Showing papers on "Inductive sensor published in 1976"

Power steering regulator for electrically operated vehicles - has servo actuated by impulses from inductive sensor excited by steering wheel movements

Abstract: A toothed wheel (4) is fitted between the steering wheel hub (1) and the steering column (3). The toothed wheel is a relatively thin disc with permanent magnetic teeth and able to turn with the steering shaft (2). An inductive sensor (7), consisting of a permanent bar magnet inside a coil, is clamped (8) to the steering column with its face (9) about 1mm from the toothed disc. Two electrical signals are induced into the sensor coil each time a tooth passes the sensor face. One impulse is positive and the second impulse is negative. The impulses are passed to a differentiation circuit which produces signals of different polarity. The signals are passed to a signal translator to produce two regulator signals of the same polarity. The signals are used to activate the power assistance steering servo. The servo can be a hydraulic unit fed by an electric pump.

Breakerless electronic ignition system

Abstract: Ignition pulses are supplied to an internal combustion engine from a breakerless electronic ignition system wherein the ignition pulses are produced in response to the movement of teeth on an electrically conductive trigger wheel past an inductive sensor. The inductive sensor is part of a LC tank circuit of an oscillator normally producing an oscillatory output signal which is detected by a bistable demodulator, and as a tooth moves into close proximity with the inductive sensor energy from the tank circuit is lost through an inductive coupling with the trigger wheel until the oscillatory output signal is terminated. The bistable demodulator responds to the absence of an oscillatory output signal by producing a timing signal which causes an ignition pulse to be supplied to the engine. The trigger wheel rotates in synchronization with the engine, and the initial timing of the ignition system is determined by setting the relative positions of the sensor and the trigger wheel. To advance or retard the initial timing of the ignition system, a resistor is connected across the tank circuit by a controllable switch to control the energy level in the tank circuit and hence the time required to terminate the oscillatory output signal. The initial timing of the ignition system may be set with the resistor electrically connected across the tank circuit, and upon the occurrence of engine conditions may result in undesirable ignition knock the controllable switch may be rendered nonconductive so as to retard the timing of the ignition pulses. Alternatively, the initial timing of the ignition system may be set with the resistor electrically connected across the tank circuit so that under certain engine operating conditions the switch may be rendered conductive to advance the initial timing of the ignition system. The switch connecting the resistor across the tank circuit may be a transistor which is rendered fully conductive or nonconductive by control signals produced according to predetermined engine operating conditions, or alternatively the conduction of the transistor may be gradually varied from fully conductive to nonconductive so as to serve as a variable resistor gradually increasing or decreasing the resistance across the tank circuit and thereby gradually advancing or retarding the initial timing of the ignition system.

Proximity sensor with ferrite sensing core - is capable of being mounted internally in several positions to provide several sensing arrangements

Abstract: An inductive proximity sensor uses a rectangular ferrite sensing core that may be mounted in several different positions to provide a variety of sensing configurations. The ferrite core (24) cross section is chosen such that it may be mounted on any of the four side walls (23, 21) or against the end surface (16). Electrical connections are made via cables (34, 59, 60, 61) to components (31, 32, 33) mounted on a printed circuit card (29). The cables are flexible ad long enough to accommodate the mounting positions of the ferrite core. All cables are brought out through a sealed end cap (43) screwed onto the plastic body.

Co-ordinate digitiser for automatic reading of technical drawings - inductive sensor provides measured position using two wire loop arrays

Abstract: A co-ordinate digitiser for use with computerized systems for the reading of technical drawings utilises an inductive sensor A number of conducting wire loops are arranged in columns with a fixed distance between each other The loops are located on a plate over which is located a cylindrical coil with a continuously supplied alternating current winding The sensor loops are represented by two pairs such that when magnetic field is moved the direction of motion may be determined Comparison of phase between the two loops enables the position to be determined Two such sensing arrangements located perpendicular to each other provide a full two axis co-ordinate digitisation