Generation of pulse-width modulated signal for controlling electropneumatic pressure control valves

摘要

The circuit has a drive amplifier 10 coupled to the valve actuator 20 and this is supplied by a voltage Uver and receives the output Uaus of a comparator. The comparator operates on a triangular waveform reference T and the command variation signal delta W. The output is fed back via an impedance converter 30. If the output is the same as the comparator supply Uelek then the feedback is independent of the drive supply Uver. If the output is zero the feedback is also zero