Arrangement for sensing the temperature of the armature of a direct current motor

US6111330A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Gunnar Lochmahr · Leonberg, DE
• Volker Aab · Lichtenau, DE
• Gerhard Knecht · Iffezheim, DE

Key dates

• Filing date: May 27, 1998
• Grant date: Aug 29, 2000
• Expiry date: May 27, 2018

Classification

• Technology area (CPC G): Physics
• CPC primary: G01K7/20
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An arrangement for the determination of the temperature of a direct-current motor. The temperature is determined in an indirect manner from the temperature-dependent armature resistance, with the armature resistance being determined as the quotient of the voltage being applied to and measured at the motor terminals and of the blocking current of the armature, and being set in relation to the respective temperature. The current signal determined from the current flowing within the armature is averaged with adjustable, calculated integration times with the aid of an integrator that can be controlled by a microcontroller. The arrangement, can be used for the indirect determination of the rpm rate (N) and/or variations that are critical or of interest in the rpm rate of the motor. The rpm rate is proportional to the voltage (U.sub.ind) induced within the armature, taking into consideration a motor-typical proportionality constant (.kappa.) according to equation N=.kappa. U.sub.ind, with the voltage induced within the armature being determined as the difference between the voltage being applied to the motor terminals and the product of armature current and armature resistance.