3069 results about "Isolation transformer" patented technology

A soft-switched single-phase quasi-single-stage (QSS) bi-directional inverter/charger converts AC-DC or DC-AC. The inverter/charger comprises a push-pull inverter/rectifier on the dc-side, an isolation transformer which provides ohmic isolation and voltage scaling, two full-bridges on the ac side in cascade, a voltage clamp branch comprising a capacitive energy storage element in series with an active switch with its anti-parallel diode, a passive filter at the ac side to smooth out the high frequency switching voltage ripple at the output, and a corresponding PWM scheme to seamlessly control the converter to operate in all four quadrant operation modes in the output voltage and output current plane, and is capable of converting power in both directions.

A power converter system advantageously employs a modular, bi-directionally symmetrical power converter assembly in a readily customizable configuration to interconnect a direct current power source to a three-phase alternating power grid. Connections external to the power converter assembly are selected to optimize the power converter system for a specific application, such as interconnecting a photovoltaic array to the three-phase electrical power grid. The electrical interconnections of various elements including isolation transformers, voltage sensors, and control switches are optimized to improve efficiency and reliability.

Stationary and on-board battery chargers, methods of charging batteries, electric-vehicle chargers, and vehicles with chargers, including electric vehicles and hybrid electric vehicles. Chargers may automatically charge at the correct battery voltage for various types of batteries. Chargers have variable AC power supplies controlled by digital controllers, isolation transformers, and rectifiers. Transformers may be foil-type, and may have copper foil. Power supplies may be variable-frequency generators and the controllers may control the frequency. Electric vehicle chargers may have card readers, and vehicles may have batteries and a charger. Methods of charging include identifying the battery type and gradually increasing the charging at different rates of increase while monitoring charging voltage, charging current, or both, until a current lid is reached. Charging may occur at constant current and then at constant voltage.

Stationary and on-board battery chargers, methods of charging batteries, electric-vehicle chargers, and vehicles with chargers, including electric vehicles and hybrid electric vehicles. Chargers may automatically charge at the correct battery voltage for various types of batteries. Chargers have variable AC power supplies controlled by digital controllers, isolation transformers, and rectifiers. Transformers may be foil-type, and may have copper foil. Power supplies may be variable-frequency generators and the controllers may control the frequency. Use of the variable frequency generator supply facilitates reduced component size and weight and better battery charging performance. Electric vehicle chargers may have card readers, and vehicles may have batteries and a charger. Methods of charging include identifying the battery type and gradually increasing the charging at different rates of increase while monitoring charging voltage, charging current, or both, until a current lid is reached. Charging may occur at constant current and then at constant voltage.

A method and system for enhancing computer peripheral safety is provided. In accordance with various aspects of the present invention, the exemplary method and system are configured to monitor and/or isolate alternating current (A.C.) supplies with and/or from any peripheral subsystems or devices. An exemplary method and system comprises an A.C. supply, a host computer system, and a peripheral subsystem or device connected to the host computer system, such as an ultrasound imaging and/or therapy peripheral, and an isolation subsystem configured for monitoring and/or isolating the A.C. supply from the peripheral subsystem or device. In accordance with an exemplary embodiment, an isolation subsystem comprises application software and associated modules and functions that when executed continuously monitors and/or polls the host computer's hardware and/or operating system for the presence of an isolated source, such as a battery, or an unisolated power source, such as through a battery charger and/or other connection path to the A.C. main supply. In accordance with other exemplary embodiments, an isolation subsystem can comprises a wireless or other safe/isolated electrical link for connecting a patient contact device, and/or a verification link or other verification mechanisms configured between an isolation transformer and host computer to monitor or observe usage to power the host computer and peripheral subsystem.

A three stage power source for an electric arc welding process comprising an input stage having an AC input and a first DC output signal; a second stage in the form of an unregulated DC to DC converter having an input connected to the first DC output signal, a network of switches switched at a high frequency with a given duty cycle to convert the input into a first internal AC signal, an isolation transformer with a primary winding driven by the first internal high frequency AC signal and a secondary winding for creating a second internal high frequency AC signal and a rectifier to convert the second internal AC signal into a second DC output signal of the second stage, with a magnitude related to the duty cycle of the switches; and, a third stage to convert the second DC output signal to a welding output for welding wherein the input stage has a regulated DC to DC converter with a boost power switch having an active soft switching circuit.

An AC-to-DC power converter configured to provide power factor correction and a single isolated low-voltage output. The power converter includes a single-stage resonant power converter including an isolation transformer, a resonant tank, a rectifier, and a bulk storage capacitor coupled to an output of the isolation transformer. In typical applications, at least one non-isolated power converter is coupled to the output of the single-stage isolated power factor correction converter.

A regulated power factor corrected power supply apparatus is provided. The apparatus includes an input rectifier circuit for receiving an input AC voltage and outputting a full-wave rectified DC voltage. A single-stage isolated buck-type converter is coupled with the input circuit. The converter circuit comprises an isolated buck-type converter circuit including an isolation transformer. An output rectifier and semiconductor tap switch are coupled to a secondary winding of the isolation transformer. The tap switch couples a larger portion of the secondary winding to an output bulk capacitor during the portions of the input sinewave half-cycle, which are low in amplitude. The tap switch enables the single-stage isolation buck-type converter to operate over a much larger portion of the input sinewave, but also allows the converter to operate at high-efficiency over the majority of the input sinewave.

The invention relates to a series resonance DC/DC converter of a photovoltaic system, which comprises a single-pole converter (40), a series resonance circuit (50), a high-frequency isolation transformer (16) and a rapid uncontrollable rectifier (20), wherein the single-pole converter (40) is used for converting a direct voltage (26) of a photovoltaic array (10) into a single-pole pulse voltage; the series resonance circuit (50) is used for converting the single-pole pulse voltage into a sine voltage with a fixed frequency; the high-frequency isolation transformer (16) is used for boosting and isolating as well as protecting; and the rapid uncontrollable rectifier (20) is used for rectifying the high-frequency sine voltage into a stable direct current voltage (28). The converter (100) is only provided with two switching elements, has the advantages of simple control mode and no switching loss, and can be used for boosting and stabilizing the larger photovoltaic array so as to be convenient for synchronizing through a three-phase converter or charging a storage battery.

A three stage power source for an electric arc welding process comprising an input stage having an AC input and a first DC output signal; a second stage in the form of an unregulated DC to DC converter having an input connected to the first DC output signal, a network of switches switched at a high frequency with a given duty cycle to convert the input into a first internal AC signal, an isolation transformer with a primary winding driven by the first internal high frequency AC signal and a secondary winding for creating a second internal high frequency AC signal and a rectifier to convert the second internal AC signal into a second DC output signal of the second stage; with a magnitude related to the duty cycle of the switches and, a third stage to convert the second DC output signal to a welding output for welding wherein the input stage and the second stage are assembled into a first module and the third stage is assembled into a second module connectable to the first module.

The high-voltage hot-line work robot equipment includes moving vehicle, lifting mechanism, insulated support platform, working mechanical arm, hydralic mechanical hand, isolated transformer, power generator, hydraulic pump and control box. The lifting mechanism, power generator and hydraulic pump are mounted on the chassis of vehicle, the insulated support platform is coupled with tail end of lifting mechansm, the working mechanical arm, isolated transformer and low-voltage control box are mounted on the insulated support platform. The working mechanical arm is driven by motor, the mechanicalhead is driven by hydraulic system, and computer can utilize low-voltage control device to control working mechanical arm, mechanical hand and its holding tool to implement various high-voltage hot-lint works.

The electronic parking meter includes a microcontroller, an input interface, an output interface, communications devices and a power supply. The microcontroller receives instructions through the input interface from a user wishing to purchase parking time, controls the output interface to provide parking related messages or indications, and controls the electronic parking meter's communications with other devices through the communications devices for transmitting and receiving information and data. The power supply, which converts a battery pack voltage up to the operating voltage, may include an isolation transformer and a flyback switcher. The parking meter is maintained in a sleep mode as a default state, is placed in a schedule wake-up mode at a predetermined frequency for a predetermined short period of time to carry-out maintenance functions, and is only placed in an event wake-up mode for the time required to process major events, such as coin chute, card reader or communications port interrupts. The maintenance-free life of the parking meter is extended by using more of the energy that is available in standard battery packs and by decreasing energy consumed in the parking meter to carry out its functions through the three operating modes including the periodic schedule wake-up mode.

A data coupler includes an acoustic isolation transformer operable to develop an isolated output signal in response to an input signal. A transmitter is coupled to the acoustic isolation transformer and generates the input signal responsive to a data input signal. A receiver is coupled to the acoustic isolation transformer to receive the isolated output signal and generates a data output signal responsive to the isolated output signal.

A transformerless power conversion circuit is interconnected with an electric grid and converts an input DC power provided by a power generator into an AC power and feeding the AC power into the grid. The power conversion circuit includes a buck-boost converter converting the input DC power into two sets of DC power levels; and at least one half-bridge inverter converting the two sets of DC power levels into the AC power for feeding into the grid. The isolating transformer can be eliminated and the common ground problem for DC side and AC side is also solved. The power conversion circuit has significant improvement for device size, manufacture cost and conversion efficiency.

A super capacitor energy storage supplementing a battery providing power to a direct current bus including charge and discharge converters is disclosed. A bank of super capacitors may be charged by a battery with a pulse-width modulation controller and an electromagnetic interference filter. The bank of super capacitors may be controllably connected to the direct current bus through an isolating transformer implemented as a isolated boost converter.

A data coupler includes first and second acoustic isolation transformers that develop first and second isolated output signals in response to first and second modulated input signals. A first and a second transmitter is coupled to the first and second acoustic isolation transformers to receive a first and a second data input signal and generate the first and second modulated input signal in response to the first and second data input signals. A first and a second receiver is coupled to the first and second acoustic isolation transformers to receive the first and a second isolated output signals and generate first and second demodulated signals responsive to the first and second isolated output signals. An output decision circuit is coupled to the first and second receivers to receive the first and second data output signals and generates a data output signal responsive to the first and second demodulated signals.

A combined AC/DC monitoring system simultaneously monitors an AC power supply and a DC power supply in a mobile unit. The monitoring system is electrically isolated from an AC input source through an AC isolation transformer. A microcontroller digitally provides various computed variables from various digitized input signals. The monitoring system simultaneously displays a plurality of the computed variables while the system monitors for various user-selected high/low conditions of the computed variables. The system monitors AC power surges and can alternately displays a high voltage level for a predetermined time and a low voltage level for a predetermined time. An algorithm determines whether the AC voltage is a true sine wave or otherwise. The system monitors DC current on the high side, or positive terminal, of a battery. User selectable DC shunts are provided to measure a range of DC currents.