초록 ▼

A valve control system for positioning a valve in response to a command signal. The valve control system comprises a sensor for detecting the position of the valve and for generating an outer feedback signal, a valve location command circuit for comparing the command signal to the outer feedback sig

A valve control system for positioning a valve in response to a command signal. The valve control system comprises a sensor for detecting the position of the valve and for generating an outer feedback signal, a valve location command circuit for comparing the command signal to the outer feedback signal to generate a correction signal, an actuator for positioning the valve in response to pneumatic pressure, a spool slidably disposed within a block to direct pneumatic pressure to the actuator, a spool positioning device for moving the spool to a desired position, a spool sensor for detecting the current position of the spool and generating an inner feedback signal, and a spool location command for comparing the correction signal to the inner feedback signal to generate a spool positioning signal to direct the spool positioning device to move the spool to the desired position.

대표청구항 ▼

[ What is claimed is:] [1.] A spool control system for positioning a spool in response to a correction signal, the spool being slidably disposed within a block to direct pneumatic pressure and the correction signal being an electrical signal whose level represents the desired position of the spool,

[ What is claimed is:] [1.] A spool control system for positioning a spool in response to a correction signal, the spool being slidably disposed within a block to direct pneumatic pressure and the correction signal being an electrical signal whose level represents the desired position of the spool, the spool control system comprisingspool sensor means for detecting the present position of the spool and generating an electrical inner feedback signal whose level represents the present position of the spool,spool movement command means for comparing a received correction signal to the inner feedback signal to generate an electrical spool positioning signal,spool positioning means responsive to the spool positioning signal for moving the spool within the block a distance represented by the spool positioning signal,a means for periodically supplying power to the stool sensor means to enable periodic sensing of the present position of the spool, anda sample and hold circuit operative to maintain the level of the inner feedback signal between periodic samples.