254 results about "Ac to dc converter" patented technology

A method of distributing charging power among a plurality of charge ports of a battery charging station is provided, where the battery charging station includes a plurality of power stages where each power stage includes an AC to DC converter and provides a portion of the charging station's maximum available charging power, the method comprising the steps of (i) monitoring battery charging station conditions and operating conditions for each charging port; (ii) determining current battery charging station conditions, including current operating conditions for each charging port; (iii) determining power distribution for the battery charging station and the charging ports in response to the current battery charging conditions and in accordance with a predefined set of power distribution rules; and (iv) coupling the power stages to the charging ports in accordance with the power distribution.

In a power factor corrected AC-to-DC power supply system, a DC-to-DC power converter is coupled to the output of an AC-to-DC power converter in order to produce a regulated DC output signal from a rectified AC input signal. The AC-to-DC power converter and the DC-to-DC power converter each includes a switch for controlling the operation of their respective power converter. The AC-to-DC converter includes an inductor. The system provides power factor correction for minimizing harmonic distortion by including a controller that receives the regulated DC output voltage as a feedback signal, and in response, produces a series of drive pulses having predetermined constant duty cycle. These pulses are simultaneously fed to each switch, to operate the respective converters alternately between ON and OFF states. When the AC-to-DC converter is driven by a fixed duty cycle of the series of pulses, power factor correction is improved since the current flowing through the inductor is substantially proportional to the waveform of the rectified AC input signal. By preselecting the value of the inductor, the AC-to-DC converter is operable in a discontinuous mode when the instantaneous rectified AC input signal is low and in a continuous mode when the instantaneous rectified AC input signal is high.

Circuits and methods for battery charging are disclosed. In one embodiment, the battery charging circuit comprises an AC to DC converter, a charging control switch, and a charger controller. The AC to DC converter provides a charging power to a battery pack. The charging control switch is coupled between the AC to DC converter and the battery pack. The charging control switch transfers the charging power to the battery pack. The charger controller detects a battery status of the battery pack and controls the charging control switch to charge the battery pack in a continuous charging mode or a pulse charging mode according to the battery status. The charger controller also controls the AC to DC converter to regulate the charging power according to the battery status.

A battery charging station is provided that includes a plurality of charge ports, a plurality of power stages where each power stage includes an AC to DC converter and where each power stage provides a portion of the charging station's maximum available charging power, a switching system that is used to couple the output of the power stages to the charging ports, a system monitor that determines current charging station and vehicle conditions, and a controller that controls operation of the switching system in accordance with a predefined set of power distribution rules and on the basis of the current charging station and vehicle conditions. Current charging station and vehicle conditions may include vehicle arrival time, usage fees, vehicle and/or customer priority information, battery pack SOC, and/or intended departure time.

The current draw of a wireless device, e.g., a cordless telephone, is minimized for a cradled remote handset drawing power from an AC outlet. This allows a greater portion of the total current amperage provided by the AC to DC converter to be allowed to charge the battery in the remote unit, and reduces the overall maximum or peak value of the current draw of the wireless device. With an improved peak power budget, a smaller (and presumably less expensive) AC to DC adapter than otherwise necessary may be used to power the wireless device. In one aspect, sniff operations of the remote handset are disabled or otherwise suppressed while the remote handset is in the cradle of the base unit, e.g., receiving a quick charge or trickle charge to its battery. In a second aspect, sniff operations of the base unit are disabled or otherwise suppressed while the remote handset is in the cradle of the base unit. In a last aspect, the charging mode of the battery in the remote handset of a wireless device changes based on activity in the remote handset.

An AC/DC adapter in which an AC to DC converter is incorporated in a multiple outlet wall adapter. The AC/DC adapter includes at least one standard AC plug receptacle and at least one DC receptacle. Electronic devices which require DC power can be plugged into to the AC/DC adapter by a power cord having a universal DC plug at one end and a connector or plug specific to the make and/or model of the electronic device at the other end. The universal DC plug corresponds with the DC receptacle provided on the AC/DC adapter. The adapter may be formed as one integrated unit or as a modular assembly which includes an AC module and a DC module. In the assembly, the AC and DC modules are constructed so that they can be fitted together and used as one conveniently sized unit, but modules can also be used independently of the other.

Apparatus and method for providing current limiting in a DC-DC converter and especially to methods and apparatus suitable for a start-up mode of operation. The invention monitors the inductor (L) current when the high side supply switch is on against a peak current limit threshold. If the inductor current reaches the peak current limit threshold the high side switch is turned off. The inductor current when the low side switch is off is monitored against a valley current threshold. As long as the inductor current is above the valley current threshold turn on of the low side switch is inhibited. In this way current limiting is provided and the problems of stair-stepping are avoided. Embodiments employing lossless current sensing are described. The invention may be implemented in a start-up mode of operation wherein the converter is controlled purely by the peak current limit and valley current threshold which are increased over time.

A variable voltage and frequency output wind turbine. Variations of the wind turbine include use of a slotless alternator to reduce alternator noise, a high power AC output to facilitate transmission of the output over extended distances, AC to DC converters and DC to AC converters, and sensors for systems and devices to receive the wind turbine output and to allow matching of the output to the receiving devices and system. Other features include a removable hatchcover for dissipating heat from components contained in the turbine or attached to the hatchcover, a swept blade design to reduce blade-produced noise, and power storage components for storing and intermittently using energy stored as a result of wind turbine power generation.

A circuit and corresponding method for controlling inrush current in an AC-DC power converter by providing a relay and a control circuit for limiting inrush current efficiently during cold startup, warm startup, and power line disturbance conditions. The relay is preferably connected in series with a bulk capacitor of the converter and in parallel with a limiting resistor and switch for shunting the resistor and switch so as to improve efficiency during operating conditions, at reduced size and cost. A preferred embodiment includes use of the circuit for AC-DC converters having active power factor correction.

The disclosed embodiments provide an AC/DC power converter that converts an AC input voltage into a DC output voltage. This AC/DC power converter includes an input rectifier stage which rectifies an AC input voltage into a first rectified voltage. The AC/DC power converter also includes a switching resonant stage which is directly coupled to the output of the input rectifier stage. The switching resonant stage converts the rectified voltage into a first high frequency AC voltage of a first amplitude. This AC/DC power converter additionally includes a transformer which is coupled to the output of the switching resonant stage and is configured to down-convert the first high frequency AC voltage into a second high frequency AC voltage of a second amplitude. Furthermore, the AC/DC power converter includes an output rectifier stage which is coupled to the output of the transformer, wherein the output rectifier stage rectifies the second high frequency AC voltage into a DC output voltage.

A dual input AC/DC power converter (10) having dual inputs (12, 14) adapted to receive both an AC and DC input and provide a selectable DC voltage output (16) and a second DC output (18). The dual input AC/DC power converter (10) comprises a power converter circuit (20) having an AC-to-DC converter (22), a DC-to-DC booster converter (24), a feedback circuit (26), a filter circuit (25) and a DC-to-DC buck converter (28). Advantageously, the power converter (10) resolves many of system management problems associated with carrying all of the different interface components necessary to power a wide variety of mobile products from either an AC or DC power supply. In addition, the power converter (10) also advantageously includes dual output voltage terminals (16/18) to allow for multiple mobile devices of varying power requirements to be powered, simultaneously, by a single converter.

An AC to DC converter with harmonic suppression is provided. The harmonic suppression is provided by forcing an instantaneous current conflict between series connected rectifier bridges 54, 80, such that a voltage waveform at 6 times the AC supply frequency of the AC supply is automatically generated. This waveform is then injected via a injection circuit to give harmonic cancellation.

The present invention discloses a safety capacitor discharging method for AC-to-DC converters, wherein the AC-to-DC converters have a safety capacitor connected between two line voltages, the method comprising the steps of: detecting at least one line voltage to generate a line-off signal, wherein the line-off signal is at a first state when the peak voltage of the at least one line voltage is above a reference voltage, and the line-off signal is at a second state when the peak voltage of the at least one line voltage is below the reference voltage; and performing discharge of the safety capacitor by generating a conduction path between two plates of the safety capacitor when the line-off signal is at the second state. The present invention also provides a safety capacitor discharging apparatus for AC-to-DC converters.

A non-outage power supply system comprises three-phase ac input terminals and three-phase ac output terminals, between which there are sequentially connected a three-phase ac-to-dc converter circuit, a capacitor, and a three-phase dc-to-ac converter circuit. A bypass switch is connected between a preselected one of the three-phase ac input terminals and a preselected one of the three-phase ac output terminals. A bypass switch control circuit holds the bypass switch closed when the three-phase ac inputs are in phase with the three-phase ac outputs, and open when they are not. Part or all of the effective current demanded by the load bypasses the three-phase dc-to-ac converter circuit when the bypass switch is closed, with a consequent reduction of power loss.

Electric vehicle supply equipment includes an alternating current to direct current converter having an alternating current input and a direct current output. A direct current bus is electrically interconnected with the direct current output of the alternating current to direct current converter. Each of a plurality of direct current to direct current converters includes an input powered by the direct current bus and an output structured to charge a corresponding one of a plurality of different electric vehicles.

In high-efficiency power source applications, AC power is converted to DC power, which is isolated from the source and regulated. A level of performance is achieved that exceeds the power quality requirements of MIL-STD-704 over the extended frequency range, typically from about 360 Hz to 800 Hz. While high-efficiency and low-weight of the invention, among other benefits, are advantageous primarily in airborne systems, its use can be extended to terrestrial applications as well. The isolation, regulation and the main power processing are achieved by low-weight, high-frequency conversion stages arranged in 2 channels that produce the line harmonic content typical of the 12-pulse rectification. Control of the conversion stages provides effective rejection of line transients, while output ripple voltage is typically an order of magnitude lower than in conventional transformer rectifier units.

A power supply for a capacitive-resistive load includes plural paralleled phase correcting modules together with current sharing controllers for tending to equalize their currents. Each module is provided with a diode, poled to prevent forward current from flowing in the return current path, for aiding in equalizing module currents. Surge currents are reduced by a single saturable reactor coupled to the combined outputs of current sharing controllers, thereby avoiding the need for soft-start in each controller. A precharging path extends from a source of pulsating direct voltage to the load, for precharging the load capacitance at turn-on.