Abstract: A cable connection between a PC and a sewing machine for transmitting data in the form of different voltage levels, wherein the cable connection for connection to the PC has an RS 232 C port and the sewing machine has a TTL port. A level converter is integrated in the cable connection, preferably in the connection jack to the RS 232 C port. The level converter has a switching transistor controllable by the sending pole of the TTL port and a switching transistor controllable by the sending pole of the 232 port for connecting the corresponding receiving pole to a voltage potential which it is able to receive.

Abstract: In a sewing machine with a microcomputer controlled step motor for the control of the magnitude and direction of the feeding action of a cloth feeder, the microcomputer is connected, via a buffer and a D/A converter, to the non-inverting input of a comparator which controls the turn-on and turn-off as well as the current intensity of each phase winding of the step motor and whose inverting input is connected to a discriminating element disposed in the phase circuit, for the step setting correction and for the torque intensification of the step motor. To adapt the correction possibilities to the step motor parameters, the D/A converter has four input stages whose biggest stage is connected to the corresponding output stage of the buffer via a voltage divider.