Abstract: A motor control apparatus for a hybrid vehicle, wherein during operations of automatic start-up/stop control of the engine, at restarting of the engine when a start-up condition is satisfied, the control means controls to said electric motor so as to start up engine by the electric motor only, during operation of automatic start-up/stop control of the engine, at restarting of the engine when a start-up condition is not satisfied, a controller controls to drive a starter motor and an electric motor by outputting an engine activation signal so that the starter motor is always assisted by the electric motor during engine start. The electric motor is started by voltage supplied by the main battery. By such system, the engine and motor are not collectively controlled, and simplification of the system is achieved. Further, synchronism of the engine and motor is obtained and quietness at restart of the engine also results.

Abstract: A variable speed fan motor controlled by a reference voltage comprises a reference voltage circuit and a differential amplifier. The reference voltage circuit outputs a proper reference voltage that is inputted to a negative terminal of the differential amplifier. When the reference voltage inputted to the negative terminal of the differential amplifier is reduced, a drive voltage outputted by the differential amplifier is increased to thereby increase the speed of the fan. When the reference voltage inputted to the negative terminal of the differential amplifier is increased, the drive voltage outputted by the differential amplifier is reduced to thereby decrease the speed of the fan.

Abstract: A thermal control variable speed fan motor comprises a rectifying circuit, a differential amplifier, and a temperature-sensing circuit. The rectifying circuit converts a speed signal detected from the fan into a voltage that is outputted to a negative terminal of the differential amplifier. A positive terminal of the differential amplifier is connected to the temperature-sensing circuit that is connected in series with a power source. The temperature-sensing circuit includes a temperature sensor having a resistance that varies in response to a change in ambient temperature. When ambient temperature rises, the drive voltage outputted by the differential amplifier increases and the fan speed increases. When ambient temperature reduces, the drive voltage decreases and the fan speed decreases, thereby changing the fan speed linearly by thermal control.

Abstract: A fan motor having a two-step speed control includes a buffer circuit, a control voltage terminal, and a fan. The buffer circuit is mounted between a voltage source and a source terminal of the fan. The buffer circuit includes a resistor and a transistor. The control voltage terminal is connected to a transistor of the buffer circuit to control conduction or non-conduction of the transistor, thereby changing the voltage of the source terminal of the fan. The varying voltage waveforms are smooth linear waveforms such that rotating speed of the fan is increased or decreased gradually during switching between a low-speed operation mode and a high-speed operation speed.

Abstract: A motor controller improves reliability and enables stable and high-accuracy control by detecting a current value running through the motor detected by current detectors by preventing changes in ambient environment, particularly the influence of temperature variations. The arithmetic and control unit of the motor controller has a storage unit for storing current detection characteristic compensation data for compensating for fluctuations in the characteristics of the current detectors, a current value computing device for computing current values by correcting detection currents from the current detectors, and a device for computing and generating drive signals for controlling the switching of the power elements based on the computed current values.

Abstract: In a known method for regulating a delivery variable of a pump, which is driven by an electric motor operated with alternating current of variable frequency, especially via a converter, the input power of the motor is measured as the actual value for the delivery variable and is regulated by comparison with a desired value. To avoid the influence of the temperature of the motor on the delivery variable at constant input power, according to the invention upon a change in the temperature in the motor a corresponding compensating variable is taken into account in the control for the purposes of correcting the input power. As an alternative, associated values of the input power and the speed of the motor at a predetermined desired pressure value are determined empirically and stored as a table, and during operation a value of the input power belonging to a measured or approximately calculated speed of the motor is retrieved from the table as the desired value for regulating the input power.

Abstract: A motor driving control device that achieves as high as possible phase coil energization level while preventing thermal destruction of the power switching element by using precise thermal detection of a portion of the power switching element inside a switching module of the control device. An electric power loss Lt at the switching element is used for calculating a saturation temperature Tjgoal. On the basis of the saturation temperature, Tjgoal, and a time constant &tgr; of temperature rise, an instant junction temperature Tjnow is calculated. A difference Error between the instant junction temperature Tjnow and an upper temperature limit value Tjmax is calculated. In a motor locked condition, a coefficient Kt is calculated for the target torque, the target torque being equal to the required torque multiplied by Kt. Kt is based on the Error for calculating the target torque. If Error is greater than or equal to a predetermined value, K3, Kt is set to be 1, even if Kt is in excess of 1.

Abstract: A circuit disconnecting member that blows on receiving radiant heat generated by heat generation of a motor circuit is connected to a motor circuit, the blowing temperature being a temperature lower than a thermal breakdown temperature of a combustible substance around the motor circuit, whereby the motor circuit is shut off, when the peripheral part of the motor circuit generates heat, to stop heat generation before an insulation cover or a contact case is subjected to thermal connection breakage. An engine starting device is prevented from being subjected to a thermal breakdown by a small-size, simple construction and an inexpensive technique without impairing the mounting layout properties of the starting motor and the performance within the rated use.

Abstract: The motor power consumption and motor winding temperature are monitored and, responsive thereto, the flow of refrigerant to the motor is controlled so as to control the temperature of the motor. The motor power consumption in the primary control input because it anticipates cooling requirements whereas the motor temperature indicates current cooling requirements. The cooling flow may be provided in an on-off manner or there may be a constant flow portion with an on-off parallel cooling flow path.

Abstract: A motor starter thermal-compensation control is disclosed in which an ambient temperature sensor is positioned to sense ambient temperature and provide an ambient temperature signal in a motor starter. Additional temperature sensors are mounted in thermal communication with each bus bar in a motor starter and to monitor the temperature of each pole. A microprocessor is connected to each of the temperature sensors and periodically receives the temperature signals to monitor change in operating temperature of the motor starter. The control adjusts the output of the motor starter based on the change in the operating temperature so as to maintain a constant output as the ambient temperature increases, or the internal resistance of the device increases with temperature increase. In order to adjust the output, the system increases the FLA ampacity to compensate for the temperature increase.

Abstract: This invention relates to a control device for a motor output (DM) comprising electrical control and protection switchgear (CD) for a motor (M) receiving contact information (a1, a2, a3) connected to the electrical switchgear (CD) and its output controlling at least one control device (KM) that controls starting or stopping the motor (M) and also receiving information from a remote sensor (C) and communicating with a “master” network controller (PLC) through a communication bus (B), characterized by the fact that the electronics (E) comprises means of locally controlling the control device (KM) stopping the motor (M) as soon as the remote sensor (C) is activated during an operating phase of the motor output and means of sending information corresponding to this stop on the bus (B) to the “master” module (PLC).

Abstract: A motor starter control is disclosed in which an ambient temperature sensor is positioned to sense ambient temperature and pole temperature sensors are used to sense each pole temperature in a motor starter. A microprocessor is connected to periodically receive the temperature signals and monitor change in operating temperature of a motor starter system. The microprocessor models cool down characteristics of the motor starter system and compares currently acquired ambient and pole temperature signals to the modeled cool down characteristics and determines whether the motor starter system is cooled to a safe start temperature. The control ensures that a maximum number of starts per hour is not exceeded and prevents attempted starts that not only waste energy, but further prolong time to a successful start.

Abstract: A temperature controlled radiating fan comprises a temperature detector, a control circuit, a power control circuit, a regulator, a loading circuit, and a driving circuit. The temperature detector is connected to the control circuit. The output of the control circuit is connected to the power control circuit. The output of the power control circuit is connected to the loading circuit. The output of the loading circuit is connected to the driving circuit. The power control circuit is connected to the regulator. Thereby, the rotary speed of the fan motor is varied according to a voltage variation, so that the characteristic of the rotary speed of the fan motor is linearly changed.

Abstract: In order to control the operating voltage of a fan in electrical equipment, the temperature of an output diode (D) of an output circuit of the power supply of the electrical equipment is monitored. The operating voltage of the fan is controlled as a function of the component temperature of this physical element such that up to a limit temperature, which is in the region of the maximum permissible component temperature of a physical element which absolutely becomes the hottest, the operating voltage of the fan is regulated at a constant, minimum level. The operating voltage is then regulated to rise continuously and rapidly up to a maximum operating voltage at which, although the component temperature of the physical element which absolutely becomes the hottest is still above the limit temperature, it is below the maximum permissible component temperature of this physical element, however.

Abstract: A combination circuit breaker/motor starter includes a circuit breaker trip unit having a microprocessor and at least one removably connectable contactor or other functional module. The functional module is encoded with an identifier, such that the microprocessor can determine the type of functional module and appropriate configuration parameters, such as trip times, for the particular application of the functional module. Power is supplied continuously to the trip unit during motor overload or short circuit conditions.

Abstract: A locomotive for model-based incipient failure detection includes at least one replaceable unit and at least one sensor to generate signals representative of current engine conditions related to the at least one replaceable unit. A controller includes an embedded replaceable unit model algorithm. Current operating conditions and ambient conditions are utilized within the algorithm to generate a model-based predicted value for the at least one sensor. The controller compares the at least one sensor signals to the model-based predicted values for calculating deviations therebetween and detecting incipient failure of the at least one replaceable unit.

Abstract: A software logic controller using flowchart programming includes exception handling elements for handling exception conditions in a manufacturing process. Exception handling is programmed using a Begin Exception element to start monitoring the occurrence of a specific exception condition and an End Exception element to stop the monitoring process. Monitoring is conducted once during every scan cycle of the computer as long as the Begin Exception element is still active.

Abstract: A speed control device for a cooling fan and a method of control thereof are disclosed, in which temperature and noise among other factors are taken into consideration, whereby changes to the voltage/current of power supply provided to the cooling fan are used to adjust the speed of the cooling fan. The speed is reduced as much as possible within the permissible range of system temperature to minimize the noise generated from the cooling fan. When the temperature exceeds the permissible range, the speed of the cooling fan is accelerated to reduce system temperature.

Abstract: A temperature sensor is located close to each of a plurality of switching elements. Each of the elements opens and closes a current supplying line from a power supply to a three phase SR motor. A generating circuit of a instruction value for the driving current of the motor generates a target value (It) of the driving current so as to achieve a requested power of the motor and an allowable value of the driving current on the basis of the highest temperature sensed by the temperature sensors. The circuit outputs the target value as an instruction value of the driving current when the target value is smaller than the allowable value and outputs the allowable value as an instruction value of the driving current when the target value is greater than the allowable value.

Abstract: A motor control processor controls motor spin-up in a disk drive by detecting environmental temperature at the spindle motor of the disk drive, controlling commutation phase advance to generate substantially maximum torque if the detected environmental temperature indicates that maximum torque is needed, and adjusts the commutation phase advance for optimal efficiency after the maximum torque is no longer needed. Following motor start and reaching operational speed, the motor is operated in a steady-state maximum operating efficiency mode unless sensed environmental temperature indicates that maximum torque, rather than maximum efficiency, is needed. The system determines that the need for maximum torque has passed either when a predetermined time interval after motor start expires or by repeatedly polling motor temperature information.

Abstract: A drive circuit with signal detection capability for a DC brushless fan motor is disclosed. The drive circuit comprises a Hall effect sensor for detecting the magnetic polarity of the rotor in the fan motor, first and second transistors connected to first and second magnetic coils respectively for alternately generating magnetic fields to continuously rotate the rotor of the fan motor and further comprises a series RC circuit and a field effect transistor for detecting the operation of the fan motor. A signal detection line connected to the source of the field effect transistor is provided for detecting the operation of the fan motor. When the fan motor is running normally, the signal detection line presents a square wave signal with frequency proportional to the rotating speed of the fan motor. When the motor stops running, the signal detection line always presents a high level signal.

Abstract: Torque is distributed by calculating first and second torque commands using a requested torque and a ratio of speeds of first and second wheels and limiting them in accordance with respective torque command approved ranges and approved change rates; converting the limited torque commands to horsepower commands and limiting them in accordance with respective horsepower command approved ranges and approved change rates; and converting the limited horsepower commands to present torque commands. Maximum horsepower available is determined by using an engine speed to determine a nominal amount of available horsepower; applying a desired load status signal and an actual engine load status signal to a proportional-integral regulator; and using the nominal amount of available horsepower and an output signal of the regulator to determine the maximum amount of available horsepower.

Abstract: Backward movement of a heavy motorcycle is assisted by a starter motor for cranking an engine of the motorcycle. A backward drive control system includes a pulse width modulation circuit for supplying operating current to the starter motor in a controlled manner and a device for estimating operating temperature of the starter motor based on the current supplied to the starter motor. When the estimated temperature reaches a predetermined maximum temperature, the operation of the starter motor is compulsorily stopped and prohibited for a certain period or until the starter motor is cooled down to a certain temperature level. Overheating of the starter motor is effectively prevented without using a temperature sensor for measuring the operating temperature.Moreover, chattering of the starter motor does not occur because its operation is prohibited for a certain period after the starter motor is once compulsorily stopped.

Abstract: A brushless direct current fan includes a driving circuit having a Hall device having at least one output terminal connected to the base of a first transistor with the collector of the first transistor connected to a first winding of the fan and also connected to the base of a second transistor via a resistor. The collector of the second transistor is connected to a second winding of the fan. A square wave generation circuit is provided to be coupled to the collector of one of the first and second transistors. The square wave generation circuit is comprised of a current limit resistor and a third transistor wherein the base of the third transistor is connected to the collector of the one of the first and second transistors of the fan via the current limit resistor to obtain an electric signal therefrom which is converted to a square wave signal by the square wave generation and output at the collector of the third transistor.

Abstract: A motor controller controls the operation of an electric motor (28). The motor controller includes sensors (30, 97, 102) for sensing at least one dynamic operating characteristic of the motor and for providing a signal indicative of the at least one sensed dynamic motor operating characteristic. A variable gain regulator (190) receives a current command request signal having a value and provides a motor current control signal having a value functionally related to the value of the received current command request signal and a gain control value. A gain scheduler (196) is operatively coupled to the variable gain regulator (190) and to the sensor (30, 97, 102) for providing the gain control value to the variable gain regulator (196) in response to the sensed at least one dynamic motor operating characteristic to thereby control the amount of gain of the variable gain regulator (190).

Abstract: Rotor temperature in induction motors is estimated without the need for any direct temperature sensors, by using only computer calculations based on data readily available in the motor control center. Thus for any given motor, it is generally possible to predetermine a relationship between rotor temperature and rotor resistance, so that by determining rotor resistance, rotor temperature can be calculated. Rotor resistance, in turn, can be calculated from measured information relating motor slip and motor torque. Any of several methods can be employed for determining torque and slip. Temperature estimation can be obtained by use of equivalent circuit methods, and additional relationships can be obtained from a simplified equivalent circuit.

Abstract: Disclosed herein is a monolithic fan controller circuit which provides the following features: a special start-up routine for the fan; a fan fault detector; a thermal fault detector; an automatic speed controller; a minimum speed controller; a routine for attempting to clear temporary fan faults; and a controllable drive signal frequency. A start-up control circuit provides an initial high duty-cycle kick to the fan in order to initiate the rotation of the fan. A temperature sensor, which may be external or internal to the monolithic fan controller, supplies a signal which is proportional to measured temperature. This signal is used to control the output pulse width of a pulse-width modulator (PWM) or control the frequency of a pulse frequency modulator (PFM). The PWM or PFM output signal regulates the speed of the brushless (or brush) DC fan motor. In a preferred embodiment, the monolithic fan controller has 8 pins.

Abstract: This invention is directed in general to a locomotive diesel engine, and more specifically, to a method and apparatus for performance based assessment of a locomotive diesel engine.

Abstract: A controller drives a fan's motor to proportionally control fan speed based on changes in heat output from electrical components in a local environment. The controller is connected to a temperature sensor and the fan motor. The temperature sensor senses local environment temperature, while exhibiting a lag time. The controller provides closed loop control and implements a system pole which cancels out the temperature sensor lag time during steady state operations. The controller implements an integration of a difference between sensed temperature and a reference temperature to generate the system pole.

Abstract: A starting system and method for a gas turbine engine checks to determine whether ignition has occurred in a light off window. If such ignition has not occurred, a starter coupled to the gas turbine engine is deactuated to allow deceleration through the light off window while still attempting to ignite gases in the combustor. By providing an extra interval of time to achieve ignition, start reliability is enhanced.

Abstract: A circuit for supplying/interrupting power to robots in a robot control system which controls two robots by use of one controller. This circuit for supplying/interrupting power to robots includes a common power interrupting circuit, which simultaneously interrupts power supplies to two robots, and power interrupting circuits for individual robots, which individually interrupt power supplies to individual robots. When a common cutoff switch circuit in the common power interrupting circuit is operated on the basis of an emergency stop signal or an alarm signal, two relays are deenergized at the same time, thereby simultaneously interrupting power supply to two robots. When one of the cutoff switch circuits in the power interrupting circuit for each robot is operated by an emergency stop signal or an alarm signal, only one corresponding relay is deenergized, thereby interrupting power supply to one appropriate robot.

Abstract: A locomotive control system for performance assessment of a locomotive engine includes a controller and at least one sensor coupled to the controller. The at least one sensor is located proximal to the locomotive engine so as to gather actual performance data from the locomotive engine. The controller monitors locomotive current operating conditions and utilizes the current operating conditions to calculate predicted performance. The controller compares the predicted performance output based upon the current operating conditions with the actual performance data to monitor any substantial deviations therefrom.

Abstract: Attention is given to that, when a catch-in state occurs while a vehicle window glass is moved upward, a current flowing in a motor serving as a drive means for moving the vehicle window glass increases. In an apparatus for comparing a predetermined current threshold value with a current detected by a motor current monitor unit to recognize a catch-in state, the predetermined current value is made variable, and the catch-in state can be correctly recognized without an erroneous operation even when the external environment changes, or when the window glass is moved upward for the first time. In particular, a current value obtained at the start of the motor and changed by a circumference temperature of the motor is set as a current threshold value, and the current threshold value is set each time the motor is started. A current value in an upward moving operation is estimated each time the window glass is moved downward to set the current value as a current threshold value.

Abstract: The electric motor is part of an electro-mechanical actuating system that is especially applicable to power assisted automotive steering systems.A phase for monitoring the cooling of the electric motor is carried out when the motor is inoperative in order to produce a value for a restarting temperature. This value is used during an electrical motor thermal control phase when the motor is operative. This prevents the motor from exceeding a maximum permissible temperature.

Abstract: A power steering system includes a housing and a first member supported by the housing for movement relative to the housing. A second member is supported by the housing for movement relative to the housing and the first member. Steerable vehicle wheels are moved in response to relative movement between the first and second members. A power steering resistance control system resists relative movement between the first and second members with a force which varies as a function of variations in vehicle speed. Material is located in a chamber circumscribing the first member. The material has a viscosity which varies as a function of the magnitude of an energy field acting thereon to vary the resistance to relative movement between the first and second members. The energy field is applied to act on the material with a magnitude that varies as a function of the vehicle speed.

Abstract: An apparatus for driving and controlling a motor which moves a movable portion of a vehicle by driving force of the motor. The apparatus includes a drive stopping circuit for comparing a value of current detected by a current detection circuit, which detects drive current of the motor when the movable portion is being moved, with a predetermined comparison current value, and for stopping driving of the motor at a time when a detected current value exceeds the comparison current value. The apparatus also includes a comparison current varying circuit for varying the comparison current value based on a temperature of an environment of the movable portion. Since it is possible to carry out temperature compensation based on ordinary drive current and lock current of the motor, the comparison current value can be set within a wide range.

Abstract: The residential structure ventilating apparatus disclosed herein employs a variable speed exhaust fan. The speed is responsive to a sensor which detects air temperature at the exhaust port. The fan is energized when the sensed air temperature rises above a first preselectable temperature and the external environmental air is cooler that the air at the exhaust port. The fan speed is increased progressively from about one-half full speed at the preselected turn on temperature to full speed at a predetermined higher temperature. The fan is turned off when the exhaust port temperature falls below a second preselected temperature, lower than the first preselected temperature or when the external environmental temperature rises above the inside temperature, the fan speed being essentially constant between the first and second preselected temperatures.

Abstract: In a thermal overload protection system three system variables are sensed and provide the inputs required for a calculation conducted in real time at one second intervals. The system variables include ambient inlet air temperature to the alternator, alternator stator winding embedded sensor temperature, and traction motor armature current. A traction motor current limit is calculated using the inlet air temperature and the sensor temperature. The thermal overload is then controlled in response to the traction motor current.

Abstract: A starter protection circuit for a starting device of an internal combustion engine of a vehicle has a thermoswitch assignable to a starter, a relay which is activated by the thermoswitch when the thermoswitch is operative and interrupts a starter operation and a relay operating key which after assumption of a cold switching state of the thermoswitch can operate again the starter.

Abstract: A thermal control variable speed DC brushless fan, especially a DC brushless fan which may change speed in accordance with the temperature sensed, includes a fan speed control circuit and a DC brushless fan. The fan speed control circuit is composed of drive ICs, operation amplifiers, transistors, diodes, capacitors resistors, and a thermal sensor. Under normal conditions, the change in the fan's rotation speed relation to the temperature is almost linear, but when the thermal sensor is open or shorted the speed control circuit of the fan causes the fan to operate at full speed to maintain a cooling effect.

Abstract: A monitoring system for an electric motor including a temperature sensor (5) for monitoring the operating temperature of a motor, a memory (4) in which is stored the absolute maximum operating temperature and a predetermined maximum permitted operating temperature of the motor, and an indicator (6) for indicating the sensed temperature as lying: a) within a safe operating range, below the predetermined maximum permitted operating temperature; b) within a hazardous operating range, between the predetermined maximum permitted operating temperature and the absolute maximum operating temperature; and c) at or above a dangerous operating range, lying at or above the absolute maximum operating temperature. The monitoring system further includes a recorder (93) for recording the number of times the motor is operating beyond the predetermined maximum permitted operating temperature and the number of times the motor is operated beyond the absolute maximum operating temperature.

Abstract: The present invention features a system and method for preventing overheating of a motor and/or power amplifier of a material handling vehicle by controlling the performance of the vehicle as a function of motor and/or power amplifier temperature. Temperature sensors are connected to the motor and power amplifier for determining their operating temperatures. A controller is connected to each temperature sensor and to the motor for controlling acceleration of the motor as a function of either or both temperatures, so that both the motor and the power amplifier will not overheat. In controlling acceleration of the motor, the invention provides a mechanism for changing acceleration by discrete steps or continuously according to a performance curve which may be linear or otherwise.

Abstract: A hydraulically assisted power steering system subject to variance in steering effort due to temperature change is compensated to give consistent response at all temperatures. A hydraulic control valve is coupled to an electromagnetic device which controls the steering effort as a function of energization current. The current is adjusted in accordance with temperature to compensate for temperature changes. A microcomputer controller stores empirical data relating to the effect of temperature on steering effort and calculates the current adjustment necessary for any measured system temperature. In one embodiment, the temperature is not measured directly but is derived from the deviation of energization current from the theoretical desired current, which deviation is a function of temperature. The effect of voltage variations is also compensated for.

Abstract: A stepping motor unit includes a stepping motor of the type wherein the interior of the stepping motor is filled with an oil, a detector for detecting the temperature of the oil in the stepping motor, a device for varying an upper limiting value of the rotational speed of the stepping motor and an upper limiting value of the rotational acceleration of the stepping motor in view of a current viscous condition of the oil based on the temperature detected by the temperature detector, and a driver for driving the stepping motor at a rotational speed and a rotational acceleration which fall in ranges, respectively, not exceeding the upper limiting values. The stepping motor unit thus constructed has rapid and accurate response characteristics and is capable of operating reliably without falling out of step even when the environmental temperature varies in a very wide range. A rotary control valve incorporating such stepping motor unit is also disclosed.

Abstract: A miniature motor having a positive temperature coefficient thermistor comprising a stator having a permanent magnet serving as a field, a rotor formed by winding a plurality of rotor windings on a rotor core, brushes supported by a motor cover plate for feeding current to the rotor windings by making contact with a commutator, positive temperature coefficient thermistor for controlling current to the rotor windings, in which the positive temperature coefficient thermistor has one pole on one pole surface thereof, and a plurality of independent split poles corresponding to the rotor windings on the other pole surface thereof, and is fitted to an end face of the rotor core;the rotor windings being connected to the split poles of the positive-coefficient thermistor in such a manner as to be connected in series with the split poles of the positive-coefficient thermistor.

Abstract: Thermal overload of a motor is avoided by measuring temperature and, when a limit temperature is exceeded, reducing the phase "window" within each power cycle during which the motor is energized. The limit temperature is sensed by a temperature sensor which is warmed either by heat conduction through a cooling body or by an air stream from the motor. The overload protection apparatus requires no measuring resistance in the load circuit.

Abstract: An apparatus for starting and controlling a motor. The apparatus includes means for monitoring the load current values in each phase of a motor. These means can include an apparatus such as a current transformer. The apparatus utilizes a circuit for modeling a motor and estimating the temperatures of the motor's windings and housing. THe circuit preferably is defined by a programmed microprocessor. The estimated temperatures are based on the load current values and time. These estimated temperatures are then compared to allowable limits and, based on the comparison, the motor is either stopped or allowed to run.

Abstract: A method for determining the temperature of a brushless d-c motor with a permanent-magnet rotor and an at least three-phase winding with electronic commutation including determining the curve of an EMF induced in a winding during one phase wherein the winding is in currentless condition, and evaluating the temperature therefrom.

Abstract: A linear actuator includes an electric drive motor which is connected to a drive screw through a gear train. Rotation of the drive screw causes the drive nut to move axially in order to impart axial motion to an extension member. Limit switches function to disengage power to the electric motor upon the extension member reaching the outer or inner limits of its stroke. Also, a thermal sensing element located in the windings of the electric motor interrupts power to the motor upon the heat-up of the motor windings above a predetermined temperature, as when the drive nut jams or locks up. A sealed housing contains the drive screw, drive nut and extension to protect against entry of dust. The housing has reaction surfaces which cooperate with the drive nut to permit linear movement of the nut while holding the nut against rotation.

Abstract: A device for monitoring the temperature in a DC shunt-wound motor for driving rotary printing machines includes a temperature measuring sensor formed of a DC shunt winding of the DC shunt wound motor.