Ignition system with essentially constant ignition coil energy supply

US4173962A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Friedrich Rabus · Schwieberdingen, DE
• Gunter Grather · Pinache, DE

Key dates

• Filing date: Jan 23, 1978
• Grant date: Nov 13, 1979
• Expiry date: Jan 23, 1998

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02P3/053
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

To provide sufficient current flow to the ignition coil in an ignition system of an automotive-type internal combustion engine under high-speed conditions, without excessive current flow under other speed conditions, a memory is provided which is loaded in the time interval between successive signals in advance of the ignition instant, separated by a time which decreases as the speed of the engine increases, the memory accumulating a stored value which is representative of the time duration. The memory is cleared or unloaded under controlled conditions in the interval between the occurrence of the second signal and the next subsequent first signal at controlled rates, one rate occurring during a timing interval established by a timing circuit, the timing interval of which depends on an operating parameter of the ignition system, for example supply voltage, and at a second rate after the timing interval, the unloaded or cleared time of the memory controlling current flow through the ignition coil for the next subsequent ignition pulse or ignition cycle to thereby maintain a minimum time of current flow through the ignition coil without extending the current flow if the time interval…