Abstract: A control circuit of a two-phase AC electric motor wherein the windings and two series capacitors are delta-connected, the winding mid point is brought to one terminal of the power source, and the winding leads connected to the capacitors are brought to the other terminal of the power source through switchgear components.The control circuit is distinguished from the prior-art control circuits in that the mid point of the capacitors is connected to the mid point of the switchgear elements, with the capacitance of each capacitor being equal to the rated phase-shifting capacitance of the electric motor.

Abstract: A directional switching device for a feeder in a machine tool driven by a direct current motor. The armature circuit of the direct current motor is provided with a relay contact circuit for switching the forward and backward movements of the conveyor. The relay contact circuit is controlled by signals from a sequencing circuit.

Abstract: A magnetically suspended rotor system is provided capable of operating at rotational speeds of 100,000 rpm or greater. The system comprises a rotor assembly and electric motor means for producing rotation of the assembly about an axis thereof. Electromagnetic means disposed near one end of the rotor is energized to exert an attractive force on the rotor to support it and preferably cooperates with permanent magnet means affixed to the rotor assembly near one (the upper) end thereof. An additional permanent magnet affixed to the rotor near the opposite (lower) end thereof cooperates with another permanent magnet disposed in juxtaposition thereto to exert an attractive force on the rotor tending to oppose the force exerted by electromagnetic means and produces a radial constraining force on the rotor tending to center the lower end of the rotor assembly.

Abstract: An automatically-openable-and-closable-door operating apparatus uses a capacitor torque motor in order to automatically open or close the door. When opening or closing the door, an exciting coil of the motor is first short-circuited as the door approaches the open or close terminal so that the motor undergoes a dynamic braking to absorb an inertia of the door and to decelerate the door. Thereafter the short-circuiting or connection and the disconnection across the exciting coil are repeated alternately to have the motor produce a driving force and a braking force alternately so that the door may be brought into its opening or closing terminal position at a low speed without accompanied by shocks.

Abstract: Automatic starters for an internal combustion engine and to a circuit for automatically starting the engine of an automotive vehicle at a predetermined time.

Abstract: Disclosed herein is a direct current motor control or energizing circuit comprising a direct current motor, a bank of series connected batteries, which bank includes opposite ends, and a switching arrangement for electrically disconnecting and connecting the bank to the motor for energizing of the motor at selective levels of potential and so that successive energizations involve alternate connection of the motor from the opposite ends of the bank to at least one of the batteries.

Abstract: An antenna adapted to be extended and retracted for car radio receivers, which is actuated by means of an on-off switch of the radio receiver and is driven by an electric motor reversible in its direction of rotation; the control circuit for the electric motor includes two limit switch contacts adapted to be opened by switching cams on a disk that moves proportional to the movement of the antenna, and a further switching contact which is adapted to be actuated by a further switching cam of the disk; the further switching contact is thereby opened at and above a predetermined extended length of the antenna while a manual switch with push-button function and possibly with detent function is provided for the further selective extension or retraction of the antenna.

Abstract: An acceleration/deceleration control circuit for a stepping motor includes a plural stage up/down counter connected to a source of pulses of constant repetition rate. The up/down counter output is connected to a decoder, such as a digital/analog converter, and conventionally, the output of the decoder is coupled to a variable rate oscillator, whose frequency increases, for example, as the output voltage of the digital/analog converter increases, and vice versa. The variable rate output is provided as an input to the stepping motor. In the improved arrangement a series RC circuit is coupled to the output of the decoder and the input of the variable rate oscillator is connected across the capacitor.

Abstract: A manually rotatable control knob is coupled to a d.c. ironless motor which maintains rotation of the knob once it is initially spun by hand. The initial back e.m.f. of the motor is sensed and is used via a feedback loop having a particular time constant to determine the subsequent rotational speed of the knob. By correctly profiling the time constant the inertial effect of a heavy flywheel can be simulated.

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: A magnetic card reader for providing an output to a utilization device. A plurality of reed switches are arranged in coplanar relationship in a manner to optimize the number of data sensors in a given area. In addition, a magnetic card is disclosed for providing completely different and independent magnetic data on the opposite surfaces thereby allowing sensing or reading devices to be placed on both sides of the card.

Abstract: The tendency of a stepping motor to oscillate or flutter under some mid-velocity conditions is minimized by reducing the deviation of the motor's rotor from its normal synchronous position by altering the time about a nominal time when a change of energization of the motor's windings is to occur after receipt of an input pulse in accordance with the duration of the decay current that existed at the prior change of energization.

Abstract: Linear velocity changes between steps are obtained by a digital circuit in a stepping motor system that receives commands of the number of steps to be produced in successive time intervals by providing a string of pulses during each interval and selecting certain of said pulses to provide motor steps with the selection being initially determined by the number of commanded steps in the interval and further being determined by whether the number of commanded steps for the interval has the same number of steps, a greater number or a lesser number than in the immediately preceding interval.

Abstract: A monitoring device which is directed to achieving a more reliable power supply for an electronic or electromechanical system; such monitoring device including a means for selecting, in response to detection of subtle failures in either of two power supplies, so as to connect one and only one of the power supplies, regardless of internal failure within the monitoring device itself.

Abstract: A stepping motor for a timepiece comprising one-piece upper stator pair, one-piece lower stator pair, and magnetic material between said one-piece upper stator and said one-piece lower stator and circular rotor having at least two pairs of magnetic poles positioned circumferentially thereof is disposed between the stator pairs, and a driving coil is connected magnetically to said one-piece upper stator pair and to said one-piece lower stator pair. The stepping motor includes means for defining a rest position of the rotor.

Abstract: Electrical energization and control circuit particularly for use in permanently installed vacuum cleaning systems having a centrally located A.C. powered vacuum turbine and a remote flexible cleaning unit equipped with low voltage A.C. or D.C. agitator motors. Energization of the A.C. turbine motor circuit is controlled by a current sensor in the one of the two wires leading to the remote low voltage agitator motor so that a selector switch in the handle of the cleaning unit may, in one position, energize the low voltage agitator motor or, in a second position, bypass the agitator motor through a resistance to initiate a current flow that is sensed by the current sensor to activate the A.C. motor circuit.

Abstract: First and second bands of separate frequencies are coupled through hybrid transformers and frequency isolation filters to each of three phase wires of a power transmission line. The hybrid transformers and filters are arranged so that both bands of frequencies are transmitted and received even though there is an open or short circuit on one of the feed lines or one of the phase wires, thus providing the reliability desired or needed, particularly when the frequency bands provide relaying functions.

Abstract: A starting control system for synchronous motors having circuits for detecting motor speed, the zero crossings of the current induced in the field windings, and the motor load angle. A circuit responsive to the detected motor speed, zero crossings and load angle triggers the DC excitation of the field at the zero crossings upon reaching a predetermined rotor speed and terminates the DC excitation at predetermined load angles. The pulsed DC excitation provides a torque that pulls the rotor into synchronism within several rotor slip cycles. In one embodiment the pulsed DC excitation is applied on both positive and negative half-cycles of the induced field current waveform.

Abstract: A key switch provided with plural elastic elements to be actuated in succession in response to the operation of key top by finger and composed to perform opening or closing operation when at least two of said elastic elements are actuated thereby reducing bouncing or chattering.

Abstract: Discloses a power system in which three single phase transformers have their primary windings connected in delta to a 3-phase isolated phase bus. Switching means is provided for connecting a spare transformer to said bus as a replacement for any one of said single phase transformers. Special interlocking means assures that the spare transformer is connected to the bus in the same manner as the transformer it replaces. .Iadd.