Fairchild - Model M25 -Reversing Relay

The Model 25 Reversing Relay is designed for applications requiring an output that equals a manually preset spring load minus a variable signal pressure. This high quality unit combines excellent sensitivity with unusually high flow capacity. The Model 25 is ideally suited for a variety of precision control applications, including converting direct acting valves to reverse action, controlling opposite acting valves from a single transmitter, and cushioning cylinder loads. The basic mathematical expression for the Model 25 is PO = K - PS where PO is output pressure, PS is signal pressure and K is the spring constant.