Circuit arrangement for protection of a heating element from overheating heating device and method for fused protection of the heating device

US8440942B2 · kind B2 · utility

Assignee

• BSH Bosch und Siemens Hausgeräte GmbH · DE

Inventors

• Manuel Otto · Lehre, DE
• Peter Schweier · Forheim, DE
• Martin Stickel · Giengen an der Brenz, DE
• Franz-Josef Wagner · Trier, DE

Key dates

• Filing date: Dec 10, 2004
• Grant date: May 14, 2013
• Expiry date: Jul 29, 2028

Classification

• Technology area (CPC G): Physics
• CPC primary: G05D23/2401
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A circuit arrangement is provided for protecting from overheating a heating element whose resistance value is a function of its temperature. The circuit arrangement includes a power supply, a switch, and a switch control circuit, a current sensor providing a signal proportional to the current flowing through the heating element, and a first scaling device whose output provides a signal proportional to the supply voltage of the heating element. An evaluation circuit compares the difference signal determined by a first detector having an output that provides a difference signal formed from the signals of the current sensor and the first scaling device with a reference signal and the switch control circuit can be switched from a conducting state when the switch control circuit is in a first state to a non-conducting state when the switch control circuit is in a second state.