Abstract: A magnetic sensor for a distributorless ignition system is useable in an internal combustion engine. A Hall-effect device is spaced intermediate a pair of opposing permanent magnets for concurrently generating dual magnetic flux fields within respective air gap regions formed between each of the magnets and the device. Alternatively a magnet is placed between two Hall-effect devices to define the regions. A toothed disk rotatably connected to the crank-shaft of the engine causes different teeth to shunt the fields in each of the regions in a predetermined sequence for generating pulses at the device output indicative of the firing order of the engine. Alternatively, a disk having outer and inner notched rims is used to shunt the fields in each of the regions. Further, an elongated channel shaped member has sides movable in the regions for detecting relative linear motion between two parts.

Abstract: A magnetic sensor for a distributorless ignition system is useable in an internal combustion engine. A Hall-effect device is spaced intermediate a pair of opposing permanent magnets for concurrently generating dual magnetic flux fields within respective air gap regions formed between each of the magnets and the device. Alternatively a magnet is placed between two Hall-effect devices to define the regions. A toothed disk rotatably connected to the crankshaft of the engine causes different teeth to shunt the fields in each of the regions in a predetermined sequence for generating pulses at the device output indicative of the firing order of the engine. Alternatively, a disk having outer and inner notched rims is used to shunt the fields in each of the regions. Further, an elongated channel shaped member has sides movable in the regions for detecting relative linear motion between two parts.

Abstract: A ferrous disk is rotatably driven by an internal combustion engine shaft. The disk has outer and inner circular rims projecting outwardly from one side thereof. The outer rim has two arcuate notches of predetermined arcuate length and position and the inner rim has three arcuate notches of predetermined arcuate length and position. A permanent magnet is mounted between and radially spaced from two Hall-effect sensor devices in fixed relation to the shaft axis such that the outer rim passes between one Hall-effect device and the magnet and the second rim passes between the second Hall-effect device and the magnet as the shaft is rotated. The notches are so positioned to provide four separate two digit binary outputs to a microcomputer that provides output signals to ignition coil drivers for the spark ignition devices of the engine and provides spark advancement and coil dwell time variation in accordance with shaft rotational speed and other engine operating conditions.