Verfahren zur Erkennung und Abschaltung eines blockierten oder überlasteten permanenterregten Gleichstrommotors

摘要

The invention relates to a method for detecting and disconnecting a jammed or overloaded permanently excited direct current engine. The operational status of the engine is detected by measuring the voltage (Ug) between the engine terminals using a bridge circuit. The bridge circuit has two parallel branches. Two resistances (R1,R2) are series connected in the first branch. The direct current engine (RM, UG) is serially arranged in the second branch in relation to a third resistance (R3). The bridge circuit is adjusted with respect to the three resistances (R1,R2,R3) and to a fourth resistance which describes the behaviour of the engine. This enables engine terminal resistance (UG) to be measured via the bridge voltage. The engine is disconnected when there is no longer any bridge voltage or when it falls below a specified set value.