US4283676A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct reading capacitance meter
Assignee: United States Department of the Navy
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Filing: 1980-03-06
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Granted: 1981-08-11
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Expires: 2000-03-06
Abstract
Abstract A high capacitance measuring apparatus which provides a direct reading of unknown large capacitor using a voltage comparator, a multi-vibrator flip-flop circuit, and a ramp generator. A timing post which corresponds to one RC time for the capacitor being measured feeds into a ramp generator. The ramp generator output produces an indication on a calibrated meter to give a direct reading.
Inventors
- 👤 Clifford O. Shaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:56
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/02; G01R27/26; G01R27/2605
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
181 words
A device for measuring the value of a capacitor comprising: terminal means for connecting a test capacitor; a voltage divider that receives an initial voltage and transmits a predetermined reference voltage; sensing means connected to the output of said terminal means and to said voltage divider; control means for transmitting a voltage to said sensing means and to said terminal means; switching means for receiving and sending a first signal, and further for receiving and sending a second signal; a ramp generator having a plurality of charging ranges connected to said switching means to receive a first signal and to supply a voltage and further, to receive a second signal and to stop supplying a voltage; a reference capacitor connected to said ramp generator; a capacitance reading meter effectively connected to said reference capacitor; a trigger having a first and a second mode such that in said first mode no voltage is transmitted and in said second mode a voltage is transmitted simultaneously to said switching means and to said control means, wherein the value of a capacitor is directly determined.
Claim 2
Independent Claim
181 words
A device for measuring the value of a capacitor comprising: terminal means for connecting a test capacitor; a voltage divider that receives an initial voltage and transmits a predetermined reference voltage; sensing means connected to the output of said terminal means and to said voltage divider; control means for transmitting a voltage to said sensing means and to said terminal means; switching means for receiving and sending a first signal, and further for receiving and sending a second signal; a ramp generator having a plurality of charging ranges connected to said switching means to receive a first signal and to supply a voltage and further, to receive a second signal and to stop supplying a voltage; a reference capacitor connected to said ramp generator; a capacitance reading meter effectively connected to said reference capacitor; a trigger having a first and a second mode such that in said first mode no voltage is transmitted and in said second mode a voltage is transmitted simultaneously to said switching means and to said control means, wherein the value of a capacitor is directly determined.
Claim 3
Dependent Claim
16 words
The measuring device of claim 1 wherein the voltage divider comprises two resistors of known value.
Claim 4
Dependent Claim
67 words
The measuring device of claim 2 wherein said switching means is a flip-flop comprising at least two transistors that operate in two modes wherein in said first mode, a first transistor is in a non-conducting state and a second transistor is in a conducting state, and in said second mode, said first transistor is in a conducting state and said second transistor is in a non-conducting state.
Claim 5
Dependent Claim
33 words
A measuring device as in claim 3 wherein said plurality of charging ranges are controlled by a manually adjustable, contact switch that connects one of a plurality of resistors to said ramp generator.
Claim 6
Dependent Claim
27 words
A measuring device as in claim 4 wherein an operational amplifier acting as an impedance matching device is connected between said reference capacitor and said capacitance meter.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-10 | 1985-02-09 | 1985-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-10 | 1989-02-09 | 1989-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-10 | 1993-02-09 | 1993-08-11 | $7700.00 | Window Closed / Lapsed |