Abstract: A compact surgical handpiece comprises a motor energizable for moving a tool member, electric energy supply actuable for energizing the motor and a manually actuable trigger actuable to control motor operation. A motor control circuit interconnects the motor electric energy supply and trigger for running and braking the motor in response to actuation and release of the trigger. The control circuit includes a compact regulated voltage supply, a motor overcurrent limiting feature and a motor braking feature which is effective even if the operator fails to fully disconnect the electrical supply to the motor upon releasing the trigger.

Abstract: An apparatus which serves to control automatically the speed of a pump acding to the temperature of the oil being pumped from a reservoir. The controller is comprised of a parallel bank of thermal switches each connected to its dropping load resistor through a series isolation relay which places the load on a motor which drives the oil pump directly related to the viscosity of the oil in the reservoir.

Abstract: An automatic controller for use with a motor. A switch interconnects the motor and a power source for selectively establing an electrical connection therebetween. A relay coil is connected to the motor. When the motor is connected to the power source via the switch, the relay coil latches the switch in a steady connecting state. When increased current overdraw of the motor is sensed, a current-limiting thermistor limits or interrupts the current flow across the relay coil, to set the switch to a disconnect state and to cause the motor to stop.

Abstract: A fan control board having a central low voltage wiring center as well as a safety interlock for electric heaters. The interlock uses diodes to insure proper fan operation in the event of miswiring of the heater sequencers. Another feature is a quick connect for the time delay relay which permits easy insertion and removal thereof for replacement and/or cleaning. Diode circuits are provided in both the circuit to normally power the fan motor as well as in the circuit to power the PTC resistor which closes the fan motor circuit with the circuit which powers the PTC resistor also being connected across the fan motor circuit to provided rectified power to the fan circuit and permit the fan motor to turn on concurrently with the application of power to the PTC resistor to prevent the heater from being turned on prior to the fan.

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: A motor control method for determining the temperature of a motor wherein the operation and nonoperation times of the motor are monitored, an estimated temperature is determined as a function of the monitored times and predetermined temperature rise and temperature fall characteristics of the motor, and the motor is stopped and/or an alaram signal is generated if the estimated temperature exceeds a predetermined temperature.

Abstract: The invention pertains to a control circuit for a collectorless DC motor where at least one power transistor (14, 16) is input-connected to each stator coil (2, 4) of the motor; said transistor is driven by at least one rotor position sensor, especially a Hall generator having commutation circuits to commute the motor current, and where a blocking protection device is provided to interrupt the motor current in an overload or blockage. The blocking protection device (26) has at least one semiconductor circuit (30) carrying the motor current which is switched through or blocked depending on its temperature.

Abstract: An apparatus for pumping fluid such as an integral pump/motor is provided. A housing having an inlet and an outlet has a rotatable assembly including an impeller located within and adapted to rotate within the housing to move fluid through the housing from the inlet to the outlet. Secured to the exterior of the housing is a stationary assembly for applying an electromagnetic field through the housing to and around the impeller to rotate the impeller and thereby to cause it to move fluid through the housing.The apparatus is for use in a cooling system, such as a cooling system of an automobile engine, to pump fluid through the cooling system. A temperature sensor is provided for sensing the temperature of the fluid within the cooling system. An electronic control, responsive to the temperature sensor, supplies electrical power to stationary assembly.Also, a method of circulating fluid within a system, such as a cooling system of an automobile engine, is disclosed.

Abstract: A switching signal, either for the switching off of the print head (20), or for a lowering of the operating frequency, or for a switching-on/switching-off control of a blower motor, is employed in connection with an installation of a temperature surveillance of a print head (20) or of a hammer block based on an electromagnetic coil construction. In order to achieve a more precise, a quicker and a more individual measurement determination, the electromagnetic coil (3), coordinated to each print element (1), is in each case switched during a current-passing pause to a primary constant current source generating a voltage (U.sub.p). A coil voltage drop (U.sub.s) at the electromagnetic coil (3) generates a reference signal (26) at the comparator (27) setting the temperature limit. The reference voltage (U.sub.ref) is received as a binary logic signal in an intermediate data memory storage (30).

Abstract: A refrigeration control apparatus especially adapted for use in conjunction with cryogenic coolers includes a brushless variable speed drive motor for powering a mechanical cooler-compressor and electronic control circuitry coupled to the motor allowing motor speed and hence cooling rate to be responsive to changes in the temperature of the volume sought to be cooled. A signal corresponding to sensed temperature is compared to a reference signal derived from motor speed. The difference therebetween used to vary the duty cycle of a high frequency pulse train. The pulse train is used to modulate the drive current applied to the motor through pulse position switching circuitry to vary the speed of the drive motor. High and low motor speed limits are provided along with sensor failure protection circuitry to insure continuous motor operation between chosen limits.

Abstract: Stall current levels are determined according to measured peak currents occurring immediately after the energization of a motor. By utilizing a fractional value of the determined peak current value, the stall current is determined each time the motor is energized to compensate for variations in current flowing in a motor at different ambient temperatures.

Abstract: A safety device for a heating apparatus detects the errors of the input power-supply voltage, failures of the respective heating device and control device, and displays the detected failure and safety stops the associated apparatus. The safety device quickly and safely stops only a faulty heating function if the heating apparatus further has a plurality of heating functions, and allows the other normal heating functions of the heating apparatus to be used.

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: Method and apparatus for monitoring the temperature of a resistor in a resistive current controller. The heating and cooling rates for the resistor are determined and a predicted temperature of the resistor is automatically calculated at the beginning each time interval of consecutive time intervals by subtracting from the previous temperature prediction for the resistor the product of the cooling rate of the resistor and the time interval and adding the product of the heating rate of the resistor and the time interval. An actuating signal is produced when the predicted temperature of the resistor for a given time interval corresponds to a threshold temperature.

Abstract: A self-contained electronic air register controller can easily be mounted directly onto the outside of an air register. When so mounted, the controller engages the register's actuating lever and permits automatic opening and closing of the air register by way of simple programming instructions and/or by way of a temperature sensor. The controller comprises a small battery, a miniature electric motor with a gear/linkage mechanism operable to engage with and to move the register's actuating lever between its OPEN and SHUT positions, and a quartz-clock-based programming means.

Abstract: The present invention comprises a relay control circuit that provides highly efficient and reliable control for devices that perform in demanding applications such as space. Multiple levels of redundant function control are provided by redundant actuators that perform mechanical operations. Each actuator is driven by redundant motors for increased reliability. Motor current sensing is provided to determine arrival of the actuator at mechanical stops, which are located at the full deploy position. Limit switches also sense when the actuators are in the full deploy position. In addition, multiple control signal so are required to initiate certain critical operations. Critical operations also are performed redundantly for increased reliability.

Abstract: A motor actuator for use in an automobile air-conditioner for actuating air-mix door, includes an electric circuit for controlling the rotational speed of a motor depending on various conditions such, for example, as a vehicle compartment temperature, and a mechanical limit switch for limiting or restricting the extent of angular movement of the air-mix door, or an electric circuit for the limitation of the angular movement of the air-mix door. According to a preferred embodiment, a built-in switching unit having a mechanical switch disposed in a first housing for producing control signals for various components for the air-conditioner, and a motor actuator having a motor and an electric circuit disposed in a second housing are detachably assembled together by a locking lug and a mating retainer recess.

Abstract: A device and method for detecting the coil temperature of a direct-current motor by determining the resistance of at least one coil of the motor. The method includes measuring a parameter of the at least one coil while the motor is running. The measurement is made at a time interval in which the coil is without current. The measuring device includes a commutation circuit of the motor which generates a time interval used for measuring the current.

Abstract: A wiper system is disclosed for motor vehicles in which during normal wiper operation the windshield wiper moves back and forth between two reversing positions, but stops in a depressed parking position outside the wiping area after the power switch is turned off. According to the invention the parking position is changed in dependence on the temperature so that in low temperatures the windshield wiper does not enter the gap between the hood and the windshield. This prevents the wiper from being blocked by ice or snow in the gap. At higher temperatures, the wiper is parked in the depressed parking position as in the prior art.

Abstract: A manually controlled positive and reverse circulating fan is used in room, usually, when in summer to blow air is downward so that the cool air at the lower level can be spread into every corner of the room. In winter, the fan is operated reversely and the warmer air at higher level can be spread evenly down in the room, thus the room temperature can be kept even and the energy can be saved. However, because of the limitation of the room space shape, there are still spaces that the air flow can not reach. This design, with a periodic positive/reverse switch operation, controls the ceiling fan to operate positively or reversely in periodicity so that it may further improve, the function of stirring the air evenly. This design can be used also ventilators/for air intake/exist as well.

Abstract: The invention employs a stabilization circuit including a longitudinal branch with a series connection of a Zener diode and a resistor and in the other longitudinal branch with the series connection of a transistor and where the motor winding of the driving electric motor and the cross-branch is provided with a transistor and a corresponding series resistor. In the case of such an operating circuit without current control, the connection of the two modes of operation is advantageously achieved by operating a voltage divider, which comprises a series connection of a temperature dependent resistor element with a relatively small series resistor and a larger adjustable resistor, and in addition in each case again with a smaller series resistor, where this voltage divider influences directly the transistor which is connected in series with the winding.

Abstract: An electric motor comprising a motor overload protection such as a thermal switch and a main relay for controlling a multipolar switch in the voltage supply conductors of the motor. The thermal switch and the main relay are mounted in a control circuit in parallel with the voltage supply conductors. An auxiliary relay is coupled in parallel with the main relay and can connect an auxiliary motor via a contact arm when the thermal switch is switched off.

Abstract: A power unit for a battery-driven toy containing a battery power source for energizing a driving means through a power switch and a controlling circuit is disclosed, in which the controlling circuit comprises a circuit element for controlling said driving means and its movable operative contact, said circuit element being provided with a thermo-switch and a reset circuit for setting said movable operative contact into an OFF position through said thermo-switch.

Abstract: A thermistor circuit for sensing the temperature of an intermittent duty wound field motor is connected between the field and armature windings of the motor. When the field and armature winding currents are substantially zero (off duty), the resistance of the thermistor circuit is sampled by the motor controller, using the armature and field winding conductors.

Abstract: A device providing protection against over-currents in the windings of an electric motor having a rotor (3) and at least two windings (1, 2) comprises at least two parallel thermistors (17, 18) each mounted in series with at least one motor winding (1, 2).

Abstract: A motor speed control apparatus which is provided with means for performing the control to always apply to a motor a driving force smaller than a frictional load of a driving system which is driven by the motor and to apply to the motor a driving force larger than the frictional force of the driving system when the motor is accelerated.

Abstract: A closed-loop, temperature-controlled cooling system includes a Stirling cycle refrigerator driven by a dc motor, wherein the motor excitation derives from pulse width modulation. Temperature control of the cooling system is provided by a temperature-sensitive bridge circuit which responds to variations in temperature by generating an error voltage which effects a change in the modulator duty cycle. The amount of cooling is directly related to the average voltage applied to the motor, which is a function of the modulator duty cycle and the amplitude of the supply voltage. A compensation circuit is disclosed which responds to variations in the voltage amplitude of an unregulated supply by coupling an error signal to the bridge circuit to thereby affect the modulator duty cycle.

Abstract: A reversible electric motor is operatively arranged to drive an air circulating fan. Circuitry is provided to reverse the direction of rotation of electric motor periodically to provide alternating direction of air movement. Timing and reversal is provided by either a timing clock, a microprocessor, a thermal relay or a rotating disc which carries a pair of touch stops therein.

Abstract: A thermally released switching mechanism which in a simple fashion and at a precisely defined switching point clearly interrupts the current to the motor when a preset, highest admissible temperature is exceeded, at least until the actual temperature has once against fallen below the highest admissible temperature. The thermally released switching mechanism is comprised of a lever element made of a memory element which, upon exceeding the highest permissible temperature set value, lifts the brush from a commutator or a slipring. This mechanism preferrably employs a memory element with a two-way effect. This thermal switching mechanism is suitable both for commutator motors with hammer or tubular brush holder systems as well as for slipring motors.

Abstract: A method of controlling a three state apparatus such as an air compressor comprises a first actuating element e.g. a motor and a second actuating element e.g. a valve, said method including the steps of sensing a variable parameter such as temperature with a sensing means whilst the apparatus is operating in a first operational state, feeding a signal produced by the sensing means to a control device, comparing the signal in the control device with datum information to detect whether the variable parameter is at a value at or above a threshold value, sending a signal to the first actuating element when the variable parameter is below the threshold value whereby the state of operation of the apparatus is changed to an off operational state, sending a signal to the second actuating element when the variable parameter is at a value at or above the threshold value whereby the state of operation of the apparatus is changed to a low load operational state.

Abstract: A process for controlling the speed of an electric motor. A reference value of motor temperature is provided and directed to a summing junction. The actual temperature of the motor is sensed and also directed to the summing junction. The two values are summed and employed as a reference of motor current. This reference is directed to a second summing junction while the value of actual motor current is sensed. The actual value is also directed to the second junction. These last two values are summed at the second junction to provide a reference for adjusting motor speed.

Abstract: A sensor is provided in a hospital bed having a bed-mat made of movable particles. This sensor is to detect an excessive bead temperature in the case of a controller malfunction and to control the operation of a cooler. In the sensor, the circuit is so designed that an air compressor runs intermittently with the aid of timers while the sensor performs its functions at a temperature above the predetermined temperature level. The sensor also enables the compressor to run again when the temperature of the mat lowers to a level where a normal operation is possible to assure temperature control of the bed-mat even in the case of controller malfunctions.

Abstract: An apparatus for compensating for thermal expansion and contraction causing structural part size variations of machine components. The apparatus senses the displacement and temperature of various components of a machine which are designed to move relative to each other along one axis and adjusts this motion in predetermined manner depending upon the sensed displacement and temperature. A programmed control system is responsive to the sensed temperature and converts various sensor outputs to the necessary correction signals for application to the motor causing the relative motion.

Abstract: To provide for effective cooling of an automotive-type alternator and/or other equipment within an automobile, for example the radiator or other heat exchanger, even under external high-temperature conditions and low engine speed (n.sub.E), for example under idling conditions, the alternator phase windings (6, 7, 8) are connected to respective phase windings (16, 17, 18) of a three-phase squirrel-cage motor which is connected to a blower (2), preferably a radial-type fan, directing forced air circulation towards the alternator and/or the vehicle radiator, the alternator then being placed within the airstream of the radiator as well. A temperature and/or speed-responsive switch can be interposed between the alternator and the motor to energize the motor only if the temperature of the alternator and/or the engine, or other component, rises above a predetermined level, or if the alternator speed drops below a predetermined level.

Abstract: To control the operation of a machine tool, which has a tool bit cutting a workpiece, the temperature of a measurement spot or area, such as on the cut surface of the workpiece, is checked by an optical element which collects infra-red radiation and focuses it on a thermal sensor. The temperature read by the thermal sensor is registered in an evaluating device which generates a signal when a predetermined temperature condition is reached for discontinuing operation of the machine tool.

Abstract: A home security and garage door operator system includes a gas sensor for detecting the level of toxic gas in the garage. When the gas level exceeds a predetermined threshold the garage door is automatically opened. Lock out circuitry is provided for preventing the door from being accidentally closed as long as the gas sensor detects an excessive level of toxic gas in the garage. A two button transmitter is used to sequentially close the garage door and set a security alarm subsystem. Warning devices are activated if the security alarm is attempted to be set without the garage door and windows in the home being closed. Once the security alarm has been set, the lock out circuitry also disables the garage door motor control circuitry until the security alarm is first deactivated. The transmitter generates a digital pulse train according to a preselected code, with the operation of the dual buttons changing the state of a particular control bit in the pulse train.

Abstract: A solid-state, multistage temperature controller for automatically controlling the operation of fans to maintain the temperature of an associated engine within preselected limits.

Abstract: When the temperatures of engine coolant and outside-air are above respective predetermined values immediately after the engine has stopped, a fan to cool the engine is operated for a predetermined time interval, thereby preventing engine compartment from being heated excessively.

Abstract: A circuit, safe against an overload, for incrementally varying the power to an electric blower motor used for heating, ventilating and conditioning vehicles, having a PTC resistor in series with other series resistors in the circuit.

Abstract: A control system for operating a bidirectional gate driven by a reversible electric motor includes an overload protection circuit to prevent motor current overload produced by gate obstructions and the like. The system includes control switches for operating gate opening and gate closing circuits which respectively energize the motor for rotation in opposite directions. The safety circuit includes a motor current sensing device and a first comparator which compares the level of sensed motor current with a temperature adjusted, selectable reference value and delivers a motor disabling signal to the opening and closing circuits if the sensed value exceeds the reference level. The safety circuit also includes a second comparator which compares the sensed current level with another reference value to produce the disabling signal in the event that the selected reference value of the first comparator is incorrect.

Abstract: In an apparatus for controlling the speed of the blower motor in response to the difference between the temperature setting and the temperature inside the vehicle, the maximum speed of the blower motor is limited in accordance with the temperature of engine coolant. Consequently, the quantity of air issuing from the blower is always such that it does not make the passengers feel uncomfortable.

Abstract: The device comprises a temperature sensor placed in contact with a heat-carrying fluid circulating in the engine and a control device responsive to the sensor for the purpose of supplying power to the motor or motors driving the ventilator or ventilators in accordance with variations in the temperature of the heat-carrying fluid. The temperature sensor comprises a component which is sensitive to a continuous range of temperatures and this component is connected, as an input element, to a continuous regulating loop regulating the power supplied to the motor or motors. This loop comprises a threshold circuit which determines the lower value of the temperature range.

Abstract: Disclosed is an apparatus for controlling a motor unit including a variable-speed reversible main motor for driving a load and a subsidiary motor for driving a fan. The control apparatus comprises a temperature sensor circuit sensing the temperature of the main motor and generating a first output signal when the temperature of the main motor exceeds a first predetermined level, a second output signal when the main motor temperature exceeds a second predetermined level higher than the first predetermined level and a third output signal when the main motor temperature drops to a level lower than the first predetermined level, and a control circuit connected to the temperature sensor circuit for energizing the subsidiary motor in response to the first output signal, deenergizing the main motor in response to the second output signal and deenergizing the subsidiary motor in response to the third output signal.

Abstract: The electric drive motor of an internal combustion engine radiator cooling fan that is arranged to be energized by the output potential of a dynamoelectric generator driven by the engine is supplied with operating potential in such a manner that the average supplied drive motor power is directly proportional to engine speed while engine temperature is within the range between a predetermined first temperature and a predetermined higher second temperature and the engine is operating within a selected speed range.

Abstract: A thermal current limiting controller for use in protecting the electric drive motor, controller and battery of an electrically propelled vehicle against damage thereto resulting from excessive temperature conditions. The controller is arranged to calculate the temperature condition of the motor as a function of the current flow therethrough and more specifically, integrates the current flow with respect to time so as to provide a control signal proportional to the calculated temperature condition. The control signal is utilized to limit the amount of current the drive motor is permitted to draw notwithstanding an attempt by the operator of the vehicle to cause the drive motor to draw greater current. The controller further includes an indicator which is responsive to the control signal to provide a variable indication of the temperature condition so as to warn the vehicle operator of the magnitude of the undesirable heating of the drive motor and, thus, the impairment of the system capabilities.

Abstract: This invention relates to a method of and means for conveying and measuring gases for gas analysis operations by means of a pump, which conveys the gas with constant volume per working cycle. The means for this purpose, as used in connection with gas analysis instruments, consists of a cyclically operating gas delivery pump with an electric motor drive which is connected to a frequency transmitter for pre-setting the speed of rotation.

Abstract: In a flue damper control system, a thermistor 64 responsive to flue temperatures upstream of the damper 12 is incorporated in a trigger circuit for a triac 52 which controls energization and deenergization of the damper motor 17, the damper motor being fully energized only when the flue temperature is below a predetermined value and there is no demand for heat by the thermostat 36.

Abstract: Apparatus for detecting the speed of an electric motor that forms part of a web transport system employs a bridge circuit adapted to measure the back emf of the motor. Thermally induced changes to the armature resistance of the motor are compensated for by varying the bridge resistances, such changes being identified by comparing the bridge circuit signal output with a reference signal.

Abstract: An indication is derived of the thermal properties of a constant load motor during acceleration and deceleration periods without actually monitoring thermal properties of the motor. The motor is accelerated and/or decelerated in response to command pulses so there is a rotational speed change during the acceleration and deceleration periods. In respnse to the command pulses, the charge on a capacitive means is changed so the charge change is proportional to (1) the change of the motor rotation speed during the periods and (2) the reciprocal of the periods. In response to the charge change there is derived an indication of the thermal properties as a function of the electrical, thermal and mechanical characteristics of the motor.

Abstract: An SCR is connected across one of three line contacts which couple the power lines to the windings of an a.c. motor. When the line contacts are opened to shut down the motor, heating current is applied to one of the motor windings through the SCR to raise its temperature above the ambient dew point. The SCR is fired every cycle of the line current and the firing angle is controlled in response to a command signal to provide the proper amount of heating current in the motor winding. The command signal is generated by summing a preselected reference signal with a negative feedback signal which is indicative of the amount of motor heating.