Patent US5148917A successfully refreshed from Google Patents.
US4027240A
Expired / Lapsed
US
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Protected voltage meter
Assignee: United States Department of the Navy
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Filing: 1975-10-20
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Granted: 1977-05-31
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Expires: 1995-10-20
Abstract
Abstract An electronic meter circuitry for use in detecting an electrical signal vage in an ordnance firing circuit for providing an unidirectional signal to an indicator which shows the presence of the signal voltage. The circuitry utilizes a first limiter to reduce the amplitude of the detected signal to a predetermined level, a bridge rectifier to provide a unidirectional signal and a second limiter to prevent overloading the indicator. A self contained test circuit utilizing a current source and two current limiting resistors is supplied so proper operation of the meter circuitry prior to use may be readily ascertained.
Inventors
- 👤 Robert C. Meade
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 04:55
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/145; G01R19/155; G01R1/00; G01R1/36; G01R19/22
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
139 words
A device for measuring an A.C. or D.C. input signal regardless of polarity comprising: input terminals; a first limiter consisting of two diodes, each connected in parallel and in opposite directions of conductance across the input terminals for limiting amplitude of the input signal; a full-wave bridge rectifier of diode-coupled transistors connected to said first limiter; a second limiter receiving output from the rectifier for protecting a microammeter and consisting of a diode-coupled transistor connected in parallel with said microammeter; a microammeter connected in parallel with the second limiter, said microammeter operating within current ranges defined by the first and second limiters whereby small currents are registered and large currents do not damage the microammeter; and a source of low current test signal connected to said input terminals when testing said device but otherwise electrically insulated from the device.
Claim 2
Independent Claim
139 words
A device for measuring an A.C. or D.C. input signal regardless of polarity comprising: input terminals; a first limiter consisting of two diodes, each connected in parallel and in opposite directions of conductance across the input terminals for limiting amplitude of the input signal; a full-wave bridge rectifier of diode-coupled transistors connected to said first limiter; a second limiter receiving output from the rectifier for protecting a microammeter and consisting of a diode-coupled transistor connected in parallel with said microammeter; a microammeter connected in parallel with the second limiter, said microammeter operating within current ranges defined by the first and second limiters whereby small currents are registered and large currents do not damage the microammeter; and a source of low current test signal connected to said input terminals when testing said device but otherwise electrically insulated from the device.
Claim 3
Dependent Claim
20 words
The device of claim 1 further comprising a resistor connected in series with said microammeter to prevent overloading the microammeter.
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) | 1980-05-30 | 1980-11-29 | 1981-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-30 | 1984-11-29 | 1985-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-30 | 1988-11-29 | 1989-05-31 | $7700.00 | Window Closed / Lapsed |