Ignition system

US4174696A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Werner Jundt · Ludwigsburg, DE
• Bernd Bodig · Leinfelden, DE
• Heinz Decker · Leinfelden, DE
• Gunther Schmidt · Biberach, DE
• Bert Wurst · Asperg, DE
• Karl Seeger · Ditzingen, DE
• Herman Roozenbeek · Schwieberdingen, DE

Key dates

• Filing date: Jan 16, 1978
• Grant date: Nov 20, 1979
• Expiry date: Jan 16, 1998

Classification

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

Abstract

A switch connected in series with the ignition coil is "on" and "off," respectively, in the presence and absence of a pulse furnished by a pulse generator operating in synchronism with the crankshaft of the engine. If the pulse width of the pulses is too small for the current in the ignition coil to reach the minimum value required for ignition, the closing time of the series switch is advanced, while if the pulse width is too long, causing excess heat dissipation in the coil, the closing time of the switch is retarded. To accomplish this, a first digital counter counts downwards for a predetermined time and upwards for a time period in which the current in the ignition coil exceeds a predetermined current. Upon interruption of the current in the coil, the then-present value in the first digital counter is transferred to a second digital counter. The second counter then counts down at a predetermined rate until a predetermined count is reached. At this time, the series switch is switched to the conductive state.