Ignition system for internal combustion engines

US4212280A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Jurgen Fresow · Schwieberdingen, DE
• Bert Wurst · Asperg, DE

Key dates

• Filing date: Dec 29, 1977
• Grant date: Jul 15, 1980
• Expiry date: Dec 29, 1997

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02P3/0456
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

The ignition coil of the system has its primary serially connected with a transistor which controls current flow therethrough. Ignition pulses are provided by an ignition pulse source, for example an inductive transducer. The recurrence rate of the ignition pulses is analyzed and a corresponding control signal is obtained which controls the timing interval of a timing circuit, the timing circuit determining the ON, or connected time, of the transistor or similar controlled switch in series with the primary of the ignition coil. Analysis of the recurrence rate is, simply, done in a pair of integrators, alternately effective and storing the time interval between alternate, succeeding ignition pulses, which permits control of current flow through the ignition coil for a period of time just sufficient for current flow to reach saturation without, however, causing current flow while the circuit is saturated, thus preventing unnecessary heating of the ignition coil and associated components. Alternate integration of alternate signals permits efficient operation also under high-speed operating conditions.