Robert Boschgmbh

Helmut Schmied

Bernd Bodig

Gerd Hohne

Ulrich Bentel

Thomas Capouschek

Hartmut Michel

Adolf R Fritz

Georg Pfaff

Bernd Bireckoven

Bernd W Kalkhof

Walter Gollin

Bernhard Eisele

Hans Berkemer

A device for ignition of an internal combustion engine is described, having a computer and an ignition output stage. A current flow through the primary side of an ignition coil is controllable by the ignition output stage. Furthermore, an arrangement is provided for measuring current flow through the primary side. A charge starting point is calculated by the computer, at which the ignition output stage begins to control a current flow through the primary side. The ignition is triggered at a preselected current through the primary side. The instant of triggering is acknowledged to the computer, which takes this instant into consideration in a further, subsequent calculation of a charge starting point.

Device for ignition of an internal combustion engine

An ignition system and a method for operating an ignition system provides reliable suppression of a closing spark ignition at relatively small expense and to achieve a reliable ignition by the ignition spark. To assure a high energy supply to the spark plug, an ignition system is created having a functional device for receiving a drive signal and for producing a pulse signal, an ignition transistor for receiving the pulse signal, an ignition coil, whose primary winding connections are connected in a primary current circuit that is fed by a vehicle power supply source and that can be switched using the ignition transistor, and whose secondary winding connections are connected in a secondary current circuit for receiving a spark plug. In the secondary current circuit, a component is provided that a) lets through a forward current in its forward direction that may be induced by reducing the magnetic field of the ignition coil, b) blocks in its blocking direction without a previous forward current, and c) over a conducting period, after a previous forward current maintains in its blocking direction a current that is suitable for maintaining an ignition process.

Ignition system and method for operating an ignition system

Described is a control circuit for an output stage for suppressing electrical and electromagnetic interference having a signal input (I), a signal output (O), and a ground terminal, two switch stages ( ) which are connected to the signal input (I) and the ground and which have one control terminal and one output terminal each, each switch stage ( ) switching over from a first state in which the potential at the output terminal follows the potential at the signal input (I) to a second state in which the potential at the output terminal is drawn to ground when a first or second threshold value (U , U ) is exceeded at its control terminal, the control terminal ( ) of the first switch stage ( ) being connected to an intermediary potential, which is between the potential at the signal input (I) and ground, the output terminal ( ) of the first switch stage ( ) forming the control terminal of the second switch stage ( ), the output terminal of the second switch stage forming the signal output (O) of the control circuit, and the threshold value (U ) of the first switch stage being higher than the threshold value (U ) of the second switch stage.

Input circuit for an output stage

A circuit arrangement of an ignition output stage in particular for an ignition circuit of a motor vehicle, having a switching arrangement which triggers a primary winding of an ignition coil, and a trigger circuit for the switching arrangement. The trigger circuit allows a two-stage closing of the ignition coil.

Circuit arrangement of a final ignition stage

An inductive coil ignition system for an engine, having at least one ignition coil which includes a primary winding fed from a voltage source and having two terminals, and a secondary winding also having two terminals. A switching apparatus is arranged parallel to the primary winding and connects the two terminals of the primary winding as a function of a control signal. An activation circuit generates the control signal.

Inductive coil ignition system for an engine

An a.c. ignition system for an engine, with an ignition transistor that switches the primary winding of an ignition coil, with a control circuit for controlling the ignition transistor and a parallel circuit including a capacitor and a diode between the emitter and collector of the ignition transistor. The control circuit can receive a measuring signal that is proportional to the collector potential of the ignition transistor, and the control circuit controls the ignition transistor depending on the measuring signal so that the ignition transistor is activated at a low voltage between the collector and emitter of the transistor.

A.C. ignition system for an engine

The invention relates to an ignition device for combustion engines. The ignition device has a switching transistor (7) which, when a trigger is energized, is current-conductive, further an ignition coil (6), the primary winding (5) of which forms with the transistor (7) a series circuit, and, further, a signal transducer (10) connected in advance of the trigger (11) to supply a capacitor-charging current, after a lapse of a time period of its control signal (a, b) reaching a peak value. The threshold of the trigger (11) can be shifted relative to the control signal (a,b) by use of an electrical storage device (30) which can be charged and discharged, and in which the charge is dependent on the predetermined current value in the primary winding (5). In accordance with the invention, the storage device (30) can be charged by the control signal (a,b) and can be discharged over a shunt circuit branch (32) with high resistance value (resistor 33) as well as over a shunt circuit branch (34) with low resistance value (resistor 37). Upon reaching of a primary current value of predetermined level, the charging of the storage device (30) is stopped and the shunt circuit branch (34) with low resistance value is completed when transistors (36,38) become conductive.

Ignition device for combustion engines

A capacitor which is charged by recurring square waves of a normally functioning microprocessor discharges at a steady rate, so that if the square waves do not continue, an operational amplifier will switch over and produce a reset pulse for the microprocessor. Repeated transitions of one polarity of the square wave recharge the capacitor during a short interval terminated by a second operational amplifier when the capacitor reaches a fixed level of charge. This second amplifier, which has feedback coupling, also initiates the timing discharge of the capacitor. A diode network at its output prevents charging the capacitor in the static state. This arrangement makes it unnecessary to provide another capacitor for quickly recharging the capacitor to prevent its discharge from switching over the first-mentioned operational amplifier.

Monitoring circuit for resetting malfunctioning electronic components,

To improve an ignition system as described in U.S. Pat. No. 4,176,645, Jundt et al., in which a threshold switch is provided which controls current flow through the ignition coil, the turn-ON point of the current flow being determined, in part, by an integrator, and to prevent malfunction due to corroded terminals, improper installation and the like, a variable resistance branch, including a transistor 66, is connected across the integrator 31, 44, and so connected that, as the supply voltage drops, the effect of the integrator 31, 44 on the threshold switch 15, 16 is decreased, thus preventing modification of the inherent threshold level of the threshold switch by the action of the integrator. The transistor 66 in the variable resistance circuit 64 may be connected as a comparator, having its base connected to a junction J at fixed voltage (Zener diode 68, resistor 69), which is compared with the emitter-collector voltage, connected across the integrator 31, 44, and simultaneously changing its resistance value as the comparison is effected.

Ignition system for an internal combustion engine

In order to increase the closure angle of an interrupter switch connected in series with the primary winding of an ignition coil with increasing engine speeds, a capacitor is connected to the input of a trigger circuit whose output controls this closure angle. The capacitor is charged through a diode while the trigger circuit is switched out. The voltage across the capacitor shifts the threshold of the trigger circuit in a direction increasing the time that the interrupter switch is conductive. The charge on the capacitor is controlled by a signal generator which furnishes an output signal having an amplitude increasing with increasing engine speeds. The closure angle of the interrupter switch therefore also varies as a function of engine speed.

Apparatus for maintaining constant ignition energy with increasing

The primary of the ignition coil is tapped to provide two partial primary portions which are serially connected; during an initial current flow, only one partial portion has current flowing therethrough, the other partial portion being short-circuited. When the current through the coil has risen to a predetermined level, as sensed by current flow through a sensing resistor, the short circuit across the second partial portion is removed so that current can continue to flow through the entire primary, causing a substantial drop in current level but maintaining the stored inductive energy. Current can thus rise rapidly initially, so that the coil will store sufficient energy to initiate sparking at high speeds of the connected internal combustion engine while, at low speeds thereof, the overall current flow through the coil is decreased.

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Marbach, Germany

Helmut Schmied