US3872385A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fixture for measuring parameters of quartz crystal units
Assignee: KABUSAI DENSHIN DENWA KABUSHIK
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Filing: 1974-03-05
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Granted: 1975-03-18
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Expires: 1994-03-05
Abstract
Abstract The present invention discloses a method and fixtures for measuring parameters of quartz crystal units in the very high frequency (VHF) range. A non-reactive frequency and resistance of the crystal unit are determined, a radio-frequency voltage is applied to a series circuit composed of said crystal unit and a circuit which is adjustable to non-reactive resistance, the phase of the terminal voltage across said circuit which is adjustable to non-reactive resistance is adjusted so as to coincide with the phase of the terminal voltage across said series circuit. Next, said crystal unit is replaced by another crystal unit, and the frequency of said radio-frequency voltage is adjusted so that the above-mentioned two phases coincide. Thus the non-reactive frequencies and or resistances of a plurality of crystal units are quickly determined.
Inventors
- 👤 Issac Koga
- 👤 Shigeo Kobayashi
- 👤 Isao Okamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:28
CPC Classifications
G; G01; G01R; G01R29/00; G01R29/22; G01R1/00; G01R1/02; G01R1/06; G01R1/067; G01R1/073; G01R1/07307
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
234 words
A fixture for measuring parameters of crystal units comprising a. two pairs of sockets, the first pair being adapted for inserting a crystal unit (say A) which may be freely selected from a plurality of crystal units to be tested and a crystal unit (say C) which is selected from the remainder of said plurality of crystal units, alternately, the second pair being adapted for inserting probetips of voltmeters thereinto, the first sockets of said two pairs are directly coupled together, the second sockets of said two pairs are directly coupled together; b. two probe receptacles which are connected to each other with a wedge shaped copper plate, and when probe sheaths are inserted into said receptacles, the probe-tips thereof are inserted into the sockets of second pair; c. a circuit (say B) which is composed of a resistor in parallel with a variable capacitor (Cn), the first terminal of the circuit B being connected to said second sockets, the second terminal of the circuit B being connected to junction points of said two probe receptacles; d. a large flat plate of copper whereto said wedge shaped copper plate, said probe receptacles and said second terminal of said circuit B are coupled for equalizing their potentials, and; e. a connector for supplying a radio frequency current from a radio frequency source to the crystal unit to be tested which is inserted into the sockets.
Claim 2
Dependent Claim
234 words
A fixture for measuring parameters of crystal units comprising a. two pairs of sockets, the first pair being adapted for inserting a crystal unit (say A) which may be freely selected from a plurality of crystal units to be tested and a crystal unit (say C) which is selected from the remainder of said plurality of crystal units, alternately, the second pair being adapted for inserting probetips of voltmeters thereinto, the first sockets of said two pairs are directly coupled together, the second sockets of said two pairs are directly coupled together; b. two probe receptacles which are connected to each other with a wedge shaped copper plate, and when probe sheaths are inserted into said receptacles, the probe-tips thereof are inserted into the sockets of second pair; c. a circuit (say B) which is composed of a resistor in parallel with a variable capacitor (Cn), the first terminal of the circuit B being connected to said second sockets, the second terminal of the circuit B being connected to junction points of said two probe receptacles; d. a large flat plate of copper whereto said wedge shaped copper plate, said probe receptacles and said second terminal of said circuit B are coupled for equalizing their potentials, and; e. a connector for supplying a radio frequency current from a radio frequency source to the crystal unit to be tested which is inserted into the sockets.
Claim 3
Dependent Claim
238 words
A fixture for measuring parameters of crystal units comprising a. two pairs of sockets, the first pair being adapted for inserting a crystal unit to be tested and a connecting piece, alternately, the second pair being adapted for inserting probetips of voltmeters thereinto; the first sockets of said two pairs are directly coupled together; the second sockets of said two pairs are directly coupled together; b. two probe receptacles which are connected to each other with a wedge shaped copper plate, and when probe sheaths are inserted into said receptacles, the pobe-tips thereof are inserted into the sockets of second pair; c. a circuit (say B) which is composed of coil Ld and an ajustable capacitor Cd which is connected in series with said coil, the first terminal of the circuit B being connected to said second sockets, the second terminal of the circuit B being connected to the junction points of said two probe receptacles; a connector for connecting the probe tip of a voltmeter to the terminal of said adjustable capacitor Cd by means of a suitable adapter; d. a large flat plate of copper whereto said wedge shaped copper plate, said probe receptacles and said second terminal of said circuit B are coupled for equalizing their potentials, and e. a connector for supplying a radio frequency current from a radio frequency source to the crystal unit to be tested which is inserted into the sockets.
Claim 4
Dependent Claim
238 words
A fixture for measuring parameters of crystal units comprising a. two pairs of sockets, the first pair being adapted for inserting a crystal unit to be tested and a connecting piece, alternately, the second pair being adapted for inserting probetips of voltmeters thereinto; the first sockets of said two pairs are directly coupled together; the second sockets of said two pairs are directly coupled together; b. two probe receptacles which are connected to each other with a wedge shaped copper plate, and when probe sheaths are inserted into said receptacles, the pobe-tips thereof are inserted into the sockets of second pair; c. a circuit (say B) which is composed of coil Ld and an ajustable capacitor Cd which is connected in series with said coil, the first terminal of the circuit B being connected to said second sockets, the second terminal of the circuit B being connected to the junction points of said two probe receptacles; a connector for connecting the probe tip of a voltmeter to the terminal of said adjustable capacitor Cd by means of a suitable adapter; d. a large flat plate of copper whereto said wedge shaped copper plate, said probe receptacles and said second terminal of said circuit B are coupled for equalizing their potentials, and e. a connector for supplying a radio frequency current from a radio frequency source to the crystal unit to be tested which is inserted into the sockets.
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) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |