US5122724A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inrush current limiter
Assignee: Boeing Co
•
Filing: 1991-07-12
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Granted: 1992-06-16
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Expires: 2011-07-12
Abstract
Abstract A circuit for limiting the inrush current in DC to DC and DC to AC power supplies. The circuit utilizes a small capacitor for taking a charge which slowly turns on a FET transistor placed in series with a large filter capacitor; the slowly reducing resistance of the transistor provides the desired inrush current limiting.
Inventors
- 👤 Loren O. Criss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:22
CPC Classifications
H; H02; H02H; H02H9/00; H02H9/001; H02M; H02M3/00; H02M3/02; H02M3/04; H02M3/10; H02M3/145; H02M3/155; H02M7/00; H02M7/02; H02M7/04; H02M7/06; H02M7/062; Y; Y10; Y10S; Y10S323/00; Y10S323/908
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
95 words
In combination in a power supply having a power source connected across a load and wherein an inductor is series connected between said power source and said load and a capacitor is connected across said load, an inrush current limiting circuit, the improvement comprising: a FET transistor having a gate electrode, said FET transistor connected in series circuit with said capacitor; a series circuit including a further capacitor and a resistor connected across said load, said gate electrode connected between said resistor and said further capacitor; and, a zener diode connected across said further capacitor.
Claim 2
Dependent Claim
95 words
In combination in a power supply having a power source connected across a load and wherein an inductor is series connected between said power source and said load and a capacitor is connected across said load, an inrush current limiting circuit, the improvement comprising: a FET transistor having a gate electrode, said FET transistor connected in series circuit with said capacitor; a series circuit including a further capacitor and a resistor connected across said load, said gate electrode connected between said resistor and said further capacitor; and, a zener diode connected across said further capacitor.
Claim 3
Dependent Claim
76 words
A power supply circuit having inrush current limiting comprising in combination: a power source; an inductor; a load; said power source series connected with said inductor across said load; a filter capacitor; a FET transistor having a gate electrode, said FET transistor connected in series circuit with said filter capacitor, said series circuit coupled across said load; an RC circuit connected in parallel with said series circuit; and, said gate electrode coupled to said RC circuit.
Claim 4
Dependent Claim
76 words
A power supply circuit having inrush current limiting comprising in combination: a power source; an inductor; a load; said power source series connected with said inductor across said load; a filter capacitor; a FET transistor having a gate electrode, said FET transistor connected in series circuit with said filter capacitor, said series circuit coupled across said load; an RC circuit connected in parallel with said series circuit; and, said gate electrode coupled to said RC circuit.
References Cited (Backward Citations)
US4678984A
Cited
US5010293A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-06-16 | 1995-12-16 | 1996-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-16 | 1999-12-16 | 2000-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-16 | 2003-12-16 | 2004-06-16 | $7700.00 | Window Closed / Lapsed |