Abstract: A control system is disclosed for acquiring and maintaining a register condition for successive repeat lengths of a moving web relative to a cut-off apparatus or the like in a web operating apparatus of the type which includes an adjustment means for advancing or retarding the web relative to the cut-off apparatus. The system operates in manual and automatic modes and while in the manual mode, an operator manipulates the adjustment means to obtain the register condition and then switches to the automatic mode which maintains the register condition.

Abstract: A servo feed system for EDM in which feed of the electrode is controlled responsive to a gap voltage signal with appropriate feedback changes to control servo velocity and upfeed and downfeed gain as the gap voltage level changes. A further feature involves the imposition of a dither circuit between the gap voltage signal amplifier and the servo valve coil in such manner as to continuously apply dither in a manner independent of changes in gap voltage.

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 proportional motor control circuit for supplying bidirectional drive to a motor as a function of variations of a sensed parameter includes a temperature sensing amplifier which is responsive to an error signal indicative of deviations of the parameter from a set point to provide an output signal representing the direction and amount of the deviation, and a pair of operational amplifiers, each of which serves as a load for the other amplifier, which are responsive to the signal output of the temperature sensing amplifier to determine the polarity of the energizing potential applied to a D.C. motor over motor drive circuits. The motor control circuit is described with reference to an application in an environmental control system to effect positioning of dampers located in air ducts for supplying heated or cooled air to an area in response to changes in the air temperature in the area.

Abstract: A motor control circuit is arranged to provide selected control signals for operating a motor to rotate a motor shaft in a predetermined direction until the motor control circuit provides a high frequency control signal for substantially stopping motor operation.

Abstract: A gyroscope unit having a horizontal spin axis hangs from a suspension band within a container. The container is rotatably supported about a vertical axis. A transducer generates a control signal representative of the angular displacement between the gyroscope unit and the container about the vertical axis from a reference position. The container is rotated about the vertical axis responsive to the control signal to reduce the angular displacement from the reference position. A torque about the vertical axis that opposes the angular displacement is directly applied to the gyroscope unit responsive to the control signal. The directly applied torque is a nonlinear function of the angular displacement, being zero below a threshold value of angular displacement and having a predetermined gradient above the threshold value.

Abstract: A machine drive system includes two motors which are to be driven with a selected velocity ratio. To one of these motors a coarse control is applied, and which the velocity ratio approximates the desired value, a fine control is applied to the other motor. The system may be hydraulic or electric. The hydraulic version employs a single pump to drive the two motors, and the fine control is conveniently a valve in a fluid line bypass around the associated motor. An error signal obtained from a comparison of the two speeds is used to govern the coarse/fine control.

Abstract: A process control system including a control station responds to the departure of a process variable from a set point to provide a direct current signal in a two-wire transmission line in a direction dependent upon the direction of such departure and time-proportioned in accordance with the magnitude of the departure. A solid state power relay that accepts the d-c signal at a single pair of input terminals includes high-current rating triacs that are adapted selectively to be fired by triggering pulses generated in response to the d-c signals to supply alternating current power from a source of single-phase or three-phase alternating current to a heavy-duty motorized valve for operation of the latter in one direction or the other and at a speed in accordance with the signals.

Abstract: A process control system including a control station responds to the departure of a process variable from a set point to provide a direct current signal in a two-wire transmission line in a direction dependent upon the direction of such departure and time-proportioned in accordance with the magnitude of the departure. A solid state power relay that accepts the d-c signal at a single pair of input terminals includes high-current rating triacs that are adapted selectively to be fired by triggering pulses generated in response to the d-c signals alternating current power from a source of alternating current to a heavy-duty motorized valve for operation of the latter in one direction or the other and at a speed in accordance with the signals.

Abstract: An integral motor controller circuit for supplying variable speed, bidirectional drive to a motor as a function of variations of a sensed parameter includes an amplifier circuit which is responsive to an error signal indicative of deviations of the parameter from a set point to provide an output signal representing the direction and amount of the deviation. The amplifier output signal is applied to a first motor terminal and to an input of a two-level comparator circuit which is responsive to an increasing error signal exceeding a predetermined amount to connect an energizing potential of one polarity to a second motor terminal and responsive to a decreasing error signal in excess of the predetermined amount to connect an energizing potential of the opposite polarity to the second terminal of the motor, the speed of the motor being determined by the level of the amplifier output signal.

Abstract: There is disclosed a motor control circuit that is particularly useful for the control of a damper motor in a heating and ventilating system. The control circuit comprises a bridge circuit having a pair of operational amplifiers with cross connected input terminals. An input signal is provided by input signal circuit means to one of the cross-connecting conductors and a reference signal is provided to the other of the conductors by a reference signal circuit means. The operational amplifiers are provided with feedback circuit means between their output and noninverting terminals to drive the amplifiers into an unstable condition where they function as on and off switches. Dead band means in the form of a load dropping resistor is provided between the input signal circuit and the noninverting terminal of one of the amplifiers.

Abstract: An adaptive filter circuit using a time modulated dead band for suppressing the effects of spurious noise associated with an error signal used in controlling a position drive motor associated with process controlling elements. The circuit includes means for restricting all signals, including both control signals and spurious noise, to a positioning motor during those periods of operation when little positioning is required. However, in those instances where a relatively large amount of repositioning is required, the system provides means for switching to a nonrestrictive mode of filtering which thereby permits maximum control over motor operation.

Abstract: A four-quadrant full-wave static converter having improved time response without current cross-over deadband. An alternating current wave is imposed on the direct current input signal, which generates gate pulses for appropriate thyristors at the desired firing angle. The applied alternating current signal can be of approximately the same magnitude as the converter deadband, so as the direct current signal varies from zero a portion of the control signal moves out of the deadband area. For fast response the magnitude of the alternating current signal can be greater than the deadband signal. As the magnitude of the direct current signal increases the relative magnitude of the alternating current signal is decreased, preventing a large DC component from being imposed on the supply during high current operations. Cycling of the imposed alternating current waves is synchronized with the firing angle point O to maintain system protection.