US3725784A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic calibrating and measuring system
Assignee: Wandel and Golterman GmbH and Co
•
Filing: 1971-06-07
•
Granted: 1973-04-03
•
Expires: 1991-06-07
Abstract
Abstract A system with a test position for measuring the amplitude (or phase) of an incoming signal wave of predetermined frequency is repetitively switched over to a calibrating position in which the system receives a reference oscillation of constant frequency and phase for automatically readjusting its circuits, if necessary. If the input signal disappears or drops below a certain minimum level, a sensing circuit reduces the rate of switchover or arrests the system in test position to reduce wear of the relay contacts employed therefor. A random or quasi-random change in that rate may be utilized to prevent false indications due to the stroboscopic effect of periodic switchover in the presence of a modulating frequency close to the switching rate.
Inventors
- 👤 H Bayer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:02
CPC Classifications
G; G01; G01R; G01R1/00; G01R1/28
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
135 words
A circuit arrangement for giving a calibrated indication of a parameter of an alternating signal voltage of predetermined frequency, comprising: circuit means connectable to a source of signal voltage to be measured; local oscillator means for generating a reference oscillation of said predetermined frequency; indicator means for measuring said parameter; sensing means for varying the transmission characteristic of said circuit means; automatic switchover means for alternately establishing a test position connecting said indicator means through said circuit means to said source and a calibrating position connecting said sensing means through said circuit means to said oscillator means; and threshold means connected to said circuit means for ascertaining the magnitude of said signal voltage in said test position and reducing the rate of operation of said switchover means upon said magnitude falling below a predetermined level.
Claim 2
Dependent Claim
135 words
A circuit arrangement for giving a calibrated indication of a parameter of an alternating signal voltage of predetermined frequency, comprising: circuit means connectable to a source of signal voltage to be measured; local oscillator means for generating a reference oscillation of said predetermined frequency; indicator means for measuring said parameter; sensing means for varying the transmission characteristic of said circuit means; automatic switchover means for alternately establishing a test position connecting said indicator means through said circuit means to said source and a calibrating position connecting said sensing means through said circuit means to said oscillator means; and threshold means connected to said circuit means for ascertaining the magnitude of said signal voltage in said test position and reducing the rate of operation of said switchover means upon said magnitude falling below a predetermined level.
Claim 3
Dependent Claim
137 words
A circuit arrangement for giving a calibrated indication of a parameter of an alternating signal voltage of predetermined frequency, comprising: circuit means connectable to a source of signal voltage to be measured; local oscillator means for generating a reference oscillation of said predetermined frequency; indicator means for measuring said parameter; sensing means for varying the transmission characteristic of said circuit means; automatic switchover means for alternately establishing a test position connecting said indicator means through said circuit means to said source and a calibrating position connecting said sensing means through said circuit means to said oscillator means; and threshold means connected to said circuit means for ascertaining the magnitude of said signal voltage in said test position and arresting the operation of said switchover means in said test position upon said magnitude falling below a predetermined level.
Claim 4
Dependent Claim
137 words
A circuit arrangement for giving a calibrated indication of a parameter of an alternating signal voltage of predetermined frequency, comprising: circuit means connectable to a source of signal voltage to be measured; local oscillator means for generating a reference oscillation of said predetermined frequency; indicator means for measuring said parameter; sensing means for varying the transmission characteristic of said circuit means; automatic switchover means for alternately establishing a test position connecting said indicator means through said circuit means to said source and a calibrating position connecting said sensing means through said circuit means to said oscillator means; and threshold means connected to said circuit means for ascertaining the magnitude of said signal voltage in said test position and arresting the operation of said switchover means in said test position upon said magnitude falling below a predetermined level.
Claim 5
Dependent Claim
149 words
A circuit arrangement for giving a calibrated indication of a parameter of an alternating signal voltage of predetermined frequency, comprising: circuit means connectable to a source of signal voltage to be measured; local oscillator means for generating a reference oscillation of said predetermined frequency; indicator means for measuring said parameter; sensing means controlling said circuit means for varying the transmission characteristic thereof; astable multivibrator means provided with reactive circuitry for establishing a testing interval and a calibration interval alternating in a rhythm determined by the time constant of said circuitry; switch means controlled by said multivibrator means for connecting said indicator means through said circuit means to said source during said testing interval and for connecting said sensing means through said circuit means to said oscillator means during said calibration interval; and a generator of irregularly varying control voltages coupled to said reactive circuitry for altering said time constant.
Claim 6
Dependent Claim
149 words
A circuit arrangement for giving a calibrated indication of a parameter of an alternating signal voltage of predetermined frequency, comprising: circuit means connectable to a source of signal voltage to be measured; local oscillator means for generating a reference oscillation of said predetermined frequency; indicator means for measuring said parameter; sensing means controlling said circuit means for varying the transmission characteristic thereof; astable multivibrator means provided with reactive circuitry for establishing a testing interval and a calibration interval alternating in a rhythm determined by the time constant of said circuitry; switch means controlled by said multivibrator means for connecting said indicator means through said circuit means to said source during said testing interval and for connecting said sensing means through said circuit means to said oscillator means during said calibration interval; and a generator of irregularly varying control voltages coupled to said reactive circuitry for altering said time constant.
Claim 7
Dependent Claim
188 words
A circuit arrangement for giving a calibrated indication of a parameter of an alternating signal voltage of predetermined frequency, comprising; circuit means connectable to a source of signal voltage to be measured; local oscillator means for generating a reference oscillation of said predetermined frequency; indicator means for measuring said parameter; sensing means controlling said circuit means for varying the transmission characteristic thereof; astable multivibrator means provided with reactive circuitry for establishing a testing interval and a calibration interval alternating in a rhythm determined by the time constant of said circuitry; switch means controlled by said multivibrator means for connecting said indicator means through said circuit means to said source during said testing interval and for connecting said sensing means through said circuit means to said oscillator means during said calibration interval; voltage-responsive control means coupled to said reactive circuitry for altering said time constant; and a generator of input voltage including threshold means connected to said circuit means for ascertaining the magnitude of said signal voltage in said test position and actuating said control means to lower said time constant upon said magnitude falling below a predetermined level.
Claim 8
Dependent Claim
188 words
A circuit arrangement for giving a calibrated indication of a parameter of an alternating signal voltage of predetermined frequency, comprising; circuit means connectable to a source of signal voltage to be measured; local oscillator means for generating a reference oscillation of said predetermined frequency; indicator means for measuring said parameter; sensing means controlling said circuit means for varying the transmission characteristic thereof; astable multivibrator means provided with reactive circuitry for establishing a testing interval and a calibration interval alternating in a rhythm determined by the time constant of said circuitry; switch means controlled by said multivibrator means for connecting said indicator means through said circuit means to said source during said testing interval and for connecting said sensing means through said circuit means to said oscillator means during said calibration interval; voltage-responsive control means coupled to said reactive circuitry for altering said time constant; and a generator of input voltage including threshold means connected to said circuit means for ascertaining the magnitude of said signal voltage in said test position and actuating said control means to lower said time constant upon said magnitude falling below a predetermined level.
Claim 9
Dependent Claim
16 words
A circuit arrangement as defined in claim 4 wherein said indicator means comprises an amplitude meter.
Claim 10
Dependent Claim
16 words
A circuit arrangement as defined in claim 4 wherein said indicator means comprises a phase meter.
Claim 11
Dependent Claim
57 words
A circuit arrangement as defined in claim 6 wherein said circuit means includes a phase shifter controlled by said sensing means and a phase comparator following said phase shifter, said switch means comprising contacts interposed between said comparator and said meter, said threshold means comprising a voltage detector connected to said circuit means ahead of said comparator.
Claim 12
Dependent Claim
46 words
A circuit arrangement as defined in claim 4 wherein said switch means comprises at least one pair of relays in series with respective sections of said multivibrator means, said relays being provided with paired contacts respectively making and breaking upon energization of either of said sections.
References Cited (Backward Citations)
US3105230A
Cited
US3196348A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |