US3810014A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Measuring instrument
Assignee: ABB Training Center GmbH and Co KG
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Filing: 1972-11-20
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Granted: 1974-05-07
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Expires: 1992-11-20
Abstract
Abstract A variable is monitored and indicated by a measuring instrument incorporated in a circuit that uses the instrument for setting and adjustment of the reference input to be used later as trigger level. The reference is supplied to the first input of a differential amplifier while the variable is supplied to the second input of the amplifier. The output of the amplifier is connected with a reversing switch which in its one switching position couples the output to a tripping or triggering stage, possibly including a relay, and in the other one of its switching positions the output is coupled to the second input of the amplifier, so that the instrument actually indicates the reference value rather than the variable.
Inventors
- 👤 H Goldner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:22
CPC Classifications
G; G05; G05B; G05B1/00; G05B1/01; G05B1/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
255 words
Apparatus for monitoring and supervising an electrical signal representing a variable comprising: a differential high-gain amplifier having a first, noninverting input, a second, inverting input, and an output; adjustable means for providing an adjustable and predeterminable reference signal and connected to said first input for applying the reference signal thereto; means for applying said signal representing said variable to said second input, said amplifier providing an output signal representing the difference between the signal representing the variable and the reference signal; a signal measuring and indicating instrument for monitoring the value of the signal applied to said second input, a switch operable at random and being coupled to said amplifier output, said switch having a first switching position and a second switching position; a trigger stage coupled to said switch and connected therewith to the output of the amplifier when said switch is in said first switching position for receiving the output of the amplifier and responding when said difference changes polarity; and d.c. circuit means connecting said output to said measuring and indicating instrument and to said second inverting input of said amplifier in d.c. circuit connection when said switch is in said second position for obtaining a negative feedback configuration for the reference signal independent of the reference signal at said first input, so that upon adjustment of the reference signal, the value of the reference signal, is indicated by the instrument, the adjusted reference signal remaining continually effective on the first input after the switch has been returned to the first position.
Claim 2
Dependent Claim
255 words
Apparatus for monitoring and supervising an electrical signal representing a variable comprising: a differential high-gain amplifier having a first, noninverting input, a second, inverting input, and an output; adjustable means for providing an adjustable and predeterminable reference signal and connected to said first input for applying the reference signal thereto; means for applying said signal representing said variable to said second input, said amplifier providing an output signal representing the difference between the signal representing the variable and the reference signal; a signal measuring and indicating instrument for monitoring the value of the signal applied to said second input, a switch operable at random and being coupled to said amplifier output, said switch having a first switching position and a second switching position; a trigger stage coupled to said switch and connected therewith to the output of the amplifier when said switch is in said first switching position for receiving the output of the amplifier and responding when said difference changes polarity; and d.c. circuit means connecting said output to said measuring and indicating instrument and to said second inverting input of said amplifier in d.c. circuit connection when said switch is in said second position for obtaining a negative feedback configuration for the reference signal independent of the reference signal at said first input, so that upon adjustment of the reference signal, the value of the reference signal, is indicated by the instrument, the adjusted reference signal remaining continually effective on the first input after the switch has been returned to the first position.
Claim 3
Dependent Claim
70 words
Apparatus as in claim 1 wherein the variable is a current flowing through a resistor and the signal measuring and indicating instrument connected in series, a voltage across the resistor being applied to the second input the side of the signal measuring and indicating instrument not connected to the junction being connected to the switch to be coupled to the amplifier output when the switch is in the second position.
Claim 4
Dependent Claim
61 words
Apparatus as in claim 1 wherein the variable is a voltage and the signal measuring and indicating instrument is connected across the voltage, the second input and the switch being connected to one terminal of the instrument so that the voltage is effective on the second input, and tHe amplifier output is connected thereto in the second position of the switch.
References Cited (Backward Citations)
US3070786A
Cited
US3311826A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-06 | 1977-11-05 | 1978-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-06 | 1981-11-05 | 1982-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-06 | 1985-11-05 | 1986-05-07 | $7700.00 | Window Closed / Lapsed |