Ignition system for detecting arc voltage of spark plug

US5438268A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Richard Schleupen · Großingersheim, DE
• Ulrich Bentel · Mühlacker, DE
• Klaus Heyke · Reutlingen, DE
• Ulrich Nelle · Mössingen, DE

Key dates

• Filing date: May 7, 1993
• Grant date: Aug 1, 1995
• Expiry date: May 7, 2013

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02B2075/027
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A circuit arrangement for ignition systems for detecting an arc voltage at a spark plug has an ignition coil having a primary side on which the arc voltage is transformed and also having a primary winding, an ignition switch located in series with the primary winding of the ignition coil, a pnp transistor working as a voltage converter and having a control stage so that the arc voltage transformed on the primary side activates the control stage. The transistor is connected on an emitter side to a connection between the primary winding and the ignition switch. The pnp transistor is connected on a base side to a battery voltage. A resistor is assigned as an emitter follower to the pnp transistor. A measuring element is formed as a resistor. The transistor with its collector connection feeds to the measuring element a collector current which is proportional to the arc voltage.