US3636448A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal source disconnection-detecting method for plural sources
Assignee: Hitachi Ltd
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Filing: 1970-07-14
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Granted: 1972-01-18
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Expires: 1990-07-14
Abstract
Abstract A disconnection-detecting method used with a system wherein analog voltages from a number of points are scanned so that the analog voltages are amplified by a preamplifier into a predetermined range of voltage levels and are then converted into corresponding digital form, said method characterized in that upon completion of an analog to digital conversion for each point of measurement, a disconnection-detecting voltage is applied to the input of the preamplifier for, on time-sharing basis, a predetermined time duration concurrent with the analog voltage to thereby detect a disconnection in the line.
Inventors
- 👤 Yoshiyuki Nihashi
- 👤 Akira Osawa
- 👤 Hiroshi Kuwahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:50
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/145; G08; G08C; G08C15/00; G08C15/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
93 words
A disconnection-detecting method used with a system wherein analog voltages from a number of points are scanned so that the analog voltages are amplified by a preamplifier into a predetermined range of voltage levels and are then converted into corresponding digital form, said method characterized in that upon completion of an analog to digital conversion for each point of measurement, a disconnection-detecting voltage is applied to the input of the preamplifier for, on time sharing basis, a predetermined time duration concurrent with the analog voltage to thereby detect a disconnection in the line.
Claim 2
Dependent Claim
93 words
A disconnection-detecting method used with a system wherein analog voltages from a number of points are scanned so that the analog voltages are amplified by a preamplifier into a predetermined range of voltage levels and are then converted into corresponding digital form, said method characterized in that upon completion of an analog to digital conversion for each point of measurement, a disconnection-detecting voltage is applied to the input of the preamplifier for, on time sharing basis, a predetermined time duration concurrent with the analog voltage to thereby detect a disconnection in the line.
Claim 3
Dependent Claim
54 words
A disconnection-detecting method according to claim 1 characterized in that the analog voltage is applied to the preamplifier through a filtering capacitor such that a disconnection in the line is detected on the condition that the output of said preamplifier exceeds a predetermined range when the disconnection-detecting voltage is not applied to said preamplifier.
Claim 4
Dependent Claim
57 words
A disconnection-detecting method according to claim 1 characterized in that the analog voltage is directly applied to the preamplifier without the intermediary of a filtering capacitor such that a disconnection in the line is detected on the condition that the output of said preamplifier exceeds a predetermined range when the disconnection-detecting voltage is applied to said preamplifier.
Claim 5
Dependent Claim
38 words
A disconnection-detecting method according to claim 3 characterized in that the value of the preamplifier gain is set to a value corresponding to the maximum level of the analog input voltages only when the disconnection-detecting voltage is applied.
Claim 6
Dependent Claim
29 words
A disconnection-detecting method according to claim 1 characterized in that the disconnection-detecting voltage is applied by changing the resistance value in accordance with the level of the analog voltage.
Claim 7
Dependent Claim
31 words
A disconnection-detecting method according to claim 1 characterized in that a disconnection-detecting voltage corresponding to the level of the analog voltage is selected and applied to the input of the preamplifier.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-17 | 1975-07-19 | 1976-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-17 | 1979-07-19 | 1980-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-17 | 1983-07-19 | 1984-01-18 | $7700.00 | Window Closed / Lapsed |