Pressure transducer regulator system of high accuracy - operates with analogue to digital conversion prior to servo-control function

摘要

The differential pressure transducer and controller comprises a pressure-frequency transducer (2) within a pressure vessel whose pressure is to be regulated. The output frequency is passed to a Schmidt trigger and the pulse counted. A high-frequency oscillator supplied a second counter which is triggered by a carry signal from the first counter. The output of the counter circuit is connected to an inverter (5) and comparator (6). A second input to the comparator is derived from a pre-settable counter (9). The comparator output drives a digital-analogue converter (12) and switch (13) connected to a servo-amplifier (14) to give a resolution of 39m V/bit to drive a servo motor (15).