Abstract: A movable barrier operator having a motor controller (10) and motor (11) that control selective movement of a movable barrier (12) also has an obstacle detector (14) that utilizes an automatically determined excess force threshold value to permit reliable detection of an obstacle under a wide variety of operational circumstances, including changing physical circumstances, aging components, temperature variations, and motor runtime. In a preferred embodiment, a characteristic force value for the system is frequently updated as a function of actual measured force requirements (and further compensated, pursuant to various embodiments, with respect to other conditions such as temperature and motor runtime). This characteristic force value is then utilized to determine the excess force threshold value.

Abstract: A control system for a door or gate which is movable between an open position and a closed position by an automated operator, comprising a door travel organizer which divides the door travel into a plurality of segments and each segment into a plurality of sectors; a sensor to sense at each sector, the resistance of the door or gate against opening and closing whilst moving between the open position and the closed position over a predetermined number of open close cycles, and to generate at least one signal representative of that resistance in each segment over the open close cycle, a recorder connected to the sensor to receive each representative signal and to store such a signal; a comparator to compare each signal with a resistance trip point set for each segment and generate a resistance profile for the door or gate over an open close cycle of the door or gate; a calculator to calculate the resistance trip point for the door or gate for each segment based upon the highest resistance encountered in any sec

Abstract: A control apparatus utilizes an electric motor to initially start-up an engine. In an engine restart under certain conditions, the control apparatus sets a motor output value for the electric motor to a value exceeding the rated performance. Thus, when starting up the engine, the control apparatus makes up for a shortage of power by executing overload driving of the motor for a short time period. When certain conditions are not met, the control apparatus operates the electric motor in combination with a starter motor to restart the engine. The electric motor is located between the engine and a transmission.

Abstract: The controller possesses a reference torque signal setting unit which generates a reference signal which becomes high when the detected signal becomes high based on at least the signal detected from the steering torque sensor; a correction torque signal setting unit which generates a correction torque signal (DN*RT*RV), which becomes high when the detected signal becomes high based on at least the signals detected from the revolution number sensor for the electric motor and from the vehicle speed sensor; and a target torque signal calculator which subtracts the correction torque signal from the reference torque signal (DN*RT*RV) to output a target torque signal (DT+−DN*RT*RV) to the electric motor; and the controller also making the correction torque signal high when failure of the vehicle speed sensor is detected.

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: An improved method of detecting the presence of an obstacle in the path of a motor-driven panel by computing the slope of a measured motor speed signal in a way that cancels the effect of periodic undulation of the speed signal, and comparing the computed slope to a slope threshold that is selected as a function of the average motor speed. A position sensor produces a series of pulses corresponding to panel movement, and a microprocessor-based controller stores an array of speed-related samples corresponding to the time periods between successively produced sensor pulses. The average speed is computed at two different points in the array, and the slope of the stored speed samples is determined according to a difference between the computed average speeds.

Abstract: In a displacement drive that provides an obstruction prevention function for movable parts, in particular such as windows and sunroofs in motor vehicles, a decrease in the rotation speed or velocity of the drive is provided in order to achieve a predefined spring rate in specific displacement ranges so as to lower the kinetic energy. Within the predefined range before the closed position is reached, the rotation speed and/or the output of the drive is reduced linearly. The reduction to a minimum rotation speed or minimum output takes place within a specific position range. The minimum rotation speed or minimum output is reached at a specific position before the closed position and is substantially constant. Corresponding to different supply output levels, a linear reduction, for example, is performed along lines of different slopes, the length of the specific position range in which the reduction is performed being constant.

Abstract: The method and the corresponding device allow to start a synchronous motor with the chosen rotation direction, with a very high static torque, without requiring any modification of the structure of the synchronous motors currently in use, by means of an adapted electronic circuit managed by a microprocessor.

Abstract: In a method of detecting a foreign matter caught by a window in a power window device which includes a window opening/closing motor, a motor drive unit, a pulse generator for generating pulses corresponding to the rotation of the motor, an MCU for executing overall control and drive processing and manually-operated switch unit, the MCU detects a parameter value indicating a motor load imposed on a window when the window is opened and closed through the motor drive unit, compares the parameter value with a preset reference median, determines that a foreign matter is caught by the window when the parameter value falls outside the reference median in a considerable amount and stops the drive of the motor or reverses the motor, wherein the reference median that is preset in the range where a foreign matter is detected within the entire moving region of the window is successively changed stepwise by the same displacement value.

Abstract: A rigid magnetic recording disk drive includes a vacuum pump attached to the disk drive housing for removing air from within the housing so that the disk drive is operated at a reduced internal gas pressure. The pump motor is controlled by control circuitry that receives an input signal representative of the pressure within the housing to enable the pressure to be maintained within a predetermined reduced pressure range. Because spindle motor current has been directly correlated with internal pressure, a signal representative of the spindle motor current is used as the input to the pump control circuitry. The pump control circuitry also prevents the pump from turning on until the spindle motor has reached its stable operating speed, and from turning on when the disk drive is reading or writing data. Because of the reduced internal pressure the disk drive operates at a significantly higher disk RPM with only a minimal increase in power consumption and without any increase in track misregistration.

Abstract: A controller for energizing a power-operable element, such as a sunroof, window, door, vehicle seat, a component of a major appliance or of a machine or of a conveyor system. The disclosed controller senses both hard and soft obstructions and de-activates or otherwise alters operation of a motor that drives the element when an obstruction is detected. The controller can also be used to actuate a brake. The controller senses obstructions during start-up of the motor and regulates the speed of the power-operable element by pulse width modulating motor energization signals.

Abstract: An obstruction detecting method for use with a power window device comprising a motor activated to open and close a window by means of a window drive mechanism, a motor drive unit for driving the motor, a pulse generator for generating pulses corresponding to revolutions of the motor, a micro-control unit for providing overall drive control, and an operation switch operated manually to instruct the opening and closing of the window. The method comprises the steps of causing the micro-control unit to detect parameter values representing loads applied onto the window when the window is opened or closed; to compare the detected parameter values with a predetermined reference median; to detect an obstruction to the window movement when any detected parameter value is judged to have deviated by at least a predetermined amount from the reference median; and to stop or reverse the motor by means of the motor drive unit on detecting the obstruction.

Abstract: In an electric power steering apparatus, it is judged whether or not a value of primary delay of temperature increase in a driving circuit for an electric motor tends to decrease, and when the value of primary delay is judged to tend to decrease, a new value of primary delay is obtained with a time constant set smaller, so that an upper limit value of a motor current can be decided on the basis of the new value of primary delay. Thus, a steering power can be rapidly recovered.

Abstract: A drill/driver (eg. an electric drill) with a screwdriver attachment, and a method of controlling the drill/driver, are described. A control circuit (30) controls the speed of rotation of the motor (38, 39) through a time delay circuit (42) and a triac (41). The control circuit (30) uses the time delay information and information inputted from a rotational speed sensor (43) to monitor the current in the motor or a parameter related at least in part to current in the motor. When a change corresponding to an increase in the rate of change of current in the motor is detected, the control circuit (30) stops the motor to provide an automatic torque control feature for a screwdriving operation.

Abstract: A drive control device for an opening and closing member is active to optimally adjust a threshold level for pinch detection. Utilizing a speed sensor or the like, the closing speed of the opening/closing member is detected. The value of the closing speed is renewed in accordance with the closing position and stored in memory. Based on memorized data, a predicting circuit derives a future closing speed. To the predicted value there is added an allowed addition value, to permit a threshold level setting circuit to set an appropriate threshold for pinch detection. The allowed addition value is adjusted in accordance with the closing speed of the opening/closing member by a threshold level adjusting circuit.

Abstract: A motor current detection circuit in which a level for detecting an overload state is varied when motor drive voltage varies so as to prevent erroneous detection due to variation in-motor current which occurs when the drive voltage varies.

Abstract: An apparatus detects stoppage of a motor of a power driven screwdriver due to the excess load. After detecting stoppage, power to the motor is increased gradually to a predetermined value to firmly tighten the screw. The time of increase of power is determined at an arbitrary value.

Abstract: An electronically controlled sewing machine, comprises a current detecting device for detecting a value of current flowing through a stepping motor that drives a machine part and current setting means for setting a value of current to be applied to the stepping motor. The sewing machine further includes a control device (CPU) for storing a plurality of different values of currents to be applied to the stepping motor and driving the stepping motor until the stepping motor passes through an initial position thereof. The control device stops the stepping motor at a predetermined angular position thereof spaced from the initial position. The control device supplies the different values of currents to the stepping motor in a predetermined sequence from a smallest value to a larger value of current under a predetermined program to drive the stepping motor until the stepping motor reaches the initial position thereof.

Abstract: A hoist for raising and lowering objects with an apparatus for detecting mechanical overload of the hoist. The system provides a hoist having an alternating current motor connected to an alternating current power supply. The level of current of the power supplied to the motor is compared to a level of power indicative of a mechanical overload condition. If the current signal representative of the actual motor current level equals or exceeds the mechanical overload reference current then an overload output signal is provided.

Abstract: A motor driving apparatus includes a motor, a signal generating device for generating a Pulse Width Modulation binary signal, a control device for applying a current to the motor, a current detecting device for detecting the current applied to the motor, and a current blocking device for blocking the current applied to the motor for a predetermined time when the current applied to the motor exceeds a predetermined value. The current blocking device is synchronized at an alternative cycle of the binary signal, whereby it is possible to limit the current applied to the motor during the overload of the motor.

Abstract: An offset current which is 180.degree. out of phase with the leakage current for a motorized bed circuit is created through the use of an additional transformer winding and series resistor which is connected between the neutral conductor and ground conductor. As the circuit is connected in the reverse polarity condition for testing to UL standards, the offset current is injected into the ground conductor which cancels out a portion of the leakage current from the motors to thereby bring it within testing standards. In the normal connection condition, the injected offset current is additive to the leakage current, although the normal leakage current is much less than the reverse polarity connection leakage current so that the overall leakage current in the normal connection condition remains within test standards.

Abstract: A protective circuit for an electric motor comprises a frequency signal generating circuit for generating a frequency signal in accordance with the rotational speed of the motor, a switching circuit switched over to either permit or cut off supply of current to the motor, and a detecting circuit for detecting that the period of the generated frequency signal has become larger than a predetermined period due to a decrease in the rotational speed of the motor, and cutting off the supply of current to the motor by the switching circuit.

Abstract: A microcomputer-based motor control system provides overload protection by incrementing a register whenever a full power condition exists and decrementing the register when less than a full power condition exists. When the register reaches a predetermined value, this indicates an overload condition.

Abstract: There is disclosed a protective system for preventing damages to a tool and a work or tool changing mechanism component parts due to any interference between the tool and the work during the tool changing operation by an automatic tool changing apparatus in a numerical control machine tool such as a machining center.The protective system monitors the load current of a driving motor for the automatic tool changing apparatus, whereby when the load current reaches an abnormally high current value during the operating period excluding the motor starting period, the operation of the automatic tool changing apparatus is reversed and then stopped.

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: An arrangement for controlling an element of a power vehicle, such as a safety belt, window pane, and the like, has a displaceable member connectable with a power vehicle element to be controlled and displaceable together with the latter from a first end position to a second end position in a predetermined direction, a drive unit for driving the displaceable member, and a safety device arranged to interrupt a power flux to the displaceable member when a resistance acts upon the latter in a direction opposite to the first-mentioned direction with exceeding of a predetermined limiting value, wherein the safety device includes a safety member arranged withdrawable between the drive unit and the displaceable member and retained in the power flux by a force adjustable in correspondence with the limiting value.

Abstract: A control system, for a motor which may be subjected to stalling loads, provides a non-linear increase in motor current during stalling conditions to maintain rated horsepower. When the maximum transient overload current is reached, this current is maintained to keep the motor torque at a maximum until the motor is stalled. This provides maximum motor torque down to a stalled condition and resists stalling. A limit controller determines the maximum time a particular overload motor current can be maintained and when this time has passed the motor current is reduced to rated current. If the motor should stall completely a further reduction in motor current is made automatically.

Abstract: A power amplifier is disclosed for controlling the current flow through a load, such as a d-c servo motor. The amplifier includes a plurality of switching elements connected in bridge fashion with the load and a predetermined power source for coupling the load across alternate output terminals of the power source in accordance with the levels of a plurality of control signals respectively coupled to the plurality of switching elements. Logic circuitry, when enabled, couples each of the control signals to their respective switching elements for controlling same. Sensing circuitry is coupled to the load for generating an actual current signal indicative of the actual level of current flow through the load. A current limiter is coupled to the sensing circuitry for comparing the actual current signal with high and low level limit signals and for generating a current disable signal when either the actual current signal exceeds the high limit signal or the low limit signal exceeds the actual current signal.

Abstract: An impending kickback condition in the operation of a power tool or machine tool system is sensed and used to control or eliminate the kickback. The ability to sense an impending kickback condition can be used in all categories of power driven tools. The change in force applied to the power driven tool or other implement is monitored with a microcomputer by measuring the rate of change of current. If the current is increasing, the microcomputer compares the rate of change of current with a threshold value which may be either preset or computed by the microcomputer. If this threshold value is exceeded, an output control signal is generated by the microcomputer which inhibits the coupling of power to the tool or other implement and/or applies a brake to stop the tool or implement. In order for power to once again be coupled to the tool or implement, the start switch must be opened and then reclosed or some other signal provided by the operator or another predetermined condition must be fulfilled.

Abstract: A system is provided to control a load responsive to a maximum load condition to disable the load when the maximum load condition exists, the control being altered first to provide a period of non-response during load start up and secondly to provide temperature compensation over a very wide temperature range and more particularly where the load device is a motor means for linearly reciprocating a closure member such as a sun roof, a window or a door, particularly for a vehicle such as an automotive vehicle.

Abstract: A controlled switch 4 provides current pulses derived from a battery 3 to a motor 1, having a series field 2 under command of a control unit 8 which provides command pulses for repetitive closing of the controlled switch 4. Current through the motor is sensed by a sensing resistor 6 and connected to a safety circuit 9 which, upon sensing of current flow in the absence of a control pulse from the unit 8, disconnects current to the motor by opening a controlled switch 5. To distinguish between (a) current flowing from the battery 3 l and (b) circulating current flowing during pulse gaps in a free-wheeling diode 7 connected across the field and armature of the motor, voltage across the free-wheeling 7 is sensed, thereby effectively sensing the conduction state of the free-wheeling diode and, if the free-wheeling diode is conductive, disabling the safety circuit to prevent spurious operation thereof during flow of inductive, circulating current through the bypass or free-wheeling diode under normal operation.

Abstract: Electronic control means for a paper handling and counting machine. An LED array provides a visual display of the number of paper documents counted during either normal counting or "batching" operations. The LED display is utilized to the exclusion of additional display devices for providing an indication of a jam condition in the event of a jam by "flashing" the zero decimal digit. A similar indication is artificially created upon turn-on of the machine. When operating in the "batching" mode the LED array, in addition to providing a visual display of a completed batch count, will display a partially completed batch count in a flashing manner. The "jam-type" display is also activated whenever the batch control selector switch is switched from the "count" mode position to any batching mode position.

Abstract: A DC motor speed control circuit in which the current to the motor is delivered in a series of pulses the width of which is variable in accordance with the setting on a throttle control potentiometer. The pulses are shaped to provide a fast turn on and slow turn off of the control transistor to avoid heat build up and lessen the inductive kickback of the motor. A novel feedback circuit senses excessive current draw and automatically shuts down the circuit and remains latched in that condition until the throttle control potentiometer is reduced to zero whereupon the circuit automatically resets itself. High efficiency is achieved by directing both the power current and the control current through the motor windings thus increasing the battery life.

Abstract: Apparatus for tightening and releasing one of the clamping nuts which act to maintain a pre-established pressure-tight sealing of a flanged reactor pressure vessel, the bolts for which clamping nuts are held and pretensioned in the flange of the vessel. The clamping nut has teeth and is turned on its bolt, via a reduction gearing cooperating with the teeth, by a three phase motor whose rotor has the smallest number of poles for a small moment of inertia and a high speed of rotation. A connecting lead for the motor has a current sensor disposed in one phase thereof, and a triac contactor responsive to an output signal from the current sensor and arranged to open-circuit the connection lead when the sensed current exceeds a predetermined threshold at a limit position of the nut. The apparatus also includes an override means which acts to prevent the motor being automatically switched off in response to start-up current during a preselected period from switch-on of the motor.

Abstract: An arrangement for generating and causing a pressing member to exert a pressing force includes an electric drive motor and a parallelogram transmission connected to the pressing member for transmitting pressing force thereto. The parallelogram transmission is coupled to and driven by the electric drive motor through a displacing member having the form of a screw spindle. An adjustable-setting switching device terminates operation of the motor when the output torque of the motor reaches a value corresponding to the setting of the switching device. The parallelogram transmission has a transmission ratio which in an undesirable manner is a function of the extent of displacement of the parallelogram transmission. Compensation of the functional dependence of the transmission ratio upon the extent of displacement of the parallelogram transmission is effected by automatically adjusting the displacement of the switching device in dependence upon the extent of the displacement of the parallelogram transmission.

Abstract: A series of electrical signals of a frequency directly proportional to the speed of a motor controlled by a speed control circuit of the type which completes an energizing circuit for the motor through the current carrying electrodes of a switching transistor is generated. These signals are employed to produce a direct current reference potential signal which increases rapidly in magnitude when the motor becomes stalled. The reference potential signal is applied across the series combination of a Zener diode and the base-emitter electrodes of an NPN transistor for supplying base-emitter drive current to the transistor when the potential level thereof reaches a magnitude equal to the inverse breakdown potential of the Zener diode. The collector-emitter electrodes of the NPN transistor are connected in circuit with the motor speed control circuit in such a manner that the control circuit switching transistor is maintained not conductive while base-emitter drive current is supplied to the NPN transistor.