Patent US3576565A successfully refreshed from Google Patents.
US3576565A
Expired / Lapsed
US
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Arrangement for measuring short distances
Assignee: SABA GmbH
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Filing: 1968-10-23
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Granted: 1971-04-27
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Expires: 1988-10-23
Abstract
Abstract A carrier signal is applied to the primary of a transformer whose secondary is center tapped. One end of the secondary winding is connected to an antenna establishing an electric or magnetic field. The other end of the secondary winding is connected to a dummy antenna which compensates for the first antenna impedance before the field established by the antenna is distorted by the target to which the distance is to be measured. When the target enters the field a signal appears at the center tap of the secondary which is amplified, demodulated by a synchronous demodulator keyed by the carrier, again amplified and fed either to an indicating instrument or a motor which serves to rebalance the bridge and whose shaft serves as an indication of the distance to the object. The first above-mentioned amplification is accomplished by a variable gain receiver amplifier, so that the output indication is a linear function of distance to the target.
Inventors
- 👤 Hans Richard Schulz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:52
CPC Classifications
G; G01; G01S; G01S11/00; G01S11/02; G01S11/023
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
131 words
Arrangement for measuring short distances between a given location and a target, comprising in combination, oscillator means for generating a carrier signal having a wave length which is long relative to said distance distance to be measured; signal radiating means located at said given location for establishing a field, said signal radiating means having an operating characteristic which changes upon external distortion of said field caused by said target; balanced bridge means for receiving said carrier signal and generating a control signal varying with said changes in operating characteristic of said signal radiating means; and synchronous demodulator means, keyed by said carrier signal, for furnishing an indicator signal corresponding to said control signal, whereby said indicator signal yields a unidirectional indication of the distance between said given location and said target.
Claim 2
Dependent Claim
131 words
Arrangement for measuring short distances between a given location and a target, comprising in combination, oscillator means for generating a carrier signal having a wave length which is long relative to said distance distance to be measured; signal radiating means located at said given location for establishing a field, said signal radiating means having an operating characteristic which changes upon external distortion of said field caused by said target; balanced bridge means for receiving said carrier signal and generating a control signal varying with said changes in operating characteristic of said signal radiating means; and synchronous demodulator means, keyed by said carrier signal, for furnishing an indicator signal corresponding to said control signal, whereby said indicator signal yields a unidirectional indication of the distance between said given location and said target.
Claim 3
Dependent Claim
84 words
An arrangement as set forth in claim 1, wherein said balanced bridge means comprise transformer means having a primary winding for receiving said carrier signal, and a secondary winding having a center tap and a first and second end terminal; wherein said signal radiating means is connected to said first end terminal; and wherein compensating means, for balancing said bridge in the absence of sAid target are connected to said second end terminal; and wherein said control signal is derived from said center tap.
Claim 4
Dependent Claim
24 words
An arrangement as set forth in claim 1 also comprising receiver amplifier means for amplifying said control signal, thus furnishing an amplified control signal.
Claim 5
Dependent Claim
56 words
An arrangement as set forth in claim 3 also comprising variable gain amplifier means coupled to said receiver amplifier means, for generating a gain control signal for controlling the gain of said receiver amplifier means in such a manner that said amplified control signal varies linearly with the distance of said target from said given location.
Claim 6
Dependent Claim
31 words
An arrangement as set forth in claim 4, wherein said variable gain amplifier means also furnish a second gain control signal for controlling the gain of said variable gain amplifier means.
Claim 7
Dependent Claim
17 words
An arrangement as set forth in claim 4, wherein said indicator means comprise an electromechanical measuring instrument.
Claim 8
Dependent Claim
46 words
An arrangement as set forth in claim 6, wherein said indicator means comprise a motor having a shaft; and means responsive to rotational movement of said shaft for rebalancing said bridge during measurement, the position of said shaft thus yielding an indication of the measured distance.
Claim 9
Dependent Claim
30 words
An arrangement as set forth in claim 1 also comprising differentiating means for differentiating said indicator signal, thus yielding a differentiated indicator signal signifying the rate of change of distance.
Claim 10
Dependent Claim
106 words
An arrangement as set forth in claim 7, wherein said motor is a two-phase motor; also comprising means for generating a modulation signal having a modulation frequency; means for modulating said carrier signal with said modulation frequency prior to application to said balanced bridge means; wherein said synchronous demodulator means yields an indicator signal having said modulation frequency; means for applying indicator signal having said modulation frequency to one phase of said two-phase motor; means for shifting said modulation signal by 90*, thus generating a phase shifted modulation signal; and means for applying said phase shifted modulation signal to the second winding of said two-phase motor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |