VALVE CONTROL SYSTEM

摘要

A valve control system including a valve body defining a flow control port having flow therethrough controlled by a poppet coupled with a pressure responsive member which forms one wall of a control chamber. Fluid flow through a bleed passage leading from the control chamber is controlled by a pilot valve which is itself controlled by an electric drive means. Current to the electric drive means is controlled by electrical resistance means which is formed with transverse portions disposed in heat exchange relationship with one another and flexible for movement toward and away from one another to adjust the rate of heat exchange between such portions to thereby adjust the mutual heating hereof and vary the overall resistance of such resistance means to control current to the electric drive means.