562 results about "Output transformer" patented technology

A method and apparatus for providing welding type power is disclosed. The power source is capable of receiving any input voltage over a wide range of input voltages and includes an input rectifier that rectifies the ac input into a dc signal. A dc voltage stage converts the dc signal to a desired dc voltage and an inverter inverts the dc signal into a second ac signal. An output transformer receives the second ac signal and provides a third ac signal that has a current magnitude suitable for welding, cutting or induction heating. The welding type current may be rectified and smoothed by an output inductor and an output rectifier. A controller provides control signals to the inverter and a controller power supply can also receive a range of input voltages and provide a control power signal to the controller, and a voltage independent of the input voltage.

In case of driving a plurality of lamps with the use of a plurality of output transformers, difference in the brightness of each lamp occurs by a dispersion of characteristics of the output transformers, and an object of this invention is to prevent such troubles. For this purpose, primary side of a plurality of output transformers of 1 input.plural output type are respectively connected, and illumination units are connected to the secondary side of each output transformer. All of the secondary output terminals of each output transformer are connected to the secondary output terminals of counter phase are connected by forming a loop circuit with the connection of the output terminals in series in closed loom form and the illumination units are connected between the secondary output terminals of the output transformer and the output terminal of the other output transformer of counter phase with the output terminal.

A resonant DC-DC converter used to drive an LED array includes a half-bridge converter configured to receive DC input power and produce a square wave voltage. A resonant tank circuit that includes an inductive element, a first resonance capacitor, and a second resonance capacitor, is coupled to the half-bridge converter to receive the square wave voltage such that a generally sinusoidal AC voltage is produced across the second resonance capacitor. An output transformer with a primary winding and one or more secondary windings, is coupled in parallel to the second resonance capacitor, and a clipping circuit is coupled to the primary winding such that the voltage across the primary winding does not substantially exceed the voltage of the DC input power. An output rectifier is coupled to the one or more secondary windings of the output transformer and is configured to produce a generally DC output voltage.

A system and method are provided to isolate outputs of parallel converter threads of a power system converter of a wind turbine generator by utilizing isolated power windings on the output transformer from the converter. Such isolation eliminates the circulating common mode current between the parallel converters of the wind turbine system and eliminates the need for a common mode inductor. System reliability is enhanced and total system cost is reduced.

An efficient and flexible current-mode driver delivers power to one or more light sources in a backlight system. In one application, the current-mode driver is configured as an inverter with an input current regulator, a non-resonant polarity-switching network, and a closely-coupled output transformer. The input current regulator can output a regulated current source in a variety of programmable wave shapes. The current-mode driver may further include a rectifier circuit and a second polarity-switching network between the closely-coupled output transformer and a lamp load. In another application, the current-mode driver delivers power to a plurality of light sources in substantially one polarity by providing a regulated current to a network of time-sharing semiconductor switches coupled in series with different light sources coupled across each semiconductor switch.

A capacitive load driving circuit includes an error amplification circuit that amplifies a difference between an external input signal provided to one input terminal and a negative feedback signal provided from the following negative feed back circuit to the other input terminal; a modulation circuit that pulse-modulates the signal outputted from the error amplification circuit; a power switching circuit that switches between a power supply voltage and a ground potential or between a positive power supply voltage and a negative power supply voltage; a gate driving circuit that generates a gate driving signal for switching-controlling a switching element configuring the power switching circuit, from a modulated signal outputted from the modulation circuit; a low-pass filter that is connected to an output side of the power switching circuit and removes switching carrier components included in an output signal of the power switching circuit; an output transformer that boosts an output signal of the low-pass filter and has a primary winding connected to an output terminal of the low-pass filter; a capacitive load that is connected in parallel with a secondary winding of the output transformer; and a negative feedback circuit that performs a negative feedback from the output terminal of the low-pass filter to an input side of the error amplification circuit.

A device for terminating operation of the power source of an electric arc welder for passing a current between an electrode and work piece from a first stud connected to the electrode by a first cable and a second stud connected to the work piece by a second cable to perform a welding process. The welder includes an output transformer with a known turns ratio, a primary winding and secondary winding. A first voltage sense lead is connected to the electrode and a second voltage sense lead connected to the work piece. The novel device comprises an executive program to implement a test sequence involving (a) a program routine for comparing a real time theoretical voltage, determined by the pulse waveform at a given time of the waveform, and the voltage at the sense leads at the given time; (b) a program routine to terminate operation of the power source when the theoretical voltage substantially exceeds the sense lead voltage; and, (c) a timing routine to perform the executive program at a set period.

This invention discloses a UPS without any output transformer including an input circuit, a rectification circuit composed of switches and inputting industrial frequency AC power and finishing boosting and rectification function by the input circuit, a DC bus, an inverse circuit connected to the rectification circuit by the DC bus and inverting stable sine waves, an output circuit outputting the sine wave to the load, in which, it has no exterior input and output midline, the input terminal of the input circuit is composed of two or three phase line voltage input voltages and the output of the output circuit is also composed of two or three-phase line voltage terminals.

The invention relates to an electric energy quality harmonic disturbance source platform. In the disturbance source platform, an input circuit breaker cabinet, a disturbance source input switch cabinet, an output filter and switch cabinet and an output test cabinet are all connected to a 10kV bus; the disturbance source input switch cabinet, an input transformer and unit cabinet, the output filter and switch cabinet, a switch and output transformer cabinet and the output test cabinet are sequentially connected; the output test cabinet, the input transformer and unit cabinet are connected with the input control cabinet; the electric energy quality harmonic disturbance source outputs 0-50 times or stacking folds of standard harmonic voltage current source with adjustable amplitude and phase under the conditions of 10kV and 0.38kV fundamental voltages, and the maximal total harmonic distortion THDu is less than 20%. The platform can be used as a standard electric energy quality harmonic output source and a power grid equipment assessment platform for testing operation stability of a power grid and performance of power grid equipment under the harmonic output condition; electric energy quality problems about sag, fluctuation and three-phase imbalance of the power grid are simulated, and a platform is built for test, analysis and assessment of electric energy quality improvement.

An electrostatic transducer includes: a class-D power amplifier that amplifies an input signal; and a low pass filter that has a plurality of pairs of inductors and capacitors, is connected to an output side of the class-D power amplifier, and serves to eliminate switching carrier components included in an output of the class-D power amplifier. An electrostatic load capacitor of the electrostatic transducer serving as a driving load is disposed at a capacitor, which is closest to the output side of the class-D power amplifier, of circuit elements forming the low pass filter, an electrostatic coupling capacitor and an output transformer are interposed between the electrostatic load capacitor of the electrostatic transducer and an inductor closest to the output side of the class-D power amplifier of the low pass filter, and a damping resistor is connected in series to a primary coil of the output transformer.

The invention relates to a radio frequency power amplifier based on a transformer, comprising an input transformer, a driving circuit, a power amplification circuit, an impedance matching network and an output transformer that are successively connected; the input end of the input transformer is respectively connected with a single-end radio frequency input (RFIN) signal and the ground; the output end of the input transformer is connected with the input end of the driver circuit; the single-end radio frequency input signal is converted into a differential signal, and the differential signal is output to the driver circuit; the differential signal of the driver circuit is output to the power amplification circuit after being amplified; and the power amplification circuit is in the cascode structure. In the radio frequency power amplifier, devices, such as an inductor, a capacitor, a transformer and the like are integrated on a substrate, impact on the performance of the amplifier by the complementary metal oxide semiconductors (CMOS) technology is effectively avoided on the premise of furthest utilizing the advantages of the CMOS technology, and circuit efficiency is improved; and compared with the traditional totally-integrated radio frequency power amplifier, the radio frequency power amplifier disclosed by the invention has the advantages of higher power and efficiency and more stable performance.

The invention relates to a flying capacitor hybrid three-level DC-AC (Direct Current-Alternating Current) inverter and a control method thereof. The inverter comprises a bridge circuit, wherein the left half bridge of the bridge circuit is provided with a first switching element, a second switching element, a third switching element and a fourth switching element which are connected in series, the right half bridge of the bridge circuit is provided with a fifth switching element and a sixth switching element which are connected in series, a flying grading capacitor CBLK is connected between the series point of the first switching element S1 and the second switching element S2 and the series point of the third switching element S3 and the fourth switching element S4, and the output ends of the bridge circuit are connected with an output transformer T1. Because the control method for the flying capacitor hybrid three-level DC-AC inverter adopts 180-degree phase-staggered carrier control and can output frequency-multiplied SPWM (Sinusoidal Pulse Width Modulation) signals, under the condition that the output harmonic quality is met, the switching frequency can be decreased, and thereby the circuit loss can be reduced.

A control system for an uninterruptible power supply (UPS) for servicing a load is disclosed. The UPS includes a first feed path and a second feed path, where the first feed path is operable in parallel with the second feed path. The first feed path is engagable via a first switch to deliver a bypass current to the load. The second feed path includes a rectifier, an inverter responsive to a control signal and in electrical communication with the rectifier, and an output transformer in electrical communication with the inverter. The second feed path is engagable via a second switch to deliver an inverter current to the load. The control system is configured for facilitating magnetization of the transformer via a back-feed from the first feed path in response to the load being fed by the first feed path, the rectifier being off, and the inverter being off.

An electronic ballast for a discharge lamp has a compact arrangement of electric parts. The ballast includes an AC-DC converter and an inverter giving a high frequency output voltage for operating the lamp. The inverter includes switching elements, a control circuit, and an output transformer for connection with the lamp. A single circuit board mounts the electric parts forming the converter and the inverter. The circuit board is accommodated within a tubular casing together with a dielectric sheet which is provided for insulating the circuit board as well as the electric parts from the casing. The output transformer is mounted on a top surface of the circuit board together with some of the other electric parts. The ballast includes chip components forming a detection circuit for lamp condition, and the circuit board mounts the chip components on a bottom surface at a location immediately opposite of the output transformer.

The invention discloses a corresponding-period grid-connection simulation platform and simulation system of a pumped power storage unit under the different working conditions. A simulation function is provided for corresponding-period grid-connection research of the pumped power storage unit. The corresponding-period grid-connection simulation platform comprises a pumped power storage unit module, an infinite power grid module, a stationary frequency converter, a back-to-back starting unit module, a main transformer module, an SFC output transformer module, a step-down transformer, a corresponding-period adjusting module, an excitation control module, a water turbine speed regulation module, a back-to-back starting speed regulation module, a grid-connection circuit breaker module, a starting circuit breaker module, a first voltage monitoring module, a second voltage monitoring module, a rotation speed detection module and a monitoring system module. Simulation models of the pumped power storage unit under the different working conditions can be established by combining and adjusting functional modules, and a grid-connection simulation function of the pumped power storage unit under multiple operating working conditions including generator working conditions, water pump working condition back-to-back starting, water pump working conditions, SFC starting and the like and multiple starting modes can be achieved.

A charging circuit is provided that charges a battery for supplying power to a motor drive system that includes a three-phase motor and a three-phase inverter for controlling the three-phase motor. The three-phase inverter includes first to third sets of switching elements. Each set corresponds to one of the three phases. The charging circuit includes a single-phase output transformer, a rectifier circuit, a line, and a controller. The single-phase output transformer includes a secondary side output section having a first terminal and a second terminal. The rectifier circuit is connected in parallel with the three-phase inverter and the battery. The rectifier circuit is also connected to the first terminal of the secondary side output section. The line connects a connecting point between the first set of the switching elements in the three-phase inverter with the second terminal of the secondary side output section. The controller performs on-off control of the first to third sets of the switching elements. During charging of the battery, the controller maintains the first set of the switching elements in an OFF state, and performs the on-off control of at least one set of the second and third sets of the switching elements.

The invention discloses an urban rail maglev train traction converter output device. The device comprises an inverter, an input switch cabinet and an output converting device, wherein the input switch cabinet is in circuit connection with an input end of the inverter; the output converting device is in circuit connection with an output end of the inverter; the output end of the output converting device is in circuit connection with a plurality of external motors; the inverter comprises a plurality of inverter modules; and the output converting device comprises an output transformer which is in circuit connection with the output end of the inverter and an output switch device which is in circuit connection with the output end of the output transformer. The urban rail maglev train traction converter output device is provided with a plurality of same inverter modules and reduces the capacity demand of the traction inverter, thereby reducing the weight and the volume of the inverter and being beneficial to the arrangement of equipment; the voltage resistant grade and the output current demand of an inverter power device are reduced, and the cost of a traction system is reduced; the voltage formed by combining two inverters is high, and the speed-up capability of a train high-speed section can be improved; and the redundancy and the reliability of the system are improved.

An amplifier is operable in push-pull mode, single-ended mode, or a composite mode that is an intermediate between single-ended and Push-pull modes. Moreover, at least one output device may be configured to operate using a high performance AC servo loop that functions the output device as a current source. Still further, a control input driver stage is provided that is capable of supplying sufficient AC current to overcome Miller capacitance induced roll off within the intended frequency spectrum of triode vacuum tubes. Additionally, methods are provided to substantially null or selectively introduce DC magnetic bias within the output transformer core. Still further, a solid state power supply stage provides substantial AC hum reduction during single-ended operation and simultaneously provides output voltage load regulation attributes similar to traditional vacuum tube rectifier circuits.

The present invention relates to an error information detection circuit and an error feedback circuit, which detect the error of an output voltage from a voltage induced to a winding. The circuit for detecting error information of an output voltage of a transformer from voltage induced to the feedback winding of the transformer and feeding back the error information includes a flyback period detection circuit (34) for detecting a flyback period from a voltage induced to the feedback winding. A comparison unit (35) compares the induced voltage of the feedback winding with a reference voltage and outputs a result of comparison. A logic unit (36) outputs error information of an output voltage of the transformer according to a flyback period detection output of the flyback period detection circuit and the output of the comparison unit. An up/down control unit (32) outputs a feedback value corresponding to the error information.