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 system for effecting the adjustment of the armature of a solenoid into a desired position as indicated by an input analog signal representation of desired armature position. When the actual position of the solenoid armature does not correspond to the desired position in a first or in a second relationship, respective mutually exclusive first and second proportional and respective corresponding mutually exclusive first and second integral error signals are produced. The corresponding proportional and integral error signals are summed and circuitry responsive to the sum of these signals effects the adjustment of the solenoid armature into the desired armature position.

Abstract: In a disc pack data storage system that has a plurality of discs and a plurality of heads for coaction with the discs, a tachometer for producing a signal indicative of the radial speed of the heads with respect to the discs. At least one of the disc surfaces is a servo surface and at least one of the heads is a servo head so that in response to radial movement of the servo head a triangular position signal is produced. Sampling pulses indicative of specific radial positions of the head are derived from the position signal so that the time required for the head to move between two positions represented by adjacent sampling pulses is inversely proportional to radial head speed. Control and computing circuitry measures the time between adjacent pulses by providing a clock pulse source and counting the number of clock pulses that occur between adjacent sampling pulses.

Abstract: A system for precisely positioning a printed circuit board relative to a component insertion tool, the system including a circuit board-holding frame movable with two degrees of freedom in a plane by a servomechanism coupled to a photo detector assembly positioned on the opposite side of the printed circuit board from a light beam generator producing a single beam or a pair of parallel light beams spaced a distance equal to the distance between a pair of holes in the circuit board. Light pipes or a pair of orthogonally oriented wedge-shaped beam splitting members are positioned between the photo detector assembly and the circuit board for splitting each of the beams and thereby illuminating orthogonally oriented pairs of photo cells equally when the board is in a desired position relative to the light beams and providing to the servomechanism with an error signal to correct the position of the board when it is not in such alignment.

Abstract: Load actuating servomechanism apparatus includes dynamic regeneration and a mechanically damped motor-load coupling to equalize and overcome a frequency-varying load/load drive train mechanical resonance. The drive circuitry comprises a per se conventional primary motor speed controlling rate feedback loop including a cascaded rate signal command source, summing error-signal producing node, and loop frequency response shaping filter and driver amplifier for exciting a load driving motor, and a rate tachometer signal feedback element connecting a measure of the motor output speed to a subtractive input of the summing node.To broaden the response band of the primary feedback circuit and accommodate a mechanical resonance otherwise interfering therewith, a secondary, positive feedback path supplements the input rate command with a signal dependent upon motor current, and thus upon motor load.

Abstract: A system for performing target acquisition and tracking under the control a human operator. The system has a slewable sensor with a line of sight and includes apparatus for slewing the sensor to align its line of sight with a target, the difference between the position of the target and the line of sight being a line of sight error. A display displays the line of sight error to the operator at either a first or a second magnification, selectable by the operator. The operator uses a control manipulator to generate input signals and supply them to the rest of the system. Circuitry is provided for automatically switching from proportional to proportional-plus-integral control upon changing from the first to the second magnification. Circuitry is also provided for initializing an integrator prior to the switchover from the first to the second magnification to eliminate control transients in the concomitant switchover from proportional to proportional-plus-integral control.

Abstract: A stepper motor drive which sequentially energizes the windings of a stepper motor (1,2,3,4). The drive includes a binary counter (11) fed by a clock signal and two multipliers (D.A.C.1, D.A.C.2) which are fed by the binary counter (11) and a reference signal. An adjustable feedback network (30) is arranged to combine a fraction of the output of the multipliers (V.sub.1, V.sub.2) with the reference signal so that the output of the multiplier represents unequal steps of a staircase waveform. A switching network (13) under the control of the counter (11) applies to the windings drive signals in accordance with the output of the multipliers.Each winding has its own amplifier (15,17) to control its current, and pairs of antiphase signals from the switching network (13) are combined in the amplifiers to produce symmetrical changes of current in a respective pair of coils (1 and 2 or 3 and 4). The feedback network (30) distorts the otherwise linear outputs from the multipliers (D.A.C.1, D.A.C.

Abstract: In a motor control circuit, a rotational speed detection signal containing a ripple component superimposed on a d.c. component is applied to both a low pass filter/phase lagging circuit and to a phase leading circuit, the output signals of which have a phase difference of approximately 180 degrees, to effectively cancel the ripple component and thereby extract only the d.c. component. The latter is balanced against an r.p.m. reference voltage in a comparison circuit whose output is fed back to a drive winding control circuit of the motor.

Abstract: A control system for controlling a motor having a plurality of electromagnetic field windings adapted to be separately energized by switching circuitry to control rotation of a rotor in the motor. Digital circuitry generates a plurality of logic signals, one for each respective motor field winding to cause the switching circuitry to energize the field windings in a two phase on mode, a one phase on mode, or in one of a plurality of fractional phase on modes. A signal command source provides a plurality of digital signals to select or gate the desired phase on energization mode of the field windings in response to a feedback signal derived from detecting rotary movement of the rotor. Related methods of controlling a multi-phase motor with digitally generated variable phase modes are also disclosed.

Abstract: In a positioning control system of the type which controls an object to be controlled to a target position by the use of a servo system, the present invention is characterized in that when a position deviation between the present position of the object to be controlled and the desired target position is smaller than a predetermined value, the servo system is actuated for a first period of time in accordance with the position deviation by means of a control signal which is greater than that normally warranted by the position feedback gain which is provided in the servo system, and is thereafter changed over to a servo system which is actuated by the position feedback gain either after a predetermined time or when a predetermined velocity has been achieved.

Abstract: A motor control system for use in a high speed teleprinter or the like for controlling the rotational position and movement of a rotor, and apparatus driven by the rotor, by detecting back EMF induced into an unenergized field winding by rotational movement of the rotor. The output and input terminals of a first amplifier responsive to a first motor control signal, and a second amplifier responsive to a second motor control signal, are reactively coupled such that the amplifiers respond to either motor control signal to develop a signal simulating the signal into an unenergized winding of the motor due to mutual inductance with an energized winding. A differential voltage comparator provides a feedback signal indicative of motor performance upon comparing the simulated signal with the signal actually induced.

Abstract: There is disclosed a propulsion and brake effort control apparatus and method operative with the motors of a transit vehicle, including programmed microprocessor control apparatus for comparing the motor current desired by the vehicle control P signal with feedback information from the motor operation to determine the requested motor current by the phase angle relationship of ON and OFF pulses supplied to the current controlling chopper apparatus. The requested current and motor effort can be controlled by the operation of an effort control parameter provided in relation to high and low determined limits of the power supply line voltage, a high determined limit of the line current in relation to the motors and the current request signal.

Abstract: A program controlled workpiece manipulator has a load cell supported between the manipulator clamp and the positioning elements which generate signals proportional to the various components of the forces exerted on the workholder by external instrumentalities. To generate a desired control program for the manipulator the outputs of the load cell and of the position transducers for the manipulator drive servos are used to generate command signals for the drive servos which urge motion of the clamp to reduce the externally imposed forces. The clamp is then manually grasped and urged toward the desired motion and the outputs of the position sensors are recorded during the motion to create a control program which may be replaced to control the manipulator to duplicate the motion.

Abstract: An axial gap, permanent magnet motor. The motor includes a stator affixed to a motor housing. The stator has two sets of series connected coils wound in quadrature. Each set of coils is disposed in an annular configuration about a spin reference axis, with the principal axis of each coil being substantially parallel to the reference axis. The motor further includes a rotor which is adapted for continuous rotation about a spin axis. The rotor includes a set of permanent magnets and a member for supporting the magnets in a substantially annular configuration about the spin axis. The magnetic moment of each of the magnets is substantially parallel to the spin axis, with the magnetic moment of adjacent magnets being oppositely directed. The rotor is positioned with respect to the stator with the configuration of magnets being adjacent to the configuration of coils so that flux from the magnets is coupled to the coils.

Abstract: System for maintaining a preselected constant torque on a loaded reel of a winding mechanism. The system includes a d.c. motor wherein both the armature and field windings are adapted for independent rotation about a common axis. The field winding is coupled to the reel so that the reel rotates at a velocity proportional to that of the field winding. A drive motor establishes a constant speed rotation of the armature winding. A torque control drives constant currents through the armature and field windings of the motor. The amplitudes of the armature and field currents are preselected so that a constant torque is maintained at the reel irrespective of variations of the load.

Abstract: An improved alternating current prime mover control system and method for, for example, the control of a valve position or other physical variable whose state can be sensed or calculated wherein the state of the physical variable is compared with a reference variable to generate, in conjunction with a waveform generator, a fixed amplitude signal that has variable time duration which feeds a part of the control system that drives the alternating current prime mover source in more than one direction.

Abstract: A window clearing arrangement particularly for the rear window mounted on an automobile liftgate is provided, being characterized by a control circuit comprising a single relay, the single reversing contact of which enables, according to its position, either wiping by powering the motor-reducer or the stopping of the motor by short-circuiting of the armature. The relay is fed by the first wire, while the second wire powers the defogging system. All of the controls, whether momentary or not, involve one or more suitable switches, one position, however, being reserved for the impulse control of the washer by electrically powering a pump, which simultaneously activates the wiper.

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: In the disclosed system, if the frequency of input signals exceeds a value suitable for a load, the input signals and output signals are stored and compared in a comparator while locking of a phase locked loop is delayed by a loop filter that allows the output of the VCO (voltage controlled oscillator) to increase or decrease only at rates slower than given rates. When the input signals end after the loop locks, the filter delay causes the VCO to keep producing signals which are passed until the comparator recognizes that the number of output signals equals the number of input signals. If the input signals end before the loop locks, a logic circuit causes the VCO frequency to keep rising until another comparator indicates that the number of output signals has reached one-half the input signals.

Abstract: A voice coil type linear motor controls the movement and positioning of a transducer which cooperates with a spinning disk. The motor is feedback controlled for separate speed (seek) and positioning modes in which respectively the transducer is moved across the disk towards a different track and is held centered above that track. In order to offset the effect of a tilted axis of carriage movement, the control condition in the positioning mode representing a correct transducer position in which it is held by the motor, is continuously sampled and held during a period when the transducer is moved to another track to be applied as correction for the control moving the transducer towards another track. This correction signal is also used in the initial phases of holding the transducer above the newly selected track, until sampling and positioning control proper takes over.