US4035669A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Operation-delayed switching circuit
Assignee: Nippon Gakki Co Ltd
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Filing: 1975-11-18
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Granted: 1977-07-12
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Expires: 1995-11-18
Abstract
Abstract A switching circuit designed to start operation after the lapse of a predetermined delay time from its connection to a power source. The switching circuit has a switch element which is rendered conductive when the terminal voltage of a capacitor of a time constant circuit connected to the power source for determining the delay time has reached a predetermined value. Thereafter the electric charge of said capacitor is quickly discharged through a low impedance discharge line including said switch element. Thus, when the switching circuit has once been brought into operation after the lapse of a predetermined delay time from its connection to the power source, the capacitor of the time constant circuit is substantially completely discharged in such a manner that the terminal voltage of this capacitor is restored to substantially the same value as that before the connection to the power source, thereby allowing the switching circuit to provide the constant delay time even if its reconnection to the power source is made immediately after its disconnection therefrom.
Inventors
- 👤 Kenji Yokoyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:25
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/28
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
211 words
An operation-delayed switching circuit comprising: a power source line having a DC voltage source connected thereto; a time constant circuit connected to the power source line and including at least a capacitor; a discharge line connected in parallel with the capacitor of said time constant circuit and including a switch element having a control terminal and inserted in series therein, for discharging the electric charge of said capacitor; a control signal generating circuit connected to said time constant circuit including a voltae divider circuit having an output terminal connected in parallel with said capacitor and a diode connected in series between said output terminal and said control terminal, said diode having a polarity as is reverse biased by a holding voltage applied to said control terminal for generating a DC voltage varying in value in accordance with the terminal voltage of said capacitor, said DC voltage serving as a control signal applied to said control terminal of said switch element for controlling the conduction of this switch element; and a self-sustaining circuit of said switch element and connected to said control terminal of the switch element and continuously applying to said control terminal said holding voltage for sustaining the conduction of said switch element after said switch element is rendered conductive.
Claim 2
Dependent Claim
211 words
An operation-delayed switching circuit comprising: a power source line having a DC voltage source connected thereto; a time constant circuit connected to the power source line and including at least a capacitor; a discharge line connected in parallel with the capacitor of said time constant circuit and including a switch element having a control terminal and inserted in series therein, for discharging the electric charge of said capacitor; a control signal generating circuit connected to said time constant circuit including a voltae divider circuit having an output terminal connected in parallel with said capacitor and a diode connected in series between said output terminal and said control terminal, said diode having a polarity as is reverse biased by a holding voltage applied to said control terminal for generating a DC voltage varying in value in accordance with the terminal voltage of said capacitor, said DC voltage serving as a control signal applied to said control terminal of said switch element for controlling the conduction of this switch element; and a self-sustaining circuit of said switch element and connected to said control terminal of the switch element and continuously applying to said control terminal said holding voltage for sustaining the conduction of said switch element after said switch element is rendered conductive.
Claim 3
Dependent Claim
28 words
An operation-delayed switching circuit according to claim 1 wherein: said time constant circuit is comprised of said capacitor and of a resistor connected in series to this capacitor.
Claim 4
Dependent Claim
23 words
An operation-delayed switching circuit according to claim 1 wherein: the switch element is a transistor having base electrode serving as said control terminal.
Claim 5
Dependent Claim
76 words
An operation-delayed switching circuit according to claim 1 wherein: said self-sustaining circuit has a transistor connected between the power source line and the control terminal of the switch element, and wherein: the base electrode of said transistor is connected to a point on the discharge line at which an electric potential capable of biasing said transistor in the direction of rendering said transistor conductive at the time when the switch element is rendered conductive is obtained.
Claim 6
Dependent Claim
51 words
An operation-delayed switching circuit according to claim 1 wherein: said self-sustaining circuit includes a switch for stopping only the supply of said holding voltage to the control terminal of the switch element and keeping the connections of said discharge line and said signal generating circuit both to said time constant circuit.
Claim 7
Dependent Claim
52 words
An operation-delayed switching circuit according to claim 1 further comprising: a switching means connected between the control terminal of the switch element and a potential point from which an electric voltage is applied to the control terminal of the switch element so as to render the switch element to the "off" state.
References Cited (Backward Citations)
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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) | 1980-07-11 | 1981-01-10 | 1981-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-11 | 1985-01-10 | 1985-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-11 | 1989-01-10 | 1989-07-12 | $7700.00 | Window Closed / Lapsed |