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.
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Positive and Negative Bias Relay (M14)
Read moreDesigned 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 Model 14 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)
Read moreThe 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. This unit, available in several bias range configurations to meet a variety of output requirements, offers excellent sensitivity and high flow capacity in a small volume. The Fairchild Model 15 Pneumatic Biasing Relay is well suited to a variety of control applications, including range shifting, and tension control, and pressure control from a remote location. 
MultiStage Positive Bias Relay (M85D)
Read moreThe Model 85D MultiStage Biasing Relay is a precision control combining the sensitivity of a precision pressure regulator with positive biasing capability. This compact, pilotoperated device offers unusually high output capacity with minimal air consumption, while providing excellent protection against supply or output pressure variations. The versatile Model 85D is recommended for use in systems requiring precision pressure maintenance and instrument biasing, in dead end service and instrument panel supply applications. The basic mathematical expression for the Fairchild 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)
Read moreThe 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 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.