Abstract: 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.

Abstract: 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, tha

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.