Abstract: In a drive system for a grinding mill the load torque plus frictional torque may increase considerably as a loaded mill is inched from its rest position and will suddenly decrease when the load tumbles or cascades. The applied torque or driving torque must increase at a corresponding rate and should also decrease when the load cascades. If the applied torque exceeds by a significant amount the load torque plus frictional torque, a destructive hammering will occur in the gear train and this will be generally proportional to the excess of applied torque for a synchronous motor drive. The drive system has a DC source which is commutated by a commutating device to provide a low frequency stepped alternating voltage to the stator windings of the synchronous motors of the drive system for inching. The output of the DC source has an alternating current component which varies as the difference between the applied torque and the load torque plus frictional torque.

Abstract: A system for control of movement of a cross sled which follows movement in an X-Y coordinate system according to a stored program, and for extending or shortening the path of movement either in the X-direction or Y-direction, or both directions.

Abstract: A device for positioning a semiconductor substrate is provided comprising magnetic field group formed from a plurality of magnetic fields disposed on a plane in a two-dimensional array. The magnetic fields are provided with a perpendicular orientation relative to the plane and adjacent magnetic fields are directed in alternate directions. Coil sets are formed of a plurality of coils, the coils having a specific dimensional relationship with the magnetic field array. Coil groups are formed by fixedly securing a plurality of these coil sets to each other the coil groups being disposed within the magnetic field group so as to be freely movable along the plane. Electric current is applied to the coils which generates a force in each coil set so as to move the coil set in either one of the longitudinal and lateral directions of the array of magnetic fields, whereby a current-motion converter and a driving device making use of the converter can be formed.

Abstract: A motor-driven rotary actuator includes an electric drive motor adapted to be configured for providing one of a plurality of output torques. A power transmission is coupled to the drive motor and includes a rotatable output shaft and drive elements adapted to be formed of disparate materials selected for transmitting one of the output torques. An electric controller is coupled to the motor for providing rotation positioning control of the output shaft in response to digital command signals.

Abstract: An acceleration/deceleration circuit for raising or lowering a feed velocity, in order to achieve a commanded velocity, over a prescribed time constant irrespective of the magnitude of a change in velocity. The acceleration/deceleration circuit includes means (301) for computing a traveling distance along each axis every sampling period (T), a first storage section (#1 through #n) for storing n samplings of traveling distance components along each axis, a second storage section SUM for storing results of computation, and an arithmetic section (ADD, ACC, DIV) for performing an operation:.sub..DELTA. Xn-.sub..DELTA. Xo+St.fwdarw.Stwhere .sub..DELTA. Xn represents the latest sampled traveling distance component, .sub..DELTA.

Abstract: A reference post assembly (50) directly mounted on a numerically controlled machining system such as a lathe obviates the need for a datum ring including reference datum surfaces (42,44) and being conventionally provided on the external cylindrical surface and face of a chuck (36) which holds the workpiece (41) being machined. The reference post assembly (50) is comprised of an elongated reference post member (52) of selected cross section, i.e., square or round, which is resiliently mounted on the lathe in a known calibrated position with respect to the workpiece (41). The post (52) is ultrasonically vibrated in a longitudinal mode by one or more piezoelectric elements (54) coupled to an electrical signal oscillator (56).

Abstract: This analog-to-digital converter includes a comparator (20) to which the samples X.sub.(n) of the signal to be converted, are applied. The output of the comparator controls a logic circuit (22) producing (N+1) bits to a digital-to-analog converter (24) the output of which is fed back to the input of comparator (20). The converter carries out a converting procedure through N successive approximation steps at the end of which the N most significant bits available at the output of the logic circuit (22) stand directly for the rounded-off digital value of sample X.sub.(n).

Abstract: A closed-loop feedback-controlled servo system is disclosed which reduces command-to-response error to the system's position feedback resolution least increment, .DELTA.S.sub.R, on a continuous real-time basis for all operating speeds. The servo system employs a second position feedback control loop on a by exception basis, when the command-to-response error .gtoreq..DELTA.S.sub.R, to produce precise position correction signals. When the command-to-response error is less than .DELTA.S.sub.R, control automatically reverts to conventional control means as the second position feedback control loop is disconnected, becoming transparent to conventional servo control means. By operating the second unique position feedback control loop used herein at the appropriate clocking rate, command-to-response error may be reduced to the position feedback resolution least increment. The present system may be utilized in combination with a tachometer loop for increased stability.

Abstract: An improvement for a controller (C) for controlling the idle speed of an engine. A logic circuit (1) is responsive to the position of switches (S1, S2) and the direction in which an extendible and retractable member (T) is to be driven by a motor (M) to energize the motor. The logic circuit includes logic gate (3) responsive to both switches being open when the member is at its extreme extended position and the member is to be retracted to energize the motor to retract the member. The logic circuit also includes a logic gate (5) responsive to both the switches being open when the member is at its extreme retracted position and the member is to be extended to energize the motor to extend the member. The motor is thus energized to move the member in the appropriate direction even though a switch which should be closed is open due to dust or debris preventing switch closure.

Abstract: In a rotary printer control system, a dual mode servo for controlling the velocity and position of a rotary print wheel and a print wheel carriage is normally operated at a relatively high gain value. When the servo is switched from the velocity mode to the position mode, the length of time the servo remains in the position mode is monitored and, if this exceeds a predetermined maximum time period, the gain of the servo loop is switched to a relatively low value in order to reduce oscillations of the print wheel or carriage about the HOME position. The gain reduction is accomplished by inserting a supplemental R-C network in parallel with the high gain R-C network, and the range or ratios of the relatively high gain to the relatively low gain values is from about 10 to about 30.

Abstract: A pulse generator for use in a digital/analog converter which generates a pulse train with pulse widths modulated in accordance with an input digital signal. The leading edge of an arbitrary pulse in the pulse train is widened by one half of a clock period and the trailing edge of another pulse is widened by one half of the clock period, in accordance with the input digital signal.

Abstract: A signal converting apparatus for converting voltage into a pulse signal with a corresponding pulse-width comprises a switching circuit for selecting either one of an input voltage to be converted or a constant voltage depending upon a binary switching signal. The selected voltage is integrated with respect to time by an integrating circuit. When the output from the integrating circuit has reached an upper limit voltage or a lower limit voltage, the above-mentioned binary switching signal which is an output signal of this signal converting apparatus is inverted by a comparator/inverter circuit.

Abstract: A control unit is provided with a memory unit for storing data representative of errors occurring in the system, as well as the order in which sequential errors occurred and the number of occurrences of the errors. An error "history" may be displayed from these data, to assist in pinpointing the cause of the trouble.

Abstract: A circuit for controlling the rotation angle of a motor by comparing an output signal from angle setting means with the detection result from a potentiometer means which detects the rotation angle of the motor while the motor is driven in response to the output signal from the angle setting means which has: a first potentiometer for detecting the rotation angle of the motor; a second potentiometer for detecting another rotation angle at a phase different from that of the first potentiometer; an interval selecting means for selecting one of a plurality of interval signals in response to the output signal from the angle setting means; a potentiometer selecting means for selecting one of the output signals from the first and second potentiometers in response to the output signal from the interval selecting means; a compensating signal generating means for generating an offset compensating signal for compensating for an offset between a selected signal from the potentiometer selecting means and the output signal

Abstract: In tuning a regulator (2) of the PID-type of a process (1) in a feed back system where the process and the regulator has a transfer function G(s) in common, a method is proposed for bringing the system into self oscillation for measuring the amplitude and frequency of the oscillation and tuning the regulator in dependence of the measurements obtained. A circuit function (NL) having non-linear characteristic and a describing function N(A) is introduced into the system in series to the process for acting on the regulator signal (e). Self oscillation is obtained if G(i.omega.).multidot.N(A)=-1 for at least one value of the angular frequency .omega. and the amplitude A of the regulator signal (e). An apparatus for performing the method is disclosed.

Abstract: A low cost servo operated digital positioning system which utilizes a phase shift control circuit in combination with an encoder and servo circuit for driving a moveable element. The encoder generates a pair of signals A which may be equivalent to a sine signal A and a cosine signal A. The phase shift circuit multiplies signals from the encoder by a sine of a demand signal B and by a cosine of the demand signal B and produces a sine (A+B) signal and a cosine (A+B) signal. These sine and cosine shift signals are introduced into a servo circuit for control of a moveable element. By phase shifting these signals it is possible to substantially increase the overall number of positions to which a moveable member may be moved and thereby substantially increase the overall accuracy of a positioning system.

Abstract: An improved memory reset arrangement for a mirror such as a rearview mirror of a motor vehicle and the like, which is so arranged that push-pull driving shafts for tilting or pivoting the mirror are directly associated with memory switches for memorizing rotational positions of the mirror so as to simplify the construction of the memory reset arrangement for the mirror, with a consequent reduction in cost.

Abstract: The disclosure provides an electronic motor control circuit which switches and amplifies to control a bi-directional electric motor, using a symmetrical circuit, each half of which consists of five transistors. The circuit has a logic level input and motor driving power output using, for control in each direction: an input transistor; a control transistor turned on and off by the input transistor; two matched, complementary motor drive transistors (at opposite terminals of the motor) turned on and off simultaneously by the control transistor; and a lockout transistor, also actuated by the control transistor, which is operatively connected to one of the motor drive transistors in the other half of the system to prevent short circuiting.

Abstract: An analog-to-digital conversion circuit, in which the coarse bits are produced by a counter (25), is made suitable for processing a video signal by having, in the event of fast large amplitude variations, an analog-to-digital converter (3), connected to the input (1) of the conversion circuit, write into the counter in response to a threshold-crossing signal produced by a difference threshold circuit (91, 93, 57), while slow and small amplitude variations are followed by a correction circuit (97, 113, 111, 119, 61, 63) coupled to an output (49) of a digital-to-analog converter (47) which is connected to the outputs of the conversion circuit, the correction circuit also being coupled to the input (1) of the conversion circuit, which correction circuit corrects the counting position, while the fine bits are obtained from a fine analog-to-digital converter (113, 97, 103, 105) which is responsive to the difference between the signal at the input (1) of the conversion circuit and the signal at the output (49) of t

Abstract: Tracking servo control system for an information read-out system such as a video disc player system or a compact disc player system, comprises a servo loop switch for opening and closing the tracking servo loop, and a timing control circuit for generating a timing signal for controlling the servo loop switch in accordance with an on-track signal generated from a pickup output signal and zero cross timings of the tracking error signal. In order to control the operation of the servo loop switch, very accurately, a phase shift circuit is provided between a tracking signal generating means and a zero cross detection means, which has substantially the same phase characteristics as that of an equalizer circuit utilized in the tracking servo loop.