Abstract: An electronic limit switch assembly including a sensor and a switching circuit controlled thereby contained in separate molded plastic housings. The sensor housing and the switching circuit housing are secured together with respective mating walls thereof in abutment and electrically coupled by leads protruding through the mating walls and protectively contained in a cavity in the mating wall of the sensor housing. A sensing coil is mountable for side sensing between a side wall of the sensor housing and an interior wall spaced therefrom defining a part of the cavity for side sensing and is also mountable for end sensing against an end wall opposite the mating wall and underlying the interior wall. Elements of the switching circuit are mounted on a printed circuit board and elongate conductive members secured to the board and connected with elements of the circuit protrude through mating holes in the top of the switching housing which function as terminal posts, heat sinks and circuit board mounts.

Abstract: A detector for a dynamic phenomenon with a cyclically varying condition, as motion of a rotating part. At least three digital sensors are separated in phase with respect to the cyclic condition. The instantaneous outputs of the sensors have a plurality of repeating sequential states so long as the dynamic phenomenon exists. The instantaneous outputs of the sensors have at least one state which does not occur during existence of the dynamic phenomenon but which does occur in the absence thereof. Logic circuits respond to the digital sensor outputs and detect information about the dynamic phenomenon. Detection of the repetition rate of an instantaneous output state of the sensors provides a measure of speed. An absence of rotation is indicated by the occurrence of another output state. In another disclosed embodiment, the detector monitors a three phase power system and detects a phase outage by the occurrence of an abnormal sensor output state.

Abstract: A proximity sensor oscillator, having a resonant circuit in which the power loss is inversely related to the distance of a conductive body from a probe containing a part of the resonant circuit, produces an oscillating output signal in the resonant circuit with a peak amplitude that varies with power loss and distance. A power source provides either the current or the voltage component of electrical power at a substantially constant value independent of changes of resonant circuit power loss and is periodically switched to the resonant circuit to provide an average input power thereto. The power loss of the resonant circuit loads the source, and thus the other component of power oscillates within the resonant circuit at a peak amplitude linearly related to the inverse of the power loss.