EP0323221A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Instantaneous voltage drop detector for DC power source
Assignee: NEC Corp
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Filing: 1988-12-28
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Granted: —
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Expires: 2008-12-28
Abstract
Abstract A device for detecting an instantaneous voltage drop of a DC power source includes first means for producing a low-level signal having a duration associated with a period of time in which a voltage of the power source remains lower than a predetermined level, and a high-level signal having a duration associated with a period of time in which the voltage of the power source remains higher than the predetermined level; second means for performing a discharging operation based on a first time constant in response to the low-level signal and a charging operation based on a second time constant smaller than the first time constant in response to the high-level signal, the second means producing a first signal having levels which are individually associated with the charging operation and the discharging operation; and third means for detecting that the voltage of the power source has become lower than the predetermined level by comparing the level of the first signal with a reference voltage level.
Inventors
- 👤 Motoyoshi Komoda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 21:26
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/165; G01R19/16533; G01R19/16538; G01R19/16542
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
165 words
A device for detecting an instantaneous voltage drop of a DC power source, comprising: first means for producing a low-level signal having a duration associated with a period of time in which a voltage of said power source remains lower than a predetermined level, and a high-level signal having a duration associated with a period of time in which the voltage of said power source remains higher than said predetermined level; second means for performing a discharging operation based on a first time constant in response to said low-level signal and a charging operation based on a second time constant smaller than said first time constant in response to said high-level signal, said second means producing a first signal having levels which are individually associated with said charging operation and said discharging operation; and third means for detecting that the voltage of said power source has become lower than said predetermined level by comparing the level of the first signal with a reference voltage level.
Claim 2
Independent Claim
165 words
A device for detecting an instantaneous voltage drop of a DC power source, comprising: first means for producing a low-level signal having a duration associated with a period of time in which a voltage of said power source remains lower than a predetermined level, and a high-level signal having a duration associated with a period of time in which the voltage of said power source remains higher than said predetermined level; second means for performing a discharging operation based on a first time constant in response to said low-level signal and a charging operation based on a second time constant smaller than said first time constant in response to said high-level signal, said second means producing a first signal having levels which are individually associated with said charging operation and said discharging operation; and third means for detecting that the voltage of said power source has become lower than said predetermined level by comparing the level of the first signal with a reference voltage level.
Claim 3
Dependent Claim
40 words
A device as claimed in claim 1, further comprising fourth means for outputting, in response to outputs of said first and third means, a control signal for commanding a start of a transmitter/receiver which is powered by said power source.
Claim 4
Dependent Claim
17 words
A device as claimed in claim 1, wherein said first means comprises a reset signal generating circuit.
Claim 5
Dependent Claim
16 words
A device as claimed in claim 1, wherein said third means comprises a voltage comparing circuit.
Claim 6
Dependent Claim
17 words
A device as claimed in claim 2, wherein said transmitter/receiver comprises a transmitter/receiver of a mobile radiotelephone.
Claim 7
Dependent Claim
20 words
A device as claimed in claim 1, wherein said DC power source comprises a battery mounted on a motor vehicle.
Claim 8
Independent Claim
151 words
A device for detecting an instantaneous voltage drop of a DC power source, comprising: a reset signal generating means for generating a reset signal by detecting a drop of a voltage of said power source below a predetermined level and clearing said reset signal by sensing a rise of the voltage of said power source above said predetermined level; a charging and discharging means for determining a period of time during which the voltage of said power source remains lower than said predetermined level; first means for charging said charging and discharging means when said reset signal is produced; second means for comparing a voltage of said charging and discharging means with a predetermined reference voltage when said reset signal is cleared and memorizing a result of the comparison; and third means for rapidly charging said charging and discharging means after said second means has memorized the result of the comparison.
Claim 9
Independent Claim
151 words
A device for detecting an instantaneous voltage drop of a DC power source, comprising: a reset signal generating means for generating a reset signal by detecting a drop of a voltage of said power source below a predetermined level and clearing said reset signal by sensing a rise of the voltage of said power source above said predetermined level; a charging and discharging means for determining a period of time during which the voltage of said power source remains lower than said predetermined level; first means for charging said charging and discharging means when said reset signal is produced; second means for comparing a voltage of said charging and discharging means with a predetermined reference voltage when said reset signal is cleared and memorizing a result of the comparison; and third means for rapidly charging said charging and discharging means after said second means has memorized the result of the comparison.
Claim 10
Dependent Claim
48 words
A device as claimed in claim 7, further comprising fourth means for producing, in response to an output of said reset signal generating means and an output of said third means, a control signal for commanding a start of a transmitter/receiver which is powered by said power source.
References Cited (Backward Citations)
No citation records indexed.
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