US4594649A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bootstrap drive for a two-transistor forward converter
Assignee: Intellectual Ventures I LLC
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Filing: 1985-03-01
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Granted: 1986-06-10
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Expires: 2005-03-01
Abstract
Abstract A DC to DC voltage converter of the type having one switching transistor on the top side of the transformer and a second switching transistor on the bottom side. Opposite ends of the transformer are diode clamped to the bottom rail reference voltage. A bootstrap winding configuration taken from the top of the transformer drives the top switching transistor to eliminate the need for a tertiary winding. A pulse width modulated circuit drives the bottom transistor.
Inventors
- 👤 Paul M. Rhoads
- 👤 Arthur H. Renkes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:04
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/3353; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/53; H02M7/537; H02M7/5383; H02M7/53832; H02M7/53835
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
112 words
A two transistor forward converter comprising: a transformer having a primary and a secondary winding, said primary winding having a first end, a second end and a tap; first transistor means for connecting the tap of said primary winding to the high side of a power supply; second transistor means for connecting the first end of said primary winding to the low side of the power supply; first switch control means connected across the first end of said primary winding and said tap for activating said first transistor means; and second switch control means connectable to the low side of the power supply and said second switch for activating said second transistor.
Claim 2
Dependent Claim
112 words
A two transistor forward converter comprising: a transformer having a primary and a secondary winding, said primary winding having a first end, a second end and a tap; first transistor means for connecting the tap of said primary winding to the high side of a power supply; second transistor means for connecting the first end of said primary winding to the low side of the power supply; first switch control means connected across the first end of said primary winding and said tap for activating said first transistor means; and second switch control means connectable to the low side of the power supply and said second switch for activating said second transistor.
Claim 3
Dependent Claim
50 words
The forward converter according to claim 1 and further comprising: a first diode means connecting the second end of said primary winding to the high side of the power supply; and a second diode means connecting the low side of the power supply to the tap of said primary winding.
Claim 4
Dependent Claim
85 words
The forward converter according to claim 1 wherein said first and said second transistor means are comprised of MOS devices having drain, source and gate electrodes and wherein said first switch control means is comprised of, a capacitor and a first resistor connected in series between said gate electrode and the first end of said primary winding, a second resistor connected across said capacitor, and a Zener diode connected between the tap on said primary winding and the gate electrode of said first transistor means.
Claim 5
Dependent Claim
32 words
The forward converter according to claim 3 and further comprising a second Zener diode connected to the gate electrode of said second transistor means and the low side of the power supply.
Claim 6
Dependent Claim
179 words
A two transistor forward converter comprising: a transformer having a primary and a secondary winding, said primary winding being tapped to form a first primary section and a second primary section, said second primary section having a number of winding turns substantially greater than the number of winding turns of said first primary section; a power supply having a high and a low side; a first switch for periodically connecting the tap of said primary winding to the high side of said power supply; a second switch responsive to a control signal for periodically conducting and connecting one end of the second primary secfion to the low side of said power supply; control means for providing the periodic control signal to said second switch means; first control means connected across said first primary section for periodically activating said first switch means in response to the potential developed across said first primary section; and rectifying means across said second primary section and said power supply to limit the potential across said second primary sections when said switches are not conducting.
Claim 7
Dependent Claim
179 words
A two transistor forward converter comprising: a transformer having a primary and a secondary winding, said primary winding being tapped to form a first primary section and a second primary section, said second primary section having a number of winding turns substantially greater than the number of winding turns of said first primary section; a power supply having a high and a low side; a first switch for periodically connecting the tap of said primary winding to the high side of said power supply; a second switch responsive to a control signal for periodically conducting and connecting one end of the second primary secfion to the low side of said power supply; control means for providing the periodic control signal to said second switch means; first control means connected across said first primary section for periodically activating said first switch means in response to the potential developed across said first primary section; and rectifying means across said second primary section and said power supply to limit the potential across said second primary sections when said switches are not conducting.
Claim 8
Dependent Claim
44 words
The forward converter according to claim 5 and further comprising: a first Zener diode connected between the tap of said primary winding and said first switch; and a second Zener diode connected between the low side of said power supply and said second switch.
Claim 9
Dependent Claim
47 words
The forward converter according to claim 5 wherein said first control means is comprised of: a capacitor; a resistor connected in series with said capacitor across said first switch means and the non-tapped side of said first primary section; and a second resistor connected across said capacitor.
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) | 1989-06-09 | 1989-12-09 | 1990-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-09 | 1993-12-09 | 1994-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-09 | 1997-12-09 | 1998-06-10 | $7700.00 | Window Closed / Lapsed |