US4520289A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drive circuit for a piezo-electric element
Assignee: Omron Corp
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Filing: 1984-05-31
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Granted: 1985-05-28
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Expires: 2004-05-31
Abstract
Abstract A drive circuit for a piezo-electric element includes a blocking oscillator circuit which has a booster transformer with primary and secondary windings, an oscillation transistor the collector of which is connected to the primary winding of the booster transformer, and a biasing circuit via which a signal at the secondary winding of the booster transformer is fed back to the base of the oscillation transistor so as to produce oscillation by positive feedback. This drive circuit also includes an electric current control circuit means for restricting electric current from flowing through the oscillation transistor when the voltage at the secondary winding of the booster transformer has become equal to or greater than a certain value, and a rectifying element through which the piezo-electric element is connected to the secondary winding of the booster transformer. Optionally, there may be further included a discharge transistor means for rapidly discharging electric charge stored in the piezo-electric element when power input to the blocking oscillator circuit is discontinued. This drive circuit may be used in a relay for driving a piezo-electric element which makes and/or breaks contacts for connecting and/or breaking switched circuits.
Inventors
- 👤 Ryuichi Sato
- 👤 Tsutomu Taniguchi
- 👤 Masatoshi Ohba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:01
CPC Classifications
H; H10; H10N; H10N30/00; H10N30/80; H10N30/802
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
128 words
For a piezo-electric element: a drive circuit, comprising: (a) a blocking oscillator circuit comprising a booster transformer with primary and secondary windings, an oscillation transistor the collector of which is connected to the primary winding of said booster transformer, and a feedback circuit via which a signal at the secondary winding of said booster transformer is fed back to the base of said oscillation transistor so as to produce oscillation; (b) an electric current control circuit means for restricting electric current from flowing through said oscillation transistor when the voltage at the secondary winding of said booster transformer has become equal to or greater than a certain value; and (c) a rectifying element through which said piezo-electric element is connected to the secondary winding of said booster transformer.
Claim 2
Dependent Claim
128 words
For a piezo-electric element: a drive circuit, comprising: (a) a blocking oscillator circuit comprising a booster transformer with primary and secondary windings, an oscillation transistor the collector of which is connected to the primary winding of said booster transformer, and a feedback circuit via which a signal at the secondary winding of said booster transformer is fed back to the base of said oscillation transistor so as to produce oscillation; (b) an electric current control circuit means for restricting electric current from flowing through said oscillation transistor when the voltage at the secondary winding of said booster transformer has become equal to or greater than a certain value; and (c) a rectifying element through which said piezo-electric element is connected to the secondary winding of said booster transformer.
Claim 3
Dependent Claim
37 words
A drive circuit for a piezo-electric element, according to claim 1, further comprising a discharge transistor means for rapidly discharging electric charge stored in said piezo-electric element when power input to said blocking oscillator circuit is discontinued.
Claim 4
Dependent Claim
64 words
A drive circuit for a piezo-electric element, according to claim 1, wherein said electrical current control circuit means comprises a control transistor whose collector is connected to said base of said oscillation transistor and a series connection of a diode and a zener diode, said series connection being connected between the base of said control transistor and said secondary winding of said booster transformer.
Claim 5
Dependent Claim
45 words
A drive circuit for a piezo-electric element, according to claim 1, wherein said feedback circuit comprises a series connection of a resistor and a condenser, said series connection being connected between said secondary winding of said booster transformer and said base of said oscillation transistor.
Claim 6
Dependent Claim
19 words
A drive circuit for a piezo-electric element, according to claim 4, wherein said oscillation transistor is a NPN transistor.
Claim 7
Dependent Claim
27 words
A drive circuit for a piezo-electric element, according to claim 3, wherein said oscillation transistor is a NPN transistor and said control transistor is a PNP transistor.
Claim 8
Dependent Claim
78 words
A drive circuit for a piezo-electric element, according to claim 2, wherein said discharge transistor means comprises a diode through which current is supplied to said piezo-electric element, a resistor, and a PNP transistor whose emitter and collector are connected between the terminals of said piezo-electric element and whose base is connected to one of said terminals of said piezoelectric element via said resistor and to the other of said terminals of said piezo-electric element via said diode.
Claim 9
Dependent Claim
74 words
A relay comprising a bimorphic piezo-electric element comprising two piezo-electric subelements layered together and a drive circuit according to claim 1, an intermediate electrode of the bimorphic element which is common to both of the piezo-electric subelements being connected to one output of said drive circuit, while two surface terminals of the bimorphic element which are connected each to one of said piezo-electric subelements are connected to the other output of said drive circuit.
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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) | 1988-05-27 | 1988-11-26 | 1989-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-27 | 1992-11-26 | 1993-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-27 | 1996-11-26 | 1997-05-28 | $7700.00 | Window Closed / Lapsed |