Abstract: A load driving device according to the present invention has: an internal circuit (DRV) that operates in response to the supply of a power supply voltage (HV or LV); an output circuit (PD1 and PD2) for driving a load in response to the supply of the power supply voltage (HV or LV); an abnormality detection circuit (12) for monitoring the power supply voltage (HV or LV) and generating an abnormality detection signal (S1); and a power supply switch (P0) for, according to the abnormality detection signal (S1), conducting or cutting off a power-supply-voltage supply line to the internal circuit (DRV).

Abstract: A rotation control apparatus includes: a controller configured to supply test currents to a plurality of different paths of a motor when the motor is stopped; and a stop position detector configured to detect a rotational position of the motor based on an order of current values of the test currents. The controller causes one of the test currents to flow through one of the plurality of different paths, measure time taken until the corresponding detection voltage reaches a reference voltage, and set electrical conduction time of the test currents based on a result of the measurement.

Abstract: A load driving device according to the present invention has: an internal circuit (DRV) that operates in response to the supply of a power supply voltage (HV or LV); an output circuit (PD1 and PD2) for driving a load in response to the supply of the power supply voltage (HV or LV); an abnormality detection circuit (12) for monitoring the power supply voltage (HV or LV) and generating an abnormality detection signal (S1); and a power supply switch (P0) for, according to the abnormality detection signal (S1), conducting or cutting off a power-supply-voltage supply line to the internal circuit (DRV).

Abstract: Focusing on the criterion of “Energy save” or “Quiet noise” or other suitable operating parameter and considering the existing limitation of the operation of the electro-dynamic shaker system, apparatus for optimizing the operating condition of the vibration test system is proposed. The apparatus 100 measures the field current and drive current under the state that the desired vibration is fed to the specimen 20, and calculates the necessary force the shaker 1 should supply. Field current is supposed to be varied, and the necessary drive current is calculated based on the necessary force data. Further, the blower rotation is supposed to be varied, and the total power consumption at the coils and the blower is calculated. Also the temperatures of the field coil 4 and of the drive coil 10 is estimated and checked whether within the limitation. Then the optimal operating condition for the focused criterion is selected.

Abstract: A technology for correctly detecting a rotating position of a rotator at the time of rotation start. A rotation control apparatus controls rotation of a motor, which includes a stator provided with a plurality of coils and a rotor having magnetism. At the time of detecting a position of the motor when the motor is stopped, a control part supplies a current to a plurality of different paths including the coils, a stopped position detecting part measures the current flowing in each of the plurality of paths, judges the order of the measured current values, and a rotating position of the motor is detected based on the order. Based on a combination of a path showing the highest current value and a path showing the second highest current value, the stopped time position detecting part judges a position of the motor.

Abstract: Focusing on the criterion of “Energy save” or “Quiet noise” or other suitable operating parameter and considering the existing limitation of the operation of the electro-dynamic shaker system, apparatus for optimizing the operating condition of the vibration test system is proposed. The apparatus 100 measures the field current and drive current under the state that the desired vibration is fed to the specimen 20, and calculates the necessary force the shaker 1 should supply. Field current is supposed to be varied, and the necessary drive current is calculated based on the necessary force data. Further, the blower rotation is supposed to be varied, and the total power consumption at the coils and the blower is calculated. Also the temperatures of the field coil 4 and of the drive coil 10 is estimated and checked whether within the limitation. Then the optimal operating condition for the focused criterion is selected.

Abstract: There is provided a brushless motor drive control circuit capable of assuring an S/N ratio of a predetermined counter electromotive voltage and suppressing lowering of efficiency of a brushless motor at a high-speed rotation.

Abstract: A technology for correctly detecting a rotating position of a rotator at the time of rotation start. A rotation control apparatus controls rotation of a motor, which includes a stator provided with a plurality of coils and a rotor having magnetism. At the time of detecting a position of the motor when the motor is stopped, a control part supplies a current to a plurality of different paths including the coils, a stopped position detecting part measures the current flowing in each of the plurality of paths, judges the order of the measured current values, and a rotating position of the motor is detected based on the order. Based on a combination of a path showing the highest current value and a path showing the second highest current value, the stopped time position detecting part judges a position of the motor.

Abstract: There is provided a brushless motor drive control circuit capable of assuring an S/N ratio of a predetermined counter electromotive voltage and suppressing lowering of efficiency of a brushless motor at a high-speed rotation.

Abstract: The drain of a power transistor M1 is connected to the non-inverting input terminal of an operational amplifier A and the drain of a transistor M2 is connected to the inverting input terminal of the operational amplifier A to make substantially equal the drain voltages of the power transistor M1 and the transistor M2, of which the gates are connected together and of which the sources are connected together. The drain current of the transistor M2 is outputted via a detection terminal 13 as a current signal proportional to the drain current of the power transistor M1.

Abstract: Connected to a power element having a first electrode, a second electrode, and a control electrode, a power element protection circuit detects a voltage between the first and second electrodes of the power element and the current flowing through the power element, then logarithmically converts a current proportional to the detected voltage and a current proportional to the detected current individually, then adds the results together, then subtracts a predetermined value from the sum, then antilogarithmically converts the result with an antilogarithmic converter, and then limits the driving of the power element based on the output of the antilogarithmic converter.

Abstract: In the driving operation of a sensorless three-phase motor to be used in a rotation at a comparatively low speed (approximately 2000 RPM or less) and to be bipolar driven, the number of rotations and a rotating position are accurately detected from an induced voltage and a reverse rotation brake is applied in an accurate phase, and furthermore, a short brake is applied at a set rotation number signal or less also in braking. Consequently, it is possible to prevent phase switching from being carried out in an erroneous timing and to prevent a rotation in a reverse direction by an inertia.

Abstract: Connected to a power element having a first electrode, a second electrode, and a control electrode, a power element protection circuit detects a voltage between the first and second electrodes of the power element and the current flowing through the power element, then logarithmically converts a current proportional to the detected voltage and a current proportional to the detected current individually, then adds the results together, then subtracts a predetermined value from the sum, then antilogarithmically converts the result with an antilogarithmic converter, and then limits the driving of the power element based on the output of the antilogarithmic converter.

Abstract: In the driving operation of a sensorless three-phase motor to be used in a rotation at a comparatively low speed (approximately 2000 RPM or less) and to be bipolar driven, the number of rotations and a rotating position are accurately detected from an induced voltage and a reverse rotation brake is applied in an accurate phase, and furthermore, a short brake is applied at a set rotation number signal or less also in braking. Consequently, it is possible to prevent phase switching from being carried out in an erroneous timing and to prevent a rotation in a reverse direction by an inertia.

Abstract: The drain of a power transistor M1 is connected to the non-inverting input terminal of an operational amplifier A and the drain of a transistor M2 is connected to the inverting input terminal of the operational amplifier A to make substantially equal the drain voltages of the power transistor M1 and the transistor M2, of which the gates are connected together and of which the sources are connected together. The drain current of the transistor M2 is outputted via a detection terminal 13 as a current signal proportional to the drain current of the power transistor M1.