ANORDNUNG ZUR BETAETIGUNG EINES STELLGLIEDES.

摘要

The deflection of a final control element (7) is proportional to the current applied to it. A controller (1) has a working mode in which the signal produced by a setpoint generator (2) is converted into a proportional current. The controller pref. has a mode switch (18) and a microprocessor (13) is pref. connected between the controller and the setpoint generator. The microprocessor sends a switching signal to the switch if an actual-value generator (6) or associated wiring is defective if the actual value fed to the processor exhibits more than a set difference from the setpoint for longer than a set time. Pref. the controller is a differential amplifier (15) receiving the setpoint at its noninverting input and the actual value at its inverting input via a resistor (16). A negative feedback resistor (17) can be bridged by means of a transistor (18). A pulse width modulator (9) is fitted between the amplifier output and the final control element.