In the servo system of a numerically controlled machine the position feedback signal is monitored by a fault indicate circuit. An absolute analog position signal is generated by an integrator circuit connected to receive a signal proportional to machine speed. Under normal operating conditions, the integrator circuit is repeatedly reset to zero by a reference reset switch and the magnitude of the absolute position signal is thus maintained below a preset limit. The reference reset switch is cont...

A liquid heating feedback system for elevating the temperature above the dew point of the liquid feed to a heat exchanger of a liquid heating system, particularly of the "once-through" type wherein the liquid feed is not recirculated through the heat exchanger. A Venturi injector is employed to permit the feedback of a portion of the heated liquid from the heat exchanger to be commingled with the liquid feed being pumped to the heat exchanger. By preheating the liquid feed up to the dew point pr...

This invention relates to a learning feedback device which utilizes symbol bearing pieces, either singly or in combination, for emplacement on a display board. These devices have one or more magnets emplaced therein. The display board has single, or a plurality, reed type magnetically actuated switches emplaced there below in hidden position located such that a correct emplacement of one of said symbol bearing devices corresponding to an indicia displayed upon the display board will close an ele...

A digital feedback integrator, especially adapted to provide increased tat detection ability in radar systems. The feedback integrator is employed in the signal processing circuitry and compensates for arithmetic truncation errors by advantageously avoiding a final truncation pedestal in the integrating output.

Material handling conveyor systems for use in cooperation with shear equipment. The conveyor system can be controlled to feedback or return sheared portions of the plates to the shear operator for further shearing operations.

A feedback amplifier circuit comprises a high gain amplifier and a negative feedback path including a current source means, e.g. a high output impedance isolation device, for providing feedback current to the amplifier input. In a differential amplifier embodiment, a pair of high output impedance feedback isolation devices provide current to an input impedance means connected between the circuit input terminals. The circuit is largely independent of input voltage level and impedance, and as a re...

A hydraulic actuator having a selectively positioned, rotary output shaft. The actuator includes a control assembly in which a spool valve controls the admission and return of working fluid through a valve port. The spool valve position is controlled by a pilot assembly which communicates with valve chambers exerting pressure on opposite ends of the spool valve. The pilot assembly includes opposed nozzles connected with the valve chambers and a flapper between the nozzles which may be moved back...

An improved bio-feedback apparatus for sensing the brain-wave potentials produced by a subject wherein the sensed brain-wave potentials are processed through separate parallel processing channels of a controlling channel, each processing channel processing a preselected frequency range of the sensed brain-wave potential to provide subject-preceivable feedback signals indicative of signal presence within the preselected frequency of each processing channel. Each processing channel is constructed ...

A hybrid amplifier for connecting a signal carrying line to a repeater. The hybrid includes an autotransformer having a center tap dividing it into two portions. The signal carrying line, an amplifier section, a terminating resistor, and a feedback network are connected to the autotransformer in such a manner that the signal carrying line and the feedback network form a first conjugate pair and the amplifier section and the terminating resistor form a second conjugate pair.

A fluidic feedback servo valve including a metering stage having a metering spool therein, a pilot stage including downstream opposed control nozzles therein for controlling the pressure at the opposite ends of the metering spool and an electromechanical transducer for varying the position of a target between the control nozzles, a pair of feedback nozzles positioned upstream of the ends of the metering spool in the pilot stage and conical feedback targets having different diameters on the oppos...