Digital ignition control for a magnetopowered ignition system of an internal combustion engine

US4378769A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Georg Haubner · Starnberg, DE
• Jurgen Wesemeyer · Nuremberg, DE
• Werner Meier · Burlington, US
• Hans Schrumpf · Oberasbach, DE

Key dates

• Filing date: Feb 18, 1981
• Grant date: Apr 5, 1983
• Expiry date: Feb 18, 2001

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

In an ignition system for an internal combustion engine, a digital system for computing the timing advance is provided. Constants approximating the curve of timing advance v. engine speed are stored in a microprocessor. The positive half waves of primary current in the magneto generate the ignition energy and also generate a reference signal for controlling the actual ignition time. The sequence of reference signals is also used to generate a digital value indicative of engine speed. The latter is used to address the read only memory in which the constants for approximating the timing advance curve are stored. After each reference signal, the value read out from the read only memory is counted down by a counter. When the counter reaches the value of zero, ignition is started.