Ignition system for internal combustion engines with tapped ignition coil

US4117818A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Bernd Bodig · Leinfelden, DE
• Helmut Schmied · Erbach, DE
• Gerd Hohne · Ludwigsburg, DE

Key dates

• Filing date: Jul 9, 1976
• Grant date: Oct 3, 1978
• Expiry date: Jul 9, 1996

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02P3/0838
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

The primary of the ignition coil is tapped to provide two partial primary portions which are serially connected; during an initial current flow, only one partial portion has current flowing therethrough, the other partial portion being short-circuited. When the current through the coil has risen to a predetermined level, as sensed by current flow through a sensing resistor, the short circuit across the second partial portion is removed so that current can continue to flow through the entire primary, causing a substantial drop in current level but maintaining the stored inductive energy. Current can thus rise rapidly initially, so that the coil will store sufficient energy to initiate sparking at high speeds of the connected internal combustion engine while, at low speeds thereof, the overall current flow through the coil is decreased.