Motor ignition system control circuit for maintaining energy storage in spark coil constant in wide speed range

US4176645A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Werner Jundt · Ludwigsburg, DE
• Gerhard Sohner · Schorndorf, DE
• Peter Werner · Wiernsheim, DE
• Herman Roozenbeek · Schwieberdingen, DE

Key dates

• Filing date: Oct 22, 1976
• Grant date: Dec 4, 1979
• Expiry date: Oct 22, 1996

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02P3/0453
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A monitoring resistor in series with the spark coil primary winding and the electronic interruptor switch provides a signal to an integrator for shifting the control thresholds of a threshold switch that controls the interruptor away from their quiescent values that are nearer the zero crossover of the timing voltage wave provided by an engine driven timing signal generator. The integrator output voltage remains constant during the time the interruptor switch is open. While current flows through the interruptor circuit, the integrator increases the control voltage until the primary winding current reaches a predetermined level and then decreases the control voltage until the timing wave recloses the interruptor. While the control voltage is being decreased, the coil current is allowed to rise to a limiting value and is then held constant by another circuit controlled by the monitoring resistor that slightly reduces the conductivity of the interruptor switch in its closed condition, but this occurs only while the engine is accelerating to the operating speed range. During this time the switch-on threshold for controlling the interruptor is raised towards the peak of the timing wave,…