Safety circuit and brush holder for preventing fault conditions in an alternator

US9893663B2 · kind B2 · utility

Assignee

• Infineon Technologies AG · DE

Inventors

• Martin Graefling · Graz, AT
• Christoph Seidl · Graz, AT

Key dates

• Filing date: Jun 10, 2015
• Grant date: Feb 13, 2018
• Expiry date: Aug 6, 2035

Classification

• Technology area (CPC —): General

Abstract

A fault protection circuit for an alternator is provided for preventing faults such as a prolonged full-field condition in the alternator. The fault protection circuit includes a safety switch that is opened when the alternator output voltage becomes too high, as may occur during a full-field condition caused by an electrical short, or when some other fault is detected within the alternator. The opening of this safety switch disconnects a supply voltage feeding an excitation current control switch. The excitation current control switch normally adjusts an excitation current provided to a rotor in the alternator, in order to regulate a voltage output from the alternator. By providing a safety switch that disconnects the supply voltage for the rotor excitation in the alternator, the alternator output voltage may be prevented from reaching excessive levels that may damage devices in an electrical system and a battery coupled to the alternator.