Prosecution Insights
Last updated: April 19, 2026
Application No. 18/751,388

ACTIVE CLAMP FLYBACK CONVERTER

Non-Final OA §102
Filed
Jun 24, 2024
Examiner
TRAN, NGUYEN
Art Unit
2838
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Sanken Electric Co. Ltd.
OA Round
1 (Non-Final)
83%
Grant Probability
Favorable
1-2
OA Rounds
2y 6m
To Grant
91%
With Interview

Examiner Intelligence

Grants 83% — above average
83%
Career Allow Rate
895 granted / 1073 resolved
+15.4% vs TC avg
Moderate +8% lift
Without
With
+7.6%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
36 currently pending
Career history
1109
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
51.6%
+11.6% vs TC avg
§102
33.9%
-6.1% vs TC avg
§112
10.7%
-29.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1073 resolved cases

Office Action

§102
DETAILED ACTION 1. This action is in response to the application filed on 6/24/24. Notice of Pre-AIA or AIA Status 2. 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 3. 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. 4. Claims 1 and 4 are rejected under 35 U.S.C. 102()() as being anticipated by Rana et al. (US 20170264206). Regarding claim 1: Rana et al. disclose an active clamp flyback converter (i.e. figures 1-2 and 10-11) comprising: a first series circuit comprising a primary winding (i.e. NP), and a main switch (i.e. S1), the main switch (i.e. S1) and the primary winding (i.e. NP) being connected in series with both terminals (i.e. terminals of rectifier diodes) of a DC power supply (i.e. from rectifier diodes); a second series circuit comprising a clamp switch (i.e. S2), and a clamp capacitor (i.e. C2), the clamp switch (i.e. S2) and the clamp capacitor (i.e. C2) being connected in series at both terminals of the primary winding (i.e. NP); a transformer (i.e. T1) comprising a secondary winding (i.e. NS) electromagnetically connected to the primary winding (i.e. NP); a controller (i.e. 101) that controls the main switch (i.e. S1) and the clamp switch (i.e. S2); a rectifier smoothing circuit (i.e. D1) that rectifies and smoothes a voltage (i.e. voltage of NS) in the secondary winding (i.e. NS); and an output voltage detector (i.e. detector for VFB) that detects an output voltage (i.e. Vout) of the rectifier smoothing circuit (i.e. D1), wherein the controller (i.e. 101) performs operations comprises: generating a first drive signal (i.e. figure 2: 140, signal LG) for controlling the main switch (i.e. S2); generating a second drive signal (i.e. figures 2: 140, signal HG of signal 161) for controlling the clamp switch (i.e. S2) during a time period (i.e. figure 2: 140, on period of 161) when the main switch is off (i.e. figure 2: 140, signal LG is off during on period 161); generating a third drive signal (i.e. figures 2: 140, signal HG of signal 162) for controlling the clamp switch (i.e. S2) after the second drive signal (i.e. figures 2: 140, signal HG of signal 161); controlling a first off period (i.e. figure 2: 140, off period the falling edge of signal LG and raising edge of signal HG 161) during which both the main switch (i.e. S1) and the clamp switch (i.e. S2) are off from an off time of the first drive signal (i.e. figure 2: 140, signal LG) to the on time (i.e. figure 2: 140, signal HG 161 on time) of the second drive signal (i.e. figures 2: 140, signal HG of signal 161); and controlling a second off period (i.e. figure 2: 140, off period between 161 and 162) during which both the main switch (i.e. S1) and the clamp switch (i.e. S2) are off from the off time (i.e. figure 2: 140, off time of signal 161) of the second drive signal (i.e. figures 2: 140, signal HG of signal 161) to the on time (i.e. figure 2: 140, on time of 162) of the third drive signal (i.e. figures 2: 140, signal HG of signal 162). Regarding claim 4: (i.e. figures 1-2 and 10-11) wherein the controller (i.e. 101) comprises: an enable signal generator (i.e. for LG on) that generates an enable signal (i.e. LG on) based on a feedback voltage (i.e. VFB) detected by the output voltage detector (i.e. detector for VFB); and a disable signal generator (i.e. for LG off) that generates a disable signal (i.e. LG off) based on the second drive signal (i.e. figures 2: 140, signal HG of signal 161 to control switch S2 to provides signal CS and VFB in order to provides signal LG off), the controller (i.e. 101) controls the second off period (i.e. figure 2: 140, off period between 161 and 162) by controlling the third drive signal (i.e. figures 2: 140, signal HG of signal 162) based on the enable (i.e. LG on) and disable signals (i.e. LG off). Allowable Subject Matter 5. Claims 2-3 and 5-7 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. Conclusion 6. Any inquiry concerning this communication or earlier communications from the examiner should be directed to NGUYEN TRAN whose telephone number is (571)270-1269. The examiner can normally be reached Flex: M-F 8-7. 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, Monica Lewis can be reached at 571-272-1838. 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. /Nguyen Tran/Primary Examiner, Art Unit 2838
Read full office action

Prosecution Timeline

Jun 24, 2024
Application Filed
Jan 31, 2026
Non-Final Rejection — §102 (current)

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

1-2
Expected OA Rounds
83%
Grant Probability
91%
With Interview (+7.6%)
2y 6m
Median Time to Grant
Low
PTA Risk
Based on 1073 resolved cases by this examiner. Grant probability derived from career allow rate.

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