Prosecution Insights
Last updated: April 19, 2026
Application No. 18/538,148

HIGH-IMPEDANCE BUS DIFFERENTIAL PROTECTION

Non-Final OA §103
Filed
Dec 13, 2023
Examiner
NGUYEN, DANNY
Art Unit
2838
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Schweitzer Engineering Laboratories Inc.
OA Round
2 (Non-Final)
90%
Grant Probability
Favorable
2-3
OA Rounds
2y 6m
To Grant
96%
With Interview

Examiner Intelligence

Grants 90% — above average
90%
Career Allow Rate
1207 granted / 1340 resolved
+22.1% vs TC avg
Moderate +6% lift
Without
With
+6.4%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
31 currently pending
Career history
1371
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
38.2%
-1.8% vs TC avg
§102
52.1%
+12.1% vs TC avg
§112
6.3%
-33.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1340 resolved cases

Office Action

§103
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 . Response to Arguments 1. Applicant’s arguments, filed on 11/13/2025, have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Pelly et al (USPN 5751530) in view of Andersson et al (USPN 2010/0053830). Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. 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. 2. Claims 1,3-5, 7, 9-11, 13-15, 17, 19 are rejected under 35 U.S.C. 103 as being unpatentable over Pelly et al (USPN 5751530) in view of Andersson et al (USPN 2010/0053830). Regarding claim 1, Pelly discloses a protective device (a protective device 30 and a control device 150 shown in figure 3, 17A) configured for use in an electric power system, comprising: an overvoltage element (an overvoltage element includes a DC blocking capacitor 58, a voltage sensor 168 is configured to sense a voltage across terminals 59, 56 of the DC blocking capacitor 58, see figure 17a) configured to monitor a voltage (a voltage across terminals 59, 56) and to initiate a protective action (by triggering the switching components 64, 66, 70, 72) when the voltage exceeds a first threshold (e.g. see col. 14, lines 43-47, col. 16, 17, lines 63-3); a variable resistor (a varistor 60) disposed in parallel with the overvoltage element (58) and to generate substantially all of an electrical resistance across the overvoltage element when the voltage is less than the first threshold (under a normal operation, the varistor 60 is high impedance and open circuit, all resistance of the varistor 60 generated across the overvoltage element, 58, 168); and a bypass device (64, 66, 70, 72) disposed in parallel with the overvoltage element and the variable resistor (60) and configured to transition from a first state (non-conducting state) to a second state (a conducting state) in response to a signal (a signal from 180, 182, see figure 17b); wherein the signal to transition the bypass device (64, 66, 70, 72) from the first state to the second state is generated a length of time (at a time t0, see figure 5) after the voltage exceeds the first threshold (270V), and after the bypass device (64, 66, 70, 72) provides a low-resistance path to dissipate the voltage across the overvoltage element and the variable resistor (60) in the second state (see 9, lines 45-49). Pelly further discloses the bypass device (64, 66, 70, 72) configured to minimize a DC offset (such as a DC component shown in figure 5 is minimized by the bypass device). However, Pelly does not explicitly disclose the signal to transition the bypass device from the first state to the second state is generated when a DC offset is minimized as claimed. Andersson discloses an overvoltage protection device comprises a bypass device (a switching device 20, see figure 2), and a control device is configured to generate a signal in response to an overvoltage detected (e.g. see par. 0010), wherein the signal to transition the bypass device (20) from the first state (a non-conductive mode) to the second state (a conductive mode) is generated when a DC offset is minimized (see par. 0010, and 0025). It 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 to have modified a control device of Pelly to incorporate a control device which generate a signal to a bypass device to minimize a DC offset as disclosed by Andersson in order to reduce voltage stress on the device and the bypass device so that enhancing a circuit performance. Regarding claims 3, 13, Pelly discloses wherein the length of time (such as a time t0) is based on a spike in the voltage (a surge voltage 91, see figure 5). Regarding claims 4, 14, Pelly discloses wherein the variable resistor comprises a metal oxide varistor (a varistor 60). Regarding claims 5, 15, Pelly discloses the protective device (figure 3) lacks a stabilizing resistor disposed in parallel with the overvoltage element (figures 3, 17a do not include a stabilizing resistor). Regarding claim 7, Pelly discloses an overcurrent element (402) configured to monitor a current and to initiate the second protective action when the current exceeds a second threshold (see col. 24, lines 20-39). Regarding claims 9, 19, Pelly discloses wherein the protective device (see figure 2) further comprises a high-impedance module (30). Regarding claim 10, Pelly discloses wherein the length of time is approximately zero (the surge voltage 91 occurs at a time to approximately zero, see figure 5). Regarding claim 11, Pelly discloses a method of operating a protective device (a protective device includes a device 30, a controller 150 in figures 3, 17A) in an electric power system, the method comprising: monitoring, using an overvoltage element (a DC blocking capacitor 58, and a voltage monitor 168, see figures 3, 17a), a voltage and initiating a protective action (by turning the SCRs 64, 66, 70, 72) when the voltage exceeds a first threshold (270V); generating, using a variable resistor (a varistor 60) disposed in parallel with the overvoltage element (58) , substantially all of an electrical resistance across the overvoltage element when the voltage is less than the first threshold (under a normal operation, the varistor 60 is high impedance and open circuit, all resistance of the varistor 60 generated across the overvoltage element, 58, 168); and transitioning a bypass device (64, 66, 70, 72) disposed in parallel with the overvoltage element (58, 168) and the variable resistor (60) from a first state (non-conducting state) to a second state (a conducting state) in response to a signal; wherein the signal to transition the bypass device from the first state to the second state is generated a predetermined length of time (at a time t0, a surge voltage 91 occurs) after the voltage exceeds the first threshold, and after the bypass device provides a low-resistance path to dissipate the voltage across the overvoltage element and the variable resistor in the second state (see col. 9, lines 45-49). Pelly further discloses the bypass device (64, 66, 70, 72) configured to minimize a DC offset (such as a DC component shown in figure 5 is minimized by the bypass device). However, Pelly does not explicitly disclose the signal to transition the bypass device from the first state to the second state is generated when a DC offset is minimized as claimed. Andersson discloses an overvoltage protection device comprises a bypass device (a switching device 20, see figure 2), and a control device is configured to generate a signal in response to an overvoltage detected (e.g. see par. 0010), wherein the signal to transition the bypass device (20) from the first state (a non-conductive mode) to the second state (a conductive mode) is generated when a DC offset is minimized (see par. 0010, and 0025). It 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 to have modified a control device of Pelly to incorporate a control device which generate a signal to a bypass device to minimize a DC offset as disclosed by Andersson in order to reduce voltage stress on the device and the bypass device so that enhancing a circuit performance. Regarding claim 17, Pelly discloses an overcurrent element (402) configured to monitor a current and to initiate the second protective action when the current exceeds a first threshold (see col. 24, lines 20-39). Allowable Subject Matter 3. Claim 20 is allowed over prior art of record. The following is an examiner's statement of reasons for allowance: The prior art of record neither anticipates nor renders obvious the claimed subject matter of the instant application as a whole either taken alone or in combination, in particular, prior art of record does not teach: A protective device configured for use in an electric power system, comprising: a plurality of current transformers in electrical communication with protected equipment in the electric power system and the overvoltage element; a series resistor disposed in series between the plurality of current transformers and the overvoltage element, the variable resistor, and the bypass device; wherein the signal to transition the bypass device from the first state to the second state is generated when the voltage exceeds the first threshold as recited in claim 20. 4. Claims 6, 8, 16, 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. Conclusion 5. Any inquiry concerning this communication or earlier communications from the examiner should be directed to DANNY NGUYEN whose telephone number is (571)272-2054. The examiner can normally be reached M-F 8:00AM-4:30PM. 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 571-271-1838. 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. /DANNY NGUYEN/ Primary Examiner, Art Unit 2838
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Prosecution Timeline

Dec 13, 2023
Application Filed
Aug 19, 2025
Non-Final Rejection — §103
Nov 13, 2025
Response Filed
Feb 05, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

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

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Prosecution Projections

2-3
Expected OA Rounds
90%
Grant Probability
96%
With Interview (+6.4%)
2y 6m
Median Time to Grant
Moderate
PTA Risk
Based on 1340 resolved cases by this examiner. Grant probability derived from career allow rate.

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