Abstract: A semiconductor device includes: a pad; a control circuit; a plurality of high-potential-side circuit regions having distances to the pad different from each other, each including a gate drive circuit, a SET-side level shifter, a RESET-side level shifter, and a circular wire; a SET-side wire electrically connects the pad with the SET-side level shifters; and a RESET-side wire electrically connects the pad with the RESET-side level shifters, wherein the circular wire located closer to the pad is electrically connected to the SET-side wire and the RESET-side wire via the circular wire 8u located further from the pad.

Abstract: An integrated circuit (IC) includes: an input terminal; an output terminal; a first reference voltage terminal and a second reference voltage terminal; a high-side power switch coupled between the first reference voltage terminal and the output terminal; a low-side power switch coupled between the output terminal and the second reference voltage terminal; a first combinational logic and a second combination logic that are coupled to the input terminal; a first driver coupled between the first combinational logic and the high-side power switch; a second driver coupled between the second combinational logic and the low-side power switch; and first comparators coupled to the second combinational logic, where the first comparators are configured to compare a voltage difference between load path terminals of the high-side power switch with a first threshold and a second threshold.

Abstract: Provided is a motor driving apparatus including: an upper-arm gate driving circuit; a lower-arm gate driving circuit; a first rotation detection unit powered by a first power source; a second rotation detection unit powered by a second power source; a first fail safe circuit that performs, by use of a detection signal from the first rotation detection unit, a fail safe control on a gate driving circuit powered at least by the first power source, from among the upper-arm gate driving circuit and the lower-arm gate driving circuit; and a second fail safe circuit that performs, by use of a detection signal from the second rotation detection unit, a fail safe control on a gate driving circuit powered at least by the second power source, from among the upper-arm gate driving circuit and the lower-arm gate driving circuit.

Abstract: A method of controlling an electric motor includes determining a PWM control signal, analyzing the PWM control signal to determine if components of the PWM signal are within a threshold amount of each other, applying duty-cycle blanking to the PWM control signal, if the components of the PWM control signal are within the threshold amount of each other, to generate an adjusted PWM control signal, and controlling the electric motor with the adjusted the PWM signal to limit parasitic effects.

Abstract: Aspects of the present disclosure are directed toward designs and methods of improving driving of switching devices. One proposed solution to improving driving of switching devices is an auxiliary control circuit that selectively guides the switching device through at least one switching region, permitting an improved operation of the switching device.

Abstract: A circuit comprises a multiphase gate driver to be coupled to a multiphase inverter for driving a multiphase motor. For each phase, the multi-phase gate driver is to, in accordance with a pulse width modulation (PWM) control signal, turn on and off a high side transistor of a given pair of high and low side transistors of the multiphase inverter, discontinue the PWM control signal turn to the high side transistor of the given pair and turn off the high side transistor of the given pair, and turn on the low side transistor of the given pair until a current level through the low side transistor falls below a threshold, at which time, turn off the low side transistor.

Abstract: In one embodiment, a first electrical network includes one or more first electricity producing elements, and a first conductive path electrically couples at least some of those elements to an end user's electrical wiring, which is coupled by a second conductive path to one or more second electricity producing elements of a public utility electrical network. A switch coupled between the first conductive path and the end user's electrical wiring and between the second conductive path and the end user's electrical wiring electrically isolates the first electrical network from the public utility electrical network. Based on a determination of whether an amount of electricity used by the end user exceeds an amount of electricity the first electrical network is capable of providing to the end user, the switch either draws electricity only from the first electrical network or from both the first electrical network and the public utility electrical network.

Abstract: A current detection device is configured by a current path through which a first current flows, a current path through which a second current flows, a switching element that switches the current paths and allows the first current and the second current to flow alternately, a common coil section through which an induction current flows by the first current and the second current, and a turn current path that alternates a first induction current flowing through the coil section by the first current and a second induction current flowing through the coil section by the second current.

Abstract: A short-circuit determination device is provided in a switching power supply device. The switching power supply device converts a power supply voltage applied between an upper power supply line and a lower power supply line and outputs the power supply voltage to a load through an intermediate node. The switching power supply device includes a plurality of upper switching elements and a lower switching element. Each of the plurality of upper switching elements has an electrical conduction terminal and a control terminal. The electrical conduction terminals are connected in series between the upper power supply line and the intermediate node. The control terminals are driven at a same level as each other. The lower switching element has an electrical conduction terminal connected between the lower power supply line and the intermediate node. The lower switching element and the plurality of upper switching elements are connected in series.

Abstract: A power module includes: a first switching device; a current-voltage conversion circuit into which current output from the first switching device flows; a measurement circuit that measures magnitude of the current; and an output terminal that outputs an output signal indicating the magnitude of the current measured by the measurement circuit. The measurement circuit measures the magnitude of the current output from the first switching device based on a resistance value of the current-voltage conversion circuit, and the first switching device and the measurement circuit are implemented in one semiconductor package.

Abstract: This application relates to methods and apparatus for powering microcontrollers (104), in particular for powering microcontrollers of a personal care product, such as a shaver product (107). The microcontroller is arranged such that a first output port (206-1) of a plurality of output ports of the microcontroller receives, in use, an AC waveform. Each output port has an associated high-side switch (207) electrically connected between the output port and a high-side DC voltage rail and an associated low-side switch (208) electrically connected between the output port and a low-side DC voltage rail. A processing module (202) of the microcontroller is configured to monitor a phase of the AC waveform and to control switching of the associated high-side and low-side switches of the first output port based on the phase of the AC waveform so as to provide a rectified voltage between the high-side DC voltage rail and the low-side voltage rail for powering the processing module.

Abstract: A motor controller for controlling the operation of a three-phase permanent magnet synchronous electric motor, wherein the three-phase permanent magnet synchronous electric motor is characterized by three phases A, B, C, and further wherein the three-phase permanent magnet synchronous electric motor is driven by regulating three phase currents iA, iB and iC for the three phases A, B, C, respectively, the motor controller comprising: a three-phase power supply for supplying the three phase currents iA, iB and iC a first sensor for sensing the phase current iA; a second sensor for sensing across the phase currents iB and iC; and a microcontroller for controlling the operation of the three-phase power supply so as to produce the three phase currents iA, iB and iC needed to operate the three-phase permanent magnet synchronous electric motor, wherein the microcontroller reads the outputs of the first sensor and the second sensor and adjusts operation of the three-phase power supply so as to produce phase currents

Abstract: A frequency tuning impedance matching method includes analyzing a start driving frequency, set by a user, and an RF output signal to vary a driving frequency. Specifically, a next frequency may be predicted using susceptance which is an imaginary part of measured admittance in an n-th pulse. Accordingly, impedance matching may be completed at high speed or an optimal frequency may be reached at high speed.

Abstract: There is provided a power conversion apparatus including: a first power supply terminal and a second power supply terminal which are paired with each other; a third power supply terminal and a fourth power supply terminal which are paired with each other; 1st to nth switches sequentially connected between the first power supply terminal and the fourth power supply terminal; 1st to nth rectifier devices sequentially connected between the first power supply terminal and the third power supply terminal; and each of 1st to (n?1)th capacitors which is physically disposed and electrically connected between an Nth terminal between an Nth switch and a (N+1)th switch, and an Nth terminal between an Nth rectifier device and a (N+1)th rectifier device, in which the 1st to nth switches are disposed to be physically aligned with the 1st to nth rectifier devices, respectively.

Abstract: The invention provides an inverter system and a method of using said inverter system. A rectifier stage of the inverter system is used to charge a DC link stage to a first voltage level and a control module determines whether voltages over series connected capacitors of the DC link stage are balanced. If those voltages are balanced, the rectifier stage charges the DC link stage to a second voltage level higher than the first voltage level.

Abstract: A switch-mode power supply includes a pair of input terminals, a pair of output terminals, and at least four switches coupled in a three-level LLC circuit arrangement between the pair of input terminals and the pair of output terminals. First and second ones of the at least four switches define a first half-bridge and third and fourth ones of the at least four switches define a second half-bridge. The power supply also includes a fifth switch coupled across the second switch and the third switch to short circuit the second switch and the third switch when the fifth switch is closed, and a control circuit. The control circuit includes a voltage-controlled oscillator (VCO) and multiple logic gates and flip-flops coupled to operate the at least four switches with zero-voltage switching (ZVS).

Abstract: A power conversion device includes six semiconductor modules. Each of the six semiconductor modules includes a first terminal (P), a second terminal (N), and a third terminal (AC) on its surface. The first terminals of two semiconductor modules configuring a semiconductor module group of the same phase are arranged to be opposed to each other. A plurality of semiconductor module groups are arranged in a direction perpendicular to an arrangement direction of two semiconductor modules in the semiconductor module group.

Abstract: A power conversion device includes first and second power semiconductor elements, and a circuit for transferring a drive signal of the first and second power semiconductor elements. The circuit board includes a first emitter wire which is formed along an arranging direction of the first power semiconductor element and the second power semiconductor element, a first gate wire which is disposed between the first power semiconductor element and the first emitter wire, a second gate wire which is disposed between the second power semiconductor element and the emitter wire, a third gate wire which is disposed to face the first gate wire and the second gate wire with the emitter wire interposed between the third gate wire and the first gate wire and the second gate wire, and a first gate resistor which connects the first gate wire and the third gate wire over the first emitter wire.

Abstract: An apparatus for controlling an inverter to drive a motor includes: a current control processor generating a voltage command for generating d/q axis current detection values, which are obtained by measuring current supplied to the motor, to follow a d/q axis current command for driving the motor, the current control processor converting the voltage command, which is sampled according to a sampling frequency generated based on a voltage vector phase of the voltage command, into a voltage vector corresponding to a point on each vertex and each side of a hexagon in a voltage vector diagram to apply a resulting value to the inverter driving the motor; and a sample frequency computing processor computing the sampling frequency based on the voltage vector phase of the voltage command and a reference number of sampling times during one rotation period of the motor.

Abstract: A method for controlling multiple switching devices (15a-d, 75a-b) of a multilevel converter (1, 70) includes providing a plurality of carrier signals (C1-C6) and a reference signal (34, 80), the reference signal (34, 80) having a waveform range divided in a plurality of contiguous bands (B1-B6), dynamically allocating the plurality of carrier signals (C1-C6) to the multiple switching devices (15a-d, 75a-b), and generating pulse width modulation signals (18, 77) to generate switching events of the multiple switching devices (15a-d, 75a-b) based on a comparison of dynamically allocated carrier signals (C1-C6) with the reference signal (34, 80), wherein the plurality of carrier signals (C1-C6) have a phase shift between the carrier signals (C1-C6), and wherein the plurality of carrier signals (C1-C6) are dynamically allocated to the multiple switching devices (15a-d, 75a-b) such that for each switching device (15a-d, 75a-b) the plurality of carrier signals (C1-C6) are rotated and selected based on a position of

Abstract: To carry out diagnosis of a current sensor while maintaining high reliability. An inverter control device according to the present invention controls an inverter circuit, calculates an estimated direct current value on the basis of a duty value and an alternating current sensor value output by an alternating current sensor, and performs diagnosis of a direct current sensor on the basis of the estimated direct current value and a direct current sensor value output by the direct current sensor.

Abstract: A charging system includes an inverter configured to receive rectified mains line voltage and current to power a primary coil to induce charge current in a secondary coil of a vehicle. The charging system also includes a controller configured to alter a switching frequency of the inverter based on charge voltage data from the vehicle to cause the inverter to operate to drive a voltage of an energy storage capacitor of a battery charger of the vehicle toward a constant value.

Abstract: Aspects of the present disclosure are directed toward designs and methods of improving driving of switching devices. One proposed solution to improving driving of switching devices is an auxiliary control circuit that selectively guides the switching device through at least one switching region, permitting an improved operation of the switching device.

Abstract: A resonant power converter includes a full bridge configuration of switching devices and a resonant tank circuit coupled between the full bridge and an isolation transformer having a primary winding and a secondary winding. A full bridge rectifier is coupled between the isolation transformer and a load. A converter controller for generating switching signals for the switching devices includes an outer controller to generate a tank command signal based on a voltage error signal between an output voltage command signal and an actual output voltage signal and an inner controller to generate an actual tank signal based on a secondary winding current and the output voltage command signal. The converter controller also includes a signal generator for generating the switching signals for the switching devices based on a tank error signal between the tank command signal and the actual tank signal.

Abstract: A method is provided for operating a frequency converter, which is designed to drive a three-phase motor, wherein the frequency converter has three half-bridges each having at least two switches. The method includes the following steps: generating three phase voltages for the three-phase motor by a pulse width modulation, wherein, for the pulse width modulation, various switching patterns of the switches are activated, wherein specific star point voltages ensue for various groups of switching patterns; and in at least one operating state of the frequency converter, within a respective period of the pulse width modulation, activating only those switching patterns in which an identical star point voltage ensues.

Abstract: A compact and thermally efficient traction drive motor inverter featuring an integrated printed circuit board carrying both power circuitry and signal circuitry on separate electrically isolated layers without significant electromagnetic interference. Electrical communication with subsequent electrically isolated layers is maintained through the use of plated blind vias. Thermal efficiency is improved by utilizing a liquid cooled insulated gate bipolar transistor module with featuring internal flow balancers to optimize coolant flow.

Abstract: When reduction of insulation resistance is detected, an FC positive side relay is opened, and a switching element is turned OFF. When the insulation resistance has returned to a normal value as a result of the relay opening and the switching element turning OFF, it is identified that the power leakage is occurring in the area between the positive side relay and the diode.

Abstract: A fiber optic-based communications network includes: a power insertion device, connected to multiple fiber links from a data source, configured to provide power insertion to a hybrid fiber/power cable connected to at least one fiber link of the multiple fiber links; the hybrid fiber/power cable, connecting the power insertion device to a connection interface device, configured to transmit data and power from the power insertion device to the connection interface device; and the connection interface device, configured to provide an interface for connection to an end device via a power over Ethernet (PoE)-compatible connection and to provide optical to electrical media conversion for data transmitted from the power insertion device to an end device via the hybrid fiber/power cable and the PoE-compatible connection.

Abstract: A system that may include, plural inverters connected to a common bus and at least one capacitor, the inverters configured to convert a direct current (DC) through the common bus to an alternating current (AC) by alternating different switches of the inverters between open and closed states in a respective switching cycle for each of the inverters, and a controller circuit configured to reduce a ripple current conducted onto the common bus to the inverters, by controlling the inverters to apply a frequency shift to the respective switching cycle of one or more of the inverters to spread a harmonic current spectrum along the common bus. The controller circuit is configured to apply the frequency shift to at least a first inverter and a second inverter of the plural inverters.

Abstract: A semiconductor device includes a first drive circuit and a bootstrap control circuit. When a voltage VB is equal to or smaller than a power supply voltage VCC, the boost control circuit turns on a MOSFET by controlling a gate signal input to a gate terminal, and a back gate control circuit makes a voltage applied to a back gate terminal smaller than the voltage VB.

Abstract: The present application relates to an abnormality determination device for a variable geometry turbocharger having a nozzle mechanism capable of changing a flow path area of exhaust gas with an actuator. The abnormality determination device includes: a first detection part configured to be capable of detecting at least one of a load of the actuator or supply energy to the actuator; and a determination part configured to determine that an abnormality is present, if a detection result by the first detection part is out of an allowable range corresponding to an operational state of the variable geometry turbocharger.

Abstract: A device includes a driver circuit, a first semiconductor chip monolithically integrated with the driver circuit in a first semiconductor material, and a second semiconductor chip integrated in a second semiconductor material. The second semiconductor material is a compound semiconductor.

Abstract: A multi-level switching power converter includes a string of N upper transistors and a string of N lower transistors, where N is an integer greater than one. The N upper transistors are electrically coupled in series between a first power node and a switching node, and the N lower transistors are electrically coupled in series between the switching node and a reference node. The multi-level switching power converter further includes N?1 flying capacitors, an inductor, a bypass transistor, and a controller. The bypass transistor is electrically coupled between the switching node and the reference node. The controller is configured to (a) control switching of the N upper transistors and the N lower transistors and (b) cause the bypass transistor to operate in its on state in response to all of the N lower transistors operating in their respective on states.

Abstract: A comparison device includes; a comparison block suitable for comparing a pixel signal with a reference voltage including a ramp-up signal and a ramp-down signal; a correlated double sampling (CDS) block suitable for performing a correlated double sampling operation on the pixel signal; a first switch suitable for selectively inputting the ramp-up signal as the reference voltage based on a first switch control signal; a second switch suitable for selectively inputting the ramp-down signal as the reference voltage based on a second switch control signal; and a feedback control unit suitable for generating the first and second switch control signals based on a result of the comparison during an initialization operation.

Abstract: Multi-level DC-to-DC converter circuits and methods that permit a full range of output voltages, including near and at zone boundaries. Embodiments alternate among adjacent or near-by zones, operating in a first zone for a selected time and then in a second zone for a selected time. Embodiments may include a parallel capacitor voltage balancing circuit that connects a capacitor to a source voltage to charge that capacitor, or couples two or more capacitors together to transfer charge, all under the control of real-time capacitor voltage measurements. Embodiments may include a lossless voltage balancing solution where out-of-order state transitions are allowed, thus increasing or decreasing the voltage across specific capacitors to prevent voltage overstress on the converter main switches. Restrictions may be placed on the overall sequence of state transitions to reduce or avoid transition state toggling, allowing each capacitor an opportunity to have its voltage steered as necessary for balancing.

Abstract: A longitudinal voltage source interconnects into a first line and a second line and feeds a longitudinal voltage into each of the two lines. The voltage source has first and second H-bridge circuits, each with four switches, and with outer terminals and center terminals. The center terminals are connectable to disconnected locations of the first and second lines. A capacitor has a first capacitor terminal connected to the two first output terminals of the two H-bridge circuits and a second capacitor terminal connected to the two second output terminals of the two H-bridge circuits. One or more switching modules are connected between the first capacitor terminal and the first output terminals of the first and second H-bridge circuits, and one or more switching modules are connected between the second capacitor terminal and the second output terminals of the first and second H-bridge circuits.

Abstract: An electric vehicle drive system includes a power battery, a drive, a motor, a detection module, a torque reference module, and a controller, and the drive includes a filtering module, a first conversion module, a first capacitor, and a second conversion module. A positive electrode of the power battery is connected to an input end of the filtering module, and a first output end of the filtering module is connected to an alternating current end of the first conversion module. One end of the first capacitor is separately connected to direct current input ends of the first conversion module and the second conversion module, and the other end of the first capacitor is separately connected to direct current output ends of the first conversion module and the second conversion module and a negative electrode of the power battery.

Abstract: A motor assembly configured to receive an external alternating voltage. The motor assembly includes a motor and a circuit assembly. The motor includes a stator and a rotor rotatable about a longitudinal axis. The circuit assembly includes a state detector and a control unit. The state detector is operable to detect whether an external device is receiving the external alternating voltage The control unit is operable to control the motor based on whether the external device is receiving the external alternating voltage.

Abstract: An electric vehicle includes: a motor that is arranged on a first side of front and rear sides of a vehicle; a rechargeable electric source that is arranged closer to a vehicle room than the motor; an inverter unit that includes an inverter which is fixed to the motor and which is configured to control and drive the motor by electric power that is supplied from the electric source; a charge circuit for charging the electric source; and a first unit that is fixed to a vehicle body at the first side of the vehicle, wherein the inverter unit is connected to the electric source by a cable, and the first unit is connected to the electric source by a cable that is independent of the cable which connects together the inverter unit and the electric source.

Abstract: A transmitting device of the present disclosure includes: a voltage generator that generates a predetermined voltage; a first driver including a first sub-driver and a second sub-driver, the first dub-driver that includes a first switch provided on a path from a first power source to a first output terminal, a second switch provided on a path from a second power source to the first output terminal, and a third switch provided on a path from the voltage generator to the first output terminal, and is allowed to set a voltage state of the first output terminal to any of a predetermined number of voltage states which are three or more voltage states, and the second sub-driver that is allowed to adjust a voltage in each of the voltage states of the first output terminal; and a controller that controls an operation of the first driver to perform emphasis.

Abstract: Disclosed is a device for detecting an instantaneous maximum output current of an inverting module as a peak-current thereof. The inverting module converts a direct current (DC) link voltage to an alternate current (AC) voltage, and includes three-phases legs. Each leg has lower and upper switching elements connected in series. The device includes a shunt resistor serially connected to a lower switching element of each leg of the inverting module; a current detection module configured for detecting an output current from a signal output from each shunt resistor; and a summer configured for receiving and summing the detected output currents from the current detection module and outputting the instantaneous maximum output current of the inverting module as the peak-current thereof.

Abstract: A switching power supply device generates a DC output voltage, which is to be outputted to a load and is based on a DC input voltage. The switching power supply device includes n converter units and a control unit. The DC output voltage is compared with a voltage range selected out of a first voltage range and a second voltage range set in advance and the control unit executes one of first driving control to fourth driving control depending on the present driving control and the comparison result for the DC output voltage. By switching between the first to fourth driving control, the control unit changes the number of converter units to be driven.

Abstract: A switching circuit includes: a DC electric power supply; a first switching element; a second switching element; a resistor that is connected to the DC electric power supply in series with the second switching element; a voltage sensor that detects a voltage applied to the resistor; and a control device, wherein: a current flowing through the first switching element is larger than a current flowing through the second switching element; and the control device is configured to: turn off the second switching element and then turn off the first switching element; and compute a voltage applied between the first collector and the first emitter by integrating a value proportional to a voltage that is detected by the voltage sensor after turning off the first switching element.

Abstract: A communication apparatus includes first communication means having a first communication function for wirelessly communicating with a partner apparatus, and second communication means having an electric power supply function for wirelessly supplying electric power to the partner apparatus and a second communication function for wirelessly communicating with the partner apparatus. The second communication function is for transmitting specific data sequence to the partner apparatus in response to reception of specific data from the partner apparatus, and the electric power supply function is for supplying electric power to the partner apparatus in a case of receiving from the partner apparatus, with the first communication means, a signal indicating that the partner apparatus has received the data sequence.

Abstract: An AC-DC converter that converts an AC power supply voltage to a DC output voltage of a prescribed magnitude with power factor regulation includes a voltage regulation unit; an instantaneous value command calculator; a current regulation unit; an output voltage command calculator; a drive signal generator that generates a drive signal for a semiconductor switching device from the output voltage command and a carrier signal, the driving signal being provided to the semiconductor switching device so as to switch the semiconductor switching device ON and OFF; and a rectified voltage estimation unit that that derives an estimated value of a rectified voltage obtained by rectifying the AC power supply voltage from the output voltage command without actually detecting a rectified voltage, for providing to the instantaneous value command calculator and the output voltage command calculator.

Abstract: Mitigation of noise in vector space representations of item collections for applications such as facial recognition and spam detection. After receiving a collection of items, each item characterized by a plurality of features, a first vector space representative of the collection is prepared. Each item in the first vector space is represented by a vector that is a function of the features characterizing the item. Based on information characteristic of the first vector space, at least one of items contributing to first vector space noise, and features contributing to first vector space noise are identified. The first identified items and features are weighted to decrease the influence of the first identified items and features on vector spaces representative of the collection. A second vector space representative of the collection is prepared based on the first weighted items and features.

Abstract: An uninterruptible power system includes a power conversion apparatus, a switch unit and a control apparatus. The switch unit outputs a mains voltage in a line mode, and output an alternating conversion voltage in a battery mode. The control apparatus is configured to generate a base triangular wave signal according to the mains voltage. When the uninterruptible power system is in a battery mode and the control apparatus detects the regeneration of the mains voltage, the control apparatus is configured to determine whether a cross-over value of the base triangular wave signal is within a predetermined range when the mains voltage is at a zero-cross point. The control apparatus is configured to control the switch unit to output the mains voltage instead of the alternating conversion voltage when the cross-over value of the base triangular wave signal is within the predetermined range.

Abstract: A power semiconductor package includes a first group of semiconductor dies attached to a first side of a substrate and evenly distributed over a width of the substrate and a second group of semiconductor dies attached to the first side of the substrate and evenly distributed over the substrate width. Each die in the first and second groups has all terminals at one side which is attached to the first side of the substrate and an insulated or isolated face at a side opposite the side with the terminals. A first intermediary metal layer of the substrate forms a first DC terminal. A second intermediary metal layer of the substrate forms a second DC terminal. These intermediary metal layers are insulated from one another and form a parallel plate waveguide. Additional power semiconductor package embodiments are described.

Abstract: An inverter has a plurality of switching elements, the states of which are each switched by a pulse signal supplied in accordance with a power grid voltage. The inverter is provided with: a switching circuit that converts an input DC voltage to an AC voltage and outputs the AC voltage to a pair of output lines; a filter circuit having output coils inserted in the output lines; a current detection sensor that detects the current flowing through the output coils; and a high-speed pulse control circuit that, when an absolute value of the detected current is a threshold value or more, stops the supply of the pulse signal to the switching circuit.

Abstract: The present invention discloses a modulation method for inverter AC waveform. The detailed steps of the modulation method comprise: generating an AC waveform which includes at least three time periods, wherein a middle time period corresponds to a peak segment of the AC waveform, and the remaining time periods are averaged corresponding to the rise and decline segments of the AC waveform; and during the at least three time periods, a duty ratio modulated driving signal is generated according to different duty ratios, so as to modulate the AC waveform and generate a stepping AC waveform converted from the AC waveform. The stepping AC waveform generated by the modulation method of the present invention will have a longer dwell time at zero potential, so as to turn on the AC electric tool more efficiently.