The P3 is an automatic closed-loop tension controller of advanced design utilizing force transducers to measure web tension. It has a pneumatic output, however all signal processing is done electronically. The output operates a standard pneumatic brake or clutch to control unwind, rewind or intermediate tension zones.
An industrial-duty steel enclosure contains all electrical and pneumatic parts. A large meter on the front displays actual web tension. Two to four (depending on options) circuit cards are installed, and easily removed, using a screwdriver. Each card has identified test jacks and a plug-in terminal strip for easy maintenance. A servo-valve is used to convert the electrical signals to a pneumatic output. It is a valve designed for closed loop control and has been proven extremely reliable over many years of use. Unlike the typical E/ P converter, it has no adjustments and does not need volume or pressure boosters.