Patent EP0601515A1 successfully refreshed from Google Patents.
EP0601515A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Oscillation circuit
Assignee: NEC Corp
•
Filing: 1993-12-06
•
Granted: —
•
Expires: 2013-12-06
Abstract
Abstract An oscillation circuit using a quartz oscillator. When the output level of the oscillation circuit falls, the reactance of the quartz oscillator is changed such that the circuit oscillates at a frequency which reduces the resistance of the oscillator. Hence, the oscillation of the circuit does not fall in level or does not stop without regard to temperature and other ambient conditions.
Inventors
- 👤 Shinichi C/O Nec Corporation Miyazaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 17:20
CPC Classifications
H; H03; H03B; H03B5/00; H03B5/30; H03B5/32; H03B5/36; H03B5/366; H03B5/368; H03B2200/00; H03B2200/0002; H03B2200/0008; H03B2200/003; H03B2200/004; H03B2200/006; H03B2200/0066; H03B2201/00; H03B2201/02; H03B2201/0208
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
70 words
An oscillation circuit comprising: a resonance circuit including a quartz oscillator; an active circuit for driving said quartz oscillator; a variable impedance circuit connected to said resonance circuit for changing a reactance of said quartz oscillator; a detecting circuit for detecting an output level of said active circuit; and an impedance control circuit for controlling said variable impedance circuit in response to an output level detected by said detecting circuit.
Claim 2
Dependent Claim
37 words
A circuit as claimed in claim 1, wherein said impedance control circuit controls, when the output level detected by said detecting circuit falls, said variable impedance circuit such that an equivalent resistance of said quartz oscillator decreases.
Claim 3
Dependent Claim
25 words
A circuit as claimed in claim 1 or 2, wherein said variable impedance circuit comprises a varactor diode connected in series with said quartz oscillator.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.