US3824459A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of measuring the electrostatic capacity of a capacitor
Assignee: Iwatsu Electric Co Ltd
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Filing: 1973-09-17
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Granted: 1974-07-16
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Expires: 1993-09-17
Abstract
Abstract This invention pertains to an invention for measuring the electrostatic capacity of a capacitor and comprises three processes. The first process is the application of a fixed voltage to both a capacitor to be measured and a standard capacitor; the second process is the discharging of the electric charges of the standard capacitor during the time a counter counts from O to n and then obtaining the terminal voltage Vs of the standard capacitor; the third process is the discharging of the electric charges of the capacitor to be measured during the time a terminal voltage of the capacitor to be measured changes from said fixed voltage to the voltage Vs and then obtaining a count m counted during this time. At the conclusion of the third process the electrostatic capacity of the capacitor to be measured is obtained according to a ratio between said counts m and n and an electrostatic capacity of said standard capacitor.
Inventors
- 👤 K Uchida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:35
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/02; G01R27/26; G01R27/2605; G01R31/00; G01R31/50; G01R31/64
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
177 words
A method of measuring the electrostatic capacity of a capacitor to be measured including: applying a fixed voltage during a first interval to a standard capacitor and to said capacitor being measured, respectively, whereby the terminal voltages of the standard capacitor and the capacitor being measured respectively reach the fixed voltage at the end of the first interval; discharging the electric charge of said standard capacitor during a second interval of predetermined time duration and the terminal voltage at one terminal of said standard capacitor at the end of the second interval is held; discharging the electric charge of the capacitor being measured during a third interval, and measuring the duration of time in which the terminal voltage of the capacitor being measured changes from said fixed voltage to said held terminal voltage, whereby the electrostatic capacity of the capacitor being measured is provided according to the electrostatic capacity of the standard capacitor, the duration of time of said predetermined time duration during said second interval and said duration of time being measured during said third interval.
Claim 2
Independent Claim
177 words
A method of measuring the electrostatic capacity of a capacitor to be measured including: applying a fixed voltage during a first interval to a standard capacitor and to said capacitor being measured, respectively, whereby the terminal voltages of the standard capacitor and the capacitor being measured respectively reach the fixed voltage at the end of the first interval; discharging the electric charge of said standard capacitor during a second interval of predetermined time duration and the terminal voltage at one terminal of said standard capacitor at the end of the second interval is held; discharging the electric charge of the capacitor being measured during a third interval, and measuring the duration of time in which the terminal voltage of the capacitor being measured changes from said fixed voltage to said held terminal voltage, whereby the electrostatic capacity of the capacitor being measured is provided according to the electrostatic capacity of the standard capacitor, the duration of time of said predetermined time duration during said second interval and said duration of time being measured during said third interval.
Claim 3
Independent Claim
226 words
An apparatus for measuring the electrostatic capacity of a capacitor comprising: a fixed voltage supply; a standard capacitor to which the fixed voltage of said fixed voltage supply is applied; a first switching means through which the fixed voltage of said fixed voltage supply is applied to the standard capacitor; a second switching means through which the fixed voltage of said fixed voltage supply is applied to the capacitor being measured; a third switching means with which a first resistor is connected in series and which series connection is bridged to the standard capacitor; a second resistor which is bridged to the capacitor being measured; a comparator having a first input which is connected to the standard capacitor and a second input which is connected to the capacitor being measured; a counter with which an output of said comparator is connected and which counts pulses from a pulse generator during selected intervals; a control circuit with which said output of said comparator is also connected and which controls the duration of said selected interval and also controls said first, second and third switching means to be conductive or non-conductive according to a predetermined sequence; whereby the electrostatic capacity is provided by counts counted by the counter during said selected intervals, the resistances of said first and second resistor and the electrostatic capacity of the standard capacitor.
Claim 4
Independent Claim
226 words
An apparatus for measuring the electrostatic capacity of a capacitor comprising: a fixed voltage supply; a standard capacitor to which the fixed voltage of said fixed voltage supply is applied; a first switching means through which the fixed voltage of said fixed voltage supply is applied to the standard capacitor; a second switching means through which the fixed voltage of said fixed voltage supply is applied to the capacitor being measured; a third switching means with which a first resistor is connected in series and which series connection is bridged to the standard capacitor; a second resistor which is bridged to the capacitor being measured; a comparator having a first input which is connected to the standard capacitor and a second input which is connected to the capacitor being measured; a counter with which an output of said comparator is connected and which counts pulses from a pulse generator during selected intervals; a control circuit with which said output of said comparator is also connected and which controls the duration of said selected interval and also controls said first, second and third switching means to be conductive or non-conductive according to a predetermined sequence; whereby the electrostatic capacity is provided by counts counted by the counter during said selected intervals, the resistances of said first and second resistor and the electrostatic capacity of the standard capacitor.
Claim 5
Dependent Claim
42 words
An apparatus according to claim 2, wherein a fourth switching means is connected in series with sAid second resistor and said control circuit controls said first, second, third and fourth switching means to be conductive or non-conductive according to another predetermined sequence.
Claim 6
Dependent Claim
20 words
An apparatus according to claim 2, wherein a bias voltage supply is connected in series with the capacitor being measured.
Claim 7
Dependent Claim
20 words
An apparatus according to claim 3, wherein a bias voltage supply is connected in series with the capacitor being measured.
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) | 1977-07-15 | 1978-01-14 | 1978-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-15 | 1982-01-14 | 1982-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-15 | 1986-01-14 | 1986-07-16 | $7700.00 | Window Closed / Lapsed |