Abstract: A superdirectional acoustic system for reproducing a sound signal supplied from a real sound source by using a superdirectional speaker and producing a virtual sound source in a vicinity of a sound wave reflection surface. The system includes an ultrasonic speaker, which includes an ultrasonic transducer for oscillating a sound wave in an ultrasonic frequency band, for reproducing an audio signal in a relatively medium to high frequency sound range, which is included in the sound signal supplied from the real sound source; and a low frequency sound reproducing speaker for reproducing an audio signal in a relatively low frequency sound range, which is included in the sound signal supplied from the real sound source. Sound in the medium-high frequency range is reproduced in a manner such that the sound is produced from a virtual sound source which is formed in the vicinity of the sound signal reflection surface such as a screen.

Abstract: A projector includes an ultrasonic speaker, a visual information generation unit that generates visual information relating to a sound reproduction range of the ultrasonic speaker, and an image projection unit that displays the visual information generated by the visual information generation unit on a screen.

Abstract: A projector includes an ultrasonic speaker, a visual information generation unit that generates visual information relating to a sound reproduction range of the ultrasonic speaker, and an image projection unit that displays the visual information generated by the visual information generation unit on a screen.

Abstract: An electrostatic ultrasonic transducer includes a diaphragm having a conducting layer and a pair of first and second fixed electrodes opposed to the corresponding surfaces of the diaphragm, the pair of fixed electrodes having a plurality of through holes in corresponding positions, wherein a DC bias voltage is applied to the conducting layer of the diaphragm and an alternating current signal is applied between the first and second fixed electrodes to generate an ultrasonic wave. Part of the pair of fixed electrodes includes s driving fixed electrode for driving the ultrasonic transducer, and the other part includes a detecting fixed electrode for detecting the amplitude of the diaphragm. The ultrasonic transducer includes a control unit that controls the vibration of the diaphragm so that the amplitude is proportional to the input signal based on the amplitude of the diaphragm detected by the detecting fixed electrode.

Abstract: A superdirectional acoustic system for reproducing a sound signal supplied from a real sound source by using a superdirectional speaker and producing a virtual sound source in a vicinity of a sound wave reflection surface. The system includes an ultrasonic speaker, which includes an ultrasonic transducer for oscillating a sound wave in an ultrasonic frequency band, for reproducing an audio signal in a relatively medium to high frequency sound range, which is included in the sound signal supplied from the real sound source; and a low frequency sound reproducing speaker for reproducing an audio signal in a relatively low frequency sound range, which is included in the sound signal supplied from the real sound source. Sound in the medium-high frequency range is reproduced in a manner such that the sound is produced from a virtual sound source which is formed in the vicinity of the sound signal reflection surface such as a screen.

Abstract: An electrostatic ultrasonic transducer includes a diaphragm having a conducting layer and a pair of first and second fixed electrodes opposed to the corresponding surfaces of the diaphragm, the pair of fixed electrodes having a plurality of through holes in corresponding positions, wherein a DC bias voltage is applied to the conducting layer of the diaphragm and an alternating current signal is applied between the first and second fixed electrodes to generate an ultrasonic wave. Part of the pair of fixed electrodes includes s driving fixed electrode for driving the ultrasonic transducer, and the other part includes a detecting fixed electrode for detecting the amplitude of the diaphragm. The ultrasonic transducer includes a control unit that controls the vibration of the diaphragm so that the amplitude is proportional to the input signal based on the amplitude of the diaphragm detected by the detecting fixed electrode.

Abstract: A recycling job supporting system is provided which is capable of efficiently carrying out a disassembly job. Information management center equipment 100 has an object disassembly information register DB 40 in which the object disassembly information is registered by associating the object disassembly information with object identification information, retrieves the object disassembly information from the object disassembly information register DB 40 based on the received object identification information when receiving the object identification information, and transmits the object disassembly information found through the retrieval to recycling center equipment 200.

Abstract: A recycling job supporting system is provided which is capable of efficiently carrying out a disassembly job. Information management center equipment 100 has an object disassembly information register DB 40 in which the object disassembly information is registered by associating the object disassembly information with object identification information, retrieves the object disassembly information from the object disassembly information register DB 40 based on the received object identification information when receiving the object identification information, and transmits the object disassembly information found through the retrieval to recycling center equipment 200.

Abstract: The present invention relates to a control method and a control device for a position sensorless motor which has position sensorless operation and synchronized operation, wherein a rotation position of a rotor is detected on the basis of counter electromotive forces generated in stator coils in the position sensorless operation, the stator coils are excited in synchronization with the detected rotation position of the rotor to rotate the rotor and a deviation between a target position and the present position is determined from a target rotation position according to the position command signal and the detected rotation position, position sensorless close loop drive is made on the basis of the determined deviation, and when the synchronized operation is made, the stator coils of the motor are excited in synchronization with the position command signal to rotate the rotor.

Abstract: The invention relates to a sensor provided with a magnet (52) and a magnetic detecting element (53) comprising a detection shaft (38a), a detection disc (59a) which is fixed to the detection shaft, a magnetic piece (59b) which is fixed to the outer circumference edge of the detection disc, a yoke (59c) which is disposed to hold the magnetic piece in a predetermined shaped gap, and the magnet and the magnetic detecting element both fixed to the yoke. The sensor is used for a drive force auxiliary device which combines a human power drive force and a motor drive force. The drive force auxiliary device comprises a torque sensor (30), a vehicle speed detecting means (40) for detecting a running speed of the drive force auxiliary device, and an auxiliary power means using a motor (M). The vehicle speed detecting means (40) detects a running speed by virtue of the drive force auxiliary device based on a rotation position signal obtained from a rotor rotation position detector.

Abstract: A power-generating device can include a dynamo for converting kinetic energy into electrical energy, a switch capable of short-circuiting output terminals of the dynamo, a controller capable of controlling the switch, a rectifier for rectifying an output of the dynamo, and a charging portion capable of storing the output of the dynamo. The controller can perform chopper control for cyclically turning on and off the switch in accordance with a PWM signal. Where an electromotive voltage of the dynamo is lower than a charged voltage, a boosted voltage can be produced by chopper amplification. If the electromotive voltage is low, it can be charged in the charging portion if the boosted voltage is increased to a sufficient level prior to charging.

Abstract: A drive for an electric vehicle includes by forming a drive unit 8 having a transmission by combining a single propelling motor 7 with the transmission, respectively interconnecting the drive unit 8 with propelling wheels to be a drive wheel, and separately controlling the drive units 8. Besides, traveling speed detecting means are provided on the respective drive units 8, 8, and the respective drive units are simultaneously controlled according to a revolution signal from one of the traveling speed detecting means. A method for controlling an electric vehicle by separately controlling the drive units 8, 8, making the output torque of the motor zero or minimum during the gear change, and producing again the output torque of the motor after completing the gear change.

Abstract: A method of manufacturing a permanent magnet rotor comprising a rotor yoke (2) of a rotor (1) which is formed by laminating a large number of steel sheets (4), (14), (24), (34) and (44), has 2n times (n is a positive integer) of magnetic poles (5) on the outer periphery, has slots (6) at the bases of all or every other magnetic poles at a substantially equal distance from a rotatable shaft hole (7), and has permanent magnets (3) for a field inserted into the slots, and a method for producing it. It has a structure that the permanent magnets for the field are prevented from coming out, or the permanent magnets for the field have their faces treated in order to improve the safety and reliability of the permanent magnet rotor.

Abstract: A DC brushless motor 3 is provided which comprises armature 31 and rotor 32. Rotor 32 is provided with a rotor yoke that has four main poles 321 on its periphery. Slots with a radial-direction size of L.sub.m are formed on main poles 321 of the rotor yoke. Magnetic-field permanent magnet 323 with an approximate thickness of L.sub.m is embedded in each slot 322, such that the radial-direction size L.sub.m of slot 322 and the air gap length L.sub.g of the air gap formed between rotor 32 and armature 31 satisfy the relationship 0<L.sub.m +L.sub.g .ltoreq.2 mm.

Abstract: A battery control system for an electric vehicle 1 which includes a propelling motor (7) and an electric power unit(10)for driving the motor comprises a plurality of discrete batteries (13a) to (13d) connected in series and outputting a predetermined motor voltage, a plurality of selection switches (25a) to (25h) which are provided corresponding in number to the discrete batteries(13a)to (13d) and selectively connect one of the discrete batteries (13a) to (13d) in parallel to a control circuit (16), a judging device (23) which determines a state of electric energy possessed by each of the discrete batteries (13a) to (13d) and a control device (23) which selects one of the discrete batteries(13a) to (13h) having a maximum energy based on the state of electric energy as determined by the judging device and activates one of the corresponding selection switches (25a) to (25h) accordingly, and a control stabilization circuit (24) provided between the selection switches (25a) to (25h) and the control circuit (16) t

Abstract: A DC brushless motor 3 is provided which comprises armature 31 and rotor 32. Rotor 32 is provided with a rotor yoke that has four main poles 321 on its periphery. Slots with a radial-direction size of L.sub.m are formed on main poles 321 of the rotor yoke. Magnetic-field permanent magnet 323 with an approximate thickness of L.sub.m is embedded in each slot 322, such that the radial-direction size L.sub.m of slot 322 and the air gap length L.sub.g of the air gap formed between rotor 32 and armature 31 satisfy the relationship 0<L.sub.m +L.sub.g .ltoreq.2 mm.

Abstract: In an electric vehicle provided with an electric motor (M), a motor drive circuit (17) and a control circuit section (15) for outputting an operation command to the motor drive circuit, a variable speed drive unit for electric vehicles has a transmission apparatus (20) which engages or disengages a drive shaft (7a) which receives the drive force from a propelling motor and a driven shaft (5a) which is interconnected with propelling wheels by an electromagnetic engagement clutch (30), the transmission apparatus has the electromagnetic clutch comprised of a first clutch (22) interconnected with the drive shaft, a second clutch (25) having a rotational speed different from the first clutch, and an output side clutch (21) interconnected with the driven shaft; and the output side clutch and the first clutch or the second clutch are alternatively connected to selectively change the motor output.

Abstract: A brushless DC motor drive apparatus according to the invention comprises a stator and a rotor, the stator including multi-phase armature windings which are connected in a star formation and generate a plurality of terminal voltages at respective terminals of the armature windings, and the rotor including a plurality of permanent magnets which form pairs of magnetic poles. The motor drive apparatus also includes an inverter coupled to the rotor for adjusting the speed of the rotor, a rotor position detection means for detecting the terminal voltages generated in the armature windings and for generating a position signal indicative of a magnetic pole position of the rotor. The rotor position detection means includes a line voltage generation means for generating line voltages corresponding to the terminal voltages of the armature windings and comparison means for comparing signals derived from the line voltages in predetermined combinations and outputting comparison signals as the positional signal.

Abstract: A controller according to one embodiment restarts the motor when a commutation timing signal is mismatched with an output pattern mode. A controller according to another embodiment compares the motor speed with the reference signal to change the chopper frequency in accordance with the compared value. A controller according to still another embodiment continuously changes the chopper frequency in accordance with the motor speed. A controller according to yet another embodiment inhibits the position detection immediately after commutation in accordance with the current flowing through the motor. A controller according to another embodiment detects the position of the rotor in accordance with the waveform of the current flowing through the motor.

Abstract: A motor control apparatus is provided which is capable of preventing large, accidental switching surges and suppressing switching surges that hamper efforts to improve the efficiency of PWM control inverters. The motor control apparatus has a PWM control inverter and axial position detector 3 that detects the position of the rotary axis of motor 14. Gate drive circuit 1 of the PWM control inverter comprises decoder circuit 4, correction gate circuit 5, and logical AND circuit 6. The correction gate circuit 5 sets a time difference at the change point for PWM signals and at the change point for commutation signals.