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:
Feb. 11, 1997
Filed:
Nov. 23, 1994
John F Curtis, Brighton, GB;
Bhalchandra V Jayawant, Kingston near Lewes, GB;
Raymond J Whorlow, Brighton, GB;
British Nuclear Fuels plc, Warrington, GB;
Abstract
An apparatus for monitoring the inductance of a coil (L1) which is not part of a resonant circuit including a second coil (L2) connected in series with the first mentioned coil and a resonant circuit which is formed by connection of a capacitor (C5) to the second coil, or optionally (C2) to a third coil (L3) which is in a mutually inductive relationship with the second coil so that the second and third coils act as the primary and secondary coils of a transformer (M), a device (1) for injecting into the circuit containing the first mentioned and second coils an a.c. signal of substantially constant peak voltage amplitude having a frequency within the resonance peak of the resonant circuit, and an amplitude detector (5) for measuring the amplitude of the voltage across a component of the resonant circuit. The apparatus may be employed as so-called integral control in closed loop control of the suspension of an object by the first mentioned coil. The output of the amplitude detector in such an arrangement may be applied successively to an error detector (7) and integrator (9).