Robert Boschgmbh

Karl-Heinz Adler

Ulrich Drews

Peter Werner

Josef Wahl

Gerhard Sohner

Friedrich Rabus

Bert Wurst

Gerd Hohne

Heinz Decker

Adolf R Fritz

Gunter Grather

Heinz Moller

Georg Pfaff

Adolf Kugelmann

Erwin Gloss

Reinhard Leussink

Gunter Brand

Eugen Kielbas

Thomas Jokh

Heinz Kammerer

An overvoltage protection circuit is galvanically, directly connected across at least part of the secondary winding in the ignition system of an internal combustion engine. The input portion of the overvoltage protection circuit is a voltage divider preferably constituted by RC elements. The voltage at the tap of the voltage divider is applied to a Schmitt trigger. When the voltage across the secondary winding becomes excessively high, the Schmitt trigger output pulse triggers a monostable multivibrator whose output pulse in turn increases the conductivity of a transistor switch located in series with the primary. The increase in primary current tends to oppose further increases in primary and secondary voltages. Alternatively, the output from the multivibrator could be used to shorten the time of current flow in the primary winding in subsequent ignition time intervals or to completely block any subsequent ignition process.

Ignition coil with overvoltage protection connected to the secondary

To provide an inherent delayed effect of spark trigger pulses derived from a magnetic transducer in which a salient pole piece of a rotor rotates with respect to a salient pole piece of a stator and, upon juxtaposition, a pulse is induced in a pickup coil magnetically coupled to the rotor-stator circuit, the rotor pole piece is formed to have an arcuate length greater than that of the stator pole piece, with stepped configuration so that, with respect to angle of rotation, the output voltage derived from the coil will have, after passing through zero or null, a half wave which has a portion (C) of decreasing rate of change of absolute value, or differential thereof, and a subsequent and adjacent portion (D) of increasing rate or differential of absolute value with respect to angular change with the sign of the differential remains the same, so that, on slow-speed operation, a trigger circuit set to respond only to the subsequent or adjacent portion will have a voltage induced therein only at a later time, that is, after the rotor has rotated to an angle beyond top dead center (TDC) position, upon high-speed operation, however, the curve portion immediately following the passage through zero or null already providing an output voltage sufficient to trigger the threshold circuit. The rotor can fit into all existing rotor structures, requiring only a modification of the shape of its salient pole piece.

Inductive signal source for internal combustion engine ignition system

Sequentially generated charge pulses are applied to the spark gap through a diode which prevents back-flow of energy applied to the spark gap, the capacity of the ignition cable, or a capacitor, and of the spark gap causing a build-up of charge accumulation as a result of the sequentially applied charges, until the gap breaks down; the breakdown voltage, therefore, will be determined by the conditions of the gap. The pulses are generated at a pulse repetition rate which is high with respect to the rate of generation of spark impulses through a circuit in which the respective capacities and winding ratios and inductances of the ignition coil and the cabling are controlled so that the pauses between sequentially generated spark pulses and the timing of the spark pulses can be matched to the system parameters.

High-voltage ignition system to generate a spark for an internal

To simplify electronic fuel injection or ignition signal generation, a transducer is provided which is formed as a segmental element providing a first or starting pulse at a certain angular position of the crankshaft of the engine and a second or termination pulse when the crankshaft of the engine has moved through a predetermined angle. A frequency controllable oscillator, typically a voltage controlled oscillator (VCO) forming part of a phase locked loop (PLL) provides counting pulses to a first counter 12, the first counter counting from the start to a termination number and then providing the trigger signal. A second counter 13 is included in the PLL and counting pulses from the oscillator in the interval between the start and the termination signals, the count being compared with a number introduced in the PLL so that the frequency of the VCO will change with change of speed of the engine and the time when the first counter, as controlled by the frequency of the VCO, will have reached its predetermined count state will be controlled in dependence of the time interval during rotation of the shaft through the predetermined angle. A third counter 24 can be connected to the first counter 12 to introduce a number therein derived parameters of the engine, or in accordance with functional characteristics thereof to preset a number into the first counter 12 and thus modify the time of generation of the trigger pulse, the first counter then, preferably, being a reverse or down counter counting to 0 or null.

Control trigger generating system, particularly to generate a trigger

To provide an undistorted square wave output signal under control of a switch subject to contact chatter so that the square wave will accurately reflect the operating instant of the switch, as commanded, regardless of contact chatter, a timing circuit is provided having a timing capacitor and a charge and discharge circuit therefor, connected to a threshold circuit, the threshold circuit response level and the charge circuit of the timing capacitor being dimensioned to cause the capacitor to charge to a level such that the threshold circuit responds only when the switch has changed state, typically closed after interrupting an inductive load, such as the primary of a spark plug, for a predetermined time period as determined by the switch contact chatter characteristics of the switch itself, for example about 0.6 to 1 millisecond in the case of automotive ignition breaker switches; a feedback connection is provided between the threshold circuit and the input stage to the circuit to disable transfer of a signal representative of change of the switch through the circuit unless the threshold level of the threshold circuit has been exceeded so that the threshold circuit could respond.

Interference-protected, switch-controlled square wave generation circuit

To permit connection of the input trigger stage to a wide variety of signal sources, such as different types of ignition systems (transistorized ignitions, coil-type ignitions, mechanical breaker system ignitions, and the like), a voltage divider is connected across the supply circuit, and the input signal is applied to a dual collector transistor forming the trigger or threshold stage, one collector of the transistor being connected to the output of the trigger stage and the other being connected to a protective circuit controlling bypassing of input signals of excessive voltage, or energy of either polarity and thus protecting the dual collector transistor.

Fuel injection system for combination with internal combustion engines,

Growing community of inventors

Leonberg, Germany

Karl-Heinz Adler