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US3700968A Expired / Lapsed US ⏱️ 0.0 years remaining

Electric fuse circuit

Assignee: Airbus Defence and Space GmbH
•
Filing: 1971-12-30
•
Granted: 1972-10-24
•
Expires: 1991-12-30
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Abstract

Abstract An electric timing circuit, for the time-delayed delivery of a voltage pulse to an electric fuse element, has a voltage source, preferably designed as a capacitor which can be charged from an external source of electric potential. The capacitor discharges across a resistance and a threshold value switch connects the fuse element with the voltage source when the source voltage falls below a preset value. The threshold value switch is constituted by a first field effect transistor having its drainsource path in the electric timing circuit and a second field effect transistor having its drain-source path connected in parallel with that of the first transistor, and having an insulated grid electrode. The drain electrode of each transistor is connected to the grid electrode of the other transistor. The fuse element, in one embodiment of the invention, is in series with a thyristor whose gating circuit is connected to a resistor connected in the drain-source path of the second transistor. In a second embodiment of the circuit, the fuse element is connected in series with the source voltage capacitor and the drain-source path of the second transistor.

Inventors

  • 👤 Johann Spies

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 13:46
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/13; H03K5/133; H03K17/00; H03K17/51; H03K17/56; H03K17/72; H03K2005/00013; H03K2005/00078; H03K2005/00084; H03K2005/00091; H03K2005/00293

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 120 words
In an electric timing circuit, for the time-delayed delivery of a voltage pulse to an electric fuse element, of the type including a self-contained voltage source and a threshold value switch connecting the voltage source to the fuse element when the voltage of the source falls below a preset value, the improvement comprising, in combination, a first field effect transistor having its drain-source path in said electric timing circuit; a second field effect transistor having its drain-source path connected in parallel with the drain-source path of said first transistor, and having an insulated grid electrode; and respective means connecting the drain electrode of each transistor to the grid electrode of the other transistor; said transistors constituting said threshold value switch.
Claim 2
Dependent Claim 120 words
In an electric timing circuit, for the time-delayed delivery of a voltage pulse to an electric fuse element, of the type including a self-contained voltage source and a threshold value switch connecting the voltage source to the fuse element when the voltage of the source falls below a preset value, the improvement comprising, in combination, a first field effect transistor having its drain-source path in said electric timing circuit; a second field effect transistor having its drain-source path connected in parallel with the drain-source path of said first transistor, and having an insulated grid electrode; and respective means connecting the drain electrode of each transistor to the grid electrode of the other transistor; said transistors constituting said threshold value switch.
Claim 3
Dependent Claim 23 words
In an electric timing circuit, the improvement claimed in claim 1, in which said voltage source is a capacitor discharging across a resistance.
Claim 4
Dependent Claim 47 words
In an electric timing circuit, the improvement claimed in claim 2, including an electric valve connected in series with said electric fuse element and having a control electrode; said threshold value switch, constituted by said first and second transistors, having its output connected to said control electrode.
Claim 5
Dependent Claim 19 words
In an electric timing circuit, the improvement claimed in claim 3, in which said electric valve is a thyristor.
Claim 6
Dependent Claim 23 words
In an electric timing circuit, the improvement claimed in claim 2, in which said electric fuse element is connected in said timing circuit.
Claim 7
Dependent Claim 48 words
In an electric timing circuit, the improvement claimed in claim 5, in which said electric fuse element is connected in a series circuit including the drain-source path of said second transistor and said capacitor; said series circuit being in parallel with said resistance across which said capacitor discharges.
Claim 8
Dependent Claim 69 words
In an electric timing circuit, the improvement claimed in claim 2, including a pair of terminals for connection to an external source of electric potential; said capacitor being connected across said terminals in series with a diode; and a second capacitor connected in parallel with the drain-source path of said first transistor and preventing conduction of said second transistor during charging of said first-mentioned transistor from said external source.

References Cited (Backward Citations)

US3403270A Cited
US3390382A Cited
US3638047A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-10-24 1976-04-24 1976-10-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-10-24 1980-04-24 1980-10-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-10-24 1984-04-24 1984-10-24 $7700.00 Window Closed / Lapsed

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