US3898635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Position measuring transformer
Assignee: International Business Machines Corp
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Filing: 1973-12-20
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Granted: 1975-08-05
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Expires: 1993-12-20
Abstract
Abstract An improved radio frequency transformer apparatus for detecting positional changes between a moving and a fixed element is disclosed. The system operates in the high frequency range (on the order of 5 megahertz) and utilizes a centered tapped pickup coil in conjunction with an elongated primary serpentine coil for detecting the null points in a signal which is inductively coupled to the pickup coil as it passes along the elongated serpentine transmitter coil or primary. The use of the null point as the sensing or trigger point simplifies the circuitry required and reduces the cost involved in building the position detecting transformer. The use of the high frequency signals reduces the size and complexity of circuits and circuit elements and enables the entire primary oscillator and detector amplifiers to be embodied in integrated circuit chips for positioning directly on circuit board apparatus. In addition, this design allows a fairly wide variation in spacing tolerance between the transmitter and the detector coils without inducing positional error indications between the moving and fixed elements. This further reduces the cost by lowering the precision required in constructing the device.
Inventors
- 👤 Robert Wayne Kulterman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:11
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/20; G01D5/204; G01D5/2073; G01D5/22; G01D5/225
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
375 words
A position sensitive transformer device, comprising: a primary inductor means for radiating flux, said primary inductor means comprising a series of uniformly spaced and parallelly disposed electrical conductors, said conductors being connected together in a series circuit; a primary oscillator means for generating high frequency alternating current signals of varying potential relative to a ground potential, said primary oscillator means being connected in parallel with said primary inductor means to complete an electrical circuit therewith; a secondary inductor means for receiving said radiated flux from said primary inductor means, said secondary inductor means comprising a series of uniformly spaced and parallelly disposed electrical conductors, the spacing thereof being equal to the spacing of the conductors of said primary inductor means, said conductors being connected together in a series circuit and further having a center tap located at the mid point of said series connected array of electrical conductors; and a detector and amplifier means for detecting and amplifying electrical signals relative to the electrical ground of said oscillator means, which signals are induced in said secondary inductor means; said detector and amplifier means being connected in parallel with said secondary inductor means to complete an electrical circuit therewith, and with said center tap being referenced to ground potential; said detector and amplifier means further including means for detecting the zero potential level of said induced signals in said secondary inductor means at the amplitude modulated minima of said signals induced in said secondary inductor by the relative motion between said primary inductor means and said secondary inductor means; said primary and secondary inductor means being mounted on adjacent surfaces and positioned parallel to one another and spaced apart by a distance less than said spacing between said conductors of said primary and said secondary inductor means, said primary and secondary inductor mounting surfaces further including means for producing relative movement between said surfaces in a direction of travel perpendicular to said parallelly disposed conductors of said primary and said secondary inductors mounted thereon and parallel to said surfaces on which said inductors are mounted, thereby varying the induction between said primary and secondary inductors and creating an amplitude modulated induced signal in said secondary inductor means during movement thereof relative to said primary inductor means.
Claim 2
Dependent Claim
375 words
A position sensitive transformer device, comprising: a primary inductor means for radiating flux, said primary inductor means comprising a series of uniformly spaced and parallelly disposed electrical conductors, said conductors being connected together in a series circuit; a primary oscillator means for generating high frequency alternating current signals of varying potential relative to a ground potential, said primary oscillator means being connected in parallel with said primary inductor means to complete an electrical circuit therewith; a secondary inductor means for receiving said radiated flux from said primary inductor means, said secondary inductor means comprising a series of uniformly spaced and parallelly disposed electrical conductors, the spacing thereof being equal to the spacing of the conductors of said primary inductor means, said conductors being connected together in a series circuit and further having a center tap located at the mid point of said series connected array of electrical conductors; and a detector and amplifier means for detecting and amplifying electrical signals relative to the electrical ground of said oscillator means, which signals are induced in said secondary inductor means; said detector and amplifier means being connected in parallel with said secondary inductor means to complete an electrical circuit therewith, and with said center tap being referenced to ground potential; said detector and amplifier means further including means for detecting the zero potential level of said induced signals in said secondary inductor means at the amplitude modulated minima of said signals induced in said secondary inductor by the relative motion between said primary inductor means and said secondary inductor means; said primary and secondary inductor means being mounted on adjacent surfaces and positioned parallel to one another and spaced apart by a distance less than said spacing between said conductors of said primary and said secondary inductor means, said primary and secondary inductor mounting surfaces further including means for producing relative movement between said surfaces in a direction of travel perpendicular to said parallelly disposed conductors of said primary and said secondary inductors mounted thereon and parallel to said surfaces on which said inductors are mounted, thereby varying the induction between said primary and secondary inductors and creating an amplitude modulated induced signal in said secondary inductor means during movement thereof relative to said primary inductor means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |