Patent US4894567A successfully refreshed from Google Patents.
US4894567A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Active snubber circuit
Assignee: Honeywell Inc
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Filing: 1988-10-17
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Granted: 1990-01-16
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Expires: 2008-10-17
Abstract
Abstract Electronic circuit apparatus for actively clamping high frequency ringing on a semiconductor switch due to leakage inductance. The apparatus includes a capacitor having first and second capacitive plates, the first capacitive plate being connected between the leakage inductance and one side of the switch and a bipolar transistor which is connected at its base to the second capacitive plate and at its collector to the first capacitive plate at the junction between the leakage inductance and one side of the switch. The emitter of the bipolar transistor is connected to the other side of the switch.
Inventors
- 👤 Ronald J. Lenk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:17
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/08; H03K17/081; H03K17/0814; H03K17/08146; H03K17/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
98 words
Electronic circuit apparatus for actively clamping high frequency ringing on a semiconductor switch having first and second poles where the ringing is due to leakage inductance comprising: (a) a capacitor having first and second capacitive plates wherein the first capacitive plate is connected to the first pole of the switch; (b) a bipolar transistor connected at its base to the second capacitive plate, connected at its collector to the first capacitive plate and having its emitter connected to the second pole of the switch; and (c) a shunting inductance connected between the base and emitter of the transistor.
Claim 2
Dependent Claim
98 words
Electronic circuit apparatus for actively clamping high frequency ringing on a semiconductor switch having first and second poles where the ringing is due to leakage inductance comprising: (a) a capacitor having first and second capacitive plates wherein the first capacitive plate is connected to the first pole of the switch; (b) a bipolar transistor connected at its base to the second capacitive plate, connected at its collector to the first capacitive plate and having its emitter connected to the second pole of the switch; and (c) a shunting inductance connected between the base and emitter of the transistor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-15 | 1993-07-17 | 1994-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-15 | 1997-07-17 | 1998-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-15 | 2001-07-17 | 2002-01-16 | $7700.00 | Window Closed / Lapsed |