Abstract: An electronic ignition system according to an embodiment of the present invention includes a Hall effect device for detecting crankshaft rotation. A circuit is provided to select first or second ignition timing responsive to the Hall effect device output based on the rate of crankshaft rotation.

Abstract: A lobe sensor arrangement for an internal combustion ignition system provides a control signal to an ignition coil of the internal combustion engine to effect sequential firing of spark plugs, the ignition system comprising a distributor camshaft having a plurality of alternate circumferentially spaced lobes and valleys. The lobe sensor arrangement includes a pair of sensors spaced from the rotating camshaft and sensing the proximity of the spaced lobes to provide a pair of sensor output signals, and a processor circuit for analyzing the two sensor output signals and generating an ignition control signal upon the occurrence of the sensor output signals having values meeting relative predetermined criteria. One criterion requires that the two output signals be equal in magnitude. Another criterion may require that both output signals have magnitudes above a predetermined threshold.

Abstract: A crank angle detecting apparatus for an internal combustion engine includes a crankshaft operationally coupled to pistons. A crank rotor provided on the crankshaft has a plurality of angular segments, each angular segment includes a group of teeth of different lengths as measured in the circumferential direction of the crankshaft, the group of teeth in each angular segment having a distinct combination. A magnetic sensor faces the teeth for detecting passage of the teeth when the crank rotor rotates. An ECU (electric control unit) receives signals from the magnetic sensor and generates a crank angle signal, wherein the crank angle signal changes in accordance with the combination of the teeth. A camshaft includes a first one hundred eighty degree segment and a second one hundred eighty degree segment.

Abstract: An engine control system in which a rotary body rotates in association with a crankshaft of an engine and has portions to be detected every predetermined angle and at least one of the portions to be detected is missing, and a pickup is arranged near an outer periphery of the rotary body and generates a pulse each time the portion to be detected passes. In the case where a reference time point to start a measurement of a time until a control start time point to start a predetermined control of the engine is a rotational angle time point of the crankshaft when no pulse is generated from the pickup due to a missing portion to be detected, a timer is allowed to measure the time from a generation time point of the pulse generated from the pickup just before the non-pulse generation period of time during which no pulse is generated until the control start time point.

Abstract: An engine control system includes a speed sensor apparatus for providing signals to an engine control module (ECM) indicative of the speed and timing of an internal combustion engine. The apparatus includes a primary and a secondary Hall device affixed to one pole of a dipole magnet. Independent flexible circuits connect each of the Hall devices to an output connector adapted to receive a cable connected to the ECM. The magnet, primary and secondary sensors and primary and secondary flexible circuits are potted and encased within a sensor housing that is configured for sealed mounting to a housing surrounding the timing wheel of the engine. The outputs from the two sensors are independent of each other and are simultaneously provided to the ECM. The ECM includes means for providing the output from the primary sensor to engine control routines utilizing speed and timing information while the primary sensor is operational.

Abstract: On the upper portion of a cylinder head 1 of an engine mounted on a vehicle body in such a way that a crankshaft faces in the lateral direction of the body, a head cover 36 is supported in a floating state through an elastic member 14 and a rubber bush 52. A pair of TDC sensors 37i and 37e for detecting the rotational positions of engine camshafts 6i and 6e, are attached from the outside to the front surface and to the rear portion of the upper surface of the head cover 36 with bolts 38 respectively in such a way as not to interfere with a bonnet 39 of the body descending forward. Consequently, while ensuring the maintainability of the TDC sensors 37i and 37e of the engine, the TDC sensors 37i and 37e can compactly be attached to the engine.

Abstract: A sensor used to detect an opening angle of, for example, a throttle valve comprising: a pivotable valve axle arranged so as to be pivoted through a pivoted angle; a magnet; a first magnetic circuit, through which a first magnetic flux branched from a total magnetic flux developed from the magnet is passed; a second magnetic circuit, through which a second magnetic flux branched from the total magnetic flux developed from the magnet is passed; a pair of first and second Hall effect devices, the first Hall effect device being interposed in the first magnetic circuit so as to output a first signal according to the first magnetic flux passing therethrough and the second Hall effect device being interposed in the second magnetic circuit so as to output a second signal according to the second magnetic flux passing therethrough; and a calculation circuit, in response to the first and second signals of the first and second Hall effect devices, for calculating a level of a detection signal (So1, So2) of the sensor fr

Abstract: It is intended to automatically correct for ignition timing of the engine and fuel injection timing of the engine even if they changed in the case where the attached position of a cam angle sensor is offset after change of distributors and therefore the reference angle is offset. The crank angle and the cam angle of an engine are detected. The phase difference between these angles is computed. The result is reflected in the ignition timing and the fuel injection timing.

Abstract: A rotation angle sensor for sensing a rotation angle of a pivotal member, such a throttle valve shaft, comprises a first unit including a magnet member and a second unit including first, second and third magnetic piece members which are circumferentially arranged to concentrically surrounds the magnet member. The first and second magnetic piece members are symmetrically arranged with respect to the magnet member. A structure is employed for connecting one of the first and second units to the pivotal member. A first electric device is employed for generating a first signal in accordance with a density of magnetic flux produced between the first and third magnetic piece members, and a second electric device is employed for generating a second signal in accordance with a density of magnetic flux produced between the second and third magnetic piece members.

Abstract: A rotary position sensor having a dual magnet structure interconnected by a pole piece forming a varying dimension air gap. The magnets, the pole piece and the air gap between the magnets define a closed magnetic circuit. A Hall effect sensor is fixedly mounted in the air gap and is exposed to a well defined but varying magnetic field coupled between the magnets. Through the use of specific magnetic materials and sloping, curved surfaces, a precise yet tolerance friendly magnetic circuit is produced so that the sensor produces signals as a function of the angular positions of the magnets.

Abstract: This invention concerns an engine with electric ignition for model cars. A cooling fan is installed in front of the finned cylinder which is supported in a case. The fan is driven by a toothed belt.

Abstract: A rotary position sensor connected to the butterfly valve of an internal combustion engine, the sensor having a dual magnet structure interconnected by a pole piece having a generally C-shaped cross section forming a varying dimension air gap. The magnets, the pole piece and the air gap define a closed magnetic circuit. A Hall effect sensor is fixedly mounted in the air gap and is exposed to a well defined but varying magnetic field. Through the use of specific magnetic materials and sloping, curved surfaces, a precise yet tolerance friendly magnetic circuit is produced so that the sensor produces signals as a function of the angular positions of the magnets.

Abstract: A sensor is provided with a rib that extends from its sensing face. The rib is arcuate to conform to a surface of a rotatable object. The rib can be a continuous arcuate rib attached to the sensing face or two or more disconnected sections that together define an arcuate rib. The arcuate rib is shaped to conform to a surface or effective surface of a rotatable object, such as a gear or other rotatable target.

Abstract: A rotation sensor includes a binary encoded target wheel and a pair of sensors disposed about the target wheel periphery. One of the sensors provides a signal indicative of the passage of regular angular intervals of the target wheel and the other of the sensors provides binary states corresponding to the regular angular intervals.

Abstract: A combined electronic ignition and fuel injection system for internal combustion engines utilizes a non-magnetic disk, attached to the engines shaft and rotates with the shaft, and contains permanent magnet along the periphery of the disk at intervals defined by the shaft's position for each cylinder group. The magnets develop voltage timing pulses within pick-ups coils which are connected to circuits for amplifying and shaping the timing signals. The coil driver switch charges the ignition coil and the spark plugs are then fired, then in another cylinder chamber the fuel injectors are opened, and the fuel is injected into the cylinder chamber. This electronic ignition and fuel injection system is an improvement and a simpler system than that which is usually utilized in internal combustion engines, because it does not require the use of a computer or distributor. It is particularly useful in the rotary-reciprocal combustion engines, and may be used in rotary and reciprocal combustion engines.

Abstract: A control apparatus for an internal combustion engine which is capable of performing engine cylinder identification rapidly, easily and inexpensively, while capable of performing a backup control upon occurrence of abnormality in a first signal series containing an angular position signal. The control apparatus includes a first signal detector for generating a first signal series in synchronism with a rotating shaft of the engine, a second signal detector for generating a second signal series in synchronism with the rotating shaft and a control means for controlling parameter on the basis of the first and second signal series. The first signal series includes an angular position signal and a constant level signal corresponding to a reference position for a specific cylinder group.

Abstract: A rotation angle detecting device according to the present invention comprises: a sensor having a first yoke made of a magnetic material on which a magnet is mounted, a second yoke made of a magnetic material on which a magnetic flux detector is mounted, which is disposed opposite to the first yoke with a predetermined space, and a housing for supporting the first yoke and the second yoke, and a vane secured on a camshaft of an internal combustion engine, having a wall portion which passes through space between the first yoke and the second yoke, and a rotation angle of the internal combustion engine is detected in accordance with a signal produced at said magnetic flux detecting device by passage of the wall portion of said vane through said space.

Abstract: For detecting the angle of rotation of a shaft, in particular of a gear shift shaft in a gear change box for a motor vehicle, a device is proposed in which a carrier arrangement carries a magnet and in its proximity magnetically sensitive sensors. A screening device, rigidly attached to the shaft, moves in the intermediate space between the magnet and the sensors. This screening device is made from a ferromagnetic material such that the magnetic field permeating the sensors is influenced in a manner whereby the sensors generate a signal that unambiguously identifies the position of the shaft.

Abstract: A modular electronic ignition system for use in internal combustion engines is provided using latching Hall effect sensing devices. Two permanent magnets are affixed to a non-ferrous member mounted to the camshaft which extends through a seal in the timing cover. A sensing module comprising the Hall effect devices is arranged annularly or angularly about the magnet containing member and senses the magnetic field as the magnets pass the Hall effect devices. Dwell time is controlled by the angular distance at which the magnets are placed from each other. The output of the Hall effect devices drives application specific integrated circuits which provide low level switching of ignition coil primaries. The modular design allows for a low part count, a simplified EMI shielding arrangement, and easy removal and replacement of system components.

Abstract: A breakerless ignition system for internal combustion aircraft engines which includes a pair of separately activated Hall effect and amplifier combinations for controlling the timing and the delivery of electrical energy to the spark plugs of the engine in a predetermined sequence.

Abstract: A misfire detection device for a multi-cylinder internal combustion engine detects levels of angular acceleration .beta. of the crankshaft corresponding to predetermined phase intervals of respective cylinders. Further, the differences .DELTA..beta. between the levels of angular acceleration corresponding to successively ignited cylinders are calculated as the combustion condition parameters corresponding to respective cylinders, and when the absolute variance .DELTA..beta.R of the levels of combustion condition parameter (i.e., difference of acceleration .DELTA..beta.) corresponding to cylinders whose ignition timings are separated by 360 degrees of the crank angle is continuously less than a predetermined judgment level, an occurrence of continuous misfires is detected.

Abstract: A dual complementary target arrangement is provided which enables the targets to be formed as an integral part of a cam shaft. By machining first and second radially enlarged integral portions of a shaft, complementary targets are provided which each comprise segments of differing radial dimension measured from the central axis of the shaft. By permitting the formation of the rotatable targets as an integral portion of a cam shaft, the complementary targets can be incorporated as an integral portion of an automobile engine without necessitating the prefabrication of complementary targets and subsequent attachment of the targets to a cam shaft. Not only does the unitary structure of the cam shaft reduce the manufacturing costs of the target and shaft combination, but in certain applications it makes possible the use of complementary targets within the structure of an automobile engine where the use of individual components attached together would not be practical.

Abstract: In order to mount a power transistor chip, a multilayered member formed by fixing a molybdenum plate to a copper base is flattened by eliminating its deformation in the member caused by heated fixing through elastic working, it is possible to prevent cracking in a power transistor chip or a solder layer caused by the deformation. Especially, it is possible to improve the reliability of an electronic distributing type ignition device mounted on an engine block formed in a unit of an ignition controller and an ignition coil.

Abstract: An apparatus and method is provided for attaching a gear tooth sensor to an object, such as an engine block of an automobile. A clamping bar and a deformable conical washer are associated with a tubular portion of the sensor in such a way that rigid attachment of the clamping bar to the engine block, such as through the use of a threaded bolt, deforms the conical washer into a generally flat shape and, in the process, causes a distal end of the tubular portion of the sensor to move away from a target by a predetermined distance. Prior to deforming the deformable washer between the clamping bar and the engine block, the sensor is moved into contact with a rotatable target, such as a gear.

Abstract: A magnetic sensor is provided with two target tracks arranged in generally parallel association with each other. Each of the target tracks comprises magnetic and nonmagnetic segments which are arranged in alternating patterns. Each magnetic segment of the first target track is disposed alongside a nonmagnetic segment of the second target track and each magnetic segment of the second target track is disposed alongside a nonmagnetic segment of the first target track. First and second magnetically sensitive components are disposed proximate the first and second target tracks, respectively, and a source of a magnetic field is disposed proximate the first and second magnetically sensitive components. Distortions of the magnetic field imposed perpendicularly on the first and second magnetically sensitive components are used to provide first and second output signals therefrom.

Abstract: A magnetic sensor is provided with a housing in which a carrier is inserted. The carrier is particularly shaped to retain a permanent magnet in a particular position relative to a plurality of electrical conductors and a substrate on which a magnetically sensitive component is attached. The carrier and its associated components is inserted into a housing which can be deformed to permanently retain the carrier within a cavity of the housing. All of the components of the sensor are designed to be easily assembly along a common axis to facilitate automatic assembly and manufacture of the sensor. The magnetically sensitive component can be a Hall effect element that is associated with other electrical components which are also attached to a substrate that is disposed proximate a front end of the carrier.

Abstract: A signal generator for an internal combustion engine containing (1) a housing and (2) a shaft penetrating the housing, at least one asymmetrical vane type rotor coupled to the shaft, one signal element mounting plate, at least one signal element, and a stray noise isolating plate provided in the housing. The shaft is coupled with the engine to drive the asymmetrical vane type rotor to rotate synchronously with the engine and move pass the signal element so as to generate a square wave signal for controlling a fuel injection and ignition of the engine. The signal element mounting plate is mounted on the housing via an outer edge of the mounting plate, which is used as a fulcrum and to cause the signal element mounting plate to be fastened to the housing in such a manner so as to allow a large space to be provided by its top and bottom surfaces for mounting a increased number of the signal elements thereon.

Abstract: A fuel pump for supplying fuel to an engine includes a rotary drive shaft (12) having an enlarged portion (18) through which the rotary part of the pump is driven. The pump also has an annular cam ring (17) which is angularly adjustable within the pump housing to vary the timing of fuel delivery. The pump includes a transducer (31) having pole pieces (33, 34) which are located in close proximity to the elongated portion (18) of the drive shaft. The pole pieces form part of a magnetic circuit including a magnet and the pole piece (33) and the adjacent surface or the portion (18) are shaped so that the flux in the magnetic circuit varies in a cyclic manner as the shaft rotates. The pole pieces and magnet are mounted on the cam ring (17) and the transducer includes a former (37) carried by the housing of the pump and upon which is wound a winding. The former surrounds a part of the magnetic circuit and the former and the part of the magnetic circuit are shaped so as to allow angular movement of the cam ring.

Abstract: An ignitor comprises an ignition coil unit mounted to a base and a control unit disposed on the ignition coil unit and electrically connected thereto for controlling a primary current to the ignition coil unit, which includes a base plate attached to the base and a crank angle sensor for detecting the turning angle of an engine crank shaft. The ignitor also comprises a rotary shaft rotatably supported by the base for rotation in synchronization with the rotation of an internal combustion engine which extends through the ignition coil unit and has a distributor rotor on an extended end thereof. The control unit further comprises a power switch package having a mold resin which hermetically molds therein a power transistor and an integrated controlling circuit into a sealed package. The power transistor interrupts an electric current flowing through a primary coil of the ignition coil and an integrated controlling circuit controls the power transistor.

Abstract: A small, light and low cost ignition distributor having improved rotary detection accuracy can be realized. A pole piece having a pickup coil wound on it and bypass pole pieces having no pickup coil are arranged on the ignition distributor. The distance between the pole piece having a pickup coil and the bypass pole pieces is about 1.5 times as long as the distance between protrusions formed on the peripheral portion of a rotary body. When the distance between the pole piece having a pickup coil and a reluctor is minimum, the distance between the bypass pole pieces and the reluctor is maximum, and the linkage of magnetic flux of the pickup coil is maximum. When the distance between the pole piece having a pickup coil and the reluctor is maximum, the distance between the bypass pole pieces and the reluctor is minimum, and the magnetic flux bypasses the pole piece having a pickup coil and passes through the bypass pole pieces.

Abstract: A measuring instrument for contactless determination of an angle of rotation of an adjusting shaft. To avert transmitting a tumbling motion from the adjusting shaft to the measuring instrument, a coupling body is provided, which with engagement protrusions, engages engagement grooves of a driver body with play. The driver body actuating the measuring ring is as a result decoupled from tumbling motion effected by the adjusting shaft. The measuring instrument is especially suitable for contactless determination of the angle of rotation of a throttle device in an internal combustion engine.

Abstract: A sensor arrangement for an internal combustion engine so as to provide a signal when one cylinder of the engine is at a pre-determined position. The sensor arrangement includes an inductive sensor that is mounted directly in the cam cover of the engine and which cooperates directly with one of the cam lobes.

Abstract: An engine control apparatus for a multi-cylinder engine is provided which precisely controls a plurality of groups of cylinders on the basis of a plurality of reference position sensors, each of which senses a reference crank position of a corresponding group of cylinders. The apparatus generates control signals for controlling the plurality of groups of cylinders even in the event of a failure of any one of the sensors thus providing a fail-safe operation. The sensors generate output signals, in synchronization with the crankshaft, which are feed to an OR gate which generates a single output signal each time a signal is received from the sensors. The output signal from the OR gate is feed to an interrupt terminal of a microcomputer whereupon the latter starts an interrupt processing which identifies the group of cylinders corresponding to the output signal and generates control signals.

Abstract: An angle detecting device including a magnetism gap where a magnetic-flux shutter rotates synchronously with a detection subject, a magnetic flux generator provided at one side of the gap, a magnetic-flux detector provided at the other side of the gap, an outlet of the signals from the detector, a frame integrally including the above-described generator, detector and outlet, and anchoring portions mechanically fixing the detector in a housing portion of the frame. In one embodiment, the anchoring portions are a pair of saw-toothed tabs formed by cutting and bending out a section of the plate. The saw-toothed tabs cut into the inner wall of the housing when the detector is inserted. In another embodiment, the anchoring portions are a pair of supporting tabs formed by bending extensions of the plate. The supporting tabs are clamped between a lower surface of the housing and a cover.

Abstract: A piece to be magnetized and a covering cap are brazed together to a member, such as a spring seat for a diesel engine injector needle lift sensor. The entire assembly is then subjected to a vacuum ion treatment to case-harden at least the cap and the wear surface of the member. Either before or after the member is case-hardened, the assembly is subjected to an electromagnetic field to magnetize the piece through the cap.

Abstract: An angular position sensor is provided with a carrier assembly in which a magnetically sensitive device is disposed. The carrier assembly has a portion which is shaped to receive a rotatable member in sliding association therein. A magnet is disposed within the rotatable member and is rotatable in response to rotation of a shaft attached to the rotatable member. A pivot means is provided for permitting the carrier assembly to move relative to a stationary housing and in response to movement of the rotatable member. A means for urging the carrier assembly toward the central axis of the rotatable member is also provided to maintain a consistent relationship between a magnetically sensitive device disposed within the carrier assembly and the magnetic disposed within the rotatable shaft.

Abstract: An apparatus for developing a signal voltage that represents the angular position of the crankshaft of an internal combustion engine. The apparatus includes a variable reluctance sensor that has a pick-up coil. The sensor is associated with means driven by the crankshaft of the engine for causing an alternating voltage to be induced in the pick-up coil as the crankshaft rotates. The apparatus includes a negative voltage clamp which clamps the voltage of a junction of the clamp circuit to substantially ground potential during negative half-cycles of the alternating voltage induced in the pick-up coil. The clamp circuit is adapted to be connected to a control circuit that is an integrated circuit having a bulk substrate diode. The clamp circuit prevents forward biasing of the bulk substrate diode.

Abstract: A solid-state, push rod actuated breakerless ignition system is disclosed that is particularly suitable for use as original equipment or an after market upgrade for many industrial engines of the type having a cam-operated push rod actuated ignition. The apparatus includes a base for mounting to the engine, a rocker arm movably mounted to the base for periodic actuation by the cam lobe and having a first transducer element fixably located thereon for movement in an arm path, a second transducer element mounted in predetermined relation to the base proximate the arm path, and a circuit for producing an electrical trigger signal in response to the movement of the first transducer element to a predetermined spatial relation with the second transducer element, the combustion being initiated in response to the trigger signal.

Abstract: A trigger system for the ignition system of an internal combustion engine having a crankcase with a rotatable crankshaft includes an aluminum disk-shaped hub for connection to the crankshaft and rotatable therewith on the end opposite the flywheel of the engine. The hub has at least one weight formed into the hub and offset from its center of gravity for balancing and reducing vibration of the engine during operation. A plurality of magnets or other magnetically responsive elements are provided in openings in a flange extending around the periphery of the hub. A stationary sensor is mounted adjacent the hub for detecting impulses from the magnetically responsive elements as the hub rotates and utilizing the impulses to trigger the ignition system.

Abstract: An off axis geartooth sensor is provided with a center line of the sensor disposed along a line which is not coincident with the center of rotation of the rotatable member to be sensed. Instead, the center line of the housing in which a Hall Effect element is disposed is positioned at a perpendicular distance from the center of rotation of the rotatable member which is determined as the function of a range of dimensions which define the allowable gap between the Hall Effect element and a surface of the rotatable member. The perpendicular distance between the center of rotation and the line along which the proximity sensor is disposed is mathematically determined as a function of the distances between the center of rotation of the rotatable member and the minimum and maximum possible locations of the Hall Effect element along with the angular distance between those two dimensions.

Abstract: A Hall effect type sensing device comprises a magnetic circuit, a Hall transducing element arranged in the magnetic circuit to output a signal depending on a change in magnetic flux, a magnetic flux changing member which is able to change the magnetic flux in the magnetic circuit, a gap part which allows the magnetic flux changing member to move therein, and a frame member having its one side provided with a recessed portion forming the gap portion, and having its other side provided with an accommodation portion at a position adjacent to the recessed portion, the accommodation portion housing the Hall transducing element and a member forming the magnetic circuit.

Abstract: Disclosed herein is apparatus for positioning a sensor relative to a rotatable timing ring included on an internal combustion engine, which apparatus includes a sensor, a structure for adjustably positioning the sensor on the internal combustion engine and relative to the timing ring, which structure is movable relative to the sensor and to the timing ring, and additional structure for fixing the sensor in adjusted position on the internal combustion engine.

Abstract: A distributor for an internal combustion engine comprising a rotational signal generator (4) which includes a rotary magnetic shield (30) for generating an electrical signal indicative of the shaft rotational speed. The rotary magnetic shield (30) comprises a rotor plate (31) attached at the center thereof to the rotary shaft and a plurality of shield tabs (37) disposed around the plate and extending perpendicularly thereto. The rotor plate (31) and each shield tab (37) are integrally connected by a transition portion (33) including a round bend (36) for moderating stress concentration. The transition portion (33) also has integral fillets (35) defining a peripheral edge smoothly connecting the edge of the main plate (31) and side edges of the shield tabs (37) for moderating concentration of stress at edges of the transition portions (33). The fillets (35) of two adjacent transition portions (33) may define a continuously curved edge in a plane of the main plate (31).

Abstract: A Hall effect type sensing device comprising a casing (20); a magnet (22), a first magnetic flux guide (21a) and a second magnetic flux guide (21b) which define a magnetic circuit; a Hall transducer (24) arranged to be opposite to the magnet (22) in the magnetic circuit; a board (23) for supporting the Hall transducer (24); an air gap formed between the magnet (22) and the Hall transducer (24); a magnetic flux shutter (5) which can shunt a magnetic flux in the air gap, and which passes through the air gap to cause a change in the magnetic flux, the change being detected by the Hall transducer (24); and an urging member (30) including a supporting arm (30a) for supporting a Hall IC assembly and an urging arm (30b) for urging the supporting arm (30a) to an inner wall of the casing (20), the Hall IC assembly being constituted by the second magnetic flux guide (21b), the Hall transducer (24) and the board (23); wherein the Hall IC assembly is located by an urging force of the urging member (30).

Abstract: A high resolution sensor for internal combustion engines has symmetric and asymmetric magnetic encoders mounted on a support plate for synchronous rotation with the engine. Hall-effect sensor devices monitor the magnetic fields of the encoders and transmit signals to an Electronic Engine Control Unit. Ignition and fuel injection timing are deduced from the positions of the magnetic encoders. The encoders are magnetized on a fixture which establishes the size, strength, and location of each pole.

Abstract: A Hall-effect sensor, wherein a Hall element is disposed in a magnetic path being formed by a magnet and a flux guide, and the magnet, flux guide, and Hall element are integrally held with a molded frame, and the Hall element is fixed to the magnet (or flux guide) or the molded frame. This Hall-effect sensor can easily position the Hall element with higher sensitivity.

Abstract: A tachometer signal generating device comprises signal coils which generate pulse signals corresponding to predetermined crank angle positions in synchronism with revolution of an engine, and a microcomputer which generates ignition control signals or fuel control signals on the basis of the pulse signals and which generates a tachometer signal of 6 pulses/one revolution.

Abstract: Apparatus for detecting the direction of rotation of a crankshaft of an internal combustion engine. The crankshaft drives wheels associated with sensors for developing two pulse trains as the crankshaft rotates. One pulse train is a square wave having consecutively occurring high and low periods of equal angular duration. The other pulse train is a square wave having a plurality of spaced window pulses of unequal angular duration. The relative high and low logic states of the pulse trains at certain window locations has one relationship for forward movement of the crankshaft and a different relationship for reverse movement of the crankshaft. These relationships are detected. At one of the window locations, the relative high and low logic states of the pulse trains is the same for either forward or reverse rotation. Engine reversal at this location is detected by detecting the occurrence of two consecutively occurring relative logic states that are the same.

Abstract: An ignition system for an internal combustion engine, such as an outboard marine engine, which includes an advanced timing schedule, a normal timing schedule, and a circuit for switching between the two schedules or disabling both schedules based upon engine operating conditions. The ignition system includes an optoelectronic time base generator which produces two sets of timing pulses relative to crankshaft position which are normal timing pulses and advanced timing pulses. The time base generator comprises a LED-phototransistor pair and an encoder disk attached to the crankshaft with slots to interrupt the emission path between LED-phototransistor pair. The normal pulses are generated based upon the trailing edge of each slot while the advanced pulses are generated based up the leading edge, wherein the width of the slots indicate the degree of advancement of the advanced schedule over the normal schedule.

Abstract: A crank angle detecting system for a multicylinder engine includes a disc formed with a large number of slits to detect one-degree crank angular positions and a small number of slits to detect a predetermined piston stroke for each cylinder. Since the widths of a small number of slits are different from each other, it is possible to separately discriminate each cylinder in crank angular position on the basis of the crank angle signals obtained by a large number of slits. In the case where the detecting system is incorporated with a group-ignition system, it is possible to detect a predetermined piston stroke for each cylinder immediately after the engine is started, thus preventing the engine from erroneous ignition.