6650 results about "Motor speed" patented technology

An apparatus for controlling the speed of an AC motor comprising a switch adapted to be coupled in parallel with power terminals for the AC motor; a capacitor coupled in series with the parallel combination of the switch and the motor; the capacitor adapted to provide an AC supply voltage from an AC source to the parallel circuit comprising the motor and the switch; and a control circuit for controlling the conduction time of the switch in order to vary the speed of the motor. The switch is preferably pulse-width modulated at a frequency twice the line frequency of the AC supply voltage, and the switch is turned on when the voltage across the AC motor is zero volts. The apparatus is operable to provide for continuously variable control of the motor speed while minimizing acoustic noise in the motor.

A drive circuit for step motors with bifilar windings is provided in which both parallel and series winding configurations for the stator coils are selectable by a motor controller based on the motor speed. For low speeds a series configuration is selected, while for higher speeds a parallel configuration is selected. Dynamic torque is optimized by the selection for more efficient motor operation with less drive current.

A surgical instrument includes a drive shaft, a motor for rotating the drive shaft, and a motor speed control. The motor speed control includes a first switch and a second switch which are in communication with the motor. The first switch is disposed over and in registration with the second switch. The first switch has an activated state such that the first switch sends a first signal to the motor. The motor rotates the drive shaft in response to the first signal. The second switch sends a second signal to the motor that varies the speed that the motor rotates the drive shaft in response to a force applied to the second switch by the first switch.

A double-ended variable speed blower for Continuous Positive Airway Pressure (CPAP) ventilation of patients includes two impellers in the gas flow path that cooperatively pressurize gas to desired pressure and flow characteristics. Thus, the double-ended blower can provide faster pressure response and desired flow characteristics over a narrower range of motor speeds, resulting in greater reliability and less acoustic noise.

A motor control system for a brushless and sensorless DC motor for driving a compressor, pump or other application, includes a protection and fault detection circuit for detecting a locked rotor and a rotor which has stopped because of lost rotor phase lock. The motor control system also includes an off-the-shelf motor control integrated circuit having an input for disabling power outputs to the motor phase coils. The protection and fault detection circuit uses a back EMF sampling circuit coupled to the motor phase coils and momentarily disables power to the motor phase coils, via the motor control integrated circuit input, to determine if the motor rotor is rotating. The system also monitors supply voltage, supply current, temperature, and motor speed limits to detect faults and protect system components.

A double-ended variable speed blower for Continuous Positive Airway Pressure (CPAP) ventilation of patients includes two impellers in the gas flow path that cooperatively pressurize gas to desired pressure and flow characteristics. Thus, the double-ended blower can provide faster pressure response and desired flow characteristics over a narrower range of motor speeds, resulting in greater reliability and less acoustic noise.

A valve actuator having an electric drive motor with a motor shaft and having an output shaft linked to the motor shaft to drive movement of a valve, the actuator further having a control system arranged to provide a first closed loop control of the actuator output shaft and including a controller coupled to a first position sensor to sense the position of the actuator output shaft, and to a second position sensor to sense the position of the motor shaft and to enable determination of the speed of the motor shaft, the control system being configured to respond to sensed signals from the first and second sensors and adjust the motor speed / position accordingly.

A low-cost CPAP apparatus in which, upon detection of the transition from inhalation to exhalation, the blower motor is de-energized to allow it to freewheel. When the pressure in the patient mask (or whatever interface is utilized) reaches a minimum pressure level during exhalation, the motor is re-energized and its speed is controlled so to maintain the pressure at a level suitable for exhalation. Upon detection of the transition from exhalation to inhalation, the motor speed is increased to provide higher pressures in the patient mask suitable for inhalation.

A method and apparatus are implemented in software to control motor speed as a function of available power in a DC source—inverter—AC motor system, i.e. to perform maximum power tracking of motor speed. An inverter or motor drive converts DC power from a DC source, such as a solar panel, to AC power, to power the motor. The inverter or motor drive is controlled by software, implemented either by programmable features built directly into the inverter or drive or by a separate programmable device connected to the inverter or drive, to track motor power as a function of source power. The software-controlled inverter or drive sets motor speed as a function of source power by sensing only a single parameter, the DC source voltage. The software-controlled inverter or drive samples the source voltage at preset intervals, and changes the frequency of the AC output of the inverter or drive to match or track the available power so that the motor operates at or near its optimum for any source voltage.

The present invention provides a system and method for automatically adjusting a continuously variable transmission (CVT) in a motorized vehicle. A microprocessor processor in the vehicle receives data about the operating status of the vehicle from a plurality. Examples of vehicle data include vehicle speed, motor speed, throttle position, current draw from a battery, and battery level. A servo motor is in mechanical communication with the CVT and provides an axial force to adjust the CVT. The microprocessor uses lookup tables of optimal set points for vehicle data to instruct the servo motor to adjust the transmission ratio of the CVT according to the vehicle data provided by the sensors.

A power factor corrected boost converter circuit includes a rectifier connectable to an ac input and having a rectified dc output provided across a dc bus, an inductor having first and second terminals connected in one leg of the dc bus, an integrated circuit comprising a control circuit for controlling a switch, the integrated circuit including a housing enclosing the control circuit, the integrated circuit having a power terminal, a ground terminal, a first control input terminal coupled to an output of the converter circuit, and a second control input terminal coupled to a sensor for sensing current in the dc bus and further having an output terminal connected to the switch, a boost rectifier diode having a first terminal, the diode coupled to the inductor, and a storage capacitor connected to the diode. The control circuit comprises a one cycle control circuit having an integrator reset by a clock signal for each cycle of the clock signal. The circuit further includes any or all of an inrush current limiting circuit for limiting the current through the inductor to a value below a predetermined level, a fan motor speed controller and a housekeeping power supply controller.