The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 26, 1996
Filed:
Apr. 25, 1995
Roderick G Brown, Nottingham, GB;
Druck Limited, , GB;
Abstract
A pressure controller of the type using pulse width modulated apply and release solenoid valves (80, 82) connected to an outlet port (74) of the controller overcomes the technical problem of poor control stability by using a digital control loop (98, 100, 76, 78) which utilizes stored bias characteristics representing the variation with pressure of the value (n.sub.o) of the pulse width modulation signal at which each valve initiates flow (n.sub.o). These values are determined in a characterisation step conducted with the controller off-line. The values may be modified during on-line operation of the controller by monitoring the stability of the controller or other signals representing the opening and closing of the valves.