摘要:
A power steering device capable of obtaining a high rotary speed in the medium low torque range of an electric motor without incurring a drastic increase in manufacturing cost. The power steering device generates an auxiliary steering power by oil pressure that is generated by a pump which is driven by an electric power motor. The electric motor is a triple-phase brushless motor, with its angle of rotation being detected by the Hall sensors. The field coils are provided with the electric current from a drive circuit which is driven by a drive signal from the motor drive control part. The motor drive control part controls the electric motor by PWM control in the low medium speed rotation range and controls the electric motor by phase advance angle control, with PWM duty at 100 percent, in the medium high speed range.
摘要:
A solid state controller is provided for a winch and includes fault detection for several parameters and overload interrupt controlled by the controller. The system uses a single controller that can be programmed for several different products and utilizes MOSFET switches for alternating the direction of current supplied to the motor.
摘要:
A wireless battery-operated window covering assembly is disclosed. The window covering has a head rail in which all the components are housed. These include a battery pack, an interface module including an IR receiver and a manual switch, a processor board including control circuitry, motor, drive gear, and a rotatably mounted reel on which lift cords wind and unwind a collapsible shade. The circuitry allows for dual-mode IR receiver operation and a multi-sensor polling scheme, both of which are configured to prolong battery life. Included among these sensors is a lift cord detector which gauges shade status to control the raising and lowering of the shade, and a rotation sensor which, in conjunction with internal registers and counters keeps track of travel limits and shade position.
摘要:
A low power consumption wireless data transmission and control system 10 is disclosed and in one embodiment, is used to automatically articulate a shade 24 by use of a transmitted command signal 14. The system 10 contains a receiver/detector 18 which is selectively activated for only certain intervals of time thereby allowing substantially all of the previously transmitted signals 14 to be received while reducing the power consumed by the detector 18 during periods in which the signals 14 are absent.
摘要:
A method and means for producing a control voltage for controlling a direct current motor makes use of a tachometer voltage providing two ninety degree phase shifted tachometer signals. From these are derived four coding signals comprising the tachometer signals and their inverse signals. The four signals are combined to produce a triangular signal, which is differentiated. The differentiated signal and its inverse are applied through a switching circuit to produce a control signal.
摘要:
An electronic control for regulating the operation of a two-speed motor in a heat transfer system such as a heat pump or air conditioner. The control receives high and low demand signals from a thermostat and a motor unit operates at high and low speeds in response to, respectively, high and low speed signals. The control includes an initial timer, high and low speed operators, and a speed change delay. The initial timer detects the occurrence of a demand signal from the thermostat, counts a predetermined period of time, and responsively issues an initial timing completion signal. The high and low speed operators detect the timing completion signal as well as either a high or low thermostat demand signal. One of the operators then responsively issues either a high or low speed signal to the motor unit. The motor unit accordingly operates at a high or low speed. The speed change delay detects the change in a thermostat demand signal from a high to a low state or a low to a high state. The delay disables the high and low speed operators for a predetermined period of time, responsively enabling either the high or low speed operator to begin after the delay period has passed.
摘要:
An apparatus and method of protecting a centrifuge from rotor overspeed and resultant mishap by computation of the rotor moment of inertia is disclosed. In the preferred embodiment, a centrifuge is driven by a rotor mounted on a shaft which shaft is in turn driven by a constant current motor. A tachometer for detecting angular velocity of the drive shaft is used. A desired and ultimate centrifuge operating speed is selected by the operator. The times at which the rotor passes through discrete speeds are recorded and from the time difference the moment of inertia is computed. The moment of inertia can thereafter be utilized to discretely identify or "finger print" rotors to disqualify certain rotors from use in particular centrifuge protocols and establish gross limits of centrifuge operating speed.
摘要:
Apparatus is provided for controlling the velocity of a portion of a load in accordance with a trapazoidal-shaped velocity versus time profile. The apparatus includes a d.c. motor having an output shaft for driving the load; instrumentalities for sensing angular displacement of the motor output shaft; a microprocessor including a clock for generating successive sampling time periods, means for providing first counts respectively representative of successive desired angular displacements of the motor output shaft during successive sampling time periods to cause the load portion to be moved in accordance with a predetermined trapezoidal-shaped velocity versus time profile, means responsive to the sensing means for providing second counts respectively representatiave of actual angular displacements of the motor output shaft during successive sampling time periods, and means for compensating for the difference between the first and second counts during each successive sampling time period and generating a pulse width modulated control signal for controlling the d.c. motor, the motor control signal causing the actual angular displacement of the motor output shaft to substantially match the desired angular displacement of the motor output shaft during successive sampling time periods, whereby the load portion is moved substantially in accordance with the predetermined trapezoidal-shaped velocity versus time profile; and a signal amplifying device for operably coupling the motor control signal to the d.c. motor.
摘要:
Motor test circuit for supplying an error indication signal if the speed variations of a motor under test exceed predetermined limits. The circuit includes a frequency-to-voltage converter or other source of voltage proportional to the motor speed and a reference source derived from the converter's output signal so that the test results are independent from errors due to drift in the converter's parameters caused by time, temperature, or other effects.
摘要:
A mounting arrangement for a rotor speed photosensor assembly includes a mounting ring fixedly attached to the stationary element of the centrifuge. The mounting ring has a cutout portion thereon which is adapted to receive a photosensor mounting board which carries the photosensor assembly. Adjustable mounting elements connect the photosensor mounting board to the mounting ring and permit the precise adjustment of the sensor with respect to the ring to thereby dispose the sensor in a predetermined optimal speed-sensing relationship with respect to the rotor.