Abstract: A dual-output AC-DC power converter with balanced DC output voltages is described. The DC power source has balanced DC voltage outputs relative to DC midpoint irrespective of DC load imbalance. The input to the power source is three-phase four-wire AC voltage source. Current draws from the AC three-phase voltage source have 12-pulse near sinusoidal waveform. Ripple voltage from DC positive rail to DC negative rail is 12-pulse.

Abstract: A dual-output AC-DC power converter with balanced DC output voltages is described. The DC power source has balanced DC voltage outputs relative to DC midpoint irrespective of DC load imbalance. The input to the power source is three-phase four-wire AC voltage source. Current draws from the AC three-phase voltage source have 12-pulse near sinusoidal waveform. Ripple voltage from DC positive rail to DC negative rail is 12-pulse.

Abstract: A hybrid rectifier that works as either a hybrid full bridge or a voltage doubler. Under 220 V AC input condition, the hybrid rectifier operates in full bridge mode, while at 110 V AC input, it operates as voltage doubler rectifier. The hybrid rectifier may be used with a DC-DC converter, such as an LLC resonant converter, in a power supply. With this mode switching, the LLC converter resonant tank design only takes consideration of 220 V AC input case, such that the required operational input voltage range is reduced, and the efficiency of the LLC converter is optimized. Both the size and power loss are reduced by using a single stage structure instead of the conventional two-stage configuration.

Abstract: A hybrid rectifier that works as either a hybrid full bridge or a voltage doubler. Under 220 V AC input condition, the hybrid rectifier operates in full bridge mode, while at 110 V AC input, it operates as voltage doubler rectifier. The hybrid rectifier may be used with a DC-DC converter, such as an LLC resonant converter, in a power supply. With this mode switching, the LLC converter resonant tank design only takes consideration of 220 V AC input case, such that the required operational input voltage range is reduced, and the efficiency of the LLC converter is optimized. Both the size and power loss are reduced by using a single stage structure instead of the conventional two-stage configuration.

Abstract: A switching power supply includes: a rectifying unit; a Bulk capacitor; a converter; a monitoring circuit; a control circuit, controlling discharging of the Bulk capacitor, being configured to perform controls such that the voltage across the Bulk capacitor maintains the peak value after the Bulk capacitor having been charged to a peak value of AC voltage, and to perform controls such that the Bulk capacitor discharges from a peak value when the instantaneous absolute value of the AC voltage is smaller than or equal to the preset voltage. A method for controlling a voltage of a Bulk capacitor in the switching power supply includes detecting an instantaneous absolute value of the AC voltage; comparing the detected instantaneous absolute value of the AC voltage with a preset voltage; and controlling discharging and charging state of the Bulk capacitor according to comparison results.

Abstract: Power converters having bleeder circuits are disclosed. For example, in an embodiment, a power converter can include a controllable TRIAC in series with a rectifier that together produces a controllable rectified voltage at a first node, a first inductor having a first end and a second end, the first inductor being electrically connected to the first node at the first end, and electrically connected to a first power lead of a transistor and an anode of a diode at the second end, a load capacitor having a first end and a second end, the load capacitor being electrically coupled to the first node at the first end of the load capacitor, and electrically coupled to a cathode of the diode at the second end the load capacitor, control circuitry to control switching of the transistor, and a bleeder circuit coupled to the second end of the inductor, the bleeder circuit including a resistor in series with a coupling capacitor.

Abstract: A multiple-input power converter transferring energy from multiple input sources to a load comprises a plurality of voltage inputs. The power converter implements soft-switching techniques thereby reducing the converter switching losses and increasing the converter efficiency while using fewer components than presently designed multiple-input power converters. Such a power converter may include multiple input sources, where serially connected switches are coupled to one of the multiple input sources in an input leg. A voltage blocking capacitor is inserted between these input legs. Furthermore, the power converter includes a transformer for isolating the load from the multiple input sources, where the voltage blocking capacitor is connected to the primary winding of the transformer.

Abstract: A single phase three-level power converter can include a first half bridge and a second half bridge. A half bridge operation is implemented in either the first half bridge or second half bridge when outputting a single phase alternating current voltage having an amplitude a half or less than that of a direct current input voltage, and also, by alternately switching between the bridges carrying out the half bridge operation. In certain configurations, the power converter can convert a direct current input voltage into alternating current phase voltages having three levels of potential, which are positive, negative, and intermediate voltages, by controlling on-off conditions of a plurality of switch elements, and a controller that, by supplying gate signals to the switch elements configuring the first half bridge and second half bridge, controls the related on-off conditions.

Abstract: The present invention provides a bootstrap driving circuit without extra power supply, which circuit includes a power unit, a switching unit, a bootstrap unit, a drive unit; the power unit is used to output a direct voltage; the switching unit is connected with the power unit, to control the turn-on or turn-off with the power unit; the bootstrap unit is connected with the switching unit, to supply drive electric energy and output drive power; the bootstrap unit includes an energy storage capacitor; the drive unit is connected with the bootstrap unit, to output control signal under the drive of the drive power. The bootstrap driving process is completed via the charging-discharging of the energy storage capacitor in the bootstrap unit of the invention and without an extra power supply, which forms the bootstrap driving circuit without extra power supply, further overcomes the requirement of an extra power supply for a common driving circuit, reduces the power consumption and meets the demand of the circuit.

Abstract: In an embodiment, a voltage conversion circuit includes a first voltage conversion unit stepping up or stepping down an input DC voltage and a second voltage conversion unit stepping up or stepping down an input DC voltage. A switcher is configured to switch between using both the first and second conversion units or just one of the first and second conversion units. The switcher can optionally be controlled according to an input voltage level such that both the first and second voltage conversion units can be used for a voltage step-up or voltage step-down operation or just one of the first and second voltage conversion units can be used.

Abstract: A power supply includes a rectification unit configured to be able to switch a rectification method between a voltage doubler rectification method and a full-wave rectification method according to an input alternating voltage, two capacitive elements serially connected between lines from the rectification unit, a monitoring unit configured to monitor a first voltage applied between the lines between which the two capacitive elements are connected and a second voltage applied across one of the capacitive elements that is connected to a lower potential side of the lines, and a switch configured to operate according to the second voltage, wherein the power supply interrupts the alternating voltage according to an operating state of the switch, the first voltage, and the second voltage.

Abstract: The present invention is a switching power source device which converts AC power of an AC power source into DC power and outputs the DC power, the device including: a rectifying-smoothing circuit configured to output a rectified-smoothed voltage signal obtained by rectifying and smoothing an AC voltage of the AC power source; a transformer having a primary winding, a secondary winding, and an auxiliary winding; a switching element connected to the primary winding of the transformer; and a control circuit configured to turn the switching element on and off based on a voltage signal which is based on an average value of current flowing through the switching element and the rectified-smoothed voltage signal from the rectifying-smoothing circuit.

Abstract: An additional electric power receiving method replacing conventional grounding with a negative voltage source includes the step of transmitting electromagnetic wave or current from a power supply source to a rectifier, wherein a grounding end of the rectifier is in electrical communication with the negative voltage source, and the negative voltage source is selected from a negative potential intrinsic of an organism. A device applicable to the electric power receiving method includes a rectifier having an input end and two output ends, wherein the input end is in electrical communication with a power supply source, and rectified direct current is transmitted from the output ends. With the method and device, not only an increase in additional electric power obtained is achieved, but conversion efficiency and stability of current and electromagnetic wave is enhanced.

Abstract: A dual-input 18-pulse autotransformer rectifier unit for more electric aircraft AC-DC converter uses an autotransformer with a nine-phase output to condition AC power prior to DC rectifying the AC power.

Abstract: Electronic devices require correct power in order to operate correctly. Receiving an incorrect power signal could potentially result in immediate and/or long term harm to the electronic device and/or catastrophic conditions. Certain devices, such as programmable logic controller (“PLC”) modules, may provide variable power to electronic devices, such as field devices comprising sensors and/or actuators. The present inventors have recognized that deciphering between AC and DC input signals before coupling electronic devices to such power sources may advantageously avoid harmful and/or catastrophic conditions. Aspects of the present invention provide an electronic circuit for deciphering between an AC and a DC input signal. Systems and methods are also described.

Abstract: A driving circuit of a light emitting diode (LED) including an AC power, a rectifier, a power converter, a waveform sampler, and a control circuit is provided. The AC power provides an AC signal. The rectifier is coupled to the AC power and outputs a driving signal. The power converter is coupled to the rectifier. The power converter includes an LED and outputs a first signal positive correlated with a current passing through the LED. The waveform sampler is coupled between the AC power and the rectifier, and outputs a second signal directly proportional to the AC signal. The control circuit is coupled between the waveform sampler and the power converter, and outputs a control signal to the power converter according to a comparison result between the first signal and the second signal.

Abstract: The invention relates to a mains plug component with a housing and a mains switch component arranged in the housing comprising a first stage for rectifying a mains AC voltage and a second stage for generating a DC voltage from the rectified mains AC voltage. The first stage comprises an electromechanical switch, by means of which a first or second voltage range may be selected. The housing has a section for a pin of an inserted plug piece such that, on insertion, the switch is activated by the inserted pin. The plug piece for insertion has no pin for the first voltage range and a pin for the second voltage range.

Abstract: A wiring board includes a conductor plate including a wiring portion and an electrode portion connected to a power conversion semiconductor element, a liquid-cooling pipe mounted near the conductor plate and causing a cooling liquid to be supplied therethrough, and an insulating resin material arranged at least between the conductor plate and the liquid-cooling pipe.

Abstract: A portable hand held power inverter/converter having a pass through device for simultaneously sourcing A.C. and multiple voltage D.C. power consuming devices through a single D.C. power source connection. Inverter and converter circuitry is provided to invert and convert D.C. voltage to an A.C. voltage source and a lower DC voltage. A.C. electrical outlets are provided to facilitate a connection to an external A.C. power-consuming device and a DC outlet to a lower volt DC power-consuming device. The pass through device provides an independent and simultaneous connection to an additional D.C. outlet that would otherwise be eliminated when occupied by the inverter thus allowing simultaneous connection and operation of both A.C. and multi source D.C. power consuming devices through a single external D.C. power outlet of a single D.C. power source.

Abstract: A power converter including a switching element, a switching power module containing a driving circuit for driving the switching element, a smoothing capacitor module for smoothing an input to the switching power module, and a heat sink for cooling the switching power module, wherein the switching power module is mounted on the heat sink, and the smoothing capacitor module is provided on a side surface of the heat sink.

Abstract: A cooling device for a semiconductor element module and a magnetic part, includes: a water-cooled type heat sink having a cooling water passage; a semiconductor element module including a plurality of chips arranged side by side in a circulation direction in the cooling water passage, the semiconductor element module being mounted on the heat sink; and a magnetic part including a core and a winding portion mounted on the core, the magnetic part being mounted on the heat sink or another heat sink. In the cooling device, a plurality of cooling fins is disposed to extend along the circulation direction in the cooling water passage in a manner that the plurality of cooling fins are separated into groups for the respective chips arranged side by side in the circulation direction, and that the groups of the cooling fins are offset from each other in a direction perpendicular to the circulation direction. Accordingly, it is possible to have improved cooling efficiency of a heat sink with cooling fins.

Abstract: A timed electrical outlet (or pluggable apparatus) and a method of operation thereof. The electrical outlet (or pluggable apparatus) includes a current sensor, a counter, and an electrical switch. When an electrical load is plugged into the electrical outlet (or pluggable apparatus), the current sensor senses the flow of current and triggers the counter to start counting. When the counter is finished counting, the counter triggers the electrical switch, opening the current path within the electrical outlet (or pluggable apparatus) such that electrical current no longer flows to the electrical load.

Abstract: An AC/DC converting circuit, has a full-bridge rectifier having two input terminals and two output terminals, a first capacitor, a second capacitor, an electronic switch having a control terminal, a trigger circuit having an input terminal and an output terminal, and a detecting circuit having an input terminal and an output terminal.

Abstract: A universal input voltage device is presented which may receive a wide range of regulated and unregulated input voltages, both DC and a wide range of variable frequency AC, and output a desired regulated current at a desired voltage independent of the fluctuation of input voltage and frequency. The circuit includes a preconditioning input circuit, a Buck converter circuit with over voltage protection, flyback and boost circuits, and a shutdown circuit configured to drive a predetermined electrical or electronic device.

Abstract: A power conversion apparatus includes a power module, four corners of which are fastened to a cooling jacket from its front surface by a front surface side fastening apparatus that includes nuts which are screwed with bolts projecting from the rear face of the cooling jacket to fasten the power module. An AC terminal of the power module, a DC positive electrode terminal connection portion, and a DC negative electrode terminal are arranged on the top surface of the cooling jacket facing the bolts.

Abstract: A motor controller, which is inexpensive and has small size, is provided by reducing the size of a heat sink used in the motor controller and the number of all parts of the motor controller, wherein said motor controller includes a heat sink, a power semiconductor modules that is in close contact with the heat sink, a substrate (4) that is electrically connected to the power semiconductor module, and a fan (6) that generates the flow of external air and supplies cooling air to the heat sink, wherein said heat sink is formed by combining two kinds of heat sinks, which include a first heat sink (7) and a second heat sink (8), so as to conduct heat therebetween, and, wherein said power semiconductor module is in close contact with the second heat sink (8).

Abstract: A power controller (10) includes a controller (11) and a trigger circuit (12). When the voltage of a power supply received at terminals T1 exceeds a threshold, for example 120 V RMS, reverse-connected Zener diodes Z1 to Z3 conduct and switch on a transistor Q1. This results in a transistor Q2 being switched off and a normally open relay SW1 remaining open. The switching or triggering phase angle of a triac THY1 thus is determined by the speed at which a capacitor C4 is charged to a triggering voltage by current flowing through resistors R6, R7, R8 and VR1. In this situation, the triggering phase angle is such that a 240 V AC input supply provides an effective 110 V AC output at terminals T3 when VR1 is at maximum power setting (zero Ohms). When the voltage of the received power supply is less than the threshold, the transistor Q1 is switched off and the relay SW1 is activated.

Abstract: AC module makers must prepare two types of AC modules for the 100-V and 200-V outputs only for domestic supply. For foreign countries, the makers must manufacture AC modules compatible with more system voltages. To solve these problems, the control circuit of an AC module controls the operation of an inverter circuit and/or the transformation ratio of a transforming circuit, and ON/OFF-controls a switch on the basis of the system voltage and connection state of an electric power system.

Abstract: An automatic power supply converting circuit includes a live input terminal, a neutral input terminal, a relay, a regulator, a voltage divider circuit, an identifying circuit, a switch circuit and a voltage doubling circuit. The live input terminal and the neutral input terminal are configured for receiving a first alternating current (AC) voltage. The regulator is configured for filtering and steadying the first AC voltage and outputting a regulated voltage. The voltage divider circuit is configured for sampling the first AC voltage and outputting a divided voltage. The identifying circuit is configured for comparing a divided voltage with a reference voltage, and outputting a control signal. The switch circuit is configured for controlling the relay to be conductive or not. The voltage doubling circuit is capable of being controlled by the relay and outputting a doubled voltage.

Abstract: A universal input voltage device is presented which may receive a wide range of regulated and unregulated input voltages, both DC and a wide range of variable frequency AC, and output a desired regulated current at a desired voltage independent of the fluctuation of input voltage and frequency. The circuit includes a preconditioning input circuit, a Buck converter circuit with over voltage protection, flyback and boost circuits, and a shutdown circuit configured to drive a predetermined electrical or electronic device.

Abstract: A modular aircraft support system is disclosed. In one embodiment, the modular system includes a mobile cart and an air conditioning system configured to provide conditioned air to an aircraft. The embodiment also includes a modular power converter for converting input power to a desired output power, which can be input to a supported aircraft. The cart is configured to receive a plurality of different interchangeable power converters, such as a 115 VAC, 400 Hz power converter or a 270 VDC power converter. In some embodiments, a variety of other components are also coupled to the mobile cart, including a local generator and engine. The generator may supply power to the air conditioning system and to the converter.

Abstract: A circuit that provides a method and apparatus to actively balance capacitor leakage current from series stacked capacitors and disconnects itself when stacked capacitors are configured for doubler operation. In one embodiment, the active circuit includes high voltage low current transistors, such as for example a PNP bipolar transistor and an NPN bipolar transistor, that are configured in a sink-source voltage follower arrangement with the bases of the transistors connected to a voltage divider network and referenced to a fraction of a DC input voltage with a very high impedance, low dissipative resistor divider network. In one embodiment, the emitters of the PNP and NPN transistors are both tied to the connection point between capacitors in the stack and provide an active sink-source drive, which maintains the voltage at this point to be bounded by the input reference voltages of sink-source followers.

Abstract: An improved switch for power factor correction circuits includes a six-terminal switch which has a first inductor connecting to a selection line which has a first switch terminal and a second switch terminal, and a second inductor connecting to a conductive line. When the switch is at a first position, the selection line is connected to the first switch terminal, and the conductive line is closed to determine the first and second inductors in a parallel coupling condition and the power conversion circuit in a first duty condition. When the switch is at a second position, the selection line is connected to the second switch terminal and the conductive line is open to determine the first and second inductors in a serial coupling condition, and the power conversion circuit in a second duty condition.

Abstract: Power converters such as power modules configured as inverters employ modularized approaches. In some aspects, semiconductor devices are thermally coupled directly to thermally conductive substrates without intervening dielectric or insulative structures. Additionally, or alternatively, semiconductor devices are thermally coupled to thermally conductive substrates with relatively large surface areas before heat transferred from the semiconductor devices encounters a dielectric or electrically insulating structure with correspondingly high thermal impedance.

Abstract: A circuit that provides a method and apparatus to actively balance capacitor leakage current from series stacked capacitors and disconnects itself when stacked capacitors are configured for doubler operation. In one embodiment, the active circuit includes high voltage low current transistors, such as for example a PNP bipolar transistor and an NPN bipolar transistor, that are configured in a sink-source voltage follower arrangement with the bases of the transistors connected to a voltage divider network and referenced to a fraction of a DC input voltage with a very high impedance, low dissipative resistor divider network. In one embodiment, the emitters of the PNP and NPN transistors are both tied to the connection point between capacitors in the stack and provide an active sink-source drive, which maintains the voltage at this point to be bounded by the input reference voltages of sink-source followers.

Abstract: Method of controlling a voltage controlled PWM (Pulse Width Modulated) frequency converter comprising a single phase rectifier bridge (10) connectable to a sinusoidal single phase supply, a DC intermediate circuit (11) and a controlled inverter bridge (12) for generating an AC output voltage with varying amplitude and frequency to a load, said inverter bridge (12) having PWM controlled semiconductor switches (V11–V16) and flywheel diodes (D11–D16) connected in inverse-parallel with the semiconductor switches, wherein the DC intermediate circuit (11) is provided with a DC capacitor unit, and wherein the frequency converter is controlled so that the supply line current (Iin) is essentially sinusoidal and in phase with the supply line voltage (Uin).

Abstract: A circuit that provides a method and apparatus to actively balance capacitor leakage current from series stacked capacitors and disconnects itself when stacked capacitors are configured for doubler operation. In one embodiment, the active circuit includes high voltage low current transistors, such as for example a PNP bipolar transistor and an NPN bipolar transistor, that are configured in a sink-source voltage follower arrangement with the bases of the transistors connected to a voltage divider network and referenced to a fraction of a DC input voltage with a very high impedance, low dissipative resistor divider network. In one embodiment, the emitters of the PNP and NPN transistors are both tied to the connection point between capacitors in the stack and provide an active sink-source drive, which maintains the voltage at this point to be bounded by the input reference voltages of sink-source followers.

Abstract: A circuit that provides a method and apparatus to actively balance capacitor leakage current from series stacked capacitors and disconnects itself when stacked capacitors are configured for doubler operation. In one embodiment, the active circuit includes high voltage low current transistors, such as for example a PNP bipolar transistor and an NPN bipolar transistor, that are configured in a sink-source voltage follower arrangement with the bases of the transistors connected to a voltage divider network and referenced to a fraction of a DC input voltage with a very high impedance, low dissipative resistor divider network. In one embodiment, the emitters of the PNP and NPN transistors are both tied to the connection point between capacitors in the stack and provide an active sink-source drive, which maintains the voltage at this point to be bounded by the input reference voltages of sink-source followers.

Abstract: A 110V/220V switchable fixing apparatus and a printer therewith including an input voltage detector unit detecting an input voltage of an AC power supply and outputting a signal corresponding to the detected input voltage, a first resistance body having a first end thereof connected to a second terminal of the AC power supply, a second resistance body having a first end thereof connected to a second end of the first resistance body, a first switching unit connected between a second end of the second resistance body and a first terminal to switch on or switch off in response to a control signal from an engine control unit, the engine control unit and a second switching unit connected between the second end of the first resistance body and the second terminal to switch on or switch off in response to the output signal from the input voltage detector unit.

Abstract: A circuit that provides a method and apparatus to actively balance capacitor leakage current from series stacked capacitors and disconnects itself when stacked capacitors are configured for doubler operation. In one embodiment, the active circuit includes high voltage low current transistors, such as for example a PNP bipolar transistor and an NPN bipolar transistor, that are configured in a sink-source voltage follower arrangement with the bases of the transistors connected to a voltage divider network and referenced to a fraction of a DC input voltage with a very high impedance, low dissipative resistor divider network. In one embodiment, the emitters of the PNP and NPN transistors are both tied to the connection point between capacitors in the stack and provide an active sink-source drive, which maintains the voltage at this point to be bounded by the input reference voltages of sink-source followers.

Abstract: When a relay (21) is controlled, an AC voltage (1) may be rectified in a full-wave rectification fashion. In a voltage-doubler rectification fashion, and a rectified output supplied to a main converter (6) or the AC voltage (1) may be rectified in a half-wave rectification fashion, and a rectified output supplied to a standby converter (10). A just detection circuit (23) detects a rectified voltage of the standby side, and a detection circuit (24) may detect a rectified voltage supplied to the main converter (6). The first and second voltage detection circuits (23) and (24) control operations of relay drive circuits (21D and 22D) based on both detection signals so that any one of two relay contacts (21a and 22a) may be turned on.

Abstract: An AC/DC input mobile charger includes an enclosure with a regulation circuitry, a DC circuitry, a control circuitry, a DC output circuitry and a PCB internally. The regulation circuitry converts AC power into DC current; the DC circuitry connects to at least one battery or the automobile cigarette lighter as input DC power; the DC output circuitry connects to the control circuitry. Either AC power or DC battery (alkaline battery) can be an input source to charge Li-Ion batteries, cellular phones and PDAs.

Abstract: A power converter includes a housing, heat generating circuitry in the housing, and a heat conducting metal sheath on the outside of the housing. The housing has an elongated-box shape including two relatively smaller ends and four relatively larger sides and a heat-conducting metal sheath on the outside of the housing. The heat conducting sheath covers substantially all of the four relatively larger sides.

Abstract: AC line harmonics are reduced in an AC-powered DC power supply by providing a boost circuit which, during the positive half-cycle of the AC input, adds the charge of a boost capacitor to the AC input voltage so as to initiate current flow through the harmonic suppression inductor before the AC input voltage rises to the level of the bulk capacitance charge. The boost capacitor is charged from a separate voltage source during the negative half-cycle of the AC input, which also provides early current flow from the neutral.

Abstract: A power supply is provided for use in a laser system including a gas ion laser tube which requires a filament voltage provided by an output section of the power supply. The filament voltage provided should not exceed a maximum AC filament voltage specified for the laser tube. The power supply is configured to receive AC utility power using one of at least first and second AC utility power sources having different first and second intended fixed magnitudes and which utility sources vary in amplitude from the intended fixed magnitudes over corresponding first and second source voltage ranges. The power supply is configured to include a power control arrangement which automatically controls the output section to generate an auto-ranging AC filament voltage from either of the first and second utility sources to be supplied as the filament voltage.

Abstract: Automatic voltage conversion module including a rectifier for receiving and rectifying a utility AC power, a smoother for smoothing a voltage rectified at the rectifier, a voltage sensor for sensing the voltage from the smoother to determine an amplitude of a supplied power, and a smoothing operation selector for changing operation paths of the rectifier according to result of the determination at the voltage senor, thereby permitting a system to make a smooth and regular operation.

Abstract: A single-stage input-current-shaping (S.sup.2 ICS) converter of the present invention integrates a voltage-doubler-rectifier front-end with a DC/DC output stage. Two families of voltage-doubler S.sup.2 ICS converters are disclosed. In one family, a 2-terminal dither source is provided between a boost inductor and a common input terminal of a storage capacitor and the DC/DC output stage. The 2-terminal dither source includes two paths connected in parallel: a first path for charging and a second path for discharging the boost inductor at a high frequency (HF). In the other family, a 3-terminal dither source includes a third terminal coupled to a pulsating node of the DC/DC output stage.

Abstract: The present invention relates to a voltage converting circuit adapted to being supplied by at least two rectified A.C. voltages of different levels, including at least two capacitors and a switching circuit to organize a parallel discharge of the capacitors, and to organize a series or parallel charge of the capacitors according to a supply voltage level.

Abstract: Switching control is remarkably simplified and a DC voltage is boosted, and then, an input power factor is sufficiently improved and harmonics are reduced by connecting a full-wave rectifier circuit to an AC power source through a reactor, and connecting a smoothing capacitor and boosting capacitors, which are connected in series with each other, in parallel between the output terminals of the circuit. In addition, a switching device is connected between the input terminal of the circuit and the connecting point between the boosting capacitors, and a control device is provided to control the switching device so that the switching device can be switched at every half cycle of the power source voltage.

Abstract: The present invention is a voltage adapter for a low voltage thermostat which permits the following input voltage ranges:100-132 VAC/50 or 60 Hz,200-264 VAC/50 or 60 Hz, and265-330 VAC/50 or 60 Hzmaintaining an output of at or just effectively about 24 VAC.