Prosecution Insights
Last updated: April 19, 2026
Application No. 17/604,180

Transformer and Method of Engineering a Transformer to Incorporate a Leakage Inductance

Final Rejection §103§112
Filed
Oct 15, 2021
Examiner
NGUYEN, TUYEN T
Art Unit
2837
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Kevin Byerly
OA Round
2 (Final)
82%
Grant Probability
Favorable
3-4
OA Rounds
2y 9m
To Grant
82%
With Interview

Examiner Intelligence

Grants 82% — above average
82%
Career Allow Rate
1001 granted / 1226 resolved
+13.6% vs TC avg
Minimal +1% lift
Without
With
+0.8%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
50 currently pending
Career history
1276
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
54.5%
+14.5% vs TC avg
§102
22.9%
-17.1% vs TC avg
§112
17.7%
-22.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1226 resolved cases

Office Action

§103 §112
DETAILED ACTION 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 § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 6-8 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Regarding claim 6, applicant should clarify the structure and/or arrangement of the primary and secondary windings intended by “responsive to the secondary winding being open and while current is applied to the primary winding, magnetizing flux in the transformer is primary contained in the first core, with the second core being at least partially excited.” It is still unclear what applicant is trying to claim, as amended. Regarding claim 7, applicant should clarify the structure and/or arrangement of the primary and secondary windings intended by “responsive to the primary winding being open and while current is applied to the secondary winding, the first core is excited and the second core experiences substantially zero excitation”. It is still unclear what applicant is trying to claim, as amended. Regarding claim 8, applicant should clarify the structure and/or arrangement of the primary and secondary windings intended by “responsive to the secondary winding being shorted circuited and while current is applied to the primary winding, magnetizing flux within the first core is substantially eliminated, and leakage flux within the second core and associated with the primary winding are retained.” It is still unclear what applicant is trying to claim, as amended. Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. Claim(s) 1-8 and 18, as best understood in view of the rejection under 35 USC 112 second paragraph, is/are rejected under 35 U.S.C. 103 as being unpatentable over Frederick [US 5,083,101] in view of applicant’s specification [AAPA para 0047] or Kapoor et al. [WO2013/156397 A1]. Regarding claims 1 and 4-5, Frederick discloses a transformer [or inductor 22], having a magnetic core structure, comprising: - an inner core [32] having a material with a first permeability; - an outer core [28] having a material with a second permeability; - a first/primary coil [38, figure 2] wound on both inner and outer cores; and - a secondary coil [36, figure 2] wound on the outer core, wherein the first permeability less than the second permeability. Frederick discloses the instant claimed invention except for the specific material for the inner and outer core. AAPA discloses MANC, a known material uses in magnetic core inductor and/or transformer application. Kapoor et al. discloses a magnetic core structure for a transformer [figure 14], the magnetic core structure [17] comprising a first core [outer core 17b] and a second core [inner core 17a], wherein the first and second outer cores formed of nano soft magnetic materials having different permeability with the inner core permeability lower than that of the outer core. It would have been an obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to use MANC material for the cores of Frederick, as suggested by AAPA or Kapoor et al., for the purpose of controlling and/or achieving magnetic flux/field. The structure of Frederick and AAPA or Kapoor et al. with the magnetic core structure and coils would provide leakage inductance. Regarding claim 2, Frederick further discloses the inner and outer cores are ungapped cores. AAPA and/or Kapoor et al. discloses the use of soft magnetic materials. Regarding claim 3, Frederick discloses the inner core having a permeability number of 70. Regarding claims 6-8, as best understood in view of the rejections under 35 USC 112 second paragraph, Frederick in view of AAPA or Kapoor et al. disclose the instant claimed invention except for the specifics responsive to the winding(s) being open/short-circuited while current is applied to the primary/secondary windings. The specific responsive to the windings being open/short-circuited while current is applied to the primary/secondary windings would have been obvious design consideration based on the intended applications/environments uses for the purpose of providing different desired magnetic fluxes/fields and/or excitations. Regarding claim 18, Frederick and/or Kapoor et al. both discloses different soft magnetic material for the inner and outer cores. The specific different MANC materials used for the magnetic cores would have been an obvious design consideration based on the specific intended applications and/or environments uses. Claim(s) 9-10 and 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fredick in view of AAPA or Kapoor et al. as applied to claim 1 above, and further in view of Miaosen [EP 3024002 A1]. Regarding claim 9, Frederick in view of AAPA or Kapoor et al. disclose the instant claimed invention except for a third core. Miaosen discloses a magnetic core structure for a magnetic device [figure 3], comprising: - a first core [130]; - a second core [116] arranged inside the first core; - a third core [132] arrange outside of the first core; and - at least one coil [124] wound about the magnetic core structure, wherein the first, second, third cores have different magnetic permeabilities. It would have been an obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to include a third core in the magnetic core structure of Frederick in view of AAPA or Kapoor et al., as suggested by Miaosen, for the purpose of improving and/or maximizing flux distribution and maintaining constant reluctance. Regarding claims 10 and 12, the specific use of the first, second, third cores are leakage and/or magnetizing cores would have been an obvious design consideration based on the intended applications and/or environments uses. Claim(s) 1-2 and 15-16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Cole [US 1,765,483] in view of applicant’s specification [AAPA para 0047] or Kapoor et al. Regarding claims 1-2 and 15, Cole discloses a magnetic core structure for a transformer [figures 1-5] comprising: - a first core [1]; - a second core [1]; - a third core [2], wherein the first, second and third cores are ungapped [figure 5]; and - a plurality of coils [3, 4] wound about the magnetic core structure, wherein the third core disposed between the first core and the second core with the first core arranged on one side of the third core and the second core arranged on the other side of the third core opposite to the first core. Cole discloses the instant claimed invention except for the specific material and permeability. AAPA discloses MANC, a known material uses in magnetic core inductor and/or transformer application. Kapoor et al. discloses a magnetic core structure for a transformer [figure 14], the magnetic core structure [17] comprising a first core [outer core 17b] and a second core [inner core 17a], wherein the first and second outer cores formed of nano soft magnetic materials having different permeability with the inner core permeability lower than that of the outer core. It would have been an obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to use MANC material for the cores of Frederick, as suggested by AAPA and Kapoor et al., for the purpose of controlling and/or achieving magnetic flux/field. The structure of Frederick and AAPA or Kapoor et al. with the magnetic core structure and coils would provide leakage inductance. Regarding claim 16, the specific use of the first, second and third cores are leakage and magnetizing cores would have been an obvious for the purpose of improving leakage. Claim(s) 11 and 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Frederick in view of AAPA and Kapoor et al. Miaosen as applied to claims 1 and 9 above, and further in view of Miljanic [US 3,534,247]. Frederick, as modified, discloses the instant claimed invention except for a tertiary coil. Miljanic discloses a transformer [figure 3] comprising: - a magnetic core including a first core [20a] and a second core [2a1]; - a primary coil [22] wound about the magnetic core structure; - a secondary coil [23] wound about the magnetic core structure; and - a tertiary/auxiliary coil [40] wound about the magnetic core structure. It would have been an obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to include a tertiary/auxiliary coil in Frederick, as modified, as suggested by Miljanic, for the purpose of providing auxiliary control of the transformer. The specific arrangement of the coils relative to the cores would have been obvious design consideration based on the intended applications and/or environments uses for the purpose of controlling magnetic flux/field. Response to Arguments Applicant’s arguments with respect to claim(s) 1-12, 14-16 and 18 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to TUYEN T NGUYEN whose telephone number is (571)272-1996. The examiner can normally be reached Mon - Fri 8:30-5:30. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Shawki Ismail can be reached at 571-272-3985. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /TUYEN T NGUYEN/ Primary Examiner, Art Unit 2837
Read full office action

Prosecution Timeline

Oct 15, 2021
Application Filed
Oct 15, 2021
Response after Non-Final Action
Feb 08, 2025
Non-Final Rejection — §103, §112
Jul 14, 2025
Response Filed
Sep 26, 2025
Final Rejection — §103, §112
Apr 01, 2026
Request for Continued Examination
Apr 02, 2026
Response after Non-Final Action

Precedent Cases

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
82%
Grant Probability
82%
With Interview (+0.8%)
2y 9m
Median Time to Grant
Moderate
PTA Risk
Based on 1226 resolved cases by this examiner. Grant probability derived from career allow rate.

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