Pneumatic controller

A pneumatic controller comprising:

• a gas supply inlet;
• a gas outlet;
• a pneumatic relay connected between the inlet and the outlet for selectively relaying a pressurized gas, the relay including a valve controlled by an established pressure in a pilot circuit, the pilot circuit having a pilot gas inlet through which a portion of the pressurized gas enters and a control port through which the portion exits, wherein the pressure is regulated by controlling the amount of gas flow through the control port;
• an inflatable bladder disposed proximate the control port, wherein inflating the bladder restricts the gas flow through the control port, thus increasing the pressure in the pilot circuit, and deflating the bladder allows increased gas flow through the control port, thus decreasing the pressure in the pilot circuit;
• and
• a regulator system for regulating inflation and deflation of the bladder in response to a controlled variable.

A pneumatic controller comprising:

• a gas supply inlet;
• a gas outlet;
• a pneumatic relay connected between the inlet and the outlet for selectively relaying a pressurized gas, the relay including a valve controlled by an established pressure in a pilot circuit, the pilot circuit having a pilot gas inlet through which a portion of the pressurized gas enters and a control port through which the portion exits, wherein the pressure is regulated by controlling the amount of gas flow through the control port;
• an inflatable bladder disposed proximate the control port, wherein inflating the bladder restricts the gas flow through the control port, thus increasing the pressure in the pilot circuit, and deflating the bladder allows increased gas flow through the control port, thus decreasing the pressure in the pilot circuit;
• and
• a regulator system for regulating inflation and deflation of the bladder in response to a controlled variable;
• the pneumatic controller further comprising a sensor that measures the controlled variable in a controlled space and provides an output to the regulator system proportional to the controlled variable,
• wherein the regulator system includes digital controller operatively connected to the sensor and to an electronic microvalve which controls gas low to the bladder.

A pneumatic controller system, comprising:

• sensing means for measuring temperature in a temperature controlled environment and providing an output in proportion to the temperature;
• supply means for supplying a gas under pressure;
• relay means connected to the supply means for selectively relaying the gas to actuate a controlled device responsive to different levels of pressure, the relay means including an input, an output, an exhaust chamber, and a valve configured to regulate the flow of gas from the inlet to the outlet and from the outlet to the exhaust chamber respectively, wherein the valve is controlled by the pressure level in a pilot circuit, the pilot circuit having a pilot inlet into which a portion of the gas flows and a control port through which the portion exits, further wherein increasing resistance to gas flow from the control port increases the pressure in the pilot circuit;
• an inflatable bladder including a control port tap disposed in proximity to the control port, wherein inflation of the bladder moves the control port tap into closer proximity with the control port increasing resistance to gas flow from the control port;
• and
• means for regulating inflation of the bladder in response to the sensing means output.