EP0124242A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Position transducer
Assignee: Moog Controls Ltd
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Filing: 1984-03-23
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Granted: —
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Expires: 2004-03-23
Abstract
Abstract A servovalve has a sensor for sensing the movement and indicating the position of the valve spool (1). The sensor comprises a ferrite core (5) mounted upon an extension (4) of the spool (1), and a pick-up coil (6) connected into the circuit of a Colpitts oscillator whose output drives, via a voltage limiter, a phase lock loop integrated circuit (IC2). The output of the circuit (IC2) is connected to a phase comparator (IC3) to produce a control signal whose amplitude represents the frequency of oscillation of the oscillator.
Inventors
- 👤 John David Unit 2 Britton
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 17:51
CPC Classifications
G; G05; G05D; G05D3/00; G05D3/12; F; F16; F16K; F16K37/00; F16K37/0025; F16K37/0041
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
64 words
A valve having a spool member and a motor, the movement of said spool member being responsive to electrical signals supplied to said motor, and means for sensing the movement of said spool member, said means including a single pick-up coil, a member of magnetic material mounted for movement with said spool member, and means for sensing changes in the inductance of the coil.
Claim 2
Dependent Claim
64 words
A valve having a spool member and a motor, the movement of said spool member being responsive to electrical signals supplied to said motor, and means for sensing the movement of said spool member, said means including a single pick-up coil, a member of magnetic material mounted for movement with said spool member, and means for sensing changes in the inductance of the coil.
Claim 3
Dependent Claim
35 words
A valve as claimed in claim 1, in which the coil and the member of magnetic material are both arranged to be located in the fluid that is to be controlled by the spool member.
Claim 4
Dependent Claim
27 words
A valve as_claimed in claim 1 or claim 2, in which the member of magnetic material is mounted upon the spool member or on an extension thereof.
Claim 5
Dependent Claim
31 words
A valve as claimed in claim 1 or 2, in which the member of magnetic material is carried by a support separate from and arranged for movement with the spool member.
Claim 6
Dependent Claim
36 words
A valve as claimed in any one of the preceding claims, in which the member of magnetic material is of tubular form, the pick-up coil being mounted coaxially with respect to the member of magnetic material.
Claim 7
Dependent Claim
32 words
A valve as claimed in any one of the preceding claims, in which the sensing means includes an oscillator whose frequency of oscillation is determined by the inductance of the pick-up coil.
Claim 8
Dependent Claim
15 words
A valve as claimed in claim 6, in which the oscillator is a Colpitts oscillator.
Claim 9
Dependent Claim
20 words
A valve as claimed in claim 6 or claim 7, in which the inductance of the pick-up coil is minimal.
Claim 10
Dependent Claim
82 words
A servovalve system including a valve as claimed in any one of claims 6 to 8, frequency-to-voltage conversion means responsive to the oscillation frequency of said oscillator, and summing amplifier means responsive to the output of such conversion means and to a valve command signal, wherein the electrical signal supplied to said motor is derived at least in part from the output of said summing amplifier means so that movement of said valve spool member is responsive to the valve command signal.
References Cited (Backward Citations)
No citation records indexed.
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