Biasing Relays Fairchild Industrial Products

Biasing Relays

Positive and Negative Bias Relays are designed for applications that require an output pressure that is the sum of a controlled input signal plus or minus a fixed bias. Fairchild's line up of biasing pneumatic relay products includes both positive biasing relays, such as the Models 15, 85D and 1500A and relays that handle both positive and negative biasing functions such as the Model 14.

Positive and Negative Bias Relay (M14)

Designed for applications that require an output pressure that is the sum of a controlled input signal plus or minus a fixed bias, Fairchild's Model 14 Biasing Pneumatic Relay provides versatility in its ability to provide either positive or negative biasing in a single unit. The output of the relay is the sum of the spring bias, set with the Range Screw, plus a pneumatic input signal. (Po = Ps � K); where Po is output pressure, Ps is signal pressure, and K is the combined spring constant.

Positive Bias Relay (M15)

The Model 15 Positive Bias Relay is designed for applications that require an output pressure that is the sum of a controlled input signal plus a fixed bias. This pneumatic relay provides an output pressure that represents the input signal pressure plus a preset bias. Mathematically Po = Ps + K where Po is output pressure, Ps is signal pressure and K is the spring constant. The Fairchild Model 15 relay, available in several bias range configurations to meet a variety of output requirements, offers excellent sensitivity and high flow capacity in a small volume.

Multi-Stage Positive Bias Relay (M85D)

The Fairchild Model 85D Multi-Stage Biasing Relay is a precision control combining the sensitivity of a precision pressure regulator with positive biasing capability. This compact, pilot-operated device offers unusually high output capacity with minimal air consumption, while providing excellent protection against supply or output pressure variations. The basic mathematical expression for the Model 85D is PO = PS + K where PO is output pressure, PS is signal pressure and K is the spring constant.

High Flow Positive Bias Relay (M1500A)

The Model 1500 Positive Bias Relay is designed for applications that require an output pressure that is the sum of a controlled input signal plus a fixed bias. This pneumatic relay provides high output flow at an output pressure that represents the input signal pressure plus a preset bias. The output of the Fairchild Model 1500A relay is the sum of the spring bias, set with the Range Screw, plus a pneumatic input signal. (Po = Ps + K); where Po is output pressure, Ps is signal pressure, and K is the spring constant set by the Range Screw.