Abstract: A circuit arrangement for supplying power to control devices in motor vehicles, having a first power supply line, a first ground line, a second power supply line and a second ground line, characterized in that the first ground line and the second ground line can be connected by a controllable switch, and in that a logic circuit closes the switch when the first ground line is faulty or interrupted.

Abstract: A circuit arrangement for supplying power to control devices in motor vehicles, having a first power supply line, a first ground line, a second power supply line and a second ground line, characterized in that the first ground line and the second ground line can be connected by a controllable switch, and in that a logic circuit closes the switch when the first ground line is faulty or interrupted.

Abstract: A stepping motor having independently energizable windings for respectively producing magnetic fields at right angles to each other and directed at the axis of a rotor having a fixed polarity perpendicular to its axis, is operated so that the advance from one step to the next is produced by energizing one winding with a voltage producing a current continuously in one direction, while the voltage applied to the other winding is a rectangularly alternating voltage of a constant period and a gradually changing keying ratio. The roles of the two windings are interchanged between successive steps. A microcomputer for control of the motor has a pulse timing table and a program memory. Two control code memories are provided, one for specifying the direction of current in each of the windings during pulses of a sequence and one for specifying the direction of current in each of the windings during pauses between pulses of a sequence, as well as during an energized interval preceding the beginning of a pulsed step.