Abstract: A system for rotating a data storage disc in a disc drive and for rapidly bringing the disc to a halt comprises a brushless motor fed with direct current in its windings by a motor drive circuit which current is also fed to a solenoid to hold a spring loaded solenoid arm from pressing a brake against a shaft to brake the disc, the motor control circuit using the current caused by back emf in the windings of the motor to provide motor braking while passing the current through the solenoid which applies the brake when the motor speed falls below a predetermined limit, the solenoid also being employed as a current smoothing choke.

Abstract: In a motor control circuit for an electronically commutated reversible motor used in a ceiling fan, a control is used to reduce the voltage supplied to the motor for variable speed or torque operation. At the same time, a substantially smooth control voltage, dependent on the variable voltage supplied to the motor, is produced. This control voltage, which is used to enhance the adjustment rate, is applied to control a pulse width modulator, which produces output pulses which also control the flow of energy to the motor. When the control voltage reaches a value slightly past the desired minimum speed or torque setting, a signal is generated to change the direction of motor rotation. Means are provided to delay the actual reversal to protect the power switches in the control circuit. When power is first applied, the initial direction of motor rotation is set by a switch on the ceiling fan. The control circuit permits control of motor reversal from a wall location.

Abstract: Described is a control system for an elevator wherein the distance between the current car position and the target position of a floor at which the car is to be halted is detected on the basis of a car position signal computed from car displacements and a preliminarily stored floor position signal for controlling the car speed. According to the present invention, the contents of a read-only floor memory concerning the respective floor positions stated in the building plan or schedule are transferred at the outset into a transient read/write floor memory. In the course of the subsequent elevator car travel, the data in said transient floor memory is corrected through the learning of the contents of the car position signal computed during car displacements. In this manner, the car may be controlled to arrive at a target floor accurately despite occasional difference between the actual floor position and the design floor positions.

Abstract: A method and apparatus for making available an electrical current, which comprises placing a conductive airfoil in a moving air mass, sinking a conductive element subsurface, and insulating the airfoil from the conductive element and producing an electrical potential between the airfoil and the element in a moving air mass.

Abstract: A method and apparatus for reducing oscillations in input electrical power to a Ward-Leonard drive system which is subject to variations in mechanical loading, the technique utilizing a notch filter in the feedback path to the dc generator, the notch filter being turned to match the resonant frequency of the synchronous motor.

Abstract: In this drive control the regulating circuits for the rotational speed of a drive motor and of an eddy current brake are matched in their static and in their dynamic behavior so that a common regulator may be used for both regulating circuits. The matching is achieved by interposing a current regulation circuit for regulating the excitation current of the eddy current brake to the rotational speed regulating circuit. The output of the common regulator is supplied via a linearization member as a reference value to a regulator in the current regulation circuit during the deceleration phase. During the acceleration phase the output of the common regulator is supplied to a matching element matching the variation of the torque to the variation of the torque during the deceleration phase with respect to time. The output of the matching element is connected to the control member of the drive motor via a linearization member. By means of the linearization members the characteristics of a d.c.

Abstract: A control system for synchronizing a combination press line comprised of a transfer press and a double-action press.The transfer press is set as a master press and the double-action press as a slave press following the transfer press in operation.The transfer and double-action press each has a synchro coupled to respective drive shafts for detecting an angular position of each press. A comparator is provided for comparing signals from both synchros and generating a signal corresponding to a difference between signals from both synchros. The output signal from the comparator is fed only to a motor for the double-action press for controlling the speed of the motor, thus enabling the double-action press to follow the transfer press in operation.

Abstract: The wave powered buoy generator includes a hollow buoy which has inner and uter surfaces. The buoy is preferably spherical in shape. One or more windings are mounted to the buoy parallel to its surfaces with each winding having a pair of ends. A magnetized device which, is preferably a ball, is located within the buoy for rolling back and forth therein. A device is connected to the ends of the windings for rectifying current flow therefrom. With this arrangement the buoy can be moored in a body of water, and, when there is water motion, the flux lines of the magnetized roller device cut the one or more windings so as to cause electrical current flow to be provided through the rectifying device.

Abstract: A windshield wiper control system has operations controlled by single touch actuators. A first such actuator provides for initiation of wiper operation in low speed with the first actuation and alternate high and low speed operation with additional actuations. A second such actuator stops wiper operation and, if actuated while the wiper is not running, initiates a single wipe of the wiper. A further actuator may be provided for initiation of either programmed or operator controlled wash operation, depending on the length of actuation. A final actuator may be provided for two touch intermittent wiper operation, in which the operator sets the delay time by two consecutive touches. Variations are described for either depressed park or non-depressed park systems.

Abstract: A flight control system increases the automatic control authority over, preferably, a helicopter yaw axis. A limited authority series servo is complemented with a full authority parallel servo. The parallel servo is driven by a combination of a trim command signal and a signal representing the excess of the yaw command signal over the amplitude limited drive signal to the series servo.

Abstract: Systems and methods for synchronizing a gas turbine-driven generator to an AC power system by employing optimal time control theory to directly drive the turbine-generator to a synchronizing point. The fuel commands, synchronization points, and trajectories are selected in view of the need to minimize thermal stress on the turbine hot-gas-path parts, while also minimizing time required for synchronization. Digital computer and analog implementations are disclosed.

Abstract: An elevator system including at least one elevator car mounted in a building to serve the floors therein. The elevator car includes a door having one or more panels, and a door operator which selectively operates the door at the end of a run from the closed to a fully open position, or from the closed to a predetermined partially open position. Door control, in response to at least one predetermined parameter of the elevator system, controls the selection by the door operator. In a preferred embodiment, an audible message informs the passengers of the decision, at least when the doors will only be partially opened.

Abstract: In the inching of a grinding mill or similar apparatus which is driven by a pair of synchronous motors through fluid actuated clutches, the motors must be angularly alined one with the other in order that the load be shared equally between the motors. The apparatus of the invention connects the field supply to both motor fields and then it connects a zero frequency supply (i.e. a DC supply) to the stator windings of both motors and ramps up or increases the amplitude of the supply. This brings the rotors into alinement without undue oscillation. When the amplitude of the low frequency supply reaches a predetermined level, the clutches are closed or locked and the motors are connected to the load with the rotors in angular coincidence or alinement.

Abstract: In a brushless DC motor having a magnet (i.e.--a field flux generating means) and multiphase coils, a current is distributed from a DC voltage source to the multiphase coils by selectively activating a plurality of output transistors according to a set of output signals of a position detector. A distributor selectively activates the output transistors according to the output signals of the position detector. A command signal generator generates a command signal, and a low-pass filter is connected between the command signal generator and the distributor. A voltage detector detects voltage drops across the output transistors during each activated period and changes its output signal corresponding to the detected voltage drops when at least one of the voltage drops across the output transistors is smaller than a predetermined voltage.

Abstract: A motor operated valve, typically a butterfly valve driven by a synchronous electric motor (16), is provided with a torque sensing arrangement wherein an cyclic electrical signal representative of the rotational speed of the motor is produced by magnets (22) on disc driven by the motor and Hall effect switches (23,24). The frequency of this signal is compared in a circuit (43) with the frequency of current supplied to the motor to provide an indication of motor torque. Switches (46,47) define preset torque limits for the valve. If the limits are exceeded, a signal is fed to control logic (41) which operates switches (18) to control the supply current to the motor. The speed signal from the Hall effect switches is also fed to a counter (31) to develop a count representative of movement of the valve. The output of counter (31) is compared with preset valves defined by switch circuits (37,38) to define limits of travel for the valve.

Abstract: A glass heating method and apparatus, such as a glass melting furnace or a forehearth, utilizing a refractory lining and electrically energized heating electrodes. The refractory lining is an erosion resistant material, preferably a chromic oxide refractory, having an electrical resistivity which is less than the resistivity of the molten glass, preferably an E glass, which is being heated. To avoid short-circuiting through the low resistance refractory, the refractory interposed between electrodes of opposite polarity is cooled to a temperature less than the temperature of the molten glass and at which the resistivity of the refractory is materially increased. Where the electrodes of opposite polarity are carried by opposing side walls, the end and/or side walls of the apparatus are cooled. Where the electrodes are all carried by a single wall, that wall is cooled.

Abstract: A rotary electric machine (motor or generator) comprises a first functional member and a second functional member rotatable with respect to the first one. One of the two functional members comprises a plurality of permanent magnet poles distributed in a ring arrangement, while the other one comprises a plurality of switchable electromagnet poles disposed in a ring arrangement opposite the permanent magnet poles, with an air gap in between. The numbers of permanent magnet poles and electromagnet poles either may be exactly or almost the same. At least one electronic circuit means controlled by at least one sensor detecting the rotational relative positions of the two functional members is provided for switching the electromagnet poles in the respective suitable direction of current flow and for the period of time of functional suitable relative positions with respect to the permanent magnet poles.

Abstract: Disclosed is a motor apparatus in which the rotation speed of the rotor is controlled by pulse width changes of drive currents which provide a rotating magnetic field around the rotor. A non-saturated type amplifier with poor efficiency can be removed from the motor power supply circuit, thus enabling the motor power supply circuit to be formed only by a circuit having a switching operation.

Abstract: In a commutation timing circuit for an electronically commutated motor (ECM), a solid state transconductance amplifier is used to convert the back emf appearing in an unenergized winding stage to a current. The current is then integrated in a capacitor, and at the correct voltage, a comparator generates the timing signal at the instant suitable for commutation of the winding stages. The transconductance amplifier has a differential input stage to which substantial degeneration has been provided to stabilize the transconductance. Subsequent stages of the amplifier, which include three current mirrors, exhibit substantially unity current gain. The circuit is provided with substantial degeneration to insure stability of the transconductance and with automatic self-nulling to correct imbalance of the amplifier.

Abstract: In a combined cycle type electric power generation system including a plurality of shafts each coupling together a gas turbine, a steam turbine and an electric generator, there is provided an output control system including a plurality of control apparatus for respective shafts. Each apparatus is contracted such that in response to an output command from a central power dispatching station or an output of a load setter, a frequency deviation and a total load of the system and load of each shaft, the total load is equally or unequally distributed among respective shafts.