Abstract: A transmission control system consists essentially of two actuating cylinders, a pressure supply system, a controllable valve system for connecting the actuating cylinders to the pressure supply system, and an electrical control system for actuating the controllable valve system. In order to create a compact control system unit, the controllable valve system, at least part of the pressure supply system, and the electrical control system are all combined into a single integrated component. Alternatively, the actuating cylinders may also be included within the single component.

Abstract: A method and apparatus for the recognition of an armature drop off in an electromagnetically actuated device supplies an on/off controlled switching current to the solenoid coil of the device. A high level of current is caused to flow through the coil for attracting the armature, and reduced level of current is applied to the coil for holding the solenoid armature in its on position. If the armature should be caused to drop off from its on position by a mechanical shock, a transitory expansion in the period of the switching current occurs, due to the sudden decrease in magnetic circuit inductance. This increased switching current period is detected and compared to a predetermined threshold value. If the detected period exceeds the threshold value, it is recognized as an armature drop off, and corrective action can be taken immediately. An alternate embodiment detects a sudden increase in the holding current amplitude as an indicator of armature drop off.

Abstract: A method and apparatus for the recognition of the state of a solenoid valve supplies an on/off control switching current to the coil of the solenoid valve. A high level of current is caused to flow through the coil for switching the device on, and a reduced level of current is applied to the coil for holding the solenoid armature in its on position. If the armature should be caused to drop off from its on position by a mechanical shock, an increase in the frequency of the switching current occurs, due to the decrease in magnetic circuit inductance. This frequency increase is detected and compared to a predetermined threshold value. If the detected frequency exceeds the threshold value, it is recognized as an armature drop off, and corrective action can be taken immediately.