POSITION SERVO SYSTEM
A load positioning servo system is comprised of a Servo, ServoJet® or Direct Drive Valve, actuator, position feedback transducer, position command generator, and a Servoamplifier. A typical linear position servo system using a double-ended piston is shown to the right (a rotary position servo system can be created by substituting the appropriate rotary components). The valve’s two output control ports are connected across the load cylinder. In the Servoamplifier, the command input is compared to the present position output of the position transducer. If a difference between the two exists, it is amplified and fed to the valve as an error signal.The signal shifts the valve spool position, adjusting flow to the actuator until the position output agrees with the command input.