Abstract: An electric tool includes an AC motor (an electric motor) and a control unit. The AC motor includes a permanent magnet and a coil. The control unit is configured to perform control on operation of the AC motor. The control performed by the control unit includes field weakening control. In the field weakening control, the control unit causes a flux-weakening current to flow through the coil. The flux-weakening current is a current that generates, in the coil, a magnetic flux that weakens a magnetic flux of the permanent magnet.

Abstract: An electric tool includes a motor and a motor control device. The motor control device is configured to update a command value of a speed of the motor based on a parameter relating to at least one of a voltage of a direct-current power supply for the motor or a magnitude of a load applied to the motor during rotation of the motor.

Abstract: An electric tool includes an electric motor (AC motor), an impact mechanism, and a control unit. The control unit includes an impact detecting unit. The control unit performs feedback control on an operation of the electric motor. In a following period after the impact detecting unit has detected that the impact mechanism has started an impact operation, the control unit changes target parameters in a preceding period before the impact detecting unit detects that the impact mechanism has started the impact operation into different target parameters. The target parameters include a control gain of the feedback control.

Abstract: An electric power tool is provided with a permanent magnet synchronous motor, and a controller. The controller is configured to control an operation of the permanent magnet synchronous motor. The controller includes a limiter that limits a current contributing to torque generation by the permanent magnet synchronous motor to a predetermined maximum set value based on a predetermined tightening torque. The controller calculates the maximum set value of the current that contributes to the torque generation by changing one of a rotation speed and an angular speed of the permanent magnet synchronous motor.

Abstract: An electric tool includes an AC motor (an electric motor) and a control unit. The AC motor includes a permanent magnet and a coil. The control unit is configured to perform control on operation of the AC motor. The control performed by the control unit includes field weakening control. In the field weakening control, the control unit causes a flux-weakening current to flow through the coil. The flux-weakening current is a current that generates, in the coil, a magnetic flux that weakens a magnetic flux of the permanent magnet.

Abstract: An electric power tool includes an electric motor (AC motor), an impact mechanism, an impact detecting unit, and a measuring unit. The impact mechanism performs an impact operation that generates impacting force by receiving motive power from the electric motor. The impact detecting unit determines whether or not the impact operation is being performed. The measuring unit measures at least one of a d-axis current or a q-axis current, each of which is supplied to the electric motor. The impact detecting unit determines, based on at least one of a measured value (current measured value) of the d-axis current or a measured value (current measured value) of the q-axis current, whether or not the impact operation is being performed. The measured values (current measured values) of the d-axis current and the q-axis current have been obtained by the measuring unit.

Abstract: An electric tool includes a motor and a motor control device. The motor control device is configured to update a command value of a speed of the motor based on a parameter relating to at least one of a voltage of a direct-current power supply for the motor or a magnitude of a load applied to the motor during rotation of the motor.

Abstract: A controller apparatus for an electric power tool is provided where the electric power tool includes a battery and a DC brushless motor. The controller apparatus includes a current detector that detects an instantaneous current flowing in the DC brushless motor; a current calculator that calculates one of an average value and an effective value of the instantaneous current detected by the current detector; a current controller configured to utilize a result from the current calculator as a detected value; and a speed controller configured to generate a target value of the current controller. The controller apparatus further includes a limiter that limits the target value of the current controller, where the limiter is provided at an output stage of the speed controller.

Abstract: An electric power tool is provided with a permanent magnet synchronous motor, and a controller. The controller is configured to control an operation of the permanent magnet synchronous motor. The controller includes a limiter that limits a current contributing to torque generation by the permanent magnet synchronous motor to a predetermined maximum set value based on a predetermined tightening torque. The controller calculates the maximum set value of the current that contributes to the torque generation by changing one of a rotation speed and an angular speed of the permanent magnet synchronous motor.

Abstract: A controller apparatus for an electric power tool is provided where the electric power tool includes a battery and a DC brushless motor. The controller apparatus includes a current detector that detects an instantaneous current flowing in the DC brushless motor; a current calculator that calculates one of an average value and an effective value of the instantaneous current detected by the current detector; a current controller configured to utilize a result from the current calculator as a detected value; and a speed controller configured to generate a target value of the current controller. The controller apparatus further includes a limiter that limits the target value of the current controller, where the limiter is provided at an output stage of the speed controller.

Abstract: A control circuit for an electric tool according to the present invention, includes a permanent magnet synchronous motor, a plurality of switching elements, and a PWM inverter circuit that drives the permanent magnet synchronous motor. The control circuit includes a current detector that detects a current flowing through the PWM inverter circuit. When braking the permanent magnet synchronous motor, the control circuit limits a current flowing through the permanent magnet synchronous motor and the PWM inverter circuit, to a predetermined current limit value. At the same time, by switching low-side switching elements or high-side switching elements of the PWM inverter circuit, the control circuit boosts an induced electromotive voltage of the permanent magnet synchronous motor, and regenerates a regenerative current to the battery.

Abstract: An impact electric power tool is provided a motor; a striking mechanism connected to the motor; and a controller configured to control an operation of the motor. The controller includes one of a speed controller and a current controller that maintains a constant rotation speed of the motor by compensating for periodic fluctuations in load torque of the motor, where the fluctuations are caused due to the striking mechanism. The speed controller or the current controller includes a repetitive compensator or a resonant filter that compensates for the fluctuations in load torque of the motor to obtain a frequency or a cycle of the periodic fluctuations in load torque of the motor, which is caused due to the striking mechanism.

Abstract: A power converting apparatus is provided with a step-up chopper circuit (2) that steps-up an input voltage (Vi) from a distributed power supply, an inverter circuit (3) that converts the output voltage (Vd) of the step-up chopper circuit (2) into alternating current, a first control circuit for controlling the output voltage (Vd), and a second control circuit for controlling the chopper input current (Ii). The first control circuit generates a target current value (Ir) so as to make the output voltage (Vd) become a target output voltage value (Vr). The second control circuit controls the step-up chopper circuit (2) so as to make the chopper input current (Ii) become the target current value (Ir). The first control circuit also has a low-pass filter (23a) that removes ripple components included in the output voltage (Vd).

Abstract: A power converting apparatus comprises a DC-DC converter circuit that steps up or steps down an input voltage from a DC power supply, a DC-AC converter circuit that converts an intermediate voltage outputted by the DC-DC converter circuit to an alternate current, and a control circuit that controls the DC-DC converter circuit and the DC-AC converter circuit. The control circuit is provided with a circuit control unit that controls the DC-DC converter circuit so that the modulation factor, which is the amplitude ratio between a signal wave for manipulating the DC-AC converter circuit and the carrier wave therefor, will become a target modulation factor.

Abstract: A power converting apparatus is provided with a step-up chopper circuit (2) that steps-up an input voltage (Vi) from a distributed power supply, an inverter circuit (3) that converts the output voltage (Vd) of the step-up chopper circuit (2) into alternating current, a first control circuit for controlling the output voltage (Vd), and a second control circuit for controlling the chopper input current (Ii). The first control circuit generates a target current value (Ir) so as to make the output voltage (Vd) become a target output voltage value (Vr). The second control circuit controls the step-up chopper circuit (2) so as to make the chopper input current (Ii) become the target current value (Ir). The first control circuit also has a low-pass filter (23a) that removes ripple components included in the output voltage (Vd).

Abstract: A power converting apparatus comprises a DC-DC converter circuit that steps up or steps down an input voltage from a DC power supply, a DC-AC converter circuit that converts an intermediate voltage outputted by the DC-DC converter circuit to an alternate current, and a control circuit that controls the DC-DC converter circuit and the DC-AC converter circuit. The control circuit is provided with a circuit control unit that controls the DC-DC converter circuit so that the modulation factor, which is the amplitude ratio between a signal wave for manipulating the DC-AC converter circuit and the carrier wave therefor, will become a target modulation factor.

Abstract: A grid interconnection inverter includes: a voltage conversion circuit configured to output an intermediate voltage by raising or lowering an input voltage from a direct current power source; and a waveform conversion circuit configured to convert the intermediate voltage into a alternating current power in a sine waveform shape. The voltage conversion circuit includes: a positive-side circuit arranged on a positive-side line between a positive polarity of the direct current power source and the waveform conversion circuit; and a negative-side circuit arranged on a negative-side line between a negative polarity of the direct current power source and the waveform conversion circuit. The positive-side circuit and the negative-side circuit have circuit configurations symmetric to each other.

Abstract: A heart beat/respiration measuring device comprising a sheet-like capacitance-type pressure sensor adapted to be pressed against the human body, and a measuring circuit for measuring a heart rate and/or respiration rate from the output of the sensor. The capacitance-type pressure sensor includes a sheet-like dielectric body elastically deformable in all directions and a pair of conductive clothes with stretchability disposed on opposite sides of the dielectric body. The measuring circuit comprises a resonant circuit wherein the capacitance-type pressure sensor serves as an oscillation capacitor, and a calculation processing circuit for detecting variations in the oscillation frequency of the resonant circuit and calculating the heart rate and/or respiration rate based on the frequency component or components of heart beats and/or respiration included in the variations.

Abstract: A sleep state of a subject is estimated from respiration signals that are readily detected without restraining the subject. From a voltage waveform based on respiratory movement of a person, positive peak values and the (time) interval between adjacent peaks are calculated. Also obtained is the area of a region that is enclosed by the voltage waveform and a time axis between peaks, and the average value and dispersion value of the obtained inter-peak areas are calculated. The calculated values are used to set a preliminary sleep state value for a given period, and sleep state values over plural periods are factored in to estimate a sleep state at a given time point.

Abstract: A sleep state of a subject is estimated from respiration signals that are readily detected without restraining the subject. From a voltage waveform based on respiratory movement of a person, positive peak values and the (time) interval between adjacent peaks are calculated. Also obtained is the area of a region that is enclosed by the voltage waveform and a time axis between peaks, and the average value and dispersion value of the obtained inter-peak areas are calculated. The calculated values are used to set a preliminary sleep state value for a given period, and sleep state values over plural periods are factored in to estimate a sleep state at a given time point.