Abstract: A system for detecting a mismatch between how a motor drive is connected electrically and how it is configured for operation is disclosed. The motor drive may either be connected in a stand-alone mode to control operation of a motor from an AC source without connection to another motor drive or be connected electrically to other motor drives, for example, in a paralleled mode, shared DC bus mode, or a combination thereof. A parameter identifies the expected electrical configuration of the motor drive. The power transferred to the DC bus is compared to the power transferred from the DC bus in the motor drive. If the difference between the power transferred to the DC bus and the power transferred from the DC bus exceeds a predetermined threshold, the motor drive detects the mismatch between 110W a motor drive is connected electrically and how it is configured for operation.

Abstract: The present invention provides a motor controller having one or more multi-functional pins. The motor controller includes a plurality of pins but does not include a dedicated pin for transmitting a clock signal and a dedicated pin for transmitting a motor specification database setting signal, wherein the clock signal and the motor specification database setting signal are for setting motor specification data. The clock signal and the motor specification database setting signal are transmitted through two of the plural pins which are multi-functional function pins shared by other functions in a normal operation mode. In a motor specification database setting mode, these multi-functional function pins are used for transmitting the clock signal and the motor specification database setting signal. In the normal operation mode, these multi-functional function pins are used for other functions.

Abstract: A motor controller for an electric motor having a stator and a rotor. The motor controller includes a power input for receiving AC power from a power source; a control input for receiving a control signal from a control; and circuitry for switching power from the power source to the electric motor in response to the control signal. The circuitry is operable to: apply a driving waveform to the stator to cause rotation of the rotor; remove the driving waveform from the stator to cause the rotor to coast and eventually stop; apply a stop detection waveform to the stator while the rotor is coasting, wherein the stop detection waveform induces a waveform on the rotor which in turn induces a waveform back to the stator while the rotor is rotating; and monitor the stator to detect a characteristic of the waveform induced back to the stator to detect when the rotor has substantially stopped rotating.

Abstract: An electric operating machine comprising a motor and a power circuit driving the motor by the electric power supplied from a battery. The power circuit comprises a voltage conversion part converting an input voltage entered in accordance with a voltage of said battery to generate an output voltage and outputting said generated output voltage to said motor. The power circuit is structured so that the voltage value of said output voltage of said voltage conversion part is changeable.

Abstract: When a failure detection part detects a failure in an inverter circuit in a first power supply system, a drive control part stops the inverter circuit from driving a motor. An on/off control part turns off a first power supply relay of a power supply on/off part. Under a state that the inverter circuit stops a motor driving operation, a first coil set of the motor generates an induced voltage by rotation caused by an external force. The induced voltage is regenerated to a battery from the inverter circuit through a second power supply relay and a parasitic diode of the first power supply relay. Thus, circuit elements in the power supply system, which is failing, are protected from breaking down.

Abstract: The motor monitoring system of the present disclosure uses several calculated monitoring values to determine a status of a motor and take a predetermined action when a threshold corresponding with the monitoring value is exceeded. The threshold may be calculated by an intelligent electronic device (IED) monitoring the motor. The predetermined action may include further monitoring of the motor. The predetermined action may include monitoring equipment not directly monitored by the IED.

Abstract: Provided is a vehicle seat apparatus including drive mechanism for moving configuring elements of a vehicle seat using a motor drive, in order to adjust a posture; control mechanism for controlling the operation of the drive mechanism; a rotation sensor which outputs pulse signals synchronized with a motor rotation; position detection mechanism for detecting a movement position of the configuring elements by counting pulse edges of the pulse signals according to the motor rotation direction; and reverse rotation detection mechanism for estimating that a reverse rotation has occurred in the motor rotation, in a situation where the pulse edges are continuously detected after the motor drive is stopped, if the rotation direction is unchanged, in a case where a motor rotation speed indicated by the pulse edges after the stop becomes faster than the motor rotation speed before the motor drive is stopped.

Abstract: A rotating electric machine for an electric vehicle, installed in a vehicle and driven by an inverter power source, includes: a partial discharge measuring device that measures partial discharges occurring in insulated areas between windings, between phases and between the rotating electric machine and a ground.

Abstract: Provided are a motor controller for suppressing a torque pulsation with a simple configuration and obtaining a sufficient output torque in the case of an open-type fault occurring in any one of windings of a motor and inverters, and an electric power steering device using the motor controller. In the motor controller for controlling a current supplied from and a voltage applied from a power source with respect to the motor including winding sets of a plurality of systems, when a fault determination unit (31) determines the occurrence of the open-type fault, the supply of the currents to the windings of one of the systems in which the fault has occurred is stopped by control performed on switching elements included in the inverter of the faulty system, whereas the supply of the currents to the windings of the normal system in which the fault has not occurred is continued.

Abstract: An electric-motor drive arrangement is proposed having at least one electric motor and having at least one control device, wherein the electric-motor drive arrangement has a measurement data processing apparatus and a non-volatile memory. In this case, the memory is connected to a comparator which operates at least one optical display block of a display apparatus when a predetermined set value is reached or exceeded.

Abstract: An electric motor (100) having a motor control system (400) including: —a current measuring means (402) for directly or indirectly measuring the electric current in the rotor windings (7) providing a rotor current value/s, —an ambient temperature measuring/estimation means (404) for measuring or estimating the ambient air temperature providing an air temperature value/s, —a rotor temperature estimation means (406, 407, 408, 409, 410, 411) for estimating a rotor temperature at least based on the rotor current value/s and the air temperature value/s, and—a current limiting means (405) for preventing overheating/burning of the rotor assembly (3) by limiting the electric current to the rotor windings (7) when the estimated rotor temperature exceeds a predetermined overheating threshold (412).

Abstract: A method for monitoring an electric motor employing a pulse-type rotational position sensor includes monitoring a signal output from the pulse-type rotational position sensor and a reference signal associated with a control signal for the electric motor. A position of a rotor of the electric motor coincident with the reference signal is determined based upon a nominal rotor position, a nominal rotational speed of the rotor and a time between the reference signal and a falling edge of the signal output from the pulse-type rotational position sensor. The electric motor is controlled based upon the position of the rotor.

Abstract: A motor drive unit includes a motor drive circuit that drives a motor by controlling on/off of current, a control unit generating a drive command signal for driving the motor, a current feedback circuit with the motor and outputs a comparison output signal based on comparison between a current detection signal of a motor current and a target value signal, a latch circuit that latches a current detection result based on the drive command signal and the comparison output signal, and a gate circuit for driving the motor drive circuit based on the drive command signal and a latch output signal output from the latch circuit. The control unit detects a failure of a current feedback system including the current feedback circuit and the latch circuit according to a state of the latch output signal inputted after a time measured based on the drive command signal reaches a predetermined time.

Abstract: A motor control device includes an anomaly detection means that detects an anomaly occurring on power feeding paths of respective phases on the basis of first electric current values, second electric current values of the respective phases and a phase electric current value obtained by the first electric current values and the second electric current values. When at least one of an absolute value of the first electric current value and an absolute value of the second electric current value exceeds a first threshold value corresponding to a limit value of an electric current detection and an absolute value of the phase electric current value is smaller than a second threshold value corresponding to zero in any one phase, the anomaly detection means determines that an anomaly of an electric current sensor has occurred as regards the corresponding phase.

Abstract: There are provided a motor driving device and a method of controlling the same. The motor driving device includes a controlling unit; a plurality of unit circuits provided within the controlling unit and controlling driving of a motor; and a time slice controller provided within the controlling unit and periodically generating a wake-up signal, wherein some unit circuits among the plurality of unit circuits are operated for a certain operation time upon receiving the wake-up signal, thereby allowing for effective power consumption of the motor.

Abstract: A sensor device, such as a torque sensor, of a motor control device or an electric power steering apparatus includes a sensor section that detects a quantity of state of a detection subject and outputs a detection signal corresponding to the detected quantity of state. When receiving a specific trigger transmitted from an external device, the sensor section outputs an abnormality diagnosis signal, which is configured by a predetermined waveform and used for determining whether there is an output abnormality of the sensor section, and then outputs the detection signal.

Abstract: A rotating electrical machine control apparatus includes a position information generator and a controller, where a reset request is given from the controller, the position information generator stores position information in accordance with a first signal indicating the rotation position of a rotating electrical machine in a position storage portion, and thereafter updates the position information stored in the position storage portion on the basis of a second signal. The controller gives a reset request to the position information generator, and determines an abnormality of the position information on the basis of the position information obtained before and after the reset request is given.

Abstract: A method for estimating a torque of a three-phase motor for a vehicle includes measuring a respective current strength in at least two of three phase lines, wherein the three-phase motor is supplied with power by a converter, and wherein the three phase lines lead from the converter to the three-phase motor of the vehicle, measuring a respective voltage at each of the three phase lines, determining a rotating field frequency as a function of the measured current strengths or the measured voltages; and determining an estimated value for the torque as a function of the measured current strengths, the measured voltages and the determined rotating field frequency.

Abstract: A safety system for an electric motor controller is provided. The safety system includes a torque safety monitor having a first processor distinct from a second processor of a main motor controller. The first processor is configured to one of decrease or shut down AC (alternating current) power, sent from a DC/AC (direct current to alternating current) inverter to an electric motor, in response to an estimated torque of the electric motor differing from a commanded torque associated with the main motor controller by more than a set amount.

Abstract: Provided are a system for controlling a motor and a method thereof. The system includes: a data storage unit in which data relating to a thermal equivalent circuit of the motor is stored; a temperature measuring unit which measures a temperature of a cooling medium which enters a cooling flow path portion; a rotation speed measuring unit which measures a rotation speed of a rotor; a driving electric current measuring unit which measures a driving electric current of the motor; a permanent magnet temperature estimating unit which estimates a temperature of the permanent magnet portion of the rotor; and a driving controller controls driving of the motor.

Abstract: In various implementations, a condition of a motor may be monitored based at least partially on time required to achieve a change in speed. A notification may be transmitted based on the condition of the motor.

Abstract: A resolver device (14) includes: a microcomputer (1) for outputting a control signal for driving a motor (4) to a drive circuit (3); a sensor section (5) (resolver) for outputting detection values (a sine signal and a cosine signal) in accordance with a rotation angle of the motor (4); and a signal circuit (13) provided between the microcomputer (1) and the sensor section (5). The microcomputer (1) determines an abnormality when the detection values of the sensor section (5) are out of a first normal range and then determines return of the sensor section (5) to normal when the detection value is present within a second normal range and in a plurality of regions obtained by dividing the first normal range.

Abstract: Methods and systems for replacing HVAC blower motors and other electric motors are disclosed including systems and methods for gathering and storing information about motors that may need to be replaced, systems and methods for selecting replacement motors, and systems and methods for programming the replacement motors. The systems and methods allow a select few replacement motors to be programmed to replace nearly any original motor.

Abstract: The present disclosure discloses a converter system, which at least includes the first and second back-to-back converters. The first back-to-back converter includes a first rectifier module and a first inverter module. The first rectifier module is used to convert a first AC voltage to a first DC voltage. The first inverter module is used to convert the first DC voltage to a second AC voltage. The second back-to-back converter includes a second rectifier module and a second inverter module. The second rectifier module is used to convert the first AC voltage to a second DC voltage. The second inverter module is used to convert the second DC voltage to the second AC voltage. The converter system can suppress the circular current through the synchronous operation of the first and second rectifiers or the synchronous operation of the first and second inverters.

Abstract: A motor control device and a motor control method are disclosed herein, where the motor control device includes a signal conversion unit, a frequency multiplication unit, a profile generation circuit and a frequency converter unit. The signal conversion unit receives a rotation speed signal from a motor and converts the rotation speed signal into a digital signal. The frequency multiplication unit generates a frequency multiplication signal based on the digital signal. The profile generation circuit performs frequency division on the frequency multiplication signal to get a profile signal. The frequency converter unit generates a reference signal and compares the reference signal with the profile signal to output a motor control signal.

Abstract: A lock detecting circuit includes: a CPU 204; switches 220 to 224 controlled by control signals FAN1 to FANn output from the CPU and supplying electric power to motors 210 to 214; gates 240 to 244 controlled by the control signals and selectively outputting, as signals XLD1 to XLDn, input motor state signals LD1 to LDn; and an element 232 outputting, as a signal LOCK, a result of logical sum of the signals XLD1 to XLDn. If the signal LOCK indicates a locked state, the CPU sets any one of the control signals to a high level and, in this state, determines the level of signal LOCK, to determine whether each motor is locked. Thus, a locked motor can be identified.

Abstract: Techniques are described for determining the amount of current flowing through an electrical conductor of an isolation device by measuring the voltage level across the electrical conductor. The isolation device also includes a sensor that provides a measure of the amount of current flowing through the electrical conductor. By using both the voltage level and the sensor to determine the amount of current flowing through the electrical conductor, the techniques provide for verifying the current measurements made by the isolation device. Also, the techniques provide for fast overcurrent protection.

Abstract: A circuit for controlling a load current through a coil is connected to an output port of a transistor H-bridge that includes two low side transistors and two high side transistors. A current sense circuit is coupled to the H-bridge and configured to provide a representation of the load current provided by the output port. A current regulator is configured to generate a modulated signal dependent on the representation of the load current and a current set-point. The modulated signal has a duty-cycle. A gate control logic drives the individual transistors of the H-bridge on and off in accordance with the modulated signal. A direction signal provides the load current to the coil. The direction signal determines the direction of the load current. An over current detection circuit is coupled to each individual transistor and is configured to signal an over-current by providing an active over-current failure signal when a transistor current through the respective transistor exceeds a respective maximum value.

Abstract: A method of monitoring a fan of a second electronic device. A first electronic device controls a baseboard management controller (BMC) of the second electronic device to return parameter values, the returned parameter values including temperature values of the second electronic device, and actual speed values of a fan of the second electronic device. The first electronic device records the returned parameter values and returned time of the returned parameter values. Upon acquiring standard speed values corresponding to the temperature values, the first electronic device draws a graph representing a relation between the actual speed values and the determined standard speed values corresponding to the returned time to monitor the fan.

Abstract: A motor controller for an electric motor having a stator and a rotor. The motor controller includes a power input for receiving AC power from a power source; a control input for receiving a control signal from a control; and circuitry for switching power from the power source to the electric motor in response to the control signal. The circuitry is operable to: apply a driving waveform to the stator to cause rotation of the rotor; remove the driving waveform from the stator to cause the rotor to coast and eventually stop; apply a stop detection waveform to the stator while the rotor is coasting, wherein the stop detection waveform induces a waveform on the rotor which in turn induces a waveform back to the stator while the rotor is rotating; and monitor the stator to detect a characteristic of the waveform induced back to the stator to detect when the rotor has substantially stopped rotating.

Abstract: A system to monitor the temperature of power electronic devices in a motor drive includes a base plate defining a planar surface on which the electronic devices and/or circuit boards within the motor drive may be mounted. The power electronic devices are mounted to the base plate through the direct bond copper (DBC). A circuit board is mounted to the base plate which includes a temperature sensor mounted on the circuit board proximate to the power electronic devices. The temperature sensor generates a digital signal corresponding to the temperature measured by the sensor. A copper pad is included between each layer of the circuit board and between the first layer of the circuit board and the sensor. The circuit board also includes vias extending through each layer of the board. The copper pads and vias establish a thermally conductive path between the temperature sensor and the base plate.

Abstract: There is provided a motor controller capable of suppressing the rotation of a motor at the time of discharging an electric accumulator, and a construction machine provided with the motor controller. A motor controller 10 is provided with a current controller 1 for controlling an electric current supplied from an electric accumulator E to a motor M, and a rotation detector 2 for detecting the rotation of the motor M. The current controller 1 supplies only a d-axis current to the motor M according to a discharge command. If the rotation of the motor M is detected by the rotation detector 2 at the time of discharging the electric accumulator E, the current controller 1 controls the d-axis current so as to suppress the rotation of the motor M.

Abstract: A control system for a motor includes an inverter coupled to the motor. The control system further includes a microcontroller coupled to the inverter. The microcontroller includes a processor programmed to measure an input voltage and acquire a back EMF voltage of the motor. The processor is also programmed to control the inverter to regulate the motor voltage based on the input voltage and the back EMF voltage to facilitate controlling the motor.

Abstract: This disclosure relates to diagnosing a power electronic device by itself and extending the diagnostics to an electric machine coupled with the power electronic device and deployed at an operational site. The power electronic device can power and control the electric machine. The diagnostics can include testing the status of the power electronic device, and monitoring hardware changes in the electric machine. The diagnostics can be performed within the power electronic device on demand, periodically, or both. In some instances, the self-diagnostics can evaluate whether components are defective or wired incorrectly, characterized by wrong inductance, and/or resistance, for example. In some implementations, the power electronic device includes a digital signal processing unit for the self-diagnostics and a data record system for recording and troubleshooting errors related to load performance and/or parameters.

Abstract: The invention relates to a method for calibrating a multiphase, in particular three-phase, inverter (1) having a respective switching element (T1, T2, T3) on the high-voltage side and a respective switching element (T4, T5, T6) on the low-voltage side for each of the phases thereof as well as a respective current sensor for at least some of the phases (I, II, III). The following steps are proposed: (f) switching off all switching elements (T1-T6), (g) switching on a switching element (T1) on the high-voltage side for a first phase (I) and a switching element (T5) on the low-voltage side for a second phase (II), (h) measuring the currents flowing through the first phase (I) and the second phase (II), (i) forming an average value from the measured currents, and (j) calibrating the inverter (1) on the basis of the formed average value. The invention also relates to an apparatus, a computer program and a computer program product.

Abstract: According to an embodiment of the invention, a motor starter includes a connection module, which includes a second and third interface, wherein the second interface is electrically conductively connected to the third interface. The security evaluation unit can be mechanically coupled to the connection module so that an electrically conductive connection is produced between the first and second interfaces. The secure switch unit can be mechanically coupled to the connection module so that an electrically conductive connection between the third and fourth interfaces is produced, so that, in the coupled state of the security evaluation unit and the secure switch unit to the connection module; there is an electrically conductive connection between the first and fourth interfaces via the connection module, so that the control command can be transmitted from the security evaluation unit via the connection module to the secure switch unit.

Abstract: Weighing system (FIG. 3, FIG. 6) to weigh items, parcels and the like while they are moving, for example, on a conveyor. A servo amplifier (14) and servo controller (20) are arranged to drive a servo motor in a feedback (15) configuration, and acquire torque sensing signals (17) responsive to commanded acceleration of the conveyor while the item(s) are on board. Preferably, constant acceleration of the item(s) is realized during one or more measurement intervals, and mass is derived by a processor (30) based on the measurement data (FIG. 5). Other embodiments are described for weighing granular and slurry materials (FIG. 7) and for weighing multiple, potentially overlapping, parcels in motion (FIG. 8).

Abstract: An electric motor driving apparatus having a failure detection circuit includes: a bridge circuit driving an electric motor; a PWM control circuit generating voltage instruction for driving the electric motor; a PWM signal generation circuit generating a PWM signal; a DC current detection circuit detecting DC current of the bridge circuit; a phase current calculation circuit calculating output phase current of the bridge circuit, based on the DC current and PWM signal; and a failure detection circuit detecting failure of the DC current detection circuit. The failure detection circuit determines failure of the DC current detection circuit from the DC current detected values in a zero voltage period in which the high-potential-side arms of the bridge circuit are all ON and in a zero voltage period in which the low-potential-side arms are all ON.

Abstract: An integrated drive motor (IDM) power distribution architecture utilizes an IDM power interface module (IPIM) to create a control voltage that is distributed to all the IDMs in a network. This power distribution may be accomplished along a hybrid cable, for example, that includes both signal conductors and power conductors. The IPIM is capable of detecting short circuits and/or overload conditions and disabling the power supply to the IDMs. Additionally, a second power supply may be utilized in the IPIM such that when the power supply to the IDMs is deactivated, the IPIM may remain functional, for example, to report one or more fault conditions to the user. Additionally, this reporting of fault status may be accomplished via a user display integrated with or coupled to the IPIM.

Abstract: An improper wiring detecting system of a parallel inverter system can include two polyphase inverters connected in parallel, and voltage detectors to detect an output voltage of each of the phases of each of the inverters. Control units can control turning-on and -off of semiconductor switching devices of the inverters, and a wiring condition deciding means can operate at least one control unit to turn-on specified switching devices in at least one inverter to form a closed circuit between arbitrary two phases of the at least one inverter. The system can carry out comparisons among values of output voltages of the two inverters corresponding to respective phases and detected by the voltage detectors, and make a decision as to whether wiring is correct or not on the basis of the results of the comparisons.

Abstract: A motor control device includes a vibration-damping-control setting unit to designate one of a plurality of candidate frequencies of a vibration-damping frequency, a signal-for-estimation computing unit to output, based on an operation signal related to a controlled object, a signal for estimation in which signal components of the other candidate frequencies excluding the designated one candidate frequency are reduced from a vibration component of a control system, and a resonance-characteristic estimating unit to estimate one resonance frequency from the output signal for estimation. The vibration-damping-control setting unit designates each of the candidate frequencies individually as one candidate frequency and sets, in a feedforward control unit, each of resonance frequencies estimated by the resonance-characteristic estimating unit related to the individually designated each one candidate frequency.

Abstract: A motor drive device according to one embodiment of the present invention includes a converter (2) for converting an AC voltage input from a main power supply into a DC voltage, a DC link unit (4) for rectifying the DC voltage output from the converter, an inverter (10) for converting the DC voltage rectified by the DC link unit into an AC voltage for driving a motor using a semiconductor switching element, a voltage application unit (6) that is provided independently of the main power supply to apply a voltage to the DC link unit, a voltage detector (7) for detecting a voltage of the DC link unit after application of the voltage by the voltage application unit, and an abnormality determination unit (8) for determining the presence or absence of an abnormality of the DC link unit based on the voltage detected by the voltage detector.

Abstract: Complete drive system, called motor-drive unit, for use in remote locations with limited radial space like downhole, narrow tunnels, pipelines and other applications with similar conditions. Given the spatial limitations the unit must have elongated shape. It includes a number of motors connected mechanically in series and a lower number of inverters, driving groups of the motors so that load is equally distributed along axis of the unit. Motors within each group can be electrically connected in series or in parallel. The motor-drive unit is supposed to be fed by DC voltage via a cable with length up to several km; therefore, it includes a buck converter for stabilization of voltage inside the unit and a power-line communication module to be controllable from the surface.

Abstract: A method for determining a temperature of an electric motor including stator windings includes injecting an AC current into a D-axis current of a stator winding at a frequency that is synchronized with a control frequency of the electric motor, determining a DC-phase current, determining a resistance of the stator winding corresponding to the DC-phase current and an applied voltage, and determining a temperature of the electric motor as a function of the resistance of the stator winding.

Abstract: A motor control device performs drive control of a motor connected to an object. The motor control device includes a rotation detection unit that detects rotation of the motor and outputs a detection signal, a counter unit that receives the detection signal from the rotation detection unit and outputs a count based on the received detection signal, and an error detection unit that receives counts from the counter unit at intervals of a reference period, computes a difference between a present count received from the counter unit and a previously received count, and detects that an error arises in the rotation detection unit when the difference is continuously less than a reference value.

Abstract: A power failure detection unit in an AC-DC converter device detects power failure of a 3-phase AC power supply at the time of driving a motor, and generates a power failure detection signal in accordance with detection of power failure. A transmitter unit in the AC-DC converter device transmits the power failure detection signal using a cable, radio, or an optical fiber. A receiver unit in a DC-AC converter device receives the power failure detection signal transmitted from the transmitter unit.

Abstract: The invention relates to a method of safety cutoff of an electromechanical motor vehicle power steering, in which safety switches (26, 27, 28) are provided for electrical separation of a servomotor from a control system or a vehicle electrical system, wherein the following steps are provided: a) receiving a fault signal in a control system (30); b) sending a switch-off signal via control lines (31, 32, 33) to the safety switches (26, 27, 28); c) checking the electrical voltages present on the safety switches (26, 27, 28); d) deciding whether the switch-off signal on each safety switch (26, 27, 28) has led to switch-off; e) if the switch-off signal on one or more safety switches (26, 27, 28) has not led to switch-off, switching those safety switches (26, 27, 28) back on, which could not be switched off; f) repeating steps b) to e) until all safety switches have been switched off successfully (26, 27, 28).

Abstract: In a device in which the rotation angle of the rotor is detected with a resolver, the rotation angle of the rotor with less error can be obtained while reducing burden of the operator. The measured angle value acquisition unit (210) acquires the measured-rotation angle value of a motor shaft. The error calculation unit (220) calculates the error included in each of measured-rotation angle values. The frequency component acquisition unit (230) determines the phase and the amplitude of a frequency component of the error based on the errors. Thus, by using the error frequency component acquisition device (121), the phase and amplitude of the frequency component of the error included in the measured-rotation angle value can be automatically calculated and the correction with respect to the measure-rotation angle value can be performed using the acquired phase and amplitude. Therefore, the rotation angle of the rotor with less error can be obtained, while reducing the burden of the operator.

Abstract: In an electric tool, in order to carry out a phase control or an antiphase control using a transistor, constant voltage generating means of the tool includes a series circuit including a resistor and a diode, and a parallel circuit including a capacitor and a Zener diode. One end of the resistor is connected between an AC power supply and an AC motor. A cathode of the diode is connected to one capacitor end and a cathode of the Zener diode. The other capacitor end and an anode of the Zener diode are connected to transistor sources. One ends of resistors are connected to gates of the transistors, and a voltage at the other ends of the resistors are switched between a voltage at a node between the series circuit and the parallel circuit and a voltage of the source of the transistors to turn the transistors ON or OFF.

Abstract: Method for diagnosing a fan, in particular in a cooling circuit of an internal combustion engine, a current driving the fan being ascertained. The fan is triggered by a defined trigger signal, and depending on the ascertained current, a diagnosis of whether the fan is defective is performed.