Transistorized ignition system for internal combustion engines

US4130101A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Werner Jundt · Ludwigsburg, DE
• Bernd Bodig · Leinfelden, DE
• Gerhard Sohner · Schorndorf, DE
• Walter Ruf · Ditzingen, DE
• Helmut Roth · Stuttgart, DE
• Peter Werner · Wiernsheim, DE

Key dates

• Filing date: Jul 21, 1976
• Grant date: Dec 19, 1978
• Expiry date: Jul 21, 1996

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02P3/0556
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

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.