Abstract: A bypass circuit conducts electrical current around a motor starter to a current limiting switch assembly upon initiation of a flow of excessive electrical current to an electric motor to protect the motor starter against excessive current flow. Upon initiation of excessive current flow to the electric motor, the current limiting switch assembly opens a main circuit to interrupt current flow through the motor starter. The current limiting switch assembly includes a conductor or contact carrier which is movable from an initial position to an actuated position under the combined influence of current flow through a coil and opposition between magnetic fields from portions of an electrical circuit through which current flows in opposite directions.

Abstract: A hydraulic servo control, particularly a hydraulic power steering system for motor vehicles, has hydraulic pressure pump which is driven by an electric motor. The rotational speed of the electric motor is controlled as a function of the load, so that a high rotational speed occurs only when there is a corresponding demand.

Abstract: An optical pickup is provided with a limiting wall spaced a predetermined distance apart from a screw shaft to limit the separation of an interlocking projection away from the screw shaft, so that the interlocking projection cannot be disengaged from the helical groove of the screw shaft and, consequently, the screw shaft becomes unable to rotate. This state in which the screw shaft is unable to be rotated, i.e., a state where the optical pickup has bee moved to its inner limit position, can be detected through the detection of a change in the coil current of a stepping motor by a coil current measuring means or through the detection of the increase of voltage induced by the rotation of the magnet of the stepping motor to a predetermined level on the basis of the measured coil current measured by the current measuring means.

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: A rotatable apparatus includes a pair of rotatable members joined by a stress dissipating structure. The stress dissipating structure can be employed in a gear, sprocket, clutch or the like. In one embodiment of the present invention, antibuckling plates generally spanning between a hub and rim define a hollow cavity. In another embodiment of the present invention, the stress dissipating structure includes a specifically configured sets of nodules moving the hub and rim. An additional aspect of the present invention provides a stress dissipating structure employing various anti-buckling plate attachment constructions. In still another embodiment of the present invention, a uniquely sized and packaged gear, gear housing and/or motor are employed in order to maximize output force per pound of material efficiencies.

Abstract: A system for controlling actuating members in the doors of motor vehicles has at least one electromotive actuating drive and at least one actuating element (switch, button) in the door of the motor vehicle, as well as a control unit located in the vehicle itself. The system employs only a two-wire connection between control unit and actuating drive. The control unit, in addition to an ordinary pole-reversing and evaluation circuit, furthermore contains a source of alternating voltage as well as means for connecting the alternating voltage and a decoder. At least two passive components (resistor, capacitor, coil) of different size are provided to be connected by the actuating element in parallel with the actuating drive into the two-wire connection.

Abstract: An object of the present invention is to secure safe driving of electric vehicles by enabling torque control regardless of sensor disorder. In the present invention, the mode of current sensor disorder is detected by a sensor disorder detection means. If it is found as a result that only 1 out of 3 current sensors is failing, the current of the failing current sensor is estimated by 2 normal current sensors and the torque control of the motor is continued by the ordinary torque control system. If 2 or more current sensors are found to be failing, a torque control system based on an AC current reference operation means is formed to control the motor torque based on the AC current reference. If a sensor failure detection means determines that only 1 phase is failing in the speed sensor, the motor torque is controlled by using the remaining 1 phase to detect the rotating angular speed of the motor.

Abstract: An adjustable cycle timer that controls on and off cycling of a livewell bait pump or similar device. The on time and off time of the cycle are each independently variable by adjusting the frequency of frequency generators, one generator (10) for on time and one generator (14) for off time in the cycle. The outputs of these frequency generators are gated to the clock input of a frequency divider (20), the output of which controls a relay driver (30) or similar device that switches the pump motor or other device to be controlled. When the output (22) of the frequency divider (20) changes state, a feedback switching circuit (29) blocks the output of one of the frequency generators, and gates the output of the other frequency generator to the input of the frequency divider (20). This allows the length of the on time segment of the cycle to be controlled by the frequency of one of the frequency generators, while the length of the off time segment of the cycle is controlled by the other frequency generator.

Abstract: Disclosed herein is an apparatus and method for controlling electrically powered liquid-moving pumps, particularly bilge and sump pumps. The apparatus is characterized by the fact that no portion thereof need be located in the hostile environment of the bilge or sump served by the pump controlled thereby.

Abstract: A motor controller or contactor is disclosed which utilizes a non-saturating current transformer for sensing the amount of current flowing in the electrical conductor connected to the contactor. The current sensor is made of homogeneous sintered powdered metal having evenly distributed microscopic air gaps therein which increase the reluctance of the magnetic circuit but resist the influence of stray magnetic flux. This increased reluctance prevents magnetic saturation over a wide range of input current and allows the secondary of the transducer to produce a voltage which is proportional to the derivative of the primary current, that is the current being sensed by the transducer. The aforementioned voltage is linearly proportional to the derivative of the current over a wide range of primary current values. This voltage is integrated to produce an output signal which is directly proportional to the aforementioned primary current over the wide range of current values.

Abstract: A motor serves to move a vehicle movable accessory. When the accessory is required to move, the motor is activated. Load on the motor is sensed. When the sensed load exceeds a reference level, the motor is deactivated. After the motor is deactivated, a device inhibits activation of the motor which induces movement of the accessory in a direction same as a direction of movement of the accessory during a period preceding the deactivation of the motor. The inhibition of activation of the motor is cancelled when the accessory is required to move in a direction different from a direction of movement of the accessory during a period preceding the deactivation of the motor.

Abstract: A motor control for a refrigeration apparatus having a cabinet, a door to the cabinet, a source of ice pieces located in the cabinet, means located in the door for dispensing the ice pieces, a power source having a supply terminal and a ground, a motor and means responsive to operation of the motor for delivering the ice pieces from the source of the ice pieces to the dispensing means, the motor control comprising means for energizing the motor, an actuable ice command switch generating an ice command signal for requesting delivery of the ice pieces from the source to the dispensing means, a processor having an input terminal coupled to the ice command switch and an output terminal, the processor generating a transistor command signal in response to the ice command signal, and a transistor having a control electrode coupled to the output terminal and first and second main current electrodes, wherein the processor output terminal is coupled to the transistor control electrode, and the motor energizing means, t

Abstract: A well pump control system is disclosed for utilization with a conventional well pump having a stationary member and a reciprocating member. The reciprocating member operates a down-hole pump and is attached to a rocking beam through a load cell. The rocking beam is driven by an electric motor through a counterbalanced crank. The strain present on the reciprocating member as detected by the load cell is utilized to operate a variable frequency drive unit which acts to control the frequency of the voltage applied to the electric motor. In this manner, the speed of the motor may be selectively and gradually varied during the pump cycle to both minimize power consumption and increase slip during heavy loading. Additionally, the maximum amount of strain present on the reciprocating member can be controlled throughout the entire cycle to minimize maintenance costs associated with excessive strain.

Abstract: An apparatus for automatically opening and closing a closure panel associated with an opening formed in the roof of an automobile is disclosed. The apparatus drives the closure panel for tilt open and tilt closed operation and for slide open and slide closed operation. During the sliding movement of the panel, the apparatus detects a load on a panel drive mechanism in a zone where the loads are normally low, and deenergizes the panel drive mechanism in the event of occurrence of an overload. In a zone where the loads are normally high as the panel presses against a weather strip, no deenergization of the panel drive mechanism occurs during an interval allocated for overload detection. The apparatus energizes alarm means during the time the panel is driven in the closing direction in a selected mode in order to draw the attention of a vehicle driver. For assuring the safeguard of the panel, the panel is stopped temporarily during the slide closed operation at a point which leaves a given opening.

Abstract: Signals indicative of full load up (FLU), no load down (NLD), and full load down (FLD) are supplied to an elevator controller (16) by a load measuring circuit (28) that is responsive to the phase angle in one line (32) of a bus feeding an AC motor. Based on the FLU and NLD signals the controller implements a slowdown/stop sequence closer to a landing than without the signals. Based on the FLU and FLD signals, the controller bypasses hall calls.

Abstract: Disclosed is a monitoring circuit responding to different operational conditions of an electric motor. The circuit includes a measuring resistor connected in series with the stator winding of the motor to produce an actual load value signal. The actual value signal is applied to one input of a comparison circuit whose other input is consecutively supplied with three different nominal reference voltages corresponding to principle operational conditions of the motor, namely to the starting phase, to the normal operational phase, and to an overload. The source of the variable reference voltage includes switching transistor cooperating with a timing member and with voltage dividers adjustable from zero to a maximum nominal voltage value corresponding to the power supply voltage.

Abstract: A motor driven drapery closure is provided with means for operating the closure between defined opened and closed positions without the use of limit switches. Means are also provided to stop the operation of the motor and back it up slightly if a significant resistance is met by the closure at a point midway of its travel or as a result of coming to the designed end of its travel. Additional means are provided for operating the closure in response to means for sensing an outside ambient condition such as the level of infrared light.

Abstract: A driving circuit for use in controlling a motor for controlling an air mixing door, an inner and surrounding air change-over door and a mode setting door and the like used in a vehicle air conditioning device, or a motor used in opening or closing of window panes of a vehicle or in opening or closing the door which includes a control transistor for use in controlling a transistor circuit having a transistor to cause both normal and reverse directed currents to flow in a vehicle motor, the control transistor being operated until a specified period of time has elapsed after the power supply switch is turned on, the motor input being shut off by the control transistor so as to prevent erroneous operation of the motor just after the power supply switch is turned on or to prevent the production of a chattering sound caused by the operation of gear trains with the motor.

Abstract: A remotely contollable, motorized valve suitable for microprocessor control. The valve is protected against over-closure by a technique of current sensing of motor current. Starting surges are ignored through the use of a timing circuit. The valve may be re-started in the event of mid-travel stoppage, but is still protected against damage due to such stoppage, by permitting manual reset after the valve is stopped.

Abstract: A process and system for distinguishing between actual and false pump off of a well and for shutting in the well only upon the occurrence of actual pump off. The process and system employs the principle that pump off may occur only after a not pumped off condition has been detected.

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: A solenoid torquer system with flux rate feed-back. The system includes a torquer coil and an associated core, and a device adapted to drive a current through the coil having an amplitude proportional to the difference between a coil current command signal and the actual current in the coil. A flux rate servo loop includes a sensor coil coupled to the core to provide a signal representative of the flux rate in the core. This flux rate signal is compared with a flux rate command signal having a ternary width-modulated form. The resultant difference signal is used as the current command signal. The system network provides a precise flux level, or force.

Abstract: A motor control system, particularly adapted for use with a battery-operated atmospheric hazard sampling pump, which can vary motor speed over a range of 50:1 with the use of a voltage controlled pulse width modulator. The system includes a back EMF circuit which develops a voltage, proportional to motor speed, which is compared with a speed reference signal to develop an error signal for the pulse width modulator. Automatic shutdown of the motor occurs for controlled periods when a blocked pump condition occurs and motor current rises above a predetermined limit.

Abstract: Motor overload current is sensed and coupled to the input of an operational amplifier, causing the amplifier output to invert and charge a plurality of parallel connected capacitors. When the overload condition is present for a predetermined time, the capacitors are sufficiently charged to change the output state of a second operational amplifier. A diode is coupled between the output and the input of the second amplifier and is poled to latch the second amplifier into its inverted state when the capacitors have reached the predetermined charge. A luminous source, such as a light emitting diode, is coupled to the output of the second amplifier and becomes non-luminous in the inverted state of the second amplifier. The diode is photo-coupled to a photo conductive circuit for disabling the power coupling to the motor circuit when the diode is non-luminous.

Abstract: A visual feed control assembly for carriage-fed, electric motor driven sawmill saws comprises in combination with the electric drive motor of the saw electric circuits including first and second trip current relays with associated first and second electrically operated lights or other signals. The trip current relays are preset, the one to operate its associated signal at a predetermined minimum saw motor amperage load and the other to energize its associated signal at a predetermined maximum saw motor amperage load. The signals enable the operator to adjust the carriage speed to suit the saw so that the saw operates at maximum efficiency at all times, irregardless of the size and character of the logs being sawed.

Abstract: A circuit for a polyphase motor which operates in response to undesirable operating conditions so as to prevent damage to the electric motor. The protection circuit converts current to voltage over a range of operating currents. The current sensitive voltage in response to an undesired current condition triggers the operation of a gating circuit to apply potential to an output switch which in turn controls the current supply and stops the motor. The gating circuit is also triggered by a detector circuit sensing a deficiency in motor current to thereby actuate the output switch and interrupt the motor operation and thus protect the motor. A timing circuit provides an inverse time function in conjunction with the voltage applied to the gating circuit. The timing circuit is adjustable to provide adjustability in the elapsed time for providing a triggering voltage to the gating circuit.

Abstract: Disclosed is a vacuum valve apparatus comprising a valve head, a motor for driving the valve head, means for checking the position of the valve adapted to issue a first signal upon detecting that the valve head is moved to be within a predetermined valve-closed range, means for checking electric current adapted to issue a second signal when the driving current for the motor is increased to a predetermined value, switching means adapted to cut the driving current supply to the motor upon detecting said second signal, and means for issueing a third signal for confirming the complete closure of the valve when both of the first and the second signals are simultaneously obtained.

Abstract: A system for measuring current or load for shutting down a motor of a walking beam type pumping unit in the event that pump-off occurs. The system employs a peak picker which picks either minimum current or maximum load and an integrator coupled to the peak picker for integrating current or load during each stroke cycle. A threshold device coupled to the output of the integrator produces a control signal for shutting down the motor if the integrator output fails to reach a predetermined threshold during each stroke cycle.

Abstract: Powderous, granular, and/or liquidous substances such as thermoplastic or elastomeric materials are mixed with each other or with fillers, additives, etc. in that the mixing operation is continued until a predetermined amount of mixing work has been expended. The mixing operation can be controlled as to its entire duration on that basis as well as with regard to completion of intermediate steps.

Abstract: To reduce noise and idling speed of electric motors, particularly series motors, the speed-torque characteristic of the motor is dropped with respect to the loaded speed-torque characteristic, by sensing no-load operation of the motor and deriving a sensed signal, the sensed signal being applied to controlled switches to abruptly change the effective voltage applied to the motor between values corresponding to the no-load speed-torque characteristic, or the load speed-torque characteristic and resulting in the desired speed, in dependence on the value of the sensed signal. Preferably, the operating condition of the motor is sensed by an inductive transducer, and a speed change is obtained by phase control, or half-wave rectification.

Abstract: A one-touch action type power window having a retaining circuit which continuously actuates a motor for raising or lowering window glass in response to a one-touch operation on a switch. A pick-up coil is located in the vicinity of a wire through which the motor operating current flows to generate a voltage varying in proportion to the rotational speed of the motor thereby to control the retaining circuit.

Abstract: A control circuit for turning off the power to the pump drive motor when the pump has exhausted the supply of liquid in the well. Means for sensing the instantaneous current to the pump motor and a circuit measuring the average current drawn by the pump drive motor, and turning off the power when the average current decreases below a preset level. An RC circuit having a time constant greater than the time required for the pump to complete one full pumping cycle for measuring the average current to the motor, and a comparator controlling switching means to shut off the power when the average current to the motor decreases to a predetermined amount. A reference voltage supplied to the comparator from an amplifier connected to the electrical power in which the output of the amplifier varies inversely to variations of the voltage of the electrical power thereby preventing fluctuations in the supply voltage from adversely affecting the control circuit.

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.