Abstract: A photoacoustic-ultrasonic dual-mode endoscope includes: a probe and a probe driving unit, wherein the probe includes: a coaxially configured optical and electromagnetic rotary waveguide assembly including an optical fiber, the optical fiber including a core and a cladding, and a conductive path coaxially arranged with the optical fiber; a scanning tip located at an end of the coaxially configured optical and electromagnetic rotary waveguide assembly and configured to deliver a laser beam to an object to be examined and detect a photoacoustic signal and an ultrasonic signal generated from the object to be examined; and a plastic catheter surrounding outer surfaces of the coaxially configured optical and electromagnetic rotary waveguide assembly and the scanning tip, wherein the conductive path includes: a first conductive path including a portion coaxially arranged with the optical fiber; and a second conductive path including a portion coaxially arranged with the optical fiber and insulated from the first co

Abstract: A motor driving apparatus comprises a motor including a rotor that is rotatable and has a magnet whose outer peripheral surface divided in a circumferential direction is magnetized in multiple poles with alternating different polarities, and a position detecting unit having a first detecting element, a second detecting element, a third detecting element and a fourth detecting element, each of which detects a magnet pole, a driving unit that drives the motor on the basis of signals output from the first to fourth detecting elements, and a controlling unit that obtains a rotational quantity of the motor on the basis of signals output from the first and second detecting elements and that outputs a control signal of the motor to the driving unit on the basis of the rotational quantity of the motor.

Abstract: An axial fan includes a fan frame, an impeller and a motor. The fan frame has a frame body, a base and plural connecting members. The base is disposed at the center of a side of the frame body. The connecting members connect the frame body to the base. The impeller is accommodated in the frame body and disposed on the base. The impeller has a rotating shaft, a hub and plural blades disposed around the hub. The motor is disposed on the base and connects with the rotating shaft to drive the impeller to rotate. When the impeller rotates forwardly, the airflow is induced to flow through the connecting members, blades, and one side of the frame body away from the base. When the impeller rotates reversely, the airflow is induced to flow through the side of the frame body, blades and connecting members.

Abstract: A machine tool including a cooling fan measures an input power source voltage to the machine tool and an input current to the cooling fan. If the measured current value is outside a predetermined current value range corresponding to the measured voltage value, the machine determines that the rotational speed of the cooling fan has decreased.

Abstract: A counter is started on the falling edge of a tach pulse. This counter counts to the rising edge of a second tach pulse, such as the next tach pulse. During the duration of the tach pulse the FPGA calculates the RPM of a motor. In this way, during each commutation period, a RPM is calculated. The present system performs a RPM calculation during each commutation period and/or tach pulse duration.

Abstract: A motor control device includes a motor lock state determining unit configured to determine whether a motor is in a rotation lock state; a position hold state determining unit configured to determine whether the motor is in a position hold state; a lock detection invalidation determining unit configured to invalidate the determination of the lock state when the motor is in the position hold state and when a predetermined condition is satisfied; a position error correction unit configured to correct an error of a target stop position of the motor when the determination of the lock state is invalidated; and a motor control unit configured to change a rotation direction of the motor in a time shorter than a time in which the motor lock state determining unit determines the lock state when the motor is in the position hold state after the error is corrected.

Abstract: An encoder having a function for detecting noise which may affect an internal signal of the encoder, without using a noise detecting circuit within the encoder, whereby the cost and size thereof may be reduced. The encoder has a detecting part adapted to detect the movement of an electric motor or a driven object; a signal processing circuit adapted to process a detection signal from the detecting part and obtain positional data of the motor or the object; and a transmitting part adapted to transmit the positional data from the signal processing circuit at regular time intervals and a fluctuation component calculated on the basis of the positional data, to external equipment. The signal processing circuit has a fluctuation component detecting circuit adapted to detect a fluctuation comment included in the calculated positional data, and the detected fluctuation component is transmitted to the external controller as an amount of noise.

Abstract: An operator ratchet mechanism for effecting reciproctable lateral movement if an element of a geared drive train in a door, gate or barrier operator. The operator ratchet mechanism can be utilized to cause disconnection between the geared drive train and an electric motor of the door gate or barrier operator to enable the door gate or barrier to me manually moved, and subsequent reconnection between the geared drive connection and electric motor. An embodiment of a tilt door operator which enables disconnection and reconnection between a geared drive train and an electric motor of the operator by effecting lateral displacement of an element of the geared drive train is also disclosed.

Abstract: An electric machine including a housing, a stator mounted within the housing, a rotor rotatably mounted within the housing relative to the stator, and a vibration sensor arranged within the housing. The vibration sensor includes a sensing member configured and disposed to detect vibrations of the electric machine.

Abstract: A fan rotary speed controlling device includes a base voltage generating circuit, a first voltage generating circuit, a second voltage generating circuit and a compensation controlling circuit. The base voltage generating circuit receives a pulse width modulation signal and outputs a base voltage signal. The first voltage generating circuit receives the pulse width modulation signal and generates a first voltage signal according to the pulse width modulation signal. The second voltage generating circuit receives a fan rotary speed signal and generates a second voltage signal according to the fan rotary speed signal. The compensation controlling circuit outputs a voltage deviation compensation signal according to the first voltage signal and the second voltage signal. Hence, the fan rotary speed controlling device provides a stable rotary speed.

Abstract: An electric drive machine includes an electric drive system including an internal combustion engine and an electrical power generator coupled to the internal combustion engine. An electronic controller is in control communication with the electric drive system and is configured to determine an estimated temperature of a rotor of the electrical power generator at least in part by determining a rotor temperature rise estimation, compare the estimated rotor temperature to a rotor temperature threshold, and initiate an excessive temperature action if the estimated rotor temperature is greater than or equal to the rotor temperature threshold.

Abstract: A fan rotary speed controlling device includes a base voltage generating circuit, a first voltage generating circuit, a second voltage generating circuit and a compensation controlling circuit. The base voltage generating circuit receives a pulse width modulation signal and outputs a base voltage signal. The first voltage generating circuit receives the pulse width modulation signal and generates a first voltage signal according to the pulse width modulation signal. The second voltage generating circuit receives a fan rotary speed signal and generates a second voltage signal according to the fan rotary speed signal. The compensation controlling circuit outputs a voltage deviation compensation signal according to the first voltage signal and the second voltage signal. Hence, the fan rotary speed controlling device provides a stable rotary speed.

Abstract: A fan system includes a pulse signal generation portion and a plurality of fans. Each of the plurality of fans preferably includes a motor portion; an impeller arranged to be rotated by the motor portion; a drive circuit arranged to drive the motor portion; a rotation detection portion arranged to detect rotation of the motor portion; and a rotation rate control circuit arranged to, based on a reference pulse signal supplied from the pulse signal generation portion and an actual rotation pulse signal supplied from the rotation detection portion, exercise feedback control on a rotation rate of the motor portion in accordance with a period of the reference pulse signal.

Abstract: An indicating instrument for a vehicle includes a step motor including a field winding, a pointer, a stopper device for stopping the pointer, which is rotating in a zero-reset direction, at a stopper position, a detecting device for detecting induced voltage of the field winding at each of detecting points, a control device for performing zero-reset control, whereby a drive signal is controlled to rotate the pointer in the zero-reset direction. In a state of abnormal detection in which the induced voltage larger than a predetermined set value is detected at a zero point; and the induced voltage equal to or smaller than the set value is detected at a next detecting point to the zero point, the control device assumes synchronization loss of the step motor and continues the zero-reset control until an assumptive electrical angle corresponding to a rotational position of the pointer reaches the zero point.

Abstract: A heat dissipation device has a main controller and a fan module having a motor coil, a connection interface, a PWM driving circuit and a fan monitor chip. The connection interface has a control pin, an error report pin, a power supply pin and a ground pin. The control pin receiving a control signal. The PWM driving circuit adjusts current magnitude and current direction of the motor coil to drive the fan module. The fan monitor chip is connected to the connection interface and the PWM driving circuit, receives the control signal, generates and sends PWM signals to the PWM driving circuit according to the control signal and sends an acknowledgement signal via the control pin after receiving the control signal. The main controller can check if the control signal is correctly received based on the acknowledge signal.

Abstract: An indicating instrument includes a step motor having a field winding, a pointer, a reduction gear mechanism having gears, a stopper device for stopping the pointer at a stopper position, a detecting device for detecting induced voltage of the winding at each of detecting points that include a zero point corresponding to the stopper position, a control device for controlling a drive signal, and an updating device for updating the zero point based on the induced voltage during zero-reset control performed by the control device. The control device performs return control, whereby the pointer rotates to a return point in an indication value increasing direction and then returns to a waiting point in a zero-reset direction to stand by at the waiting point, prior to zero-reset control, whereby the pointer rotates from the waiting point in the zero-reset direction.

Abstract: In a closure panel control apparatus, an ECU controls a rotational speed of an electric motor, which provides a drive force to drive a closure panel in an opening movement and a closing movement thereof. The ECU obtains a vehicle speed measured with a vehicle speed sensor and receives a command signal from a switch, which is operable by an occupant of a vehicle to command the opening movement or the closing movement of the closure panel. The ECU controls the rotational speed of the electric motor based on the measured vehicle speed that is obtained at the time of receiving the command signal from the switch.

Abstract: A fan speed control system for a machine is disclosed. The control system may include a fan to provide a flow of coolant to the machine. The system may further include a first sensor configured to generate a first signal indicative of an operational parameter of the machine, a second sensor associated with the fan to generate a second signal indicative of an actual speed of the fan, and a controller communicatively coupled to the fan, the first sensor, and the second sensor. The controller may be configured to generate a third signal indicative of a desired fan speed based on the first signal, and a fourth signal indicative of a difference between the desired fan speed and the actual fan speed. The controller may drive the fan based on the third signal and the fourth signal.

Abstract: A method for controlling a fan speed is disclosed. The fan cools a CPU in a computer. The method includes defining a CPU-max-temp value of a CPU, such that the first fan speed is linearly enhanced with the increase of a real temperature value of the CPU, when the real temperature value of the CPU is lower than the CPU-max-temp value, and changing the CPU-max-temp value to a higher CPU-max-temp value in a basic input output system. A second fan speed is linearly enhanced with an increase of the real temperature value, when the real temperature value is lower than the higher CPU-max-temp value. The second fan speed is less than the first fan speed at the real temperature value.

Abstract: Overspeed protection of sensorless electric drives is needed in the aerospace industry. Methods for overspeed protection may include software implementations, hardware implementations or combinations thereof. Typical high-speed rotating machinery is designed to sustain overspeed operation of up to 50% beyond maximum normal operation. This requirement leads to substantial penalties in weight and volume. The methods of the present invention may allow for an opportunity to reduce this overspeed design to about 5 to 15%, typically about 7%.

Abstract: A system and method is provided for monitoring the speed signals of a first fan and a second fan. The system includes a selection signal generation device, a logic gate, a counter and a control device. The selection signal generation device outputs a selection signal to the logic gate having two different states. Based upon the speed signals and the state of the selection signal, the logic gate outputs an output speed signal representing the speed signal of the first fan or second fan to the counter. The counter converts the output speed signal to a digital speed datum. The control device calculates the speed of the first fan or the second fan according to the selection signal and the digital speed datum. The changes of state of the selection signal permit the system to obtain the respective speeds of the two fans in different access cycles.

Abstract: An apparatus provides protection to an electric traction motor of a vehicle. The vehicle has a first powertrain and a second powertrain. The first powertrain includes an engine and it is coupled with a first set of road wheels. The second powertrain includes the electric traction motor and it is coupled with a second set of road wheels. The apparatus comprises a revolution speed sensor operatively associated with the electric traction motor. The apparatus also comprises at least one controller. The controller includes control logic for modifying operation of the vehicle in response to monitoring the revolution speed sensor to restrain the vehicle speed from increasing in such a manner as to limit revolution speed of the electric traction motor to revolution speed values below an allowable upper revolution speed limit.

Abstract: A method and apparatus for determining the velocity of a rotating device is described herein. The apparatus includes a magnet assembly affixed to a rotating shaft of a rotating device and a circuit assembly. The circuit assembly includes a circuit interconnection having a sense coil and sensors affixed thereto. The circuit assembly is adapted to be in proximity to the magnet assembly, wherein the magnet assembly combines with the circuit assembly to form an air core electric machine such that voltages generated from the sense coil exhibits an amplitude proportional to the velocity.

Abstract: The invention provides a device to generate an rpm-dependent signal, or a tachogenerator, having a plurality of magnet elements with alternating polarity which are arranged and distributed around the circumference of the rotor shaft. The magnet elements preferably take the form of a magnetic ring which has alternatively polarized sections and is held on a support attached to the rotor shaft. The tachogenerator of the present invention has at least one coil parallel to the axis which is arranged on a second supporting device at an axial distance to the magnet elements. The magnets and coils are arranged spatially relative to each other and can be rotated in relation to each other with the rotation of the rotor shaft in order to induce an rpm-dependent signal in the coils. In accordance with the invention, a signal displacement device is provided which superimposes a DC voltage on the signals induced in the coils in order to generate a voltage-displaced signal.

Abstract: A spatial notch filter is described that adapts in accordance with changes to an angular velocity of a rotating component within a manufacturing system. In a manufacturing system, noise may appear in feedback signals due to spatially distributed physical features in the system, such as imperfections in the components or sensors. This noise may be concentrated in a frequency band that changes as the angular velocity of rotating system components changes. The invention provides techniques for filtering this noise with one or more notch filters, and for adapting the center frequency of the notch filter as a function of angular velocity. The center frequency of the notch filter tracks the noise when the noise frequency changes.

Abstract: A downhole compressor system is disclosed for assisting in extracting gas from the well. The system comprises a compressor 14, an electric motor 10 for driving the compressor 14 which motor has a stator winding and a rotor 12 and, in use, is lowered into the well together with the compressor. A control system 18, which when in use is disposed outside the well, is connected to the stator winding for controlling the current supply to the motor 10. The control system 18 receiving a signal indicative of the speed and phase of the rotor from a feedback sensor 16 mounted for rotation with the rotor 12. In the invention, the feedback sensor is a current generator having a permanent magnet 16a mounted for rotation with the rotor 12 and a second stator winding 16b connected to the control system 18.

Abstract: A speed sensor for an electric motor detects the variation in the electric field of the armature due to commutation to produce an output signal indicative of the speed of rotation of the motor.

Abstract: A method of starting a brushless DC motor 12 at any initial speed (A) establishes a initial stator-field speed and setting a counter of synchronization, (B) measures a speed of a rotor of the motor, (C) compares the speed of the rotor with the stator-field speed to determine if the rotor is synchronized with the stator-field. If the rotor is not synchronized with the stator-field, the method includes (a) re-setting the counter of synchronization, (b) increasing an acceleration portion of motor current (Iacc) to enhance torque, (c) setting the stator-field speed higher than the rotor speed, (d) calculating a period of an open-loop timer, (e) calculating a value for a load portion of the motor current (Ild), where total motor current I=Iacc+Ild, (f) performing commutation based on the open-loop timer and returning to step (B) until the rotor is synchronized with the stator-field.

Abstract: A circuit is arranged to pulse-width modulate the duty cycle of a power supply signal that is used to control the rotational speed of a fan in a temperature-controlled system. The control system includes an edge detector for monitoring a tachometer signal that is provided by the fan. The tachometer signal is monitored at a rate (e.g., one Hertz) that is substantially lower than the rotational speed of the fan. The control system also includes a timer for recording time intervals between selected edges of a monitored tachometer signal. The fan speed is determined from the recorded time intervals. The control system extends the duty cycle of the pulse-width modulated signal to ensure that the fan power remains stable over the period in which the tachometer signal is to be monitored. Maintaining fan power ensures the validity of the tachometer signal during the period that the fan power is maintained.

Abstract: A method of starting a brushless DC motor 12 at any initial speed (A) establishes a initial stator-field speed and setting a counter of synchronization, (B) measures a speed of a rotor of the motor, (C) compares the speed of the rotor with the stator-field speed to determine if the rotor is synchronized with the stator-field. If the rotor is not synchronized with the stator-field, the method includes (a) re-setting the counter of synchronization, (b) increasing an acceleration portion of motor current (Iacc) to enhance torque, (c) setting the stator-field speed higher than the rotor speed, (d) calculating a period of an open-loop timer, (e) calculating a value for a load portion of the motor current (Ild), where total motor current I=Iacc+Ild, (f) performing commutation based on the open-loop timer and returning to step (B) until the rotor is synchronized with the stator-field.

Abstract: The apparatus comprises a motor, a motor driver, a pulse generator, an MCU incorporating a memory, and an open/close switch. The MCU compares the motor load torque detected at the time of opening or closing the window, with a reference value stored in the memory; when the torque considerably exceeds the reference value, it concludes that there is a foreign object caught in the window and stops or reverses the motor and inactivates the function of foreign object detection until there is no transitional torque fluctuation in the transitional period from a start of the motor. The MCU compares the torque variation per unit time with a permissible variation range stored in the memory; when the number of successive torques which fall within the permissible variation range reaches a maximum permissible number of such successive torques stored in the memory, it activates the function of foreign object detection.

Abstract: An operating circuit (1) for controlling the speed of a cooling fan motor (3) for computer cabinetry (7), and for determining an under-speed condition in the fan motor (3) comprises a control circuit (15) which controls a variable output signal generator circuit (18) for outputting a pulse width modulated signal corresponding to the desired fan speed for switching a switching circuit (8) in a power supply circuit of the fan motor (3) for pulse width modulating the power supply to the fan motor (3). A monitoring resistor (R1), a capacitor (C1) and a circuit (12) provides a tachometer signal to the operating circuit (1). A gate circuit (22) gates the second and fourth pulses of the tachometer signal to a counter (20) which counts clock pulses from a clock signal generating circuit (19) between the rising edges of the second and fourth pulses which are in turn stored in a register (23) for comparison with a reference count by a comparator (25).

Abstract: A method for the electronic monitoring and control of the opening and closing operation of electrically operated aggregates, particularly of window lifters and sunroofs in motor vehicles, is described. A regulating unit of the aggregate is connected to a vehicle electrical system. The regulating unit is directly influenceable via electrical operating control elements, i.e., via a control-electronics interfacing circuitry connected to the aggregate. The control electronics interfacing circuitry is supplied with a signal that is a function of an accelerative force acting on a motor-vehicle body. The signal which is a function of the accelerative force, is determined from a motor speed of the regulating unit.

Abstract: A power drive unit having drive roller elements that transport cargo and a sensor that detects motion of the cargo, e.g., the speed at which the cargo is transported, where the sensor operates substantially independently of the motion of the-drive roller elements. Specifically, the power drive unit comprises a motor, an output shaft driven by a motor, at least one drive roller element fixedly mounted on the output shaft, the drive roller element thereby driven by the motor, a sensor frictionally coupled to the output shaft conditionally permitting relative rotation between the sensor and the output shaft, and a motion detector that detects motion of the sensor. Associated electronics are configured to remove power from the motor driven roller elements where cargo is jammed or parked upon them, thereby increasing the useful lifetimes of the motor and the drive roller elements of the power drive unit.

Abstract: Apparatus for monitoring fan speeds within a computing system includes a tachometer turning with the fan, providing a tachometer signal including a number of pulses during each revolution of the fan. This tachometer signal is provided as an input to a signal generator in the form of a flip-flop, which generates a square-wave signal having transitions between high and low levels corresponding to tachometer signal pulses. The square-wave signals are provided as inputs to separate input ports of a microprocessor. These input ports are sequentially sampled at a rate providing at least two samples per period of the fastest square-wave signal, so that transitions of each square wave signal during a predetermined time interval can be detected and counted. For each input port, the number of counted transitions is compared to a stored acceptable value to establish whether the fan is operating in an acceptable speed range.

Abstract: An excimer laser device which is capable of keeping the rotational speed of a fan constant and uniformizing a laser gas flow between main discharge electrodes even when the pressure of a laser gas filled in a casing varies. The excimer laser device includes a casing filled with a laser gas; a pair of main discharge electrodes disposed in the casing for producing an electric discharge to discharge-pump the laser gas at a high repetition rate; a fan for producing a high-speed laser gas flow between the main discharge electrodes; bearings, the fan having a rotatable shaft rotatably supported by the bearings; a motor for actuating the fan; a rotational speed detecting device for detecting a rotational speed of the fan; and control device for controlling at least one of a voltage and a frequency to be supplied to the motor based on the rotational speed of the fan detected by the rotational speed detecting device, thereby to control the rotational speed of the fan at a constant level.

Abstract: An integrated control and diagnostics system for a controlled system (e.g., a motor) includes a diagnostics module and a controller coupled to the motor. To optimize operation, the diagnostics information signal is used to modify the control provided by the controller as required. Moreover, the output of the control module is coupled to the diagnostics module so that the health assessment made by the diagnostics module can be based at least in part on the output of the controller. The invention uses a model-based diagnostics approach that allows integration of control algorithms with diagnostics algorithms to intelligently trade off optimizing performance to avert or accommodate failures, and to meet performance requirements in a wide range of applications.

Abstract: A method for controlling non-synchronous actuators using a first and second estimate of the position of the actuator to create a variable position estimate window between which the actual position of the actuator is always bound. The first and second estimates of position are calculated based on the maximum and minimum speeds at which the actuator could be moving in each of first and second directions, and further wherein motion of the actuator in a saturated direction is disabled for as long as the first and second estimates converge at one of two final positions.

Abstract: A fan speed pulse filter is used for a PWM fan. The filter comprises a comparator, a latch circuit and a synchronizer. The fan unit, including a tachometer pulse output, is controlled by a PWM signal for determining the fan speed. By comparing the PWM signal with a reference voltage, the comparator generates a reset signal. The latch circuit, coupled to the comparator and the fan unit, receives the reset signal and the tachometer pulse and outputs a filtered tachometer pulse containing no phantom pulses. Furthermore, a synchronizer generates an output signal without interruption when the PWM signal is switched off.

Abstract: High resolution and accuracy of the measured values for detection of the position, speed and/or acceleration of a drive is ensured. The tolerances are determined and considered in signal evaluation on a partitioned basis. Measurement errors caused by inaccuracies of the signal generator due to manufacturing difficulties are greatly reduced or eliminated such that use of signal generators without particularly high quality specifications is possible. Thus, use of less exact components in generation and detection is possible.

Abstract: The variable frequency drive of a motor monitors pulse generator feedback while the motor is stopped and an electromechanical brake is set. When the pulse generator feedback exceeds a predetermined level indicative of brake failure, tie controller actuates the motor to operate in zero servo mode and maintain the load. An alarm is also sounded, allowing an operator to safely lower the load.

Abstract: A method for determining the active power (P) of asynchronous electric motors of winning and conveying equipment in underground mining. According to the invention, particularly easy and accurate determination of the instantaneous active power of the motors is obtained by storing the individual motor characteristic (P(n); M(n)) of each motor in a computer, by detecting the instantaneous speed (n, n') of the motor with the aid of a tachometer and by comparing this speed with the characteristic stored in the computer, the active power being derived from the torque value or power value assigned to the detected instantaneous speed, as stored in the computer. This particularly rapid and simple calculation of the power value does not require any readings to be taken at the power supply to the motors.

Abstract: An absolute angular position calculator for a rotating motor and a velocity control apparatus adopting the same, in which a separate pulse generator is not used. The motor is manufactured so that a modified frequency generator generates a modified frequency signal by removing one pulse from the predetermined number of pulses of a frequency signal, by changing a duty of one pulse of the frequency signal, or by changing a magnitude of the frequency signal. When the motor is in use, a modification point of the frequency signal is detected to produce an absolute angular position which is used for producing a disturbance correction value, via learning, to be stored. Velocity control is performed using the stored disturbance correction value.

Abstract: Drive device for closing parts in motor vehicles, especially sliding roofs, sliding/lifting roofs, and the like, with a drive motor, a sensor for determining the actual rpm of the drive motor and a clamping protection means for disengaging or for reversing the direction of rotation of the drive motor when the danger of clamping of the closing parts arises. The device has a speed controller which delivers an actuating signal which is a function of the deviation of the actual speed from a set speed of the drive motor. The drive device also includes an actuating means for varying the supply voltage delivered to the drive motor depending on the actuating signal of the speed controller, and an evaluation means which triggers the clamping protection means and which determines the existence of incipient clamping based on a signal which is dependent on the actuating signal of the speed controller.

Abstract: An opening/closing device for an automobile door comprising a speed sensor for detecting a moving speed of a door, a motor for applying an opening/closing assisting force to the door, and a control unit for controlling the driving of the motor, is provided. The control unit includes an acceleration computing unit for differentiating speed signals supplied from the speed sensor to compute accelerations and output acceleration signals and a control variable setting unit for setting control variables of the motor based on acceleration signals from the acceleration computing unit. Thereby, even if a torque sensor for detecting the operating force of a person operating the door is omitted, it is possible to generate control variables corresponding to acceleration signals which are equivalent to control variables corresponding to torque to drive the motor.

Abstract: A motor control system accurately and reliably controls the speed of a motor so that the motor operates in accordance with a predetermined motor speed profile, and therefore does not exceed a predetermined safe speed, decelerates at a controlled rate, maintains a safe minimum speed, and does not turn in reverse. If the motor operates out of these limits, a malfunction is indicated and the control system halts operation of the motor. The motor speed is determined using an electronic tachometer that analyzes the current in at least two phases of the motor to provide extremely precise and reliable velocity information for the motor.

Abstract: A low noise brushless dc motor has a rotor with a permanent magnet and a stator with a bearing system mounting a shaft for rotating the rotor. The motor has an operating circuit that includes a tachometer winding connected to the base of a first transistor whose collector is in series with a first resistor. The other end of the tachometer winding is connected to the base of a second transistor whose collector is in series with a second resistor.

Abstract: A safety window for a car which is capable of being automatically moved to its window closing position when the car speed exceeds a predetermined speed. The safety window comprises a control device for controlling the operation of the power window, which comprises a sensor for detecting a car speed, a comparator for comparing the car speed with a predetermined window closing car speed, and a power supply circuit for supplying the reference voltage to the comparator in an automatic window operation mode. The power supply circuit includes a select switch provided with a manual operation contact and an automatic operation contact, a reference voltage generator connected to the automatic operation contact and adapted to generate the reference voltage in the automatic window operation mode, and a limit switch adapted to send selectively the reference voltage from the reference voltage generator to the comparator.

Abstract: An apparatus and a method for protecting against a person being caught in a closing automatic door provides constant force values up to the few last millimeters of a door closing movement. A regulating error or difference signal representing the difference between the desired door motor speed and the actual motor speed is generated during the door closing travel and is continuously compared with a maximum predetermined tolerance signal produced by a target value generator and a door stop with subsequent reversing is initated if the tolerance value is exceeded. A learning travel computer, during periodic learning travels, determines values for mass compensation and for friction compensation and adds these values to generate a compensation signal which is added to the difference signal as an input to a regulator for controlling the door motor through an electronic switching system.

Abstract: A safety device for a tool powered by an electric motor. It has a main switch, electronic controls, and a tachometer-generator. In order to provide a device for switching off a motor as a function of motor speed that is simple and economical and that will retain the same nominal switch-off value for the total life of the device, a relay is wired in parallel with the motor and controls the supply of power to the motor through a relay contact.