Abstract: A current regulator for an inductive load especially for a coil of an electromagnetic solenoid valve. The current flow through the coil is regulated and compared by means of an operational amplifying nominal current value. The inductive load comparator is initially controlled by a first conductive diode. A second diode having a higher voltage rating than that of the first diode is rendered conductive whenever the nominal current value in an inductive coil decreases rapidly. The current regulator ensures that the magnetic energy in the inductive load remains unchanged when the nominal current value remains constant or changes in small amounts. When a rapid decrease of the coil current occurs, the second diode is rendered conductive.

Abstract: An electropneumatic door control, particularly for the control of doors in public transportation, which includes for the purpose of detecting the respective position of the door linear motion sensors (1, 2) which are mounted on the pneumatic door cylinders (4, 5) or on the axes of rotation of the door wings, and whose output signals are evaluated by electronics (3). The electronics (3) include a computer which automatically detects the end positions as well as the motion behavior of the door or obstructions, respectively, and triggers a monitoring function, if necessary. The proposed door control increases reliability and eliminates previously used limit switches and electropneumatic differential pressure switches.

Abstract: An electronic control arrangement including a plurality of inputs and outputs, whereby the outputs are controlled in relationship with the inputs according to a predetermined program. Additionally, the outputs are coupled to another input by way of a special-function line. When the control is switched on, the external wiring is called upon to supply information regarding the state of certain controllable circuit elements. Through this, the electronic control circuit automatically checks which one of the several stored programs is appropriate under the circumstance.