Abstract: The invention presents a highly efficient, tightly regulated DC-to-DC converter which can be used in various applications, especially multiple output converters. The converter uses a buck converter to produce an intermediate bus voltage. A current-fed double ended circuit, such as bridge or push-pull circuit, couples to the buck converter to provide power to outputs. The double ended circuit operates at about 50% duty. The secondary output filter inductor is not required. With 50% duty cycle operation, the secondary rectifiers are easily controlled by either a self-driven or an external driven circuit. The secondary windings can also be stacked up to simplify the transformer design. In addition, bias voltages needed for control circuitry can also be obtained by adding extra windings to the power transformer and extra rectifier devices.

Abstract: The invention presents a highly efficient, tightly regulated DC-to-DC converter which can be used in various applications, especially multiple output converters. The converter uses a buck converter to produce an intermediate bus voltage. A current-fed double ended circuit, such as bridge or push-pull circuit, couples to the buck converter to provide power to outputs. The double ended circuit operates at about 50% duty. The secondary output filter inductor is not required. With 50% duty cycle operation, the secondary rectifiers are easily controlled by either a self-driven or an external driven circuit. The secondary windings can also be stacked up to simplify the transformer design. In addition, bias voltages needed for control circuitry can also be obtained by adding extra windings to the power transformer and extra rectifier devices.

Abstract: A first charge/discharge element is connected in parallel to a coil porion of the primary coil of a converter transformer. A second charge/discharge element is connected in parallel to a coil portion of the primary coil. The first charge/discharge element is charged with the energy stored in the primary coil when the first switching element turns off. A smoothing capacitor is charged with the charge energy when the second switching element turns off. The second charge/discharge element is charged with the energy stored in the primary coil when the second switching element turns off. The smoothing capacitor is charged with the charge energy when the first switching element turns off.

Abstract: A transformer has a primary winding and a secondary winding. A center tap of the primary winding is connected with one end of a d.c. power supply. Both ends of the primary winding are connected to the drains of transistors (Q1) and (Q2) that constitute switching elements, respectively. Also, the sources of the transistors (Q1) and (Q2) are connected to the other ends of the d.c. power supply. The gates of the transistors (Q1) and (Q2) are connected to one ends of gate resistors (R1) and (R2), respectively. The other ends of the gate resistors (R1) and (R2) are connected to a control circuit, and the resistance of the gate resistor (R2) is larger than the resistance of the gate resistor (R1).

Abstract: A DC—DC voltage converter has a controller, two switches, a transformer and two rectifying diodes. The transformer has a first winding, a second winding and a center tap. Input voltage is connected between the center tap and ground. An anode of each diode is connected to the outer ends of the two windings and the cathodes of the two diodes are connected together to provide a positive output with respect to ground. Each switch is connected between an outer end of one winding and ground. The controller generates control signals to turn the switches on and off for limited periods of time in phase opposition to alternately connect the outer ends of the first and second winding to ground to cause current to flow alternatively in one of the windings and induce a voltage in the other winding that is additive to the input voltage, thereby providing an output voltage greater than the input voltage.

Abstract: Although increasing the switching frequency is effective to downsize a power supplying apparatus, the switching loss of a switching element increases if the switching frequency is increased. In a power supplying apparatus including a transformer having a very high boosting ratio, and a plurality of switching elements for supplying AC power to the primary side of the transformer, the frequency of the AC power is set to 0.25 to 2 times the self-resonance frequency of the transformer.

Abstract: A power converter controller and a method for controlling a power converter are provided. The power converter includes first and second power transformers, each having first and second primary windings and a secondary winding; and first and second switches that alternately couple primary windings of the first and second power transformers to an input power source. The power converter controller receives a feedback signal, such as a DC power output voltage from the power converter. A voltage controlled oscillator responsive to the feedback signal provides a variable frequency signal. A phase shift controller coupled to the voltage controlled oscillator provides a variable phase shifted signal responsive to the variable frequency signal. Gate drive signals are decoded using the variable frequency signal and variable phase shifted signal for driving first and second switches of the power converter.

Abstract: Briefly, in accordance with one embodiment of the invention, a DC-to-DC converter includes: a synchronous rectifier converter. The synchronous rectifier converter includes a buck converter. The transformer of the synchronous rectifier converter employs less than five windings on the secondary.

Abstract: The invention relates to a DC—DC converter and a power supply unit formed thereby, with which a DC input voltage (Vdc) may be converted into two DC output voltages (U1, Usb) via a resonant switched-mode power supply. Via a circuit stage (M1, M2), a control circuit (C) generates a first AC voltage (VAC), which is converted via two resonant circuits with different transmission behavior and two rectifiers (G1, Gsb) in frequency-dependent manner into DC output voltages (U1, Usb). To achieve a standby mode, in which the first DC output voltage (U1) is designed to be very low and hardly any power is drawn on the output side, a second, thinner auxiliary circuit stage (M3, M4) is provided, which is coupled to the resonant circuits via an inductor (L2). The current consumption of the circuit in standby mode may be reduced considerably by appropriate dimensioning.

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: A voltage transformer has input terminals for the application of an alternating voltage and output terminals for the provision of a rectified output voltage. The voltage transformer has two inductive energy storage elements and two switch configurations, in each case with a first rectifier element and a first controllable switch element, wherein each of the switch configurations couples one of the energy storage elements to the input terminals and wherein the energy storage elements are coupled to the output terminals by a coupling circuit.

Abstract: A switching power supply includes a transformer having a primary winding connected to a pair of a.c. input terminals via a rectifier circuit, and a secondary winding connected to a pair of d.c. output terminals via a rectifying and smoothing circuit. Connected between the pair of outputs of the rectifier circuit via an inductor, reverse-blocking diode, and part or whole of the transformer primary, a primary switch is turned on and off at a repetition frequency higher than the frequency of the a.c. input voltage. A soft-switching circuit is provided which comprises a serial connection of a transformer tertiary, an ancillary diode and an ancillary switch. This serial circuit is connected in parallel with the serial connection of the transformer primary and primary switch for zero-voltage switching of the primary switch.

Abstract: A DC-DC voltage converter comprises a controller, two switches, a transformer and two rectifying diodes. The transformer has a first winding, a second winding and a center tap. Input voltage in connected between the center tap and ground. An anode of each diode is connected to the outer ends of the two windings and the cathodes of the two diodes are connected together to provide a positive output with respect to ground. Each switch is connected between an outer end of one windings and ground. The controller generates control signals to turn the switches on and off for limited periods of time in phase opposition to alternately connect the outer ends of the first and second winding to ground to cause current to flow alternatively in one of the windings and induce a voltage in the other winding that is additive to the input voltage, thereby providing an output voltage greater than the input voltage.

Abstract: Briefly, in accordance with one embodiment of the invention, a DC-to-DC converter includes: a synchronous rectifier converter. The synchronous rectifier converter includes a buck converter. The transformer of the synchronous rectifier converter employs less than five windings on the secondary.

Abstract: Single, multistage, and distributed magnetic switched and tank resonant power conversion systems use a non saturating magnetic element (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.

Abstract: The switched power converter comprises a first rectifier module (11-1) connected to a first capacitor (11-2) that, in turn, is connected to an excitation module (11-3) that applies a voltage to some input terminals (PT-1, PT-2) of a piezoelectric transformer (PT). A controller device (11-3-3) governs the excitation module (11-3) in order that the piezoelectric transformer (PT) works at constant frequency and regulates the power delivered to the output of the converter by enabling/disabling the voltage applied to the terminals (PT-1, PT-2). When the piezoelectric transformer (PT) is not transferring energy between its input terminals (PT-1, PT-2) and its output terminals (PT-3, PT-4), the converter output voltage is supplied by a second capacitor included in a second filter (11-6).

Abstract: Single, multistage, and distributed magnetic switched and tank resonant power conversion systems can use a transformer with a magnetic element operating in a non-saturated region (NSME). The NSME provides 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 many circuit strategies, some of which are disclosed herein. Efficient energy storage and transfer is achieved by the optimized application of NSME. The use of efficient rectifying flyback management techniques protects switches and provides additional output. The preferred embodiment teaches against common theories of transformers and uses a NSME in the core.

Abstract: The invention relates to a DC-DC converter and a power supply unit formed thereby, with which a DC input voltage (Vdc) may be converted into two DC output voltages (U1, Usb) via a resonant switched-mode power supply. Via a circuit stage (M1, M2), a control circuit (C) generates a first AC voltage (VAC), which is converted via two resonant circuits with different transmission behavior and two rectifiers (G1, Gsb) in frequency-dependent manner into DC output voltages (U1, Usb). To achieve a standby mode, in which the first DC output voltage (U1) is designed to be very low and hardly any power is drawn on the output side, a second, thinner auxiliary circuit stage (M3, M4) is provided, which is coupled to the resonant circuits via an inductor (L2). The current consumption of the circuit in standby mode may be reduced considerably by appropriate dimensioning.

Abstract: The invention relates to a power supply arrangement (2, 3) comprising a DC/DC converter (3) including:

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: The invention relates to a power supply unit for direct current to direct current DC-DC conversion having multiple outputs. Such power converters comprise a DC-AC converter 100, a transformer 200 and a plurality of AC-DC converters 300-i i=1 . . . n each for generating an individual DC-output voltage Vi being provided to a respective load impedance 330-i. Lossy components in said transformer and said AC-DC converters cause undesired voltage drops causing undesired fluctuations of the DC-output voltages. A reduction of said fluctuations of said DC-output voltages is achieved by feeding-back the DC-output voltage of at least one AC-DC converter to said DC-AC converter. Starting from that prior art it is the object of the invention to improve a power supply unit for DC-DC conversion such that a more uniform sharing of the fluctuations of the output voltages is achieved easily and cheaply.

Abstract: A drive transformer and associated circuitry for providing power and appropriate delays to primary switches and synchronous rectifiers in switch-mode power converters. The circuitry takes advantage of the leakage inductances of the drive transformer windings as well as the input capacitance of the primary switches (MOSFETs) to provide the necessary delays. No separate circuitry is needed to provide such delays, thereby providing reliability. Exemplary embodiments further disclose means to disable or enable the primary winding from a condition sensed on the secondary side even with a control and feedback circuit located on the secondary side.

Abstract: The invention concerns a voltage converter of a flux converter type with a self-regulating synchronous rectifier in the secondary circuit related to a transformer (17), with a capacitor device (C1; C1, C2) being provided, for driving an active switching element (V1, V2) of the synchronous rectifier, which is charged by means of an auxiliary winding (W1 W2) of the transformer in the secondary circuit, and its charge is applied to a control terminal of the active switching element by means of a semiconductor element (D1, D2; 30, 32), with the capacitor device being implemented in such a way that the charge allows synchronous switching operation of the active switching element.

Abstract: A non-contact power supply device having a primary unit and a secondary unit of a coupling transformer for driving a load such as decoration lamps. The primary unit is installed inside of premises and the secondary unit is installed outside of the premises and the decoration lamps are connected to the secondary unit. The primary unit and the secondary unit are attached to an intervening body such as a window or a wall in a face-to-face fashion. The non-contact power supply device is able to control and change an output voltage of the secondary unit and lighting patters of the decoration lamps solely from the inside of the premises without need for a user to go outside.

Abstract: A transformer has a primary winding and a secondary winding. A center tap of the primary winding is connected with one end of a d.c. power supply. Both ends of the primary winding are connected to the drains of transistors (Q1) and (Q2) that constitute switching elements, respectively. Also, the sources of the transistors (Q1) and (Q2) are connected to the other ends of the d.c. power supply. The gates of the transistors (Q1) and (Q2) are connected to one ends of gate resistors (R1) and (R2), respectively. The other ends of the gate resistors (R1) and (R2) are connected to a control circuit, and the resistance of the gate resistor (R2) is larger than the resistance of the gate resistor (R1).

Abstract: The present invention comprises an isolated dual power supply having an internal feedback loop. The dual power supply comprises a modulated switched power converter generating an internal regulated voltage output coupled to an alternating current tank. The alternating current tank has a first and a second power switch that are alternately switched ON at a 50% duty cycle. When the first switch is ON, the internal regulated voltage output is coupled to a storage capacitor and a primary winding of a transformer in the alternating current tank wherein the storage capacitor is charged and a current flows in a first direction through the primary winding. Alternatively, when the second switch is ON, the charged storage capacitor discharges and a current flows in a second direction opposite to the first direction through the primary winding. In this fashion, the transformer becomes a linear device, allowing the use of internal feedback to control the external output of the transformer.

Abstract: An audio amplifier comprising a power amplifier section, a power supply, and a control circuit. The power supply is made up of a positive and negative power supply section, with the positive supply section and the negative supply section delivering, respectively, positive and negative power inputs through the power amplifier section. Each power supply section comprises a transformer and a switch section to supply current pulses to the primary winding of the transformer. A filter circuit component is connected to an output of each secondary winding. The control circuit controls the strength of the current pulses of the power supply sections in accordance with the strength of the audio signal.

Abstract: A system and method for generating an AC power output signal from a DC power input signal. The system incorporates a DC-to-DC boost regulator including a plurality of boost stages coupled in series for receiving a DC input signal and producing a boosted DC power signal. The system further incorporates a DC-to-AC converter coupled to the transformerless DC-to-DC boost regulator, for receiving the boosted DC power signal and generating an AC power output signal. A control element is coupled to both the DC-to-DC boost regulator and the DC-to-AC converter. In at least one embodiment, the system and method for generating an AC power output signal from a DC power input signal are used in connection with an uninterruptible power supply.

Abstract: Briefly, in accordance with one embodiment of the invention, a DC-to-DC converter includes: a synchronous rectifier converter. The synchronous rectifier converter includes a buck converter. The transformer of the synchronous rectifier converter employs less than five windings on the secondary.

Abstract: A power supply circuit includes an input stage having a primary winding of a transformer, a drive pulse circuit producing clock and drive pulses, and an input control circuit for driving the primary winding with the drive pulse; and an output stage including a secondary winding, a first transistor having an input, and an output path connected with one end of the secondary winding; a second transistor having an input, and an output path connected with another end of the secondary winding; the first and second transistors being connected with the drive pulse circuit and the second transistor controlled to turn off by the clock pulse immediately before the first transistor turns on; an inductor connected to the output paths of one of the first and second transistors; and a capacitive circuit connected to the inductor.

Abstract: A transformer having a coil winding structure for transforming a voltage which is inputted through a primary coil section and for outputting a transformed voltage toward a secondary coil section. In the transformer, the primary coil section includes a plurality of sub-coil sections which are connected in parallel, and a plurality of terminals are connected to the plurality of sub-coil sections, respectively, in a manner such that corresponding portions of the sub-coil sections have the same current direction.

Abstract: A dual input power supply, a method of operating the power supply and a telecommunications power plant incorporating the power supply or the method. In one embodiment, the power supply includes: (1) a single stage power converter, coupled to an input of the power supply, configured to receive primary power subject to interruption and provide therefrom DC power to a DC bus; (2) an output power stage, coupled to the DC bus, configured to condition the DC power for delivery to an output of the power supply; and (3) a backup power stage, couplable to a backup power source and having an output coupled to the DC bus, configured to provide backup power during the interruption, the single stage power converter configured to restrict a reverse flow of the backup power therethrough during the interruption.

Abstract: A push-pull converter, coupled through an isolation transformer to a crowbar circuit for controlling an isolated output voltage across an output capacitor, has a compact circuit arrangement with a minimal number of components. The switching devices of the push-pull converter have integrated, ultra-fast anti-parallel diodes. The crowbar circuit is a voltage-controlled bi-directional switch coupled between the transformer and the output capacitor. The converter is controlled in an output-voltage-on mode by turning on and off the first switching device, and in an output-voltage-off mode by applying a gating signal to the second switching device sufficient to both activate the crowbar circuit and discharge the output capacitor for very fast isolated output voltage turn-off. In addition, a primary-side circuit comprising a switch and a resistance can be used to avoid excessive residual output voltage build-up.

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: 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 DC/DC converter which can be operated alternately as a step-up converter in a first direction of energy flow and as a step-down converter in a second direction of energy flow is disclosed. Potential isolation between the low-voltage side and the high-voltage side of the converter is achieved by a magnetic compound unit, which has not only a transformer function but also an energy store function. The converter operates as a push-pull converter in both directions of energy flow. The DC/DC converter can be used for example in motor vehicles with an electric drive fed by fuel cells.

Abstract: Disclosed is inductive coupling of power to devices having negative resistances, such as gas-filled discharge lamps (fluorescent tubes, neon signs, and the like) from a primary inductive loop, using resonant conditioning of the power provided to the device. A “C” shaped inductor (202) around the loop and a resonating capacitor (406) in parallel with the inductor provide a current source to the lamp (403) from across the capacitor. The circuit is capable of first igniting a lamp using a higher voltage available when the Q of the unloaded circuit is high, then running the lamp or other device at a controlled current. The lamp current is substantially proportional to the primary inductive loop flux, and substantially independent of the lamp resistance. A second inductor (404) in series with the first though not itself a collector of flux acts as a current limit. Applications include lighting, displays (optionally isolated and dimmable), and production of ultraviolet radiation.

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: A power system utilizing a method and apparatus to cost-effectively and efficiently supply power to an electrical system requiring a switchable main power source and a continuous auxiliary power source. Specifically, the power system utilizes an improved power converter having a main output circuit and an auxiliary output circuit coupled to a common input circuit. Primary switching circuitry in the input circuit, secondary switching circuitry in the main output circuit, and capacitance in the auxiliary output circuit allow for the systematic control of the main output from the power converter to the electrical system. In particular, the main output circuit can be switched on and off without interrupting the auxiliary output circuits supply of electrical power to the electrical system. Moreover, switching at a zero current state allows for the use of more cost-effective and efficient circuitry.

Abstract: A transformer for switched mode power supplies and the like comprises an input stage transformer section which is designed for very good coupling and very low primary leakage inductance, without regard for insulation above "working insulation" or for interwinding capacitance. One or more additional stage transformer sections are optimized for very low interwinding capacitance and very high dielectric isolation. The secondary of the input stage drives the primary of the next stage, so that the transformer stages are in series. Accordingly, the total interwinding capacitance from end to end is very low and the total dielectric isolation from end to end is very high. The secondary of the input stage transformer is isolated from both the input and the output, so it can be grounded as a safety ground.

Abstract: A switch circuit comprising a semiconductor switch and an inverse-parallel diode is connected between a main electricity storage unit 4 and a primary winding 142P of an insulating transformer 142 and a switch circuit including a semiconductor switch and a diode is connected in inverse-parallel between a secondary winding 142S of the insulating transformer 142 and an auxiliary electricity storage unit 10. The switch circuits are controlled on/off, whereby power is supplied from the main electricity storage unit 4 to the auxiliary electricity storage unit 10 or from the auxiliary electricity storage unit 10 to the main electricity storage unit 4 for charging the electricity storage unit 10 or 4.

Abstract: An asymmetrical power converter and method of operation thereof. In one embodiment, the asymmetrical power converter includes (1) an isolation transformer having series-coupled first and second primary windings providing differing turns ratios therefrom, (2) a first power switch and a first input capacitor series-coupled to the first primary winding to form a first circulation path between the isolation transformer and an input of the asymmetrical power converter and (3) a second power switch and a second input capacitor series-coupled to the second primary winding to form a second circulation path between the isolation transformer and the input.

Abstract: An input-side rectifier of a DC power supply apparatus receives and rectifies an AC voltage selected from first and second groups of AC voltages. The AC voltages in the second group are lower than those of the first group. A voltage boosting/lowering converter boosts or lowers the output voltage of the input-side rectifier to a voltage having a predetermined value. An inverter converts the output voltage of the voltage boosting/lowering converter to a high-frequency voltage. A voltage transformer transforms the high-frequency voltage from the inverter. An output-side rectifier rectifies the transformed high-frequency voltage from the transformer.

Abstract: A single-switch ac-to-ac converters for driving ac loads which are particularly suitable for gas discharge lamp ballast applications based upon integration of automatic current shapers and converters that resemble a class-E converter, both parts sharing a single active switch. The first part comprises a high power factor (HPF) converter having automatic input current-shaping means and internal energy storage means operated by the single active switch driven at a constant frequency and duty ratio, and the second part comprises a resonant converter means operated by the aforesaid single active switch as it is being driven. Integration of the HPF converter having automatic current shaping means and the resonant converter through the single active switch operation brings advantages from both parts into the whole circuit, such as soft-switching characteristics so that the combined circuit can shape the input current without switching losses in a compact structure.

Abstract: A large bandwidth analog isolation circuit is disclosed. Isolation transformers (11, 12) isolate the nonfloating side on the right hand from the floating side on the left hand. The input signal (1a, 1b) and a high frequency sinusoidal signal (3a, 3b) via a transformer (16) from an oscillator (18) are applied to a multiplier (20). The floating multiplied signal is supplied to a nonfloating multiplier (60). Thereby, the signal (6a, 6b) is multiplied by the high frequency sinusoidal signal (8a, 8b). The nonfloating multiplied signal (9a, 9b) is obtainable and is filtered (67, 68) to send out the output signal (2a, 2b) reproduced from the input signal (1a, 1b). Thus, replica of the input signal is obtained in the nonfloating side.

Abstract: A power supply circuit for powering a load circuit comprises a load circuit and includes a converter circuit for inducing current in the load circuit. The converter circuit comprises first and second converter switches serially connected in the foregoing order between a bus conductor at a d.c. voltage and a reference conductor, and connected together at a common node through which the load current flows. The first and second converter switches each comprise respective interconnected control nodes and references connected together at the common node. The voltage between a control node and associated reference node determines the conduction state of the associated switch. A first node is coupled to the bus conductor, and a second node is coupled to the reference conductor. A bridge network is connected between the first and second nodes and has first and second input nodes on which respective first and second input signals are applied.

Abstract: A voltage regulator illustrating one embodiment of the apparatus of the present invention is described. The voltage regulator includes an output stage for providing a primary output voltage on a primary output terminal and a secondary output voltage on a secondary output terminal, a switch for charging the output stage, a switch for discharging the output stage, and a controller for controlling the charging and discharging of the output stage to maintain the stability of the output voltages. The output stage includes a transformer for generating the primary and secondary output voltages, a switch for regulating the secondary output voltage, and capacitors for storing charge to maintain the primary and secondary output voltages. The transformer includes a primary inductor for generating the primary output voltage and a secondary inductor for generating the secondary output voltage.

Abstract: A ballast circuit for a gas discharge lamp comprises a resonant load circuit incorporating the gas discharge lamp and including a resonant inductance and a resonant capacitance. A d.c.-to-a.c. converter circuit induces an a.c. current in the resonant load circuit. The converter circuit comprises first and second converter switches serially connected in the foregoing order between a bus conductor at a d.c. voltage and a reference conductor, and being connected together at a common node through which the a.c. load current flows. The first and second converter switches comprise respective interconnected control nodes respective reference nodes interconnected together at a common node. The voltage between each control node and associated reference node determining the conduction state of the associated switch. A voltage-limited energy source is connected between first and second nodes.

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: An uninterruptible power supply (UPS) includes a transformer, a low voltage converter (02), a rectifier, and a high voltage inverter (01). The low voltage converter comprises a battery, a first switching device (Q3), a second switching device (Q4), and first drive circuits (41, 42). The high voltage inverter (01) includes first and second load terminals adapted to be coupled across a load in an emergency situation; an output capacitor (C); a third switching device (Q1) and a fourth switching device (Q2), and second drive circuitry (43, 44) for driving the third and fourth switching devices from conducting to non-conducting states and vice versa so as to produce a quasi-sinusoidal output voltage waveform across the load terminals.