1. DE000019630027 - Anordnung zur Erfassung der Temperatur des Ankers eines Gleichstrommotors

In an arrangement for sensing the temperature of the armature of a direct current motor (1), the temperature is indirectly recognised from the temperature-dependent armature resistance (RA) determined as the quotient of the measurable voltage (Ubat) currently applied to the terminals of the motor (1) and the blocking current (Iblock) of the armature, and is correlated with the momentary temperature. The current signal (V1) derived from the current (IA) flowing in the armature is advantageously averaged by means of an integrator (5, 7) which can be controlled by a microcontroller at adaptable, calculated integration times. In a very appropriate application, the arrangement can be used to indirectly determine the number of revolutions (N) and/or critical changes or changes of interest in the number of revolutions of the motor. When a motor-typical proportionality constant ( kappa ) is observed, the number of revolutions is proportional to the voltage (Uind) induced in the armature, according to the equation N = kappa . Uind, and the voltage induced in the armature is determined as the difference between the voltage (Ubat) applied to the terminals of the motor and the product of the armature current by the armature resistance.