Patent US5278422A successfully refreshed from Google Patents.
US5278422A
Expired / Lapsed
US
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Normally open solid state relay with minimized response time of relay action upon being turned off
Assignee: Panasonic Electric Works Co Ltd
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Filing: 1992-08-26
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Granted: 1994-01-11
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Expires: 2012-08-26
Abstract
Abstract A solid state relay circuit includes a MOSFET receiving a photovoltaic output generated across a photovoltaic diode array responsive to a light signal from a light emitting element, a control electrode of a normally ON type driving transistor made to be at a high impedance state by a voltage generated across an impedance element connected in series to the photovoltaic diode array upon application of the photovoltaic output across the gate and source of the MOSFET and at a low impedance state upon disappearance of the photovoltaic output is connected to a connecting point between the diode array and the impedance element, and the driving transistor is connected across the gate and source of the MOSFET with a resistor interposed. A falling gradient of output signal upon being turned OFF of the relay circuit is made thereby sufficiently gentle, and relay operation upon being turned OFF can be minimized in response time.
Inventors
- 👤 Fumio Kato
- 👤 Sigeo Akiyama
- 👤 Masahiro Izumi
- 👤 Noriteru Furumoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:56
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/16; H03K17/161; H03K17/162; H03K17/163; H03K17/04; H03K17/041; H03K17/0412; H03K17/04123; H03K17/51; H03K17/78; H03K17/785
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
219 words
A normally open solid state relay with minimized response time of relay action upon being turning OFF, comprising: a light emitting element which emits a light signal upon receipt of an input current, a photovoltaic diode array optically coupled to said light element for generating a photovoltaic output upon receipt of said light signal from the light emitting element, an impedance element connected in series with said photovoltaic diode array, an output MOSFET of a normally OFF type connected to said photovoltaic diode array for being varied from first impedance state to second impedance state with said photovoltaic output applied across the gate and source of said MOSFET, a normally ON type driving transistor connected across the gate and source of said output MOSFET to be biased into a high impedance state by a voltage generated across said impedance element upon application of said photovoltaic output across the gate and source of said output MOSFET but turned into a low impedance state upon disappearance of the photovoltaic output, said driving transistor having a control electrode connected to a connecting point between said photovoltaic diode array and said impedance element, a resistor interposed in a connection between said normally ON type driving transistor and said gate of said output MOSFET, and a constant element connected in parallel with said resistor.
Claim 2
Dependent Claim
219 words
A normally open solid state relay with minimized response time of relay action upon being turning OFF, comprising: a light emitting element which emits a light signal upon receipt of an input current, a photovoltaic diode array optically coupled to said light element for generating a photovoltaic output upon receipt of said light signal from the light emitting element, an impedance element connected in series with said photovoltaic diode array, an output MOSFET of a normally OFF type connected to said photovoltaic diode array for being varied from first impedance state to second impedance state with said photovoltaic output applied across the gate and source of said MOSFET, a normally ON type driving transistor connected across the gate and source of said output MOSFET to be biased into a high impedance state by a voltage generated across said impedance element upon application of said photovoltaic output across the gate and source of said output MOSFET but turned into a low impedance state upon disappearance of the photovoltaic output, said driving transistor having a control electrode connected to a connecting point between said photovoltaic diode array and said impedance element, a resistor interposed in a connection between said normally ON type driving transistor and said gate of said output MOSFET, and a constant element connected in parallel with said resistor.
Claim 3
Dependent Claim
31 words
A relay according to claim 1, wherein said constant voltage element is a Zener diode rendering a direction from the source to the gate of said output MOSFET to be forward.
Claim 4
Dependent Claim
32 words
A relay according to claim 1, wherein said constant voltage element is an enhancement type MOSFET connected at its drain and source across said resistor and short-circuited at its gate and drain.
References Cited (Backward Citations)
US4390790A
Cited
US4777387A
Cited
US4755697A
Cited
US4804866A
Cited
US4801822A
Cited
US4916323A
Cited
US4912335A
Cited
US4864126A
Cited
US5105090A
Cited
US5057694A
Cited
US5013926A
Cited
US5151602A
Cited
US5138177A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-01-10 | 1997-07-12 | 1998-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-10 | 2001-07-12 | 2002-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-10 | 2005-07-12 | 2006-01-11 | $7700.00 | Window Closed / Lapsed |