EP0336725A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Switching power supply
Assignee: Panasonic Holdings Corp
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Filing: 1989-04-04
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Granted: —
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Expires: 2009-04-04
Abstract
Abstract A switching power supply comprises first switching circuit (4) for making an input voltage on and off, a transformer (3) having a primary winding (3a) connected in series with the first switching circuit (4), first rectifying and smoothing circuit (7, 9) connected to a secondary winding (3c) of the transformer and a second switching circuit (8) for releasing the output of the rectifying and smoothing circuit (7, 9) back to the secondary winding (3c) of the transformer (3) during the off-period of the first switching circuit. The switching power supply may further comprise a control circuit (10) for controlling on or off the second switching circuit (8) in response to the output of the first rectifying and smoothing circuit. The power supply may alternatively comprise a second rectifying and smoothing circuit (60, 61) connected to additional secondary winding (3f) to control on or off of the first switching circuit. Thus a stabilized switching power supply is provided with lower power loss, higher efficiency and lower noise.
Inventors
- 👤 Nobuyoshi Nagagata
- 👤 Osamu Hiromura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 13:48
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/33569; H02M3/33576; H02M3/33584
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
138 words
A switching power supply comprising: first switching means (4) for making an input voltage on and off; a transformer (3) having a primary winding (3a) connected to said first switching means (4); first rectifying and smoothing means (7, 9) connected to a secondary winding (3c) of said transformer (3); and second switching means (8) for releasing the output of said first rectifying and smoothing means (7, 9) back to said secondary winding (3c) of said transformer (3) during the off-period of said first switching means (4); whereby the output of said first rectifying and smoothing means (7, 9) which is applied to said secondary winding (3c) is released back to said primary winding (3a) of said transformer (3), and wherein said second switching means (8) is controlled by the output of the rectifying and smoothing means (7, 9).
Claim 2
Dependent Claim
138 words
A switching power supply comprising: first switching means (4) for making an input voltage on and off; a transformer (3) having a primary winding (3a) connected to said first switching means (4); first rectifying and smoothing means (7, 9) connected to a secondary winding (3c) of said transformer (3); and second switching means (8) for releasing the output of said first rectifying and smoothing means (7, 9) back to said secondary winding (3c) of said transformer (3) during the off-period of said first switching means (4); whereby the output of said first rectifying and smoothing means (7, 9) which is applied to said secondary winding (3c) is released back to said primary winding (3a) of said transformer (3), and wherein said second switching means (8) is controlled by the output of the rectifying and smoothing means (7, 9).
Claim 3
Dependent Claim
31 words
A switching power supply according to claim 1, wherein said second switching means (8) is connected in parallel with first rectifying means (7) of said rectifying and smoothing means (7, 9).
Claim 4
Dependent Claim
38 words
A switching power supply according to claim 1, wherein said second switching means (8) is formed of an FET (34) which also serves as said first rectifying means (7) of said first rectifying and smoothing means (7, 9).
Claim 5
Dependent Claim
51 words
A switching power supply according to claim 1, wherein said primary winding (3a) is connected with a second rectifying means (5) for allowing the energy released back to said primary winding (3a) to flow therein, and capacitors are connected in parallel with said first and second rectifying and smoothing means respectively.
Claim 6
Dependent Claim
27 words
A switching power supply according to claim 4, wherein said second rectifying means (5) and said first switching means (4) are formed of a signle FET (34).
Claim 7
Dependent Claim
34 words
A switching power supply according to Claim 1, wherein said second switching means (8) is connected to a separate secondary winding (3d) which is connected to said first rectifying and smoothing means (7, 9).
Claim 8
Dependent Claim
18 words
A switching power supply according to claim 1, wherein said transformer (3) is formed of an inductance element.
Claim 9
Dependent Claim
150 words
A switching power supply comprising: first switching menas (4) for making an input voltage on and off; a transformer (3) having a primary winding (3a) connected to said first switching means (4); first and second rectifying and smoothing means (7, 9, 36, 37) connected to first and second secondary windings (3c, 3f) of said transformer (3); second switching means (8) for releasing the output of said first rectifying smoothing means (7, 9) back to said secondary winding (3c) of said transformer (3) during the off-period of said first switching means (4); and control means (6) for controlling said second switching means (4) by the output of said second rectifying and smoothing menas (7, 9); whereby the output of said first rectifying and smoothing means (7, 9) supplied to said first secondary winding is released through said second switching means (3c) back to said primary winding (3a) of said transformer (3).
Claim 10
Dependent Claim
150 words
A switching power supply comprising: first switching menas (4) for making an input voltage on and off; a transformer (3) having a primary winding (3a) connected to said first switching means (4); first and second rectifying and smoothing means (7, 9, 36, 37) connected to first and second secondary windings (3c, 3f) of said transformer (3); second switching means (8) for releasing the output of said first rectifying smoothing means (7, 9) back to said secondary winding (3c) of said transformer (3) during the off-period of said first switching means (4); and control means (6) for controlling said second switching means (4) by the output of said second rectifying and smoothing menas (7, 9); whereby the output of said first rectifying and smoothing means (7, 9) supplied to said first secondary winding is released through said second switching means (3c) back to said primary winding (3a) of said transformer (3).
Claim 11
Dependent Claim
33 words
A switching power supply according to claim 8, wherein said primary winding (3a) is connected with rectifying means (5) for allowing the energy released back to said secondary winding (3c) to flow therein.
Claim 12
Dependent Claim
21 words
A switching power supply according to claim 9, wherein a capacitor (41) is connected in parallel with said rectifying means (5).
References Cited (Backward Citations)
No citation records indexed.
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