Abstract: A new configuration of DC motor/generator is based on a Halbach array of permanent magnets. This motor does not use ferrous materials so that the only losses are winding losses and losses due to bearings and windage. An "inside-out" design is used as compared to a conventional motor/generator design. The rotating portion, i.e., the rotor, is on the outside of the machine. The stationary portion, i.e., the stator, is formed by the inside of the machine. The rotor contains an array of permanent magnets that provide a uniform field. The windings of the motor are placed in or on the stator. The stator windings are then "switched" or "commutated" to provide a DC motor/generator much the same as in a conventional DC motor. The commutation can be performed by mechanical means using brushes or by electronic means using switching circuits. The invention is useful in electric vehicles and adjustable speed DC drives.

Abstract: A control for an AC motor has first and second sets of three-phase stator windings wound physically in parallel and a three-phase inverter for each set. A first current sensor is responsive to a first phase current of the first set of three-phase stator windings; and a second current sensor is responsive to a phase current of the second set of three-phase windings other than that corresponding to the first phase current of the first set of three-phase windings. The control is responsive to signals from the first and second current sensors to generate a set of motor phase voltage control signals, which are provided to first and second three-phase inverters connected across a source of DC electric power.

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: An image reading device has two different modes for controlling the switchover of a motor drive pattern. Either one of the two modes is selected in accordance with various drive conditions including a drive speed. In one mode, in response to every drive pattern switching pulse, pattern data are output by software processing while a position signal is referenced. In the other mode, a macro transfer function is used to output the pattern data by DMA (Direct Memory Access) while the position signal is referenced at every repetition cycle of the drive patterns. The device is capable of reading an image at high speed by switching the drive pattern rapidly, thereby obviating irregularity in a reference position for reading an image.

Abstract: A driver for driving a loading motor of a single-unit video camera-recorder. In the driver, a DC voltage supplied from a battery is boosted by a DC/DC converter, and the boosted DC voltage is supplied to the loading motor through a switch unit in which the polarity of the boosted DC voltage is switched.

Abstract: A protective circuit controls the operation of a floor cleaning machine provided with a brush motor and a vacuum motor. The protective circuit disables the vacuum motor when an operator starts the brush motor and then restarts the vacuum motor provided it was previously running. The floor cleaning machine is also provided with provisions for adjusting the action of the brush and thus changing the load current of the brush motor. The load current of the brush motor is continuously compared to a first level overload current and an indicator alerts the operator to a first level overload condition allowing a predetermined time for the load current to be reduced by adjusting the brush. If the load current is not reduced, then the brush motor is de-energized. If a second level overload condition of the brush motor occurs at any time, the brush motor is de-energized immediately.

Abstract: A motor includes a stationary assembly and a rotatable assembly in magnetic coupling relation thereto. The stationary assembly includes a winding, the rotation of the rotatable assembly inducing a back EMF in the winding. A power supply for supplying a voltage across the winding drives a current through the winding. A back EMF sensor connected to the winding generates a back EMF signal representative of the back EMF induced in the winding during periods of time when the voltage is being supplied across the winding. An inverter connected between the power supply and the winding commutates the winding as a function of the back EMF signal, whereby the rotatable assembly rotates. A method of operating the motor and a control circuit for the motor employ the back emf induced in the winding during periods when the voltage is being applied to the winding by the power supply.

Abstract: A method for settling a transducer (18) of a hard disc drive (10) on a target track (30) on a rotating disc (12) of the disc drive at the end of a seek to the target track in a determined time period. The time period is divided into two deadbeat intervals(58, 60), each of which is divided into a plurality of time intervals in each of which the location of the transducer with respect to the target track is measured (80) and an accepted value of transducer velocity is measured (82) or determined from successive locations of the transducer. In the first time interval of the each deadbeat interval, a deadbeat value of a control signal is determined (88) on the basis of ideal deadbeat settle of the transducer to the target track and outputted to a power amplifier (36) that drives the actuator (40) on which the transducer is mounted for radial movement of the transducer across the disc.

Abstract: Only in a transient band of a filter, substantially all frequency bands of the musical tone waveform are subjected to filter processing. Due to this, the drawback that the amount of change of the frequency characteristic of the musical tone gradually changes as a whole from a fundamental wave toward a harmonics and only one part of the frequency characteristic of the musical tone changes is eliminated.Also, the density of frequency components of the frequency band of the musical tone waveform does not change, the related frequency band is shifted in frequency, subjected to filter processing, and further shifted to a frequency in accordance with the musical tone pitch. Due to this, a specific range of the filter characteristic is selected, and the musical tone is subjected to the filter control only within this range.

Abstract: To extend an operable range of a hybrid excitation type permanent magnet synchronous motor having a field of a permanent magnet and a dc excitation coil, magnetic flux of the field is controlled so as to keep constant when a rotation speed of the motor is smaller than a predetermined base speed and so as to change in reverse proportion with the rotation speed of the motor when the rotation speed is larger than the predetermined base speed. Electric current and voltage to an armature of the motor is controlled such that a current ratio of a direct-axis component and a quadrature-axis component which components are obtained by dividing an electric current to the armature coil into the direct-axis component and the quadrature-axis component relative to the voltage induced in the armature coil, is kept constant.

Abstract: A circuit for powering a three-phase AC induction motor. The circuit generates a first signal of the form Vdc+A sin (2.pi.ft-0.degree.) and a second signal of the form Vdc+A sin (2.pi.ft-90.degree.) as is done in conventional circuits for powering two-phase AC induction motors. A vector summation circuit is used to create a third signal from the first two signals. The third signal is of the form Vdc+A sin (2.pi.ft+60.degree.). The first signal is input to a first error amplifier along with a first sampled difference signal from the motor. The third signal is input to a second error amplifier along with a second sampled difference signal from the motor. The outputs from each of the first and second amplifiers is input into a first comparator and a second comparator along with a sawtooth waveform to create a first sinusoidally modulated square wave signal and a second sinusoidally modulated square wave signal.

Abstract: A method and apparatus used with a motor controller for determining transient inductance and rotor resistance upon commissioning of the motor. The estimator drives a single phase of the motor with an excitation current at an operating frequency, determines the d-q axis stator synchronous feedback voltages, divides the excitation current by 2 to produce a positive current signal, multiplies the operating frequency by the positive current signal to produce a current frequency signal and then divides the q-axis voltage feedback by the current frequency signal to produce the transient inductance estimate, divides the d-axis voltage feedback signal by the positive current signal and subtracts stator resistance estimate therefrom to obtain a rotor resistance estimate.

Abstract: A drive control device for an opening/closing member may be advantageously utilized in vehicular power window systems and the like. The drive control device is active to detect occurrence of pinching of an object obstructing the path of motion of the opening/closing member and, upon detection of such pinching during closing operation is controlled so as to move in the opening direction for a predetermined distance for preventing serious pinching from being applied to, for example, a persons hand or arm which may be blocking a power window while being closed by a vehicle driver. The drive control device further includes timing functions such that closing operation may not be immediately resumed after pinch detection, until a predetermined time period has elapsed. The pinch detection operation is effective to compensate for overrun of the opening/closing member caused by a lag between the time a closing control signal is stopped and the acutal motion of the opening/closing member finally and completely stops.

Abstract: An estimator initialization circuit for a sensorless switched reluctance machine system pulses phase windings of the machine a certain number of times and derives initial values for an estimator of the system.

Abstract: A three-phase, low-pass filter for use in an electronic speed control system and wherein an adjustable speed drive is disposed in signal transmitting relation relative to an electric motor by an electrical conduit having a predetermined length, and wherein each single-phase circuit of the three-phase, low-pass filter includes an inductor having input and output nodes, a first resistor electrically coupled in parallel to the inductor, a second resistor having input and output nodes, and wherein the input node of the second resistor is electrically coupled to the output node of the inductor, and a capacitor having input and output nodes, and wherein the input node of the capacitor is electrically coupled to the output node of the second resistor, and wherein the low-pass filter is electrically coupled to the electrical conduit and operable to substantially filter out frequencies that tend to excite the natural resonant frequency of the electrical conduit.

Abstract: An additive sound synthesis process for generating complex, realistic sounds is realized in a computationally efficient manner. In accordance with one aspect of the invention, polyphony is efficiently achieved by dosing the energy of a given partial between separate transform sums corresponding to different channels. In accordance with another aspect of the invention, noise is injected by randomly perturbing the phase of the sound, either on a per-partial basis or on a transform-sum basis. In the latter instance, the phase is perturbed in different regions of the spectrum to a degree determined by the amount of energy present in the respective regions of the spectrum. In accordance with yet another aspect of the invention, a transform sum representing a sound is processed in the transform domain to achieve with great economy effects achievable only at much greater expense outside the transform domain. Other transforms besides the Fourier transform may be used to advantage.

Abstract: A security device which is particularly suitable for motor vehicles is proposed. It comprises an electronic control unit (10) for controlling the functions of an apparatus to be protected, at least two sensors (U.sub.1, U.sub.2) for detecting specific operating states of the apparatus to be protected and a circuit (42) to which the output signals of the sensors (U.sub.1, U.sub.2) are fed. The circuit (42) carries out an exchange of data with the electronic control unit (10) in order to control its operational capability, the output signals of the sensors (U.sub.1, U.sub.2) influencing the exchange of data according to the detected operating state such that the electronic control unit (10) is only operative in a prescribed operating state of the apparatus to be protected. For this purpose, the circuit (42) has a memory (44) in which at least one predetermined code is stored.

Abstract: To improve charging efficiency of a storage battery and extend the service life of each of vehicle laps, the output voltage of a generator is adjusted to a first voltage value (13.5 V, for example) without grounding a voltage dividing point B when the duty ratio for turning on or off a field current detected by a detector is lower than a predetermined value and to a second voltage value (14.5 V, for example) by grounding the point B when the detected duty ratio is higher than the predetermined value.

Abstract: A garage door opening and closing apparatus having improved operational safety is disclosed. The apparatus includes a control circuit which responds to a number of input stimuli to generate commands to open and close a garage door as well as to stop garage door movement. Three relays respond to the commands via drive circuitry to actually connect door operating voltages to the windings of a door controlling motor. By redundancies in the operation of the three relays, faults in the operation of those relays result in safe door operating conditions. Additionally, the control circuitry upon issuing a door stop command, performs a test to determine whether or not the door is still moving. If the door is still moving, door up commands are generated by the control circuitry to place the door in a safe position.

Abstract: A control circuit for controlling the speed and stopping time of an electronically commutated motor having a rotary drive member and a stator having at least one phase coil, electric power being supplied to the phase coils by current supply elements which are controlled by the control circuit to obtain a given phase voltage and a given load angle during operation. In response to a supplied stop signal the control circuit decelerates the drive member by controlling the phase voltage and load angle so as to produce a deceleration force which changes dependent on the speed of the drive member; there being a high speed range over which the deceleration force increases to a maximum value as speed is reduced; an intermediate speed range over which the deceleration force remains substantially constant at the maximum value as speed is further reduced, and a low speed range over which the deceleration force reduces as speed is still further reduced to a stop.