Apparatus for generating engine speed-dependent ignition control signals

US4268888A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Bernd Bodig · Leinfelden, DE
• Werner Jundt · Ludwigsburg, DE

Key dates

• Filing date: Aug 15, 1979
• Grant date: May 19, 1981
• Expiry date: Aug 15, 1999

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02P7/067
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

In order to prevent ignition power losses at low engine speeds and further to provide for the use of ignition control signals of both unipolar and bipolar nature, the invention provides that a Schmitt trigger which generates the principal ignition control signal is actuated by the transducer. The switching thresholds of this Schmitt trigger are changeable by a secondary threshold recognition circuit which can shift at least the negative threshold of the principal threshold circuit to more positive values. The invention also includes a delay circuit which prevents the return of the shifted threshold to more negative values. Still further included is a third threshold circuit which is engaged only at some higher engine speed.