Robert Boschgmbh

Walter Ruf

Gerhard Sohner

Werner Jundt

Helmut Roth

Peter Werner

Bernd Bodig

Karl Seeger

Reinhard Leussink

Dieter Neuhaus

Erich Jesse

Heinz Krauss

Ignition control pulses as well as fuel injection control pulses can be obtained from a single signal generator structure by providing two generator units (28, 29) on the structure (1) which includes a rotating shield, vane or gate element (20) to generate by magnetic, for example Hall generator elements, or optical couplers, pulses (U28, U29). The vanes are so positioned, and the rotation thereof, at half engine speed, so arranged that the pulses (U28) generated by the first generator (28) extend over the pulse gaps or intervals of the pulses (U29) from the second pulse generator (29). At least one, and for example two vanes are foreshortened, so that the pulse generated by the first signal generator (28), upon passage of the foreshortened vane (23, 26) commences only when part of the pulse gaps of the second generator (29) has already elapsed. The pulse is applied to an OR-function gate which, then, will provide the fuel injection pulses; the trailing flanks of the pulses from the first signal generator are applied to control the ignition pulses, for example through a frequency divider (43). The number of vanes (22, 23 . . . 27) is twice the number of cylinders (in the example: three).

Ignition and fuel injection pulse generating system for odd-numbered

A safety device is included in a circuit comprising a power source and a user device. The power source has one terminal connected to ground, as does the user device, with the safety device connected in a conducting path leading to the ground in the user device. In the event of an incorrect polarity connection between the power source and user device, a current path through the safety device and to ground is established.

Safety device for a conducting path in a load device

To permit use of shaft position transducers which provide needle pulses at predetermined angular positions of the crankshaft of an engine, such as Wiegand-type, and still enable generation of a counted dwell time even under transient conditions, or under low-speed conditions, the output from the Wiegand transducer is connected to a logic circuit which, under normal operating conditions, by use of a counter counts a predetermined time interval after opening of a switch in series with the ignition coil to determine the dwell period or initiation of current flow for a subsequent ignition event by resetting the counter with a reverse polarity subsequent pulse, thereby passing, upon reset, a predetermined count state which, similar to the normal counting of the count state, initiates closing of the switch. Thus, even though the normal counting time has not yet been reached, the reset operation of the counter will trigger closing of the switch and hence sufficient current flow through the ignition coil to store the appropriate electromagnetic energy therein for a reliable spark at the spark plug.

Internal combustion engine ignition system

Changes in the magnetic field around a Wiegand wire created by a magnetic rotor coupled to a shaft of the engine induce a signal in a sensing coil. The signal is applied to an input switch which forms part of a control circuit. The output of the control circuit is connected to an interrupter switch connected in series with an ignition coil such that a spark is created at the secondary of the ignition coil when the interrupter switch opens. The control circuit maintains the interrupter switch in the nonconductive state for a predetermined percentage of the ignition cycle at low engine speeds and for a lesser percentage at high engine speeds so that enough energy can build in the ignition coil prior to the next interruption at the higher speeds.

Ignition system using a Wiegand wire

A voltage divider across the interruptor switch contacts provides a measure of the high voltage produced before a spark occurs at the sparkplug. A Zener diode connected to the upper tap of the voltage divider breaks down when this voltage has risen a certain amount as the result of wear of the sparkplug electrodes that widen the gap. The Zener voltage breakdown causes a relay to lock in and to short-circuit a current-limiting resistor in the spark coil primary circuit that allows a higher voltage spark to be produced to assure proper firing of the sparkplugs with the wider gap. Another Zener diode is connected to the lower tap of the voltage divider to sound an alarm and to disable the ignition circuit when the high voltage at which sparks strike in the sparkplug rises to a value for which the insulation of the spark coil and its connection is not designed to withstand.

Engine ignition system with voltage monitoring

To provide for gradual turn-off of an ignition coil current control transistor, a control capacitor which provides turn-off current has its charge state changed gradually by means of an auxiliary transistor so connected to the capacitor that the conduction of the emitter-collector path of the auxiliary transistor is gradually changed, the main switching transistor being connected to and controlled by the auxiliary transistor and likewise changing gradually from conductive to blocking state in dependence on the gradual change in conduction of the emitter-collector path of the auxiliary transistor to prevent rapid turn-off of the main switching transistor and hence an undesired pulse at the secondary of the ignition coil which may induce continued operation of the internal combustion engine even though the ignition has been turned off.

Transistorized ignition system for internal combustion engines

To provide for gradual decay of current flow through the primary of an ignition coil, and hence suppression of spurious sparks at spark plugs, a main switching transistor has its conductivity controlled by the conductivity of the emitter-collector path of a control transistor, the base-emitter path of which forms part of a discharge circuit of a control capacitor, which discharge circuit has a sufficiently high resistance to provide for gradual discharge of the capacitor and hence gradual transition of the conductivity of the control transistor.

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Korntal-Munchingen, Germany

Walter Ruf