Method for measuring resistance of load connected to a rotation transformer

US6133741A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Bernhard Mattes · Sachsenheim, DE
• Hartmut Schumacher · Freiberg, DE
• Ralf Henne · Sachsenheim, DE

Key dates

• Filing date: Oct 13, 1998
• Grant date: Oct 17, 2000
• Expiry date: Oct 13, 2018

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R27/14
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A method for measuring the resistance of a load, preferably the firing pellet of an airbag, that is connected on the secondary side of a rotary transformer, in which the resistance measurement is largely unaffected by the magnetic coupling between the windings of the transformer. According to this method, the capacitor is partially discharged twice in succession. During the first partial discharge, the capacitor is discharged continuously, and during the second partial discharge, the capacitor is discharged in steps. After the two partial discharges, the residual charge voltages at the capacitor are measured and the difference between the two charge voltages is obtained. This difference is an indication of the resistance of the load connected on the secondary side of the transformer.