Abstract: For activating a stepper motor, a pulse-width modulated current is supplied to a coil of the stepper motor and it is determined whether the current flowing through the stepper motor, based on a default value, lies within a current bandwidth defined by an upper switching threshold and a lower switching threshold. The current supply to the coil is switched on when the detected current has dropped to the lower threshold and is switched off when the detected current has risen to the upper threshold. In order to detect a step loss, the signal form of the current or its change, respectively, is analyzed and deviations from desired values or desired value ranges, respectively, which have been caused by step losses, are detected. The determination of the signal form of the current or its change, respectively, may occur indirectly by analyzing a corresponding control signal.

Abstract: A process and liquid preparation is disclosed for removing residues from ers sawn from crystalline rods. In sawing rod-shaped workpieces such as semiconductor rods, for example, into wafers, by means of an internal-hole saw, auxiliary sawing materials such as for example cutting strips are often attached to the rods. According to the present invention, the residues of such auxiliary sawing materials remaining on the wafers obtained after the sawing operation can be removed particularly easily by means of immersion in baths of aqueous carboxylic solutions and, in particular, aqueous formic acid.