Abstract: An adaptive power distribution system is presented for extending the dynamic range of AC/RF rectifiers. The power distribution system distributes the AC/RF input power amongst several different rectifier cells adaptively based on input power level. Consequently, high rectification efficiency can be maintained over a very wide dynamic range.

Abstract: An alternate arm converter includes at least one converter limb that defines first and second limb portions. Each limb portion includes at least one director switch connected in series with a chain-link converter between one of two DC terminals and an AC terminal of the converter. The chain-link converters are operable to generate a voltage waveform at the AC terminal, and the director switches are operable to switch the respective chain-link converters in and out of circuit between the respective DC terminal and the AC terminal. The converter also includes a controller configured to selectively control the switching of each director switch to form a current circulation path including each limb portion and the DC network. The controller, during formation of the current circulation path, forces an alternating current to flow through the current circulation path to transfer energy between the chain-link converters of the limb portions.

Abstract: A control circuit in a power factor correction (PFC) circuit includes: a multiplier, used for multiplying a voltage sampling signal by a feedback signal, and outputting a first signal; and a waveform generating module, used for generating a second signal related to a filter capacitor connected in parallel to an input end and/or an output end of a rectifier bridge. A control signal for controlling a state of a main switch transistor is generated by using the first signal, the second signal, and a current sampling signal of the main switch transistor in the PFC circuit.

Abstract: An apparatus and a method for wireless power reception include converting a received wireless power to a wireless power for charging using a synchronous rectifier and a direct current/direct current (DC/DC) converter having a structure providing a high efficiency and low heat generation even when a high charging current is supplied.

Abstract: A power system for a reactive gas generator can include a direct three phase inverter. A resonant tank can further be included to receive a square wave output of the direct three phase inverter and provide a sine wave output. The power system can include an inverter controller that turns on and off selected switches of the direct three phase inverter based on states of the three phases of a three phase AC power supply, where a switch is turned on with an adaptive ON time and a modulated OFF time depending on a desired output power.

Abstract: A method for changing a capacitance value of an output capacitor of a power factor corrector (PFC) includes applying AC power to a power conversion circuit. It is sensed whether an instantaneous power failure occurs in the AC power. Output capacitors of the PFC of the power conversion circuit are connected in parallel to each other to increase capacitance values of the output capacitors, when it is sensed that the instantaneous power failure does not occur in the AC power.

Abstract: This relates to a rectifier with indicator switch circuit that may be used in a power conversion system. The rectifier with indicator switch circuit may be configured to rectify an ac line voltage and output an indicator signal that is representative of a fault condition in the ac line voltage. The rectifier with indicator switch circuit may include a storage capacitor configured to be charged by the ac line voltage during a first half-cycle of the ac line voltage and a detection capacitor configured to be charged by the storage capacitor during a second half-cycle of the ac line voltage. A switch coupled to the detection capacitor may be configured to generate the indicator signal based on a voltage across the detection capacitor. The indicator signal may be provided to a controller to disable operation of the power conversion system in response to the detection of a fault condition.

Abstract: Power conversion apparatus for controllably converting alternating current (AC) to direct current (DC). An example apparatus includes multiple AC sources, galvanically isolated from one another, and multiple bridge rectifier circuits, including one or more controllable bridge rectifier circuits, where each bridge rectifier circuit has respective AC-side terminals and DC-side terminals and each bridge rectifier circuit is connected to a corresponding one of the AC sources via its AC-side terminals. The DC-side terminals are connected so that the outputs of the bridge rectifier circuits are combined in series.

Abstract: An output voltage error detection unit outputs an auxiliary winding voltage generated across an auxiliary winding having the same number of turns as a secondary winding a certain period after a secondary conduction period starts. A correction amount calculation unit calculates a secondary voltage drop caused by a secondary current flowing in the conduction period based on a primary current flowing when the conduction period starts and outputs a calculation result as a correction amount. A reference voltage generation unit generates a reference voltage by adding the correction amount to the output voltage. A control unit generates a feedback signal to minimize the error between the auxiliary winding voltage obtained after a certain delay period and the reference voltage. A PWM signal generation unit controls a PWM signal based on the feedback signal, adjusts switching of the switching element, and maintains the output voltage at a constant level.

Abstract: A switch mode power supply (SMPS) includes a buck converter circuit that includes a first inductor coupled to an output terminal and a switch device coupled the first inductor. A controller is configured for regulating the output current based at least in part on controlling a peak current in the first inductor according to a ratio between an instantaneous voltage to an average voltage at the negative output terminal. The controller is configured to cause the SMPS to operate in a boundary conduction mode (BCM). The controller is configured to maintain a constant average output current that is substantially independent of the input voltage and the output voltage, and also provide a high power factor.

Abstract: A CR snubber circuit capable of increasing a reduction effect of the effective inductance component and suppressing a ringing component generated at the time of switching the switching element is obtained. A first current path formed on one surface of the substrate and a second current path formed on the other surface, which is the opposite side of the one surface of the substrate, are opposed to each other with the substrate being sandwiched therebetween, and the capacitor 5 and the resistor 6 are arranged such that current flows in opposite directions in the first current path and the second current path, and a band elimination filter is formed by the capacitor 5, the resistor 6, and an effective inductance component obtained by coupling an inductance component included in the first current path and an inductance component included in the second current path.

Abstract: Techniques and mechanisms for a memory device to concurrently receive and process signals each based on a different respective reference voltage level. In an embodiment, an input/output (I/O) interface of a memory device includes receiver circuits each to process a respective signal received via a corresponding signal line of a bus. In response to one or more configuration commands, a first receiver circuit is configured to process a first signal based on a first reference voltage level and a second receiver circuit is configured to process a second signal based on a second reference voltage level. In another embodiment, a memory controller sends the one or more configuration commands to such a memory device based on an evaluation of voltage swing characteristics each corresponding to a different respective signal line of a bus.

Abstract: An activation circuit for activating a power bridge circuit of a resonance converter, including an inductive activation transformer that transfers a pulsed control signal generated via a CMOS driver to the power bridge circuit, wherein a clamping circuit is arranged at the output of each CMOS driver, where the clamping circuit clamps a primary winding of the activation transformer to a ground potential during the dead time between two pulses of the pulsed control signal such that overvoltages, which otherwise arise when switching the activation transformer inductance, are thus clamped during a dead time and a circuit breaker switches off securely.

Abstract: In a control device of a power converter circuit repeating accumulation of energy to an inductor and release of energy from the inductor at each turn on/turn off timing of a switch, a zero cross detecting circuit detects a time when a current flowing through the inductor becomes zero by inputting a voltage between both terminals of the inductor directly without any resistance for detecting the inductor current. There is no electricity loss caused by the resistance for detecting the inductor current and critical mode control of the power converter circuit is precisely carried out.

Abstract: The invention relates to a rotary transmitter (2) for machine tools, having an inductive energy transmission section (31), which is arranged between a stator part (4) fixed to the machine and a rotor part (6) fixed to the tool, and a contactless bidirectional data transmission section (35). A special feature of the invention consists in that, in order to make maximum use of the capacity of the energy transmission section (31), precautions are taken with which the optimal operating frequency (fopt) of the energy transmission operating according to the transformer principle is determined at every system start in a test run with a connected test resister (51) and a variable frequency (fp). Furthermore, for the purpose of interference-free data transmission, buffer storage of the data to be transmitted via the data transmission section (35) is proposed, which data are synchronized in predefined time windows with interference-free periods of the energy transmission.

Abstract: An example power supply controller includes a signal separator circuit that generates a feedback signal. An error signal generator generates an error signal in response to the feedback signal. A control circuit generates a drive signal in response to the error signal. The drive signal controls switching of a switch. A multi-cycle modulation circuit is included in the control circuit and generates a skip signal in response to a start skip signal, a stop skip signal and a skip mask signal. The skip mask signal is generated in response to the skip signal. The start skip and stop skip signals cause the drive signal to start skipping or stop skipping, respectively, on-time intervals of cycles. The skip mask signal disables the start skip signal from causing the drive signal to start skipping the on-time intervals of cycles.

Abstract: A capacitor power supply unit converts a mains voltage (U) into a lower operating voltage (V1) for a controller and a supply voltage (V2) for an electrical small load. A series circuit including a mains capacitor and a zener diode is connected to the mains voltage (U) whereat the supply voltage (V2) for an electrical small load having a permissible operating voltage is tapped off. The capacitor power supply unit provides for the supply voltage (V2) to be greater than the permissible operating voltage of the electrical small load and for the small load to be connected to the supply voltage (V2) via a buck converter. Here, the buck converter is controlled as a current source having a variable operating frequency.

Abstract: A battery charging system includes a PFC converter which converts an alternating current input voltage which is input from a power supply to a direct current output voltage, a DC-DC converter which changes an output voltage of the PFC converter, a battery which is charged by the DC-DC converter, and a controller which calculates power conversion efficiency based on the input current and the input voltage, a charged voltage of the battery, and a charging current for the battery, and updates the output voltage of the PFC converter according to the power conversion efficiency. A battery charging method includes steps of: calculating power conversion efficiency using the input current and the input voltage from the power supply, and the charging current and the charged voltage of the battery; and updating the output voltage of the PFC converter according to the calculated power conversion efficiency.

Abstract: A method, a controller unit for a bridge rectifier, and a bridge rectifier system are disclosed for detecting a shorted diode in a bridge rectifier. The method can include determining a phase-to-phase voltage between two phase inputs of the bridge rectifier, wherein a phase input is provided between the two series connected diodes of the respective phase, and indicating a shorted diode fault by determining whether the phase-to-phase voltage is zero for more than a commutation time of the bridge rectifier.

Abstract: This disclosure relates to a power conversion system to power a variable impedance load with a variable power source, the power conversion system comprising a power converter including input terminals adapted to receive variable power from the variable power source and output terminals providing a converted power to the variable impedance load based on the variable power received at the input terminals. The power converter increases the input voltage to an output voltage. The power converter is configured to reflect a source impedance of the variable power source to the variable impedance load.

Abstract: An electric three-phase power supply system includes a primary stage arranged to receive an input of three-phase alternating current power; a transformer stage arranged to receive power from the primary stage and to reduce the three-phase AC power in voltage level, the transformer stage include an independent secondary winding for each of the phases in the alternating current power; a power factor correction (PFC) stage having a plurality of PFC units that each receive AC power for one of the phases in the alternating current power from the transformer stage; and a pair of output terminals that receive power form the PFC units, wherein output terminals of each of the PFC units are tied to each other, and ground terminals of each of the PFC units are tied to a common ground.

Abstract: In order to detect deterioration of a DC link capacitor between a DC source and an inverter load in an electric propulsion vehicle, capacitance of the link capacitor must be accurately measured during in-service use. A charge is established on the link capacitor. The capacitor is isolated from the source and the inverter load. A constant current circuit is activated to discharge the capacitor. A first voltage is measured across the capacitor at a first time during the discharging. A second voltage is measured across the capacitor at a second time during the discharging. A discharge current flowing from the capacitor is measured during the discharging. The capacitance is calculated in response to the discharge current multiplied by a ratio of a difference between the second and first times to a difference between the first and second voltages. The calculated capacitance is monitored for a decline indicative of a failure.

Abstract: A power transfer system for transferring power from a first circuit to a second circuit by a differential signal generated in the first circuit includes a first isolation element for transmitting a first component of the differential signal between the first and second circuits. The system also includes a second isolation element for transmitting a second component of the differential signal between the first and second circuits. A digital rectifier is coupled to the first and second isolation elements for generating a rectified voltage in response to the first and second components of the differential signal. The system includes circuitry for monitoring the rectified voltage and generating a signal representative of the rectified voltage. The system also includes a controller for changing the rectified voltage in response to the signal representative of the rectified voltage.

Abstract: A protection circuit protects transistors in a DC-DC conversion circuit from over voltages. The transistors in the conversion circuit include first and second transistors. Converted energy is driven across a transformer by an H-bridge circuit. With a first configuration of the H-bridge circuit, a third transistor is turned on to discharge an inductor that was previously charged. The inductor is coupled to the third transistor. The discharging of the inductor boosts an output current of the conversion circuit. A capacitor is charged through a diode. The capacitor and diode are disposed in the protection circuit. The diode is coupled to the first transistor and the charging of the capacitor is effective to limit voltage across the first transistor.

Abstract: The invention relates to a rotary transmitter (2) for machine tools, having an inductive energy transmission section (31), which is arranged between a stator part (4) fixed to the machine and a rotor part (6) fixed to the tool, and a contactless bidirectional data transmission section (35). A special feature of the invention consists in that, in order to make maximum use of the capacity of the energy transmission section (31), precautions are taken with which the optimal operating frequency (fopt) of the energy transmission operating according to the transformer principle is determined at every system start in a test run with a connected test resister (51) and a variable frequency (fp). Furthermore, for the purpose of interference-free data transmission, buffer storage of the data to be transmitted via the data transmission section (35) is proposed, which data are synchronized in predefined time windows with interference-free periods of the energy transmission.

Abstract: An improved power supply unit for a vehicle electrical system of a motor vehicle, which has an a.c. generator, that provides a phase signal, having an excitation coil, a field regulator assigned to the excitation coil and a rectifier having rectifier elements for the rectification of the generator voltage supplied by the a.c. generator. The field regulator has a voltage detection range for the evaluation of the phase signal having a minimum value and a maximum value, the maximum value being adjusted to the nominal voltage of a power supply unit of the motor vehicle.

Abstract: A passive coupled-inductor soft-switching circuit of a power factor corrector is provided. The passive coupled-inductor soft-switching circuit includes a power input terminal, a first inductor, a first diode, a power output terminal, a power switch and a buffer circuit. The first inductor has a first terminal and a second terminal, wherein the first terminal of the first inductor is electrically coupled with the power input terminal. The first diode has a positive terminal and a negative terminal, wherein the positive terminal of the first diode is electrically coupled with the second terminal of the first inductor. The power output terminal is electrically coupled with the negative terminal of the first diode. The buffer circuit is electrically coupled with the power switch. By using the buffer circuit, the voltage and current have phase interlacing shifts and thereby reducing the switching loss.

Abstract: A controller outputs a pulse signal to a first switch and a second switch on the basis of a circuit current flowing through a power conversion circuit and a voltage of an alternating-current power supply. The first switch and the second switch alternately open and close. According to the opening and closing, an electric current in which a high-frequency current is mixed with a low-frequency component of the alternating-current power supply flows to the power conversion circuit.

Abstract: An LED lighting apparatus is provided. The apparatus has an LED luminous unit having multiple plurality LEDs and a switching arrangement. The LED luminous unit has different forward voltages in different switching states. The apparatus also has a control device for driving the LED luminous unit and a current sink device in a normal operating mode, in which the forward voltage and the LED current of the LED luminous unit are adapted to an instantaneous value of a supply voltage. An energy storage module of the apparatus provides a storage voltage and supplies the storage voltage to the LED luminous unit. The control device drives the LED luminous unit and the current sink device in a storage operating mode, such that the forward voltage and the LED current of the LED luminous unit are adapted to an instantaneous value of the storage voltage.

Abstract: A passive power factor correction circuit includes: a DC capacitor and an input capacitor, coupled to a rectifying circuit and charged by a DC voltage from the rectifying circuit; an output capacitor, coupled to a load; first diode and a second diode, coupled to the input capacitor and the output capacitor; and an inductor, coupled to the load, the input capacitor and the output capacitor. Charging into and discharging from the DC capacitor are completed within a half cycle of an input AC voltage.

Abstract: According to one embodiment, a semiconductor device includes a first semiconductor layer, a second semiconductor layer provided in a portion on the first semiconductor layer, a first insulating layer provided on the first semiconductor layer on a terminal region side of the second semiconductor layer, a third semiconductor layer provided on the first semiconductor layer on the terminal region side of the first insulating layer, a second insulating layer provided on the first semiconductor layer on the terminal region side of the third semiconductor layer, a fourth semiconductor layer provided between the first semiconductor layer and the second insulating layer, and a plurality of field plate electrodes provided inside an inter-layer insulating film, the plurality of field plate electrodes having mutually-different distances from the first semiconductor layer.

Abstract: A control circuit for reducing touch current of a power converter includes an auxiliary pin, a zero-crossing signal generator, a frequency limiting signal generator, and a gate signal generator. The auxiliary pin is used for receiving a voltage generated by an auxiliary winding of the power converter. The zero-crossing signal generator is used for generating a zero-crossing signal according to the voltage generated by the auxiliary winding and a first reference voltage. The frequency limiting signal generator is used for generating a frequency limiting signal according to a gate control signal, a burst mode signal, and the voltage generated by the auxiliary winding. The frequency limiting signal is used for limiting the gate control signal to a predetermined frequency. The gate signal generator is used for generating the gate control signal to a power switch of the power converter according to the frequency limiting signal and the zero-crossing signal.

Abstract: A power control device includes a first terminal, a second terminal connected to a transmission line, a first cascade multilevel inverter (CMI) and a second CMI. The first CMI is connected to the second terminal. The second CMI connected in series between the first terminal and the second terminal.

Abstract: A circuit for converting an A.C. power supply voltage into a D.C. voltage, including: a first branch capable of providing a first power level; and a second parallel branch capable of providing a second power level greater than the first one, the second branch including a bidirectional activation switch.

Abstract: A structure is disclosed, comprising: a first magnetic core portion comprising: a first plurality of leg posts that are to be surrounded by a first set of windings; and a first plurality of center portions that are not to be surrounded by windings; and a second magnetic core portion comprising: a second plurality of leg posts that are to be surrounded by a second set of windings; and a second plurality of center portions that are not to be surrounded by the second set of windings, wherein the first set of center portions and the second set of center portions are configured to provide a plurality of physically separate magnetic flux paths.

Abstract: A power supply system includes a first power module for outputting a first voltage and a second power module for outputting a second voltage. The first power module includes a first switch element, and a second switch element. The second power module includes a third switch element, and a fourth switch element. When the first power module is in a working state and the second power module is then plugged into the power supply system in a hot-swappable manner, only if a phase difference or a voltage difference between the first power source and the second power source is lower than a threshold value, the second switch element and the fourth switch element are controlled to be turned on. Subsequently, if the second voltage is higher than the first voltage, the third switch element is controlled to be turned on.

Abstract: A system includes a current source rectifier which has a plurality of switches configured to receive an input current from an AC voltage source and to receive a plurality of control signals. The switches are configured to produce a rectified output current based on the input current and the control signals. The system also includes a rectifier controller configured to receive a current sense signal indicative of the rectified output current and to generate the control signals based at least in part on the current sense signal, where the control signals cause the current source rectifier to attenuate at least one of a plurality of harmonic frequencies in the rectified output current.

Abstract: A battery discharge device according to an exemplary aspect of the present disclosure includes, among other things, a sensor configured to sense a parameter of a high voltage source, a controller in communication with the sensor and a discharge circuit that discharges energy stored on the high voltage source in response to a command signal from the controller. The discharge circuit includes a plurality of resistors connected in parallel to one another.

Abstract: A switch-mode power supply and associated control circuit for a light-emitting device are disclosed. The switch-mode power supply having a first switch which is turned ON or OFF by a control signal. The control circuit having an error amplifier, a minimum-off time control circuit and a logic circuit, wherein the error amplifier is configured to provide a compensation signal based on a dimming signal and a feedback signal. The minimum-off time control circuit is configured to provide a minimum-off time control signal to adjust a minimum-off time period of the first switch based on the compensation signal. The logic circuit is configured to provide the control signal based on the minimum-off time control signal.

Abstract: A first conversion section converts, into a first direct-current voltage, an alternating-current voltage input from input lines, and applies the same between power supply lines. A diode is arranged between the power supply lines such that an anode thereof faces toward the power supply line side. A capacitor has both ends connected to a direct-current load, and is connected in series with the diode. A switch section selects conduction/non-conduction between an alternating-current power supply and the first conversion section. A second conversion section converts, into a second direct-current voltage, the alternating-current voltage input without passing through the switch section, and is connected to a connection point located between the capacitor and the diode to apply the second direct-current voltage to the capacitor.

Abstract: The invention relates to a rotary transmitter (2) for machine tools, having an inductive energy transmission section (31), which is arranged between a stator part (4) fixed to the machine and a rotor part (6) fixed to the tool, and a contactless bidirectional data transmission section (35). A special feature of the invention consists in that, in order to make maximum use of the capacity of the energy transmission section (31), precautions are taken with which the optimal operating frequency (fopt) of the energy transmission operating according to the transformer principle is determined at every system start in a test run with a connected test resister (51) and a variable frequency (fp). Furthermore, for the purpose of interference-free data transmission, buffer storage of the data to be transmitted via the data transmission section (35) is proposed, which data are synchronized in predefined time windows with interference-free periods of the energy transmission.

Abstract: A multiphase power converter includes a plurality of subconverters and a control circuit. Each subconverter has an input circuit, an output circuit, and a magnetic core coupling the input circuit to the output circuit. The magnetic core of at least one of the plurality of subconverters has a core section that is shared by the magnetic core of another one of the plurality of subconverters. The control circuit is configured to operate the input circuits of the plurality of subconverters with different phases. The magnetic cores may be cores of a transformer, a coupled inductor, etc.

Abstract: A rectifier assembly and method are provided. The rectifier assembly includes an annular bus bar including an electrically conductive material, and an insulator ring receiving the annular bus bar. The insulator ring defines radially-extending resistor pockets and diode pockets therein. The rectifier assembly also includes resistors disposed in the resistor pockets and electrically connected with the annular bus bar, and diodes disposed in the diode pockets and electrically connected with the annular bus bar. The rectifier assembly also includes an outer housing receiving the annular bus bar and the insulator ring, such that the insulator ring is positioned radially between the annular bus bar and the outer housing.

Abstract: The accuracy and flexibility of a branch circuit monitor is improved by storing specifications, including error correction factors, for a plurality of current transformers in the monitor's memory and enabling current transformers with stored specifications to be selected for use with the monitor.

Abstract: A light fixture includes a converter operable to drive a light source of the light fixture. The buck converter is operable to provide a predetermined average current to the light source or load. A switch of the buck converter is located in the low side of the buck converter such that a controller of the buck converter may drive the switch directly without the use of an isolation transformer. The buck converter controls operation of the switch based on current through the switch and current through the primary inductor of the buck converter.

Abstract: The invention relates to a method of opening a shunt switch carrying a current, the switch being connected in parallel with at least one thyristor of a high voltage DC network, interruption of the current flowing through the switch being initiated at the time of a current zero of the current flowing through the switch, the method being characterized in that it includes, based on a measurement effected by means for measuring the current flowing through the switch, a step of adjusting a control angle of the thyristor to position the current zero in a zone in which the time derivative of the measured current is a continuous function and the absolute value of a peak value of the measured current is substantially equal to the absolute value of the inaccuracy of the measurement of the current zero.

Abstract: The present invention implements an equivalent circuit to a semiconductor device for an upper arm by electrically connecting a terminal for E1C2 and a terminal for K with the use of an external wiring in a semiconductor device. On the other hand, in a semiconductor device including a circuit having the same structure as the semiconductor device, an external wiring is used to electrically connect a terminal for A and a terminal for E1C2. Consequently, there is implemented an equivalent circuit to a semiconductor device for a lower arm which is of a different type from the semiconductor device for the upper arm.

Abstract: A method for actuating an AC/DC voltage transformer is specified, which has a DC voltage output between which at least one series circuit of at least two capacitors and at least one series circuit of n switching elements is arranged, where n?4. A connecting point of the switching elements is connected to a connection of an AC voltage input between n/2 switching elements. Two diodes are connected in an antiparallel arrangement to the two switching elements lying closest to the connecting point. In addition, a connecting point of the capacitors is connected to a connecting point of the diodes. An output voltage at the DC voltage output and a potential of the connecting point of the capacitors or diodes are provided as controlled variables, an input current at the AC voltage input is provided as a manipulated variable and the switching elements are provided as an actuating element of a control loop.

Abstract: A two-wire load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

Abstract: An alternating-current/direct-current converter includes a rectifier, a reactor, a capacitor, and a switching rectifier. The rectifier is configured to rectify alternating-current voltage output from an alternating-current power source, thereby converting the alternating-current voltage into direct-current voltage, and to output the direct-current voltage. The capacitor includes terminals. The switching rectifier is coupled to the AC power source and switchable to output the direct-current voltage to the capacitor.