Abstract: An electric vehicle having a separately excited field controlled direct current drive motor powered by a direct current power supply wherein field current is pulse-width modulated in response to operator control and the vehicle operating parameters. An armature current demand signal which is dependent on a throttle setting is compared with an actual armature current signal derived from an armature shunt and the difference is applied to a field current output amplifier which supplies current to the separately excited field to reduce the difference to zero. The armature current demand signal is responsive to the operator's control of the throttle in the electric vehicle. The drive motor of the electric vehicle can be operated in the driving mode for moving the electric vehicle or a regenerative mode for braking the electric vehicle and supplying energy to the power supply. The armature demand signal is also influenced by various operating conditions to improve operation of the electric vehicle.

Abstract: Means for controlling the speed of the secondary of a linear motor, particularly the shuttle of a linear motor powered loom, consists of a series of uniformly spaced markings on the secondary and a sensor responsive to the markings and located adjacent to the linear motor primary. The markings cause the sensor to produce an oscillating output, the frequency of which is dependent on the speed of the secondary. A control signal derived from the sensor output is used to turn off the supply of current to the linear motor primary when the secondary is travelling at the required speed.

Abstract: A template controlled machine tool, especially for machining the crankpins of crankshafts. A first template member rotates in unison with a crankshaft mounted on the work axis of the machine. A second template member is mounted on a carriage so that the second template member and carriage are actuated when the first template member rotates. The machine tool has a work carriage on which a tool is mounted. The work carriage is driven by a motor which receives power from an electric circuit that is controlled in conformity with the movement of the template carriage. Each of the carriages actuates a digital measuring device and a comparator compares the pulses therefrom and adjusts the speed of movement of the tool carriage to maintain the tool carriage position in close conformity with that of the template carriage.

Abstract: A rotary body control apparatus for controlling both speed and phase of the rotary body such as d.c. motor in a single circuit. Speed control is accomplished on the basis of a reference signal without provision of independent control system and, a phase comparison unit serving as means for detecting speed is provided to control phase. A number of stabilized regions is provided so as to effect locking-in with the reference signal in a suitable stabilized region with a reduction in time. The apparatus consists of speed signal generating means, reference signal introducing means, output signal forming means, output signal sampling means, and oscillating means.

Abstract: A sonar flasher motor speed control for driving a D.C. electric motor from a varying voltage source. A rotating magnet and coil system generates a first voltage pulse once each revolution of the motor. A capacitor charged through a series resistor in combination with transistor means controlled by the first voltage pulse to generate a ramp voltage once each cycle. The ramp voltage is compared with a reference voltage by means of a voltage comparator, which generates a control second voltage pulse, whenever the ramp voltage exceeds the reference voltage. Transistor amplifier means responsive to said second voltage pulse increases the motor current during the second pulse so as to maintain the speed of the motor relatively constant.

Abstract: In a control circuit for an electrically driven vehicle, there is an accelerator pedal which when depressed sets the armature current of a traction motor, and a brake pedal which when depressed provides electrical braking of the vehicle. The electrical braking is inhibited unless the vehicle speed is above a predetermined value.

Abstract: In a position transducer arrangement one or more AC operable position transducers are energised by the output of a variable amplitude oscillator. The output signals from the oscillator and the or each transducer are demodulated, or detected in turn by the same demodulator and the demodulated oscillator signal is compared with a reference signal to produce a difference signal. The difference signal is used to adjust the amplitude of the oscillator signal in the sense to reduce the difference signal to zero.

Abstract: In a control circuit for an electrically driven vehicle, there is a main thyristor in series with a traction motor and a commutating thyristor for turning the main thyristor off. Firing pulses for the thyristors are provided by an operational amplifier having two states in which it fires the main thyristor and commutating thyristor respectively, and delay means operates when the main thyristor is fired to drive the operational amplifier to its other state after a predetermined delay.

Abstract: In the automatic reading of a weave design from a pattern including weft rows and warp rows, the advance of the reading assembly (photo-electric cells) from one weft row to the next one is effected by a step-by-step electric motor which receives "secondary" pulses from a ring counter to which "primary" pulses are applied, whenever the number of such "primary" pulses received by said counter is equal to the quotient of the number of "primary" pulses required to displace said assembly from one extreme weft row to the other one, divided by the number of weft rows minus one unit, this quotient being taken as an integer.The incremental advance of the reading assembly for each step of the motor is much smaller than the centering tolerance of said assembly required to place it in front of each weft row, and the number of "primary" pulses required to determine such a step is selected much higher so that the error which results from the fact that the quotient is limited to an integer is also negligible.

Abstract: A manually shiftable actuator-position input member and an actuator-operator feedback member cooperate as switch means for controlling the operation of an actuator including a rod connected to be reciprocably driven by a reversible electric motor. The input and feedback members normally occupy neutral positions relative to each other wherein electrical current is disconnected from the motor. Energization of the motor to cause it to drive in the forward and reverse directions may respectively be accomplished by moving the input member in opposite first and second directions from its neutral position. The distance through which the input member is moved preselects the distance through which the motor drives the rod, the motor driving the feedback member via the rod such as to restore the neutral positions of the input and feedback members when the rod has been driven to the preselected position.

Abstract: Apparatus for advancing magnetic tape with respect to a recording head through small, discrete, and uniform displacement increments. A direct current drive motor has an armature shaft that drives a displaceable member. Controls develop signals that energize and deenergize the motor. Included in these controls are a speed responsive tachometer and an acceleration control utilizing a saturable amplifier.

Abstract: A circuit is disclosed for controlling and regulating the speed of a D.C. motor fed from a single-phase A.C. supply. A full-wave power bridge using two diodes and two silicon controlled rectifiers (SCR's) supplies unfiltered rectified A.C. to the motor. A first programmable unijunction transistor (PUT) is used to trigger the SCR's in response to a timing capacitor voltage applied to its anode. The timing capacitor is charged from a zener-regulated, full-wave bridge source through a speed-control resistor and thus provides triggering of the SCR's at a phase angle determined by said speed-control resistor. To obtain consistent triggering at the same phase angle, a second PUT is used to reset the voltage on the timing capacitor to zero at the end of each half cycle of the A.C. voltage to insure that the initial charge condition of said capacitor is always the same.