Patent ID: 7505818

Claim:
An automatic control system for converting an input x to a pressure P, the system comprising: an input for inputting an input signal representing a value x, wherein the input signal is a current; a first valve including a movable element responsible for regulating pressure, wherein the movable element is operable to be moved only between fully open and fully closed positions wherein the movable element is biased against and physically supported by a structure in the first valve and is not throttled to a partially open positions, such that no substantial pressure variation is sensed in switching between the positions, and wherein the movable element comprises at least one of a valve leaf and valve diaphragm responsible for regulating pressure through the first valve; a second valve in fluid communication with the first valve and configured to relieve pressure in order to open the first valve by venting fluid through a vent port that is not connected to an output of a pressure regulator; a pressure sensor configured to sense output pressure P of the first valve; a valve controller configured to control the output pressure P provided by the first valve based on the input signal and the output pressure P by moving the first valve only between the two positions without throttling the first valve to intermediate positions, wherein no substantial pressure variation is sensed in switching between positions; and a controlled valve of an automation device configured to control fluid flow, wherein the controlled valve is controlled according to the output pressure P provided by the first valve.