Abstract: A Hall effect type sensor comprises a magnet and a magnetic flux guide which cooperate to form a magnetic circuit and a Hall IC disposed in the magnetic circuit wherein these elements are fixed to a frame through holding members so that the magnetic flux guide and the Hall IC are placed at correct positions on the frame.

Abstract: An assembling structure of a Hall-effect sensor device suitable to be used as a crankshaft angle sensor of an automotive internal combustion engine is disclosed.

Abstract: A sensor for detecting a number of revolutions of a rotary shaft is provided which comprises a ring magnet secured to the outer peripheral surface of the rotary shaft, the number of revolutions of which is to be detected, a Hall IC arranged near the outer peripheral surface of the rotary shaft, for detecting the magnetism of the ring magnet. The ring magnet has one circumferential half of the outer peripheral surface thereof magnetized to serve as the north pole and the other circumferential half of the outer peripheral surface thereof magnetized to serve as the south pole.

Abstract: An electromagnetic pickup has a coil and a core. A noise shielding cylindrical member of magnetic material is provided around the coil to form an open magnetic circuit between the noise shielding member and the core.

Abstract: An ignition distributor of an automotive vehicle has a magnetic pick-up device mounted in the housing of the ignition distributor and including a magnetoresistor. The magnetoresistor is electrically connected to a primary ignition circuit in the ignition coil, which produces a high voltage when said magnetic pick-up device produces a voltage pulse output signal. A permanent magnetic plate is attached to the magnetoresistor and provides a magnetic field perpendicular to the direction of the current flow through the magnetoresistor. When each of the teeth of an armature rotated with the distributor shaft mounted in the ignition distributor passes the magnetic pick-up device to change temporarily the magnetic field applied to the magnetoresistor, the resistance of the magnetoresistor is correspondingly varied so that said magnetoresistor can produce a voltage pulse by the magnetoresistance effect, and open and close the primary ignition circuit for firing the spark plugs.

Abstract: An electronic control ignition system, for internal combustion engines, is disclosed in which a rotation angle of a crank shaft of an engine is calculated. The angle is calculated based on a crank angle signal generated every time the crank shaft rotates by a certain angle. Further based on the calculation result, ignition timing is controlled. The control is made to obtain an optimum ignition timing. This optimum ignition timing is based on one train of signals generated every time the crank shaft of the engine rotates by a certain angle, and (n/2-1) (n is an even number equal to or larger than 4) identical train of signals, generated subsequently with a phase delay of 1/n wavelength.

Abstract: A signal generator has a Hall-effect sensor and a magnet which are disposed inside a distributor housing. A vane which is secured to a distributor shaft passes through a gap between the Hall-effect sensor and the magnet when the distributor shaft rotates. An ignition coil is disposed inside the distributor housing in a location such that the magnetic field which it generates combines subtractively with the magnetic field generated by the magnet in the vicinity of the Hall-effect sensor. Magnetic by-passes are disposed inside the housing to cause leakage flux from the ignition coil to by-pass the Hall-effect sensor.

Abstract: An asymmetric excitation type magnetic device is provided with a composite magnetic body composed of a first magnetic layer having a relatively strong coercive force and a second magnetic layer having a relatively weak coercive force which layers are combined so as to have their respective magnetic anisotropy oriented in the same direction. To such a composite magnetic body are applied external positive and negative asymmetric magnetic fields in a specified order thereby to produce variations in magnetic flux due to an escpecially quick magnetization reversal and resultantly to generate steep pulse outputs across a detecting coil.

Abstract: A Hall-effect magnetic sensor arrangement comprises a sensor element utilizing the Hall-effect and disposed in a magnetic circuit including a magnetic pole unit in an opposing relationship with respect to the magnetic pole unit with a predetermined distance therebetween, a sensor frame surrounding the sensor element and having a cave defined at the opposite side of the magnetic pole unit with respect to the sensor element and at a side perpendicular to a magnetic path and a soft filler material filled in the cave for protecting the sensor element. The sensor arrangement comprises a nonmagnetic thin plate member disposed at the side of the sensor element opposite to the magnetic pole unit and supported at its outer edge by the sensor frame for preventing the filler material to flow out from the cave.

Abstract: An ignition distributor for an internal combustion engine has a magnetic-permeable flat plate fixed to the rotating shaft of the ignition distributor so as to extend in the direction perpendicular to the shaft, and a sensor having forked sensing parts which are extended inside the housing so as to adjoin a part of the flat plate.

Abstract: A method of and apparatus for generating a cylinder discriminating signal in a distributor for an internal combustion engine are disclosed. The cylinder discriminating signal is generated by a combination of a cylinder discriminating reluctor installed on a centrifugal spark advance member and a cylinder discriminating sensor attached to a vacuum spark advance plate to detect approach and passage of the cylinder discriminating reluctor. The width of the cylinder discriminating reluctor in the direction of rotation is set so as to correspond to an angle smaller than the entire range of spark advance of the ignition timing signal. The cylinder discriminating signal is advanced by both centrifugal spark advance and vacuum spark advance so as to overlap the ignition timing signal despite having a relatively narrow width. Since the width of the cylinder discriminating signal is reduced, it is possible to improve the control tolerances of the associated microcomputer.

Abstract: This invention relates to an ignition distributor for an internal combustion engine and more specifically relates to a novel reluctor included in an ignition distributor for discriminating between cylinders of an engine. The reluctor has an elongated shape and is arranged relative to the rotating shaft of an ignition distributor so that the gravity center of the reluctor is located exactly on the rotational axis of the shaft. This arrangement enables the rotational movement of the shaft to be concentrated, so that the wear to which the bearings supporting the shaft is subjected is significantly reduced. The reluctor is attached to the governor base of an ignition distributor without any rivets by virtue of the novel configuration thereof, so that a reduction in the number of parts can be achieved, together with reduction in the total production cost.

Abstract: An engine ignition and charging system employs magnets mounted on a rotor, and a stator positioned relative to the rotor such that charge coils, alternator coils, and a power coil on the stator are located such that the magnets pass in close proximity thereto as the rotor rotates. The rotor also has a magnetic timing means for generating a timing flux path at a predetermined location relative to the rotor. A Hall effect transducer circuit is positioned in proximity to the rotor such that as the flux path passes, the flux path is sensed so as to generate a timing trigger voltage. This trigger voltage is employed in conjunction with an ignition voltage generating circuit to supply an ignition voltage to a spark plug in timed sequence with rotation of the rotor. The power coil on the stator supplies power to the Hall effect transducer for operation thereof. A charging circuit connects an output of the alternator coils to a system battery for charging thereof.

Abstract: A device for controlling an internal combustion engine of a motor vehicle and comprising a transmitter disk which rotates with a shaft of the internal combustion engine relative an opposite stationary receiving element, the transmitter disk being provided at its circumference with a plurality of segments proportional to the number of cylinders, and a permanent magnet assigned to at least one of the segments for generating a marking signal to be fed to a control circuit for the ignition, injection and the like of the motor vehicle via the receiving element.

Abstract: An ignition timing signal generating rotor adapted to be operatively coupled to the shaft of a distributor for an internal combustion engine is disclosed wherein the rotor generates an ignition timing signal in cooperation with an ignition timing sensor operatively coupled to the housing of the distributor. The rotor comprises a reluctance varying rotor portion of a magnetic material and a tube of a non-magnetic material carrying the magnetic rotor portion. The magnetic rotor portion and the non-magnetic tube are made of formed powder materials which are simultaneously sintered together into a single piece.

Abstract: An ignition circuit for an internal combustion engine includes an angle signal generating coil 1, an ignition control circuit 15, an ignition coil 16 and a bistable circuit connected between the angle signal generating coil and the ignition control circuit. The bistable circuit comprises a NPN transistor and a positive feedback circuit.

Abstract: An engine stroke discriminating method and apparatus for a 4-cycle internal combustion engine which discriminates a stroke of the engine with accuracy, the method and apparatus being simple in construction and low in cost. The stroke discriminating method and apparatus is characterized by taking advantage of the fact that the rotational speed of a crankshaft after the top dead center of a cylinder of an engine rises substantially relative to that before the top dead center in a compression stroke of the cylinder but does not rise in an exhaust stroke. The stroke of the engine is thus, discriminated by determining the difference in rotational speed of the crankshaft before and after the top dead center of the cylinder.

Abstract: A rotation angle detector has magnets of different polarities arranged with one polarity alternately with the other polarity on the circumferential surface of a rotary body, wherein a plurality of magnets on the portions of the circumferential surface having a width which is different from that of a plurality of magnets on the remaining portions. A single rotation angle sensor arranged to oppose the circumferential surface of the rotary body scans the magnets when the rotary body is rotated, thereby outputting a reference signal and a rotation angle signal. Mutually adjacent magnets which differ in width are so formed that whichever is scanned earlier by the rotation angle sensor will have a width narrowed by a predetermined amount if it is wider than the other or a width widened by the predetermined amount if it is narrower than the other. Irrespective of the altered width, the sum of the magnetized areas of these mutually adjacent magnets is held constant.

Abstract: There is disclosed an engine ignition control device including a control switch element arranged, in its ON state, to pass a current through a primary side of an ignition coil and, in its OFF state, to break the current passing through the primary side of the ignition coil, thereby inducing a high voltage across a secondary side of the ignition coil to cause an ignition of an engine.

Abstract: A rotation angle measuring apparatus comprises a throttle valve for controlling the amount of air flow of an internal combustion engine, a throttle sensor coupled to a rotation shaft of the throttle valve, and a logic circuit which includes absolute rotation angle detecting means for receiving an output signal of the throttle sensor to produce an absolute signal, forward/reverse rotation direction discriminating means for receiving an output signal of the throttle sensor to produce a direction signal, and an up/down counter for receiving the absolute signal, the direction signal and a count signal outputted from the forward/reverse rotation direction discriminating means to output a signal representative of a rotation position of the rotation shaft of the throttle valve.

Abstract: A distributor for an internal combustion engine includes an ignition timing reluctor provided on a centrifugal spark advance member, ignition timing signal generating means for generating an ignition timing signal by detecting approach and passage of the ignition timing reluctor, a cylinder discriminating reluctor provided on the centrifugal spark advance member, and a cylinder discriminating sensor for generating a cylinder discriminating signal by detecting approach and passage of the cylinder discriminating reluctor. The distributor has a structure for compensating for any imbalance of its rotator. The cylinder discriminating signal is centrifugally advanced in the same way as the ignition timing signal, so that it is possible to reduce the width of the cylinder discriminating signal.

Abstract: A system is described for measuring the angular position of an internal combustion engine crankshaft, comprising a magnetic sensor and at least two projections provided on a flywheel which is rigid with the crankshaft. The main characteristic of the present invention is that the sensor has its longitudinal axis parallel to the axis of the crankshaft and is supported by that portion of the crankcase which faces the flywheel. As the projections pass in proximity to the sensor, this latter generates an electrical pulse which is utilized in a central control unit for electronic ignition and/or electronic injection.

Abstract: A device for controlling an internal combustion engine of a motor vehicle comprises a stationary pickup element provided with a control circuit for ignition or the like of a motor vehicle, and a transducer wheel arranged to rotate with the shaft of the engine of the motor vehicle and operatively connected with the stationary pickup element, the transducer wheel having a circumference and being provided on the circumference with a number of segments that is proportional to a number of cylinders of the engine, the segments affecting the pickup element and extending substantially in a circumferential direction, at least one of the segments having a perforation with a width which is measured in a direction transverse to a direction of elongation of the segment and which increases in the direction of elongation of the segment to supply a signal serving as a marking for the control circuit.

Abstract: The invention relates to a miniature high-energy continuous spark electronic igniter composed of a magnetic pulse generator having a magnetic flux attracting gap, a voltage-stabilizing circuit, a signal amplifying circuit, a two-stage switching circuit, a protection circuit, a voltage-raising output circuit, a trigger signal circuit, an oscillation maintaining control circuit and a trigger signal continuous current circuit. The igniter is adapted to withstand both overload and largely varying supply voltage.

Abstract: A light, compact angle-of-rotation sensor is provided that is comprised of a magnetic ring bonded to a shaft by means of resin. The magnetic ring is provided around its periphery with a number of magnetized zones, with each such magnetized zone having a different number of magnetic poles, and magnetic interference between magnetized zones is prevented by leaving non-magnetized spaces between the magnetized zones. The prevention of magnetic interference can be further enhanced by the provision of non-magnetized portions between the magnetic poles of the magnetized zones.

Abstract: A light, compact angle-of-rotation sensor is comprised of a magnetic ring within which resin is used to fix the ring to the periphery of a shaft. Formed on the magnetic ring are insets into which the resin enters, providing a strong bond between the resin and the magnetic ring. In addition, a key inset into the shaft provides a strong bond between the resin and the shaft. Magnetized zones are formed on the outer surface of the magnetic ring, and magneto electric transducer means are arranged in the proximity of these zones to face said zones, and the angle of rotation is detected from the changes in magnetism that accompany the rotation.

Abstract: A control circuit which includes a circuit for regulating the time taken to desaturate the switching transistor. This regulating circuit is arranged to control the time for which the transistor is conductive, so that the desaturation time of the transistor is substantially nil when the rate of rotation of the engine is greater than a predetermined value.

Abstract: Control signals are provided by means of a magnet, a sensor sensitive to magnets, and elements influencing the magnetic field and having a relative movement. A magnetoresistive circuit is placed between one stationary and at least two simultaneously linear or circular movable magnetic flux concentrators having an U- or V-shaped arrangement and being alternately effective in the magnetic circuit. The magnetoresistive circuit is operated in its saturation range, if at least one of the magnetic flux concentrators is effective.

Abstract: A very high performance digital ignition system is disclosed which includes a precision angular position sensor within the distributor of an internal combustion engine (or otherwise coupled to the engine to sense its angular position) to provide accurate timing information which is applied to gating means for selectively passing bursts of triggering pulses having, in the exemplary embodiment, a 7-to-1 duty cycle ratio. The selected burst of pulses are applied to a driver circuit which provides power amplification to energize the primary circuit of an ignition coil. An alternative mode of operation is also disclosed which simulates a conventional make and break ignition system to effect a service mode. In the service mode of operation, a single pulse is issued to the ignition coil upon the occurrence of the first or second pulse of the pulse burst after the angular position sensor has sensed that a cylinder firing operation should be instituted.

Abstract: The invention proposes a rotor arrangement for use with an automotive Hall generator for detecting the precise position of a select or predetermined one of a plurality of pistons, or the precise rotational position of the crank shaft, of an Otto cycle engine, by providing a distinct marking on a trigger wheel preferably mounted for rotation with the drive shaft of a distributor for generating a signal in a Hall element which signal is then detected by evaluation or discriminating circuitry.

Abstract: There is provided a rotational signal detecting apparatus comprising a housing, a rotor shaft attached to said housing so as to be freely rotatable, said rotor shaft rotating in synchronism with a crankshaft or a cam shaft of an engine, a photoelectric pickup comprising a rotating portion fixed to said rotor shaft so as to rotate with said rotor shaft as one body and a fixed portion integrally attached to said housing, said fixed portion having photoelectric conversion means for outputting a signal varying according to the quantity of incident light varied in synchronism with the rotation of said rotating portion, an electromagnetic pickup comprising a rotating portion fixed to said rotor shaft so as to rotate with said rotor shaft as one body and a fixed portion integrally attached to said housing, said fixed portion having magnetic field detecting means for outputting a signal varying according to the magnetic field varied in synchronism with the rotation of said rotating portion, one of said photoelectric

Abstract: A system for stroke identification of an internal combustion engine, comprising first sensor means for detecting given angles of a drive shaft; second sensor means for detecting given angles of a distributor shaft; third processing means for receiving signals from the first and second sensor means and for identifying the strokes on the engine; and on which the aforementioned second sensor means comprise a single sensor element.

Abstract: The disclosure illustrates a self calibrating control system for a variable area turbocharger incorporating a pneumatic actuator having a limiting position achieved at low actuating pressure levels. The calibration takes place by monitoring the demanded actuator signal. If it stays at a level reflecting a physically limiting position of the actuator for a predetermined time air pressure to the actuator is terminated to positively maintain the actuator in the no air position. A signal reflecting the actual position of the actuator is then substituted in the control system as a new zero pressure condition. This procedure is performed periodically and is aborted if normal control inputs are demanded thus resulting in a minimum disruption to normal control inputs. In addition the system provides for fault indications if the calibration procedure fails to result in a zero pressure calibration within predetermined limits.

Abstract: An ignition timing control system for an internal combustion engine comprises magnetic pick-up means for magnetically sensing the angular position of the crankshaft and for generating an output signal indicative thereof, control means for controlling the ignition timing of the engine based on the output signal from the magnetic pick-up means, and correction means for correcting the ignition timing to be controlled by the control means for a delay in the generation of the output signal, which delay increases with a rise in the rotational speed of the engine.

Abstract: A device for controlling ignition or fuel injection and the like of an internal combustion engine includes an angular position sensor of a shaft of the engine. The sensor is in the form of a disc rotating together with the shaft and being provided on its periphery with as many radially projecting segments separated by gaps as many cylinders has the engine. A gap between the segments is provided with a single sloping ramp terminating with a steep flank. The flank of one segment and the steep flank of the ramp cooperate with a detector which generates a marking pulse coordinating during single rotation of the shaft the distribution of control pulses to respective cylinders.

Abstract: An ignition timing control system for an internal combustion engine comprises first signal generating means for generating a first signal at a crank angle position of the engine corresponding to each one of a plurality of cylinder groups; second signal generating means for generating a second signal at a crank angle position corresponding to a top-dead-center position of each cylinder, and distributing means for distributing ignition command signals to ignition devices provided for respective cylinder groups, in response to the first and second signals. Further, cylinder-discriminating means is provided for generating a third signal at a crank angle position corresponding to a particular one of the cylinders in response to the first and second signals.

Abstract: A device for controlling an internal combustion engine of a motor vehicle comprises a sensor disk rotating with the shaft of the engine and a stationary signal receiving element scanning signals from the sensor disk. Sensing elements are positioned on the sensor disk. The number of these elements is proportional to the number of cylinders of the engine. Each sensing element includes a sickle-shaped portion and a lug coordinated with the signal receiving element. The control system is formed as an assembly of prefabricated structural components.

Abstract: A distributor accommodates an angle-of-rotation sensor having a magnetic rotating member which is provided to detect the crank angles in an internal combustion engine. The air vent of the distributor is provided with a magnetic trap means that collects any ferrous particles and other such dust in air drawn into the distributor from the outside, preventing such particles adhering to the magnetic rotating member and producing otherwise detection output errors.

Abstract: A multicylinder internal combustion engine includes a pair of camshafts, a pair of driven pulleys fixed to ends of the camshafts, a crankshaft, a driver pulley fixed to an end of the crankshaft, and a single endless belt trained around the driven pulleys and the driver pulley. A rotation sensor for detecting the rotation of the engine is disposed between a fixed engine member and the one of the driven pulleys around which a portion of the endless belt subject to greater tension is trained. A distributor is coupled coaxially to an opposite end of the camshaft to which said one driven pulley is fixed.

Abstract: Two Hall sensor devices are positioned at a predetermined angular position with respect to each other, and with respect to a distributor, by mounting a first Hall sensor in a primary carrier, forming a first alignment means at a firing point of the first Hall sensor, mounting a second Hall sensor in a secondary carrier, and forming a second alignment means in the secondary carrier at the firing point of the second Hall sensor. A third alignment means is formed in the primary carrier at the predetermined angle from the first alignment means and the secondary carrier is mounted to the primary carrier so that the second and third alignment means are aligned and the two Hall sensors provide output signals displaced by the predetermined angular rotation.

Abstract: A displacement sensor is provided with first and second piezoelectric elements, a pair of electrodes at one and the other ends of each of the first and the second piezoelectric elements; a permanent magnet mechanically fixed to one end of the first piezoelectric element; a small piece mechanically fixed to one end of the second piezoelectric element and having almost the same weight as that of the permanent magnet; and a base plate to which the other ends of the first and the second piezoelectric elements are mechanically fixed; wherein the electrodes provided at the other end of each of the first and the second piezoelectric elements are electrically connected, and the electrodes provided at one end of each of the first and the second piezoelectric elements are used as output terminals.Also, a pair of small pieces made of a magnetic material and a non-magnetic material can be used instead of the above permanent magnet and small piece.

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.

Abstract: Two Hall sensor devices are positioned at a predetermined angular position with respect to each other, and with respect to a distributor, by mounting a first Hall sensor in a primary carrier, forming a first alignment means at a firing point of the first Hall sensor, mounting a second Hall sensor in a secondary carrier, and forming a second alignment means in the secondary carrier at the firing point of the second Hall sensor. A third alignment means is formed in the primary carrier at the predetermined angle from the first alignment means and the secondary carrier is mounted to the primary carrier so that the second and third alignment means are aligned and the two Hall sensors provide output signals displaced by the predetermined angular rotation.

Abstract: An interrupter and Hall Effect switch for generating a unique signal when the window-in-vane interrupts the Hall signal in an ignition distributor and is designed to synchronize the ignition and fuel pulses in a multi-point injected internal combustion engine.

Abstract: A voltage generating ignition distributor for an internal combustion engine that has a pickup coil and a magnetic rotor. In order to prevent high frequency voltages, developed at the gap between the rotor contact and the outer electrodes of the distributor cap, from distorting the voltage generated in the pickup coil the outer turns of the pickup coil are grounded through a capacitance. The outer turns of the pickup coil thus form a grounded shield for the inner turns of the pickup coil at the high frequency of the voltage at the rotor gap discharge.

Abstract: An internal combustion engine ignition control includes a variable reluctance pick-up with a winding providing signals to an integrator the output of which controls an ignition switching circuit. The ignition switching circuit includes a current limiter circuit which operates to limit the coil current at a maximum level until the instant of ignition. A capacitor is charged and discharged under the control of the current limiter circuit so that the voltage on it depends on the ratio of the time for which the current limiter circuit is in operation to the ignition cycle duration. An active clamping circuit operates to override the integrator under the control of this capacitor so as to apply a variable preconditioning bias to the output of the integrator which has the effect of varying the instant at which the coil current is switched on. Closed loop dwell control is thus provided in a simple and convenient manner.

Abstract: A transducer for creating an electrical signal proportional to the angular position of a member pivotally mounted on a given axis, which transducer comprises an element pivoted directly by the member and containing a means for creating a flux field linearly varying in intensity along a given operating line extending in an air gap between spaced portions and having a preselected arcuate shape. A linear Hall Effect device, with an output voltage proportional to the intensity of the flux field to which the device is exposed, is mounted at a fixed position on the operating line and in the air gap. Consequently, as the element is pivoted by the monitored member, the output voltage from the Hall Effect device varies proportionally to the position of the Hall Effect device along the operating line.

Abstract: An ignition apparatus for internal combustion engines for preventing input noises out of an ignition signal line from affecting the ignition timing of the engine to make knocking or a start malfunction. A bistable circuit is provided for eliminating such input noises. The bistable circuit is associated with a Schmitt circuit which serves to energize or de-energize an ignition coil for inducing a discharging voltage. The Schmitt circuit is overridden by the bistable circuit for a time interval corresponding to a time for which such input noises exist. Afterwards, the Schmitt circuit receives as an input the ignition signal synchronizing with an engine speed and controls the ignition timing.

Abstract: Improved magnetic pulse timer components provide increased timer voltages with steeper bipolar waveforms. Such improvements are residual in terms of a permanently magnetized timer rotor (30, 40, 60, 70, 80). Rotors (30, 40, 60) have regularly spaced protrusions at the rotor's outer periphery and are permanently magnetized. Rotors (70, 80) have regularly spaced slots in their outer peripheries and may also be permanently magnetized. Such slotted rotors provide the capability of high level and steep bipolar voltage waveforms. Additional magnetic flux switching capability in the timer may be provided by utilizing a permanently magnetized component mounting base plate (90, 100, 110).

Abstract: A distributor for a contactless ignition apparatus of an internal combustion engine is disclosed. An ignition control circuit unit of contactless type is comprised of a case containing the ignition control IC circuit and a mold resin of the pick-up coil integrally formed with the case. The distributor contains closed magnetic circuit-forming means comprising a distributor shaft rotatable in synchronism with the engine, a reluctor or rotor fixed on the shaft and having claws in the number corresponding to the number of engine cylinders, a stator having a pair of claws opposed to the claws of the reluctor and mounted on the movable base of the angle advancer for advancing the ignition timing in response to a negative vacuum pressure, and a permanent magnet for generating a closed magnetic circuit through the reluctor stator and shaft. The pick-up coil of the ignition control circuit unit is arranged to cross the closed magnetic circuit, which unit is fixed within the distributor.