factor for the switches is selected to be higher than 50%.

Abstract: In a voltage converter for converting an AC input voltage into a DC high voltage and further DC power supply voltages, in which the AC voltage applied to the converter is applied to a rectifier arrangement (1, 2, 3, 4) whose output signal is coupled to two consecutively switched electronic switches (6, 7), and in which this DC voltage is converted into the DC high voltage and into the DC power supply voltages, the circuit arrangement has a simple structure in that a series arrangement of a capacitance (8), an inductance (9) and a primary winding (10) of a transformer (11) is arranged in parallel with one of the electronic switches (6, 7), in that a secondary winding (12) of the transformer (11) precedes a capacitance (15) at the output end, in that a control circuit (20) is provided which controls the switching frequency of the electronic switches (6, 7) in such a way that a DC voltage of the desired value decreases across the capacitance (15) at the output end, and in that the transformer (11) is provided wi

Abstract: A power terminal is connected to a DC power source. A differential amplifier has primary and secondary input terminals and an output terminal, and a device applies a reference voltage to the secondary input terminal of the differential amplifier. A phase inverter has an input terminal connected to the output terminal of the differential amplifier and has primary and secondary output terminals that output two output signals of opposite phase. A push-pull drive circuit has primary and secondary input terminals connected to the primary and secondary output terminals of the phase inverter, and has primary and secondary output terminals connected to a switching element that alternately turns on and off by being driven by the two output signals of opposite phase that are provided from the output terminals of the phase inverter.

Abstract: In a method of driving vibrating compressors having such a construction that a-c voltage is fed to a vibrating compressor by converting d-c voltage into a-c voltage with two MOS-FETs, the two MOS-FETs as switching elements are driven to convert d-c voltage into a-c voltage by changing the ON time of each of the MOS-FETs corresponding to suction and compression strokes in one cycle of the vibrating compressor to improve the operating efficiency of the vibrating compressor. To this end, suction and compression time in one cycle of the vibrating compressor is changed by means of a timer IC.

Abstract: A cold-cathode fluorescent lamp lighting device which enables to perform high-efficiency lighting of a cold-cathode fluorescent lamp.

Abstract: An uninterruptable power supply module includes a DC power supply having an output for outputting a first DC voltage signal, a battery backup module in parallel connection to the output of the DC power supply and having an identical voltage level to that of the first DC voltage signal, boost converter means having an input coupled to the first DC voltage signal from the battery backup module for converting said first DC voltage signal to a second DC voltage signal, DC/AC conversion means having an input coupled to the second DC voltage signal from the boost converter means and an output for generating a first AC voltage signal in response to a variable duty cycle oscillation signal, pulse width modulator means powered by said battery backup module and having an output coupled to said DC/AC conversion means for generating said variable duty cycle oscillation signal, and shaping means having an input coupled to the first AC voltage signal from the DC/AC conversion means and an output for supplying a second AC v

Abstract: This invention relates to a push-pull inverter used, for example, as a driver for cold-cathode discharge tube, hot-cathode discharge tube, etc. and comprises a boosting transformer including an input coil, an output coil and a feedback coil, and first and second switching elements for input coil current of this transformer, wherein the output of the boosting transformer is divided into a pair of output coil sections connected in series with each other and a conductor section lying between these output coil sections is circuit-arranged so that this conductor section be at the negative potential of the DC source.

Abstract: In an AC to DC power converter (off line switcher) and a method of converting AC power to DC power in high voltage systems the flyback converter's low side semiconductor switch has a lower breakdown voltage than its high side semiconductor switch. The lower breakdown voltage is achievable by means of a shunt regulator that controls a clamp voltage across the low side switch. The efficiency of the converter's post regulator is improved by processing only a fraction of the system's total power output.

Abstract: A modular power supply system (10) is provided for providing a multiplicity of output voltages from a plurality of respective converter modules (70a-70n). Each of the converter modules (70a-70n) has an input coupled to a DC high voltage bus (22) from which a respective output voltage is generated. The voltage supplied on DC bus (22) is generated by a power factor corrected boost converter circuit (20) which is coupled to an AC input source (12). Further, a battery backup module (40) is coupled to the high voltage DC bus (22) for supplying backup power whenever the bus voltage drops below a predetermined level.

Abstract: To provide a resonant switching power supply switch with a simple structure and little noise, a push-pull resonant switching power supply circuit includes a transformer 104, a capacitor 105, two transistors 106a and 106b (bipolar transistors or field-effect transistors), and a bias circuit 201. The transformer 104 has a rectification circuit 340 connected to its secondary winding. The capacitor 105 forms a parallel resonant circuit in combination with the transformer 104. The transistors 106a and 106b are push-pull connected to the primary winding of the transformer 104 and the bases of which are connected to a feedback winding 104 of transformer. The bias circuit 201 applies a variable bias voltage to the base of the transistors.

Abstract: A power-supply and control circuit is provided for driving a fluorescent lamp from a low-voltage DC power source such as a battery. In typical lamp-driving circuits, a step-up transformer is used to apply well known magnetic techniques to achieve the low-to-high voltage conversion required by the lamp. The present invention uses a new approach, applying piezoelectric characteristics of certain ceramic materials to replace the magnetic transformer. Resonant characteristics of such ceramic materials permit them to be self-resonated. A DC-to-AC converter coupled to a switching regulator converts low DC voltage into a higher AC voltage for driving the fluorescent lamp. In one embodiment, the lamp is included in a feedback loop which includes a circuit for producing a feedback signal indicative of the magnitude of current conducted by the lamp. The feedback signal is applied to the switching regulator to produce in the lamp a regulated current and, hence, a regulated lamp intensity.

Abstract: An inverter circuit for use with a discharge tube or lamp such as a cold-cathode fluorescent lamp, a hot-cathode fluorescent lamp, a mercury arc lamp, a metal halide lamp, a neon lamp or the like is provided. The secondary side circuit of a step-up transformer used in the inverter circuit is constructed as a high frequency power supply circuit and a parasitic or stray capacitance produced in the secondary side circuit of the step-up transformer is utilized as a portion or component of a resonance circuit consisting of an inductive ballast or the inductive output of a leakage flux type step-up transformer and the parasitic capacitance.

Abstract: This resonant power supply produces a varying magnetic field from a resonant inductor. Two active switches drive, but remain outside, a resonant circuit, also including resonant capacitor. A phase-splitting transformer provides, via a decoupling inductor, one connection for a power supply; the return is through the active switches, which are either off or are from time to time driven alternately by the controller so as to maintain the resonant current in the resonant circuit. Applications include induction heating and induction hobs for cooking, and also a power source for inductively powered vehicles (or other inductively powered devices) adjacent to an inductive pathway.

Abstract: AS uninterruptible power supply (UPS) is disclosed in which AC line power is used to charge back-up battery and to operate a load during a stand-by mode of operation of the UPS. In the back-up mode of operation when AC line power is not available, the battery is used to supply power to the load. The UPS is implemented with only one inexpensive high frequency transformer and a single bi-directional power converter. Thus, the UPS of the present invention is lower in cost and complexity than such UPSs known in the prior art.

Abstract: Synchronous switching inverter and regulator suppress rf emissions, and FET push-pull switching for the inverter provides high efficiency power transfer by sinusoidal transformer operation. Feedback control for both pass transistors switching and duty cycles insures overall synchronous behavior.

Abstract: A power convertor wherein a piezoelectric ceramic transformer generates a voltage, a resulting current passes through a load and a comparative voltage generator to generate a comparative voltage. The comparative voltage is amplified and compared to a standard voltage to obtain a control voltage. The control voltage is regulated to provide base potentials of a power amplifier. As a result, variations in a variable resistor will change the comparative voltage to obtain different output currents as required.

Abstract: A dual push-pull heating device of induction cooker having multiple burners is provided with a microprocessor controlling a logic amplifying drive circuit outputting a high-frequency pulse signal, so as to drive alternately at least a power element or power transistor having two parallel electromagnetic induction coils arranged at an end thereof in such a manner that a common end of said induction coils is connected with a common connection point of a relay whose normal close point is connected with a non-common end of one of the induction coils and whose normal open point is connected with a non-common end of another one of the induction coils.

Abstract: A power source having a first rectifier, a transformer having a primary coil and a secondary coil, switching elements having one end thereof connected to one of the terminals of the primary coil, a capacitor connected between other ends of the switching elements, diodes respectively connected between the terminals of the primary coil and the other ends of the switching elements, a choke coil for supplying the input DC voltage from the first rectifier directly to one of the terminals of the primary coil, and a second rectifier for supplying an output DC voltage to a load by rectifying the output AC voltage from the secondary coil.

Abstract: An inverter circuit for providing an AC driver voltage for a capacitive load from a DC input voltage. The circuit uses a pair of balanced transistors supplying a split primary winding of a transformer, a feedback winding thereof being coupled thereto to supply a feedback signal to the transistor inputs. Resistors are used to optimize inverter efficiency by adjusting transformer saturation and the DC bias of the drive transistors. A capacitor is connected across the two primaries to provide harmonic suppression an aid in starting the inverter. A second capacitor, connected from base to collector of the transistors opposite the transistor with DC bias being introduced, provides suppression of undesirable high frequencies which will occur if this capacitor is not present. The AC output is supplied from the secondary winding of the transformer.

Abstract: Here is disclosed a push-pull inverter used to drive a cold cathode discharge tube, a hot cathode discharge tube and the like, comprising a boosting transformer having a first primary coil, a first secondary coil, a second primary coil and a second secondary coil; first and second switching elements each having a control electrode adapted for controllably interrupting primary current flowing through said first and second primary coils; a capacitor connected between the respective control electrodes of the respective switching elements; and a feedback circuit in which one end of the first secondary coil is connected to the control electrode of the first switching element and one end of the second secondary coil is connected to the control electrode of the second switching element so that load current from a load connected between the other ends of the respective first and second secondary coils flows through the capacitor.

Abstract: A high voltage power supply having a low voltage input comprising a transformer having a primary winding, an input switching means coupled to the primary, first and second groups of secondary windings each of which are sub-divided into a plurality of component windings, and voltage converters coupled to each of the component windings for producing series output voltages of opposite polarities across the groups of secondary windings. First and second output switching means alternately switch the series output voltages to provide an intermediate voltage at a common point which is the input of a diode capacitor multiplier circuit thereby producing at its output a high voltage output.

Abstract: A voltage and frequency converter device for converting a primary voltage and frequency from an electrical supply to a secondary voltage and frequency particularly useful in powering the timing mechanisms in appliances made to operate at the secondary voltage and frequency, includes a rectifier circuit for converting the alternating current oscillating at the primary frequency to direct current, circuitry for causing the current to oscillate at the second frequency and for converting the primary voltage to the secondary voltage. The output of the converter is preferably coupled only between the power source and the timing circuitry of the appliance but may also be coupled to the power circuitry for motors and the like provided the converter is further configured to generate a true sine wave output.

Abstract: Magnetic direct current to direct current converter with the input isolated from the output. A pulse generator from the feedback is incorporated in the feedback circuitry to regulate the output relative to the input.