Abstract: A throttle valve test system for a large steam turbine functions in a turbine control system to provide throttle and governor valve test operations. The control system operates with a valve management capability to provide for pre-test governor valve mode transfer when desired, and it automatically generates feedforward valve position demand signals during and after valve tests to satisfy test and load control requirements and to provide smooth transition from valve test status to normal single or sequential governor valve operation. A digital computer is included in the control system to provide control and test functions in the generation of the valve position demand signals.

Abstract: An SCR motor speed control system is provided with circuitry for fast braking of the motor. The circuitry senses when it is desired to stop the motor and simultaneously short circuits the motor armature and applies half-wave rectified line voltage to the motor field windings.

Abstract: Control device responding to current changes in a load circuit including a supervisory circuit carrying a current proportional to the current in the load circuit, a transformer coupling the supervisory circuit to the load circuit, and an overcurrent sensor and an overcurrent relay electrically connected in series in the supervisory circuit. The overcurrent sensor being set to deliver a signal when a given first current value is reached after a response delay, the overcurrent relay being able to interrupt the load circuit if a given second current value is reached after an adjustable response delay, and a method of operating the control device in a waste crushing machine.

Abstract: A control method and circuit providing smooth transition between two regulating modes involving two regulating parameters, one active and one inactive. The method comprises the steps of providing a reference signal and developing a signal representing the inactive parameter. The two signals are then compared to provide an inactive output signal that is indicative of any difference existing between them. Another signal is developed that represents the active parameter, and this signal is compared to the inactive output signal. The inactive output signal is then forced continuously to the value of the signal representing the active parameter when the values of the two signals are different. Change from the one parameter and mode to the other parameter and mode can now be made without a disturbing effect.

Abstract: Disclosed is a stepping motor control utilizing a microprocessor. The control is suitable for driving one or more stepping motors one at a time or in unison. In the illustrated embodiment when plural motors are driven together they are driven at the same rate or at rates in a fixed proportion to one another although several of the features of the invention are suitable for use in circuits providing contouring control; i.e., where separate motors are driven at separate stepping rates proportional to the relative distances each is to traverse for a single movement. An acceleration/deceleration circuit is utilized which provides simple yet highly accurate and efficient control of the stepping motors. Feed rate compensation for simultaneous drive of two motors is provided. Also a means is provided to allow stepping rates in excess of the counting rate capability of the microprocessor.

Abstract: A variable speed electronic motor which may be powered by an ac or dc source and wherein both the speed of the motor and the input power thereto are controlled and related to one another.

Abstract: A speed control system for an electric motor is provided for use, for example, in dental offices to control dental drill motors, and the like, which in one embodiment provides speed control from either a foot-operated potentiometer or a panel hand-operated potentiometer. The system includes a negative resistance generating circuit which maintains constant speed of the motor for any particular speed setting in the presence of variations in the mechanical load on the motor. The circuit also provides dynamic braking which immediately slows the motor and brings the motor to an almost immediate stop when the speed control potentiometers are returned to their neutral positions. A guardian circuit is also provided in the system which prevents motor burn-up in the presence of a sustained overload condition.

Abstract: Means and method for controlling the power delivered to the shaft of a DC motor when the field of the motor becomes saturated and prevents control of armature voltage by the field of the motor. The method involves the step of increasing the current in the armature by an amount corresponding to the decrease in the voltage of the armature caused by a decrease in the speed of the armature during saturation of the field. Increasing armature current is effective to maintain power output of the motor constant. If the speed of the armature increases after the occurrence of saturation, the voltage of the armature increases, such that the method includes the additional step of decreasing armature current in proportion to the increasing armature voltage to maintain constant power output of the motor.

Abstract: Controlled semiconductor switches are inserted in series with the armature windings of the motor. To effect commutation when the difference between counter emf and applied voltage is small, that is, when the counter emf is high, so that commutation of armature current is effected during low, or no armature current flow, the control circuit includes circuit elements connected to and controlling current flow in the stator winding to considerably reduce the flow therethrough shortly before the theoretical commutation time, and increase current, or connect current to flow only shortly after the theoretical commutation time so that reliable commutation is effected. These circuit elements may, for example, be capacitors, R/C networks, artificial inductances, and the like, or circuits superimposing additional commutating signals derived directly from the induced counter emf, or by a separate sensing coil to the power supply for the commutating element.

Abstract: An electronically commutating motor having a phase winding connected in at least one of the branches of a bridge circuit. A comparator measures the voltage across one of the diagonals of the bridge and switches the voltage across the other bridge diagonal as a function of the polarity of the first-mentioned voltage.

Abstract: A bidirectional, axial air gap, brushless, printed circuit DC motor having a stationary, low inductance armature bonded to the motor frame and having a plurality of rotating permanent magnets. Electro-optical sensing is employed which produces a unique digital representation of the magnet position. The digital output of the electro-optical sensor is decoded and, using brush substitution techniques, is used to selectively and progressively energize fields in the armature winding ahead of the rotating magnets. Both single field per pole and multiple field per pole commutation techniques are taught. The armature may be cut so as to produce several independent coils which may be combined in various ways, depending on the application.

Abstract: A speed control circuit arrangement for controlling a rotational speed of an AC commutator motor by an AC controlled rectifier element. The speed control circuit arrangement comprises a pulse transformer which is connected at the secondary winding to the control electrode of the AC controlled rectifier element and one of two main electrodes of the controlled rectifier element and supplies a trigger pulse to the control electrode, a variable resistor for adjusting the rotational speed of the motor, a first capacitor connected at one end through the variable resistor to the other main electrode and at the other end to one end of an AC power source, a pulse generating element connected across said first capacitor with the primary winding of the pulse transformer intervening therebetween, and a first resistor connected at one end to the one main electrode and at the other end to the other end of the AC power source through the first capacitor.

Abstract: In a D.C. motor in which signals generated by an angular position transmitter control the commutation of the current flowing through the stator winding via a selection circuit containing Exclusive OR gates by means of which the polarity of the signals generated by the angular position transmitters can be reversed for the reversal of the direction of rotation, operating modes of "Operation" and "Braking" can be specified with only one command input for the Exclusive OR gates using an additional Exclusive OR gate.

Abstract: A control system for a steam turbine includes an operator's panel and a programmed digital computer which generates valve position signals for the turbine throttle and governor valves. Mode select signals are generated at the panel and the computer includes a mode selector which provides for structuring the control system to implement external synchronizer, load runback, automatic turbine startup, operator automatic, manual and other mode selections.

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 transformer having a secondary winding that delivers a regulating magnitude to a speed regulator circuit that approaches zero as the speed approaches the speed setting, is provided with two primary windings wound and connected so that they oppose each other in operation. The first is the conventional primary winding in series with the universal motor of which the speed is being controlled (as by a conduction phase angle control of the input voltage) while the second primary winding is in series with a resistance and, in some cases, also with a capacitor, with this series combination being connected in parallel with the armature winding of the motor for the best regulation, or in parallel with the motor as a whole if it is important to avoid additional internal connections to the motor. The capacitor is used to compensate for the inductive reactance of the second primary winding in cases in which that reactance is not negligible. A second capacitor across the secondary filters out commution "hash.

Abstract: A brushless d-c motor having an electric commutation circuit in which the motor and circuit are inter-connected by a mating connector is disclosed. The mating parts of the connector may be connected in two configurations. In one configuration, the motor rotates in one direction and in the other configuration, the motor rotates in the opposite direction. The mating connector is disclosed as a plug connector having a plug and a mating jack in which the connection of the motor and circuit to the pin connectors of the plug and to the jack connectors of the jack, and the arrangement of the pin connectors and jack connectors is such that the motor rotates in opposite directions in the two configurations.

Abstract: A permanent magnet motor designed for d-c operation with pulsed current supply through at least two, and preferably four or more stator coils, has a rotor magnetized such that, with respect to 180.degree.-electrical, about 120.degree. are magnetized in one magnetic polarity, and the remaining about 60.degree. are magnetized with dual polarity to provide a monopole zone of magnetization and a dipole zone of magnetization, a galvano-magnetic sensing element being exposed to the path of circumferential rotation in which the same polarities of the dipole and monopole zones are contiguous for control of pulse current flow through the windings of the motor. A tacho generator winding may additionally be included in the air gap, exposed only to the rotary path of one magnetic pole of the dipole zone and the monopole zone.

Abstract: This invention relates to apparatus for converting into useful energy movements imparted thereto by movement of water, preferably sea waves and/or sea currents, the apparatus comprising two or more interconnected members of which at least one is buoyant and which in use of the apparatus are movable relative to each other due to vertical motions of the water, at least one of said members being provided with or connected to means which in use of the apparatus is responsive to horizontal motions of the water, and means for converting the relative movements of said interconnected members and operation of the means responsive to horizontal motions of the water into useful energy, such as electricity.

Abstract: A motor control system for controlling the speed and direction at which a motor operates. A drive circuit is provided for supplying a drive current to the motor, the magnitude of the drive current being determinative of the speed at which the motor operates. A direction-determining circuit determines the direction at which the motor operates and, for example, may comprise a steering circuit for steering the drive current to the motor in first and second current paths. A potentiometer having a resistance connected between first and second terminals and an adjustable wiper which is settable along the resistance is used to determine the desired speed and direction of operation of the motor. The setting of the wiper includes a predetermined zero speed setting which, preferably, is at some intermediate point along the resistance. A power supply having a power terminal and a reference terminal produces an operating potential across these terminals.