US3852667A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Probe for electrostatic voltmeter
Assignee: Trek Inc
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Filing: 1973-05-10
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Granted: 1974-12-03
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Expires: 1993-05-10
Abstract
Abstract A probe or sensor for an electrostatic voltmeter including a voltage sensitive electrode which is vibrated or oscillated within a housing and in a direction to vary the amount of a surface of the electrode which is exposed through an opening or viewing aperture in the housing to an external electrical potential being measured. The electrode is connected to one tine of a tuning fork which is oscillated or vibrated when a driving signal is applied to a piezoelectric transducer on the fork. An electrical conductor which connects the electrode to the voltmeter circuitry is provided with an electrically driven shield, and a reference potential is applied to the housing surface surrounding the viewing aperture, to enhance the accuracy of measurement.
Inventors
- 👤 B Williams
- 👤 C Hare
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:32
CPC Classifications
G; G01; G01R; G01R29/00; G01R29/24; G01R1/00; G01R1/02; G01R1/06; G01R1/067; G01R1/07; G01R5/00; G01R5/28
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
180 words
A sensor for an electrostatic voltmeter comprising: a. a housing including an operative surface having an opening therein; b. a voltage sensitive electrode having an operative surface disposed toward said opening; and c. vibrator means in said housing to vibrate said electrode in a direction generally transversely of said opening to vary the amount of said electrode operative surface which is exposed through said opening to an external electrical field or potential being measured, said vibrator means comprising a generally elongated element having a resonant mechanical vibration characteristic, electro-mechanical driver means adapted to be converted to an electrical signal source and operatively connected to said element adjacent one end thereof and means to connect said electrode to said element adjacent the other end thereof; d. whereby the capacitive coupling between said electrode operative surface and the external field or potential being measured is varied as a function of the rate of vibration of said electrode whereby an alternating voltage is induced on said electrode having an amplitude proportional to the amplitude of the external electricAl field or potential being measured.
Claim 2
Dependent Claim
180 words
A sensor for an electrostatic voltmeter comprising: a. a housing including an operative surface having an opening therein; b. a voltage sensitive electrode having an operative surface disposed toward said opening; and c. vibrator means in said housing to vibrate said electrode in a direction generally transversely of said opening to vary the amount of said electrode operative surface which is exposed through said opening to an external electrical field or potential being measured, said vibrator means comprising a generally elongated element having a resonant mechanical vibration characteristic, electro-mechanical driver means adapted to be converted to an electrical signal source and operatively connected to said element adjacent one end thereof and means to connect said electrode to said element adjacent the other end thereof; d. whereby the capacitive coupling between said electrode operative surface and the external field or potential being measured is varied as a function of the rate of vibration of said electrode whereby an alternating voltage is induced on said electrode having an amplitude proportional to the amplitude of the external electricAl field or potential being measured.
Claim 3
Dependent Claim
31 words
Apparatus according to claim 1, wherein said electrode operative surface is disposed in a plane substantially parallel to the plane of said opening and said electrode is vibrated in said plane.
Claim 4
Dependent Claim
41 words
Apparatus according to claim 1, wherein said electrode is moved between a position where a minimum portion of said electrode surface is exposed to a position where a maximum portion of said electrode surface is exposed during each vibratory cycle thereof.
Claim 5
Dependent Claim
49 words
Apparatus according to claim 1, wherein said electrode is moved between a position where said electrode surface is out of registry with the area of said opening to a position where said electrode surface is in registry with the entire area of said opening during each vibratory cycle thereof.
Claim 6
Dependent Claim
42 words
Apparatus according to claim 1, wherein said housing operative surface is of a material capable of holding an electrical potential, and further including means to apply a reference potential substantially equal to the electrical potential bring measured to said housing operative surface.
Claim 7
Dependent Claim
68 words
Apparatus according to claim 1, further including: a. insulated electrical conductor means for connecting said electrode to circuit means for providing an indication of the magnitude of the electrical potential being measured; b. a shield surrounding said conductor and being of a material capable of holding an electrical potential; and c. means to apply a signal substantially identical to the signal induced on said electrode to said shield.
Claim 8
Dependent Claim
173 words
A sensor for an electrostatic voltmeter comprising: a. a housing including an operative surface having an opening therein; b. a voltage sensitive electrode having an operative surface disposed toward said opening; and c. vibrator means in said housing to vibrate said electrode in a direction generally transversely of said opening to vary the amount of said electrode operative surface which is exposed through said opening to an external electrical field or potential being measured, said vibrator means comprising a tuning fork, means to connect a tine of said tuning fork to said electrode, and piezoelectric means mechanically connected to said tuning fork and adapted to be connected to an electrical signal source for oscillating said tuning fork; d. whereby the capacitive coupling between said electrode operative surface and the external field or potential being measured is varied as a function of the rate of vibration of said electrode whereby an alternating voltage is induced on said electrode having an amplitude proportional to the amplitude of the external electrical field or potential being measured.
Claim 9
Dependent Claim
173 words
A sensor for an electrostatic voltmeter comprising: a. a housing including an operative surface having an opening therein; b. a voltage sensitive electrode having an operative surface disposed toward said opening; and c. vibrator means in said housing to vibrate said electrode in a direction generally transversely of said opening to vary the amount of said electrode operative surface which is exposed through said opening to an external electrical field or potential being measured, said vibrator means comprising a tuning fork, means to connect a tine of said tuning fork to said electrode, and piezoelectric means mechanically connected to said tuning fork and adapted to be connected to an electrical signal source for oscillating said tuning fork; d. whereby the capacitive coupling between said electrode operative surface and the external field or potential being measured is varied as a function of the rate of vibration of said electrode whereby an alternating voltage is induced on said electrode having an amplitude proportional to the amplitude of the external electrical field or potential being measured.
Claim 10
Dependent Claim
33 words
Apparatus according to claim 7, wherein said means to connect said tuning fork tine to said electrode comprises a reed member disposed so as to be relatively stiff in the direction of vibration.
Claim 11
Dependent Claim
33 words
Apparatus according to claim 7, wherein said means to connect said tuning fork tine to said electrode comprises a reed member disposed so as to be relatively flexible in the direction of vibration.
Claim 12
Dependent Claim
25 words
Apparatus according to claim 9, wherein said reed member has a mechanical resonant frequency substantially equal to the mechanical resonant frequency of said tuning fork.
Claim 13
Dependent Claim
28 words
Apparatus according to claim 1 wherein said housing is elongated and said operative surface is at one end thereof generally perpendicular to the longitudinal axis of said housing.
Claim 14
Dependent Claim
30 words
Apparatus according to claim 1, wherein said housing is elongated and said operative surface is on a side thereof and disposed generally parallel to the longitudinal axis of said housing.
Claim 15
Dependent Claim
56 words
Apparatus according to claim 1, further including means in said housing for defining a path for light or other radiation to travel from the interior of said housing through said opening in said housing operative surface whereby the electrical field or potential of an external surface sensitive to said light or other radiation can be measured.
Claim 16
Dependent Claim
59 words
Apparatus accordinG to claim 1, further including another opening in a surface of said housing spaced from said operative surface, said openings being at least partially in alignment, whereby light or other radiation from an external source can be directed through said housing and onto an external surface which gives rise to an electrical field or potential when irradiated.
Claim 17
Dependent Claim
55 words
Apparatus according to claim 1, wherein the initial or rest position of said electrode is where said electrode surface is in registry with said opening and wherein said vibrator means moves said electrode surface into and out of exposure through said opening to said external electrical field or potential twice during each vibratory cycle thereof.
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) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |