DETAILED ACTION
This Office action is in response to the application and claims set filed on 07 March 2024, and the amended drawings and specification as filed in the preliminary amendment on 11 June 2024.
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 1-3 and 5 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Bissell (US Patent 6,232,752).
In re claim 1, Bissell discloses a two-stage switching power converter (Fig. 10), comprising:
a first power stage (80, 83, 84, 89, 88) including a first power transfer winding (80);
a second power stage (82, 85, 86, 91, 92) electrically coupled in series with the first power stage (Fig. 10), the second power stage including a second power transfer winding (82) that is magnetically coupled to the first power transfer winding (Fig. 10; col. 8:52-60); and
a controller (87) configured to:
control switching of the second power stage (via drive circuits 91, 92) to regulate at least one parameter of the two-stage switching power converter (col. 9: 6-20; see also col. 13: 1-4), and
control switching of the first power stage such that the first power stage switches in a complementary manner with respect to the second power stage (see Fig. 10 and col. 8:52 – col. 9:20; it is understood that the labeling convention for control signals d, d’ is indicative of the signals being complementary with respect to one another).
In re claim 2, Bissell discloses wherein each of the first power transfer winding (Fig. 10: 80) and the second power transfer winding (Fig. 10: 82) are part of a common coupled inductor (col. 8:52-60).
In re claim 3, Bissell discloses wherein each of the first power stage and the second power stage has a respective topology selected from the group consisting of a buck-type topology, a boost type topology, and a buck-boost type topology (Fig. 10; Abstract).
In re claim 5, Bissell discloses wherein the first power stage comprises a plurality of phases (see col. 3:63 – col. 4:7, where the term “phase” is interpreted as a phase in time, or in other words as a portion of the total control cycle).
Claim(s) 12-14 and 16 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Ramabhadran et al. (US Patent 10,574,144; “Ramabhadran”).
In re claim 12, Ramabhadran discloses a two-stage switching power converter (Fig. 4), comprising:
a first power stage (Fig. 4: 304, 320, 322) including a first coupled inductor including a first boost winding (308) and a plurality of first power transfer windings (328, 334; see col. 6:51-58);
a second power stage (Fig. 4: 306, 336, 338) electrically coupled in series with the first power stage (see note, below, regarding series coupling of the two boost windings), the second power stage including a second coupled inductor including a second boost winding (314) and a plurality of second power transfer windings (344, 350), the second boost winding being electrically coupled in series with the first boost winding (boost winding 308 is coupled in series with winding 314 between the switching node of circuit 304 and the switching node of circuit 306 as shown in Fig. 4); and a
controller (Fig. 4: 374) configured to control switching of the second power stage to regulate at least one parameter of the two-stage switching power converter (see Fig. 5 and col. 7:58-col. 8:33 teaching the general control scheme of the converter as a whole).
In re claim 13, Ramabhadran discloses wherein the controller is further configured to control switching of the first power stage such that the first power stage switches in a complementary manner with respect to the second power stage (See Fig. 5 and col. 8:34-39).
In re claim 14, Ramabhadran discloses an inductor electrically coupled in series with each of the first boost winding and the second boost winding (Fig. 4: any of the resonant inductors L21-L24 are additionally coupled in series with 308, 314 in the manner described above with respect to claim 12).
In re claim 16, Ramabhadran discloses an injection switching stage electrically coupled to the first boost winding at a switching node (Fig. 4: switches 310, 312 correspond to an injection switching stage coupled to boost inductor 308 at the switching node of circuit 304).
Allowable Subject Matter
Claims 7-11 are allowed.
Claims 4, 6, 15 and 17-18 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
With respect to claim 4, the closest prior art in Bissell discloses the invention according to claim 1 as explained above, but does not further disclose wherein: the second power stage comprises a plurality of phases; and the controller is further configured to control switching of the first power stage such that the first power stage switches in the complementary manner with respect to the second power stage by causing the first power stage to switch in a complementary manner with respect to each phase of the plurality of phases of the second power stage.
That is, while Bissell discloses complementary switching between first and second stages as explained above, Bissell does not teach a plurality of phases in the second stage. Further, although Ramabhadran and Ikriannov each provide a teaching to use a plurality of phases in a second stage (Ramabhadran: Figs. 2, 4 and Ikriannikov: Fig. 12A), neither of these documents explicitly teaches controlling the first stage in a complementary manner with respect to each phase of the plurality of phases of the second power stage, as recited in claim 4.
With respect to claim 6, the closest prior art in Bissell discloses the invention according to claims 1 and 5 as explained above, but does not further disclose wherein the controller is further configured to control switching of the first power stage such that the first power stage switches in the complementary manner with respect to the second power stage such that the plurality of phases of the first power stage alternately switch in a complementary manner with respect to the second power stage.
Further, while additional prior art in Ramabhadran, as well as in US Patent 8,772,9671 (“Ikriannikov”), disclose similar two-stage power converters including multiple phase circuits in one of the stages, none of these documents disclose a control scheme in which the plurality of phases of the first power stage alternately switch in a complementary manner with respect to the second power stage, as recited in claim 6.
With respect to claims 7-11, the closest prior arts in Bissell, Ramabhadran and Ikriannikov as described above all disclose similar two-stage power converters. However, none of these documents disclose the claimed second power stage that is electrically coupled in series with the first power stage, together with the controller controlling switching of the first power stage such that the first power stage switches in a complementary manner with respect to each phase of the plurality of phases of the second power stage, as recited in independent claim 7.
That is, for instance, Ramabhadran at Figs. 4 and 5 discloses, at best, a first power stage (e.g. 304) switching complementary to second stages (336, 338) that are not coupled in series to said first stage (see Fig. 5). Instead, the first stage (304) switches at the same time as a second stage (320, 322) that is actually coupled in series to said first stage (Figs. 4 and 5).
With respect to claim 15, the closest prior art in Ramabhadran discloses the invention according to claim 12 as explained above, but does not further disclose a transformer, the second boost winding being electrically coupled in series with the first boost winding via the transformer. The additional prior art on record, most notably Bissell and Ikriannikov as described above, also do not disclose this feature, and thus there is no indication that it would have been obvious to modify any of these prior arts in a manner that would arrive at the invention as claimed.
With respect to claim 17, the closest prior art in Ramabhadran discloses the invention according to claims 12 and 16 as explained above, but does not further disclose wherein: the second power stage is electrically coupled in series with the first power stage via an intermediate power node; and the injection switching stage is configured to repeatedly switch the switching node between the intermediate power node and ground.
That is, Ramabhadran, at best, discloses the second stage as circuits 306, 336, 338 as described above. Under this interpretation, the injection power stage, as switches 310, 312 in Fig. 4 of Ramabhadran, do not repeatedly switch the switching node, between the intermediate power node and ground as recited in claim 17.
With respect to claim 18, With respect to claim 17, the closest prior art in Ramabhadran discloses the invention according to claims 12 and 16 as explained above, but does not further disclose a tuning inductor electrically coupled in parallel with a series combination of the first boost winding and the second boost winding. Furthermore, the additional prior art on record, notably Bissell and Ikriannikov as described above, also do not teach such a feature, and thus there is no indication that it would have been obvious to modify any of these prior arts in a manner that would arrive at the invention as claimed.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
US Patent 6,897,641 discloses Buck (or Boost) Converter With Very Fast Output Current Transitions And Low Ripple Voltage, utilizing multiple power stages and/or phases with magnetically coupled inductors.
WO 2021/195692 discloses A BI-DIRECTIONAL AC-DC POWER CONVERTER – INVERTER including multiple power stages with magnetically coupled inductors.
The IEEE article by Khamis et al. discloses a split duty cycle coupled multi-phase boost-buck converter having magnetically coupled inductors.
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/FRED E FINCH III/Primary Examiner, Art Unit 2838
1 Cited by Applicant in the IDS filed 08 March 2024