Trigger circuit for an electromagnetic device

US5235490A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Bruno Frank · Asperg, DE
• Martin Muller · Chicago, US
• Helmut Rembold · Stuttgart, DE

Key dates

• Filing date: May 30, 1991
• Grant date: Aug 10, 1993
• Expiry date: May 30, 2011

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02D2041/2075
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A trigger circuit for an electromagnetic device, in particular a solenoid valve of an injection system for an internal-combustion engine, has a control element for causing excitation of the electromagnetic device to be lowered at least once and then raised after the electromagnetic device is activated. The control element has a delay circuit which slows down the rate at which excitation of the electromagnetic device changes during the lowering and/or raising action.