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 Amendment
This action is responsive to the amendments filed 05/21/2026. Claims 1-9 are pending in this application. As directed, claims 1 and 9 have been amended; claims 10-15 cancelled.
With respect to 35 U.S.C. 112 Claim Rejections: Applicant’s amendments to the Claims filed on 05/21/2026 have overcome the 35 U.S.C. 112(b) Claim Rejections set forth in the Non-Final Office Action dated 02/24/2026.
Response to Arguments
With respect to 35 U.S.C. 103 Claim Rejections: Applicant’s arguments filed on 05/21/2026 have been fully considered but are moot based on new ground(s) of rejection necessitated by amendments.
Specifically, Applicant’s amendment to claim 1 changes the scope of the claim by requiring that the recited three-phase input power be “received at an input”. The amendment thereby further defines the location and relationship of the recited three-phase power with respect to the welding-type power supply and, in conjunction with the remaining limitations of claim 1, requires the claimed reference-node and the phase-detection arrangement to operate with respect to the three-phase power received at the input. Accordingly, the amendment necessitated reconsideration of the prior art replied upon for the reference-node arrangement. The previously cited primary reference Anders et al. (U.S. Pub. No. 2019/0337081 A1, previously cited) remains applicable to the claimed welding-type power supply and the determination of the number of phases connected to the input based on a frequency comparison; however, the newly cited prior art Evans (EP 0041374 A1, newly cited) is relied upon to teach the additionally defined input-side three-phase arrangement, including respective phases of a three-phase supply coupled through corresponding impedances to a common star/reference point. To be more specific, the newly cited prior art Evans (EP 0041374 A1, newly cited) is necessitated by the Applicant’s amendment because the amendment explicitly limits the three-phase power associated with the claimed arrangement to three-phase input power “received at an input”, thereby requiring prior art more specifically addressing the claimed reference node arrangement in connection with three-phase supply/input power.
Examiner would like to further note that in response to Applicant’s arguments regarding the prior art of record Anders et al. (U.S. Pub. No. 2019/0337081 A1, previously cited) – see details on pages 4-6 of the Remarks dated 05/21/2026, Applicant’s arguments filed on 05/21/2026 have been fully considered but they are not persuasive for the following reasons:
Applicant alleges that Anders does not disclose “a reference node coupled to each winding of the three-phase input power via a corresponding impedance” and “a phase detection circuit coupled to the reference node” as recited in claim 1, Applicant further alleges that the previously relied upon Shigeta (U.S. Pub. No. 2020/0295595 A1, previously cited) does not cure these deficiencies. To the extent Applicant’s arguments are directed specifically to the teachings of Shigeta and the previous combination of Anders and Shigeta, such arguments are moot because the present rejection set forth in this Office Action is no longer relied upon Shigeta. The rejection has been modified to rely upon Anders in view of Evans, see detailed rejection in the 35 U.S.C. Claim Rejections section below.
Additionally, Applicant alleges that Anders determines the phase condition by monitoring ripple on DC power bus 108 after rectification and that Anders does not disclose or suggest “a reference node coupled to each winding of the three-phase input power via a corresponding impedance” and “a phase detection circuit coupled to the reference node” as recited in claim 1. Applicant further alleges that modifying Anders to perform phase detection at such reference node would change the principle of operation of Anders and would require additional circuitry that Anders seeks to avoid.
Examiner respectfully disagrees. In response to Applicant’s arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). In this case, Anders is not relied upon as teaching the claimed reference node and corresponding impedances. Rather, the newly cited prior art Evans is relied upon for these features, specifically, Evans teaches a reference node coupled to each winding of the three-phase input power via a corresponding impedance; and the phase detection circuit coupled to the reference node as required by independent claim 1. To be more specific, Anders discloses a welding-type power supply having an input 102 configured to receive AC input power, wherein the power source 104 may provide single-phase or three-phase AC power to the input, rectifier circuit 106 conditions the AC power received at input 102 to DC power at DC power bus 108, and processor 122 determines whether single-phase or three-phase power is connected to the input. Anders further discloses determining the phase condition based upon characteristics of the ripple signal and in disclosed embodiments, comparing the detected condition with a threshold to determine whether single-phase or three-phase input power is present. Evans is relied upon for the input-side reference-node arrangement that is not explicitly disclosed by Anders. In particular, Evans teaches a three star-connected capacitors C1, C2, and C3, wherein the respective branches are connected to the red, yellow, and blue lines R, Y, and B of a three-phase supply. Evans further teaches a sensing lead 1 connected to the star point of the capacitors. Accordingly, Evans teaches the claimed reference node coupled to each phase of the three-phase input power through a corresponding impedance and sensing circuitry coupled to that reference node, as required by claim 1.
Therefore, in the instant case, the purpose of combining Anders with Evans is not defeated, for, at least, the benefit of providing an input-side indication of the condition of the respective phases of the three-phase supply and thereby permit the phase condition of the power received at input 102 of Anders to be determined from a common sensing point associated with the three input phase since Evans explicitly demonstrates that a common star point coupled to each of the three supply lines through respective impedances provide such a sensing point for detecting an abnormal condition of a three-phase supply. As the obviousness can be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so. In re Kahn, 441 F.3d 977, 986, 78 USPQ2d 1329, 1335 (Fed. Cir. 2006). Moreover, MPEP § 2144.01, suggests that “[I]n considering the disclosure of a reference, it is proper to take into account not only specific teachings of the reference but also the inferences which one skilled in the art would reasonably be expected to draw therefrom.” In re Preda, 401 F.2d 825, 826, 159 USPQ 342, 344 (CCPA 1968); In re Lamberti, 545 F.2d 747, 750, 192 USPQ 278, 280 (CCPA 1976)”. As such, Applicant’s argument that there is no motivation to modify Anders, is not persuasive.
Furthermore, Applicant’s argument that modifying Anders would require moving Anders’s DC power-bus ripple detection circuitry to the reference node, and therefore would change Anders’s principle of operation, is not commensurate with the rejection. The Examiner is not proposing physically relocating DC power bus 108, processor 122, or Anders’s existing DC-bus sensing circuitry to Evans’s star point. Rather, the proposed combination employs Evans’s known input-side reference-node sensing arrangement to provide the claimed reference-node signal while retaining Anders’s welding power-conversion architecture and its determination of whether single-phase or three-phase power is connected to the input. Nor does the proposed modification render Anders unsuitable for its intended purpose. Anders’s underlying purpose remains the same: determining whether single-phase or three-phase AC power is connected to the input of the welding-type power supply so that appropriate protective/control action may be taken. Anders explicitly recognizes that direct measurement of phase-to-phase voltages or phase currents represents a conventional manner of detecting single-phase operation. Anders’s preference for DC-bus monitoring is explained as avoiding additional circuitry and cost, it does not establish that input-side single phase sensing would be technically incompatible with Anders’s welding-type power supply.
Applicant further alleges that the proposed modification would be contrary to Anders because Applicant relies on Par.0012 of Anders stating that conventional phase-detection approaches may require additional circuitry and cost. Applicant’s argument has been fully considered but is not persuasive.
As explicitly stated in Par.0012 of Anders, Anders identifies two particular conventional direct approaches for detecting sing-phase operation: (1) measuring phase-to-phase voltages and (2) measuring phase currents of the input. Anders explains that a drawback of “these methods” is that phase-to-phase voltages and phase currents are not typically measured in a welding-type power supply and therefore, measuring those quantities would require additional circuitry and cost. Thus, the identified drawback is specifically associated with implementing circuitry for directly measuring phase-to-phase voltages or phase currents.
The modification proposed in the present rejection, however, does not require Anders to separately measure phase-to-phase voltages or phase currents. Rather, Evans teaches a different sensing arrangement in which the respective phases of the three-phase supply are coupled through corresponding impedances to a common star/reference node, and the electrical condition associated with the common node is sensed. Accordingly, the proposed modification does not merely incorporate either of the particular conventional direct-measurement approaches identified by Anders in Par.0012. Moreover, Anders’s statement that an approach requiring less additional circuit and cost is “desirable” identifies an advantage of Anders’s disclosed implementation, but does not establish that the use of any additional sensing circuitry is technically infeasible, prohibitively expensive, or otherwise unsuitable for a welding-type power supply. Anders does not state that additional circuitry must be avoided under all circumstances, nor does Anders criticize or discourage the particular common-reference-node sensing arrangement taught by Evans. Rather, Anders recognizes additional circuitry and cost as design considerations associated with selecting among known approaches for detecting the input phase condition. Even assuming that incorporating the sensing arrangement of Evans into Anders would result in some additional circuitry, such a result represents a predicable engineering tradeoff rather than a reason that would have discouraged a person of ordinary skill from making the modification. The additional sensing components provide a corresponding technical benefit of obtaining phase-condition information from a common reference node directly associated with the respective phases of the three-phase input. A person of ordinary skill would have been capable of weighing the additional circuitry against the benefit provided by such input-side phase-condition sensing and selecting the known arrangement where that benefit was desired. Further, the proposed modification does not require a substantial redesign of Anders’s welding-power conversion circuitry. The reference-node arrangement of Evans employs conventional impedance elements associated with the respective phases and a common sensing point. Anders’s principal power-conversion components and functions may remain intact. Accordingly, one of ordinary skill in the art would have been motivated to incorporate the reference-node sensing arrangement of Evans into the welding-type power supply of Anders in order to provide a common input-side sensing point coupled to each phase of the three-phase input through a corresponding impedance, thereby enabling phase-condition information to be obtained directly from the three-phase input and facilitating reliable detection of an abnormal or missing phase condition. Such an arrangement advantageously permits the condition of the three input phases to be evaluated from a common reference point without requiring separate phase-to-phase voltage or phase-current measurements, thereby providing a simple and effective manner of monitoring the condition of the multiphase input. The modification would further provide phase-condition information directly associated with the power received at the input, thereby allowing the welding-type power supply to more reliably determine the condition of the incoming power and take appropriate protective or control action.
For given above reasons, Applicant’s arguments regarding the prior art Anders and that there is no motivation to modify Anders, and that it’s not obvious to modify Anders, are not persuasive. Accordingly, Anders in view of Evans properly teaches all limitations recited in the amended claim 1, see detailed rejection in the 35 U.S.C. Claim Rejections section below.
Specification
The title of the invention is not descriptive. A new title is required that is clearly indicative of the invention to which the claims are directed.
The following title is suggested: SYSTEMS TO DETECT THREE-PHASE INPUT POWER AND CHANGE-OF-PHASE ON THREE-PHASE INPUT POWER.
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 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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-2, 4-5, 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over Anders et al. (U.S. Pub. No. 2019/0337081 A1, previously cited) in view of Evans (EP 0041374 A1, newly cited, Reference is attached).
Regarding claim 1, Anders discloses a welding-type power supply (welding-type power supply 100, Anders Fig.1), comprising:
power conversion circuitry (rectifier circuit 106, Anders Fig.1) configured to convert three-phase input power to welding-type power (Anders Par.0023 discloses: “The welding-type power supply includes an input 102 configured to receive AC input power from a power source 104. The power source 104 may be the AC power grid, an engine/generator set, or a combination thereof. The power source 104 may provide single phase AC power or three-phase AC power to the input. The welding-type power supply 100 also includes a rectifier circuit 106 to condition the AC power received at the input 102 to DC power at a DC power bus 108. A welding inverter 110 provides power from the DC power bus 108 to a welding output 112. The welding output 112 provides welding-type power to a welding-type load 114, for example a welding torch.”), the three-phase input power received at an input (input 102, Anders Fig.1) (Anders discloses the three-phase input power received at an input because Anders Par.0023 discloses: “The welding-type power supply includes an input 102 configured to receive AC input power from a power source 104. The power source 104 may be the AC power grid, an engine/generator set, or a combination thereof. The power source 104 may provide single phase AC power or three-phase AC power to the input. The welding-type power supply 100 also includes a rectifier circuit 106 to condition the AC power received at the input 102 to DC power at a DC power bus 108.”); and
a phase detection circuit (detection circuit of the processor 122 [see the processor 122 in Anders Fig.1] because Anders Par.0029 discloses the processor 122 is configured to determine number of phases; thus, there is detection circuit associated with the processor 122) configured to determine a number of phases connected to the input (input 102, Anders Fig.1) based on comparing a frequency of a signal at a reference point to a threshold frequency (Anders Par.0029 discloses: “The processor 122 determines the frequency of the ripple on the DC power bus 108, and compares the frequency to the AC input frequency (e.g., measured or known) and/or to a threshold frequency between twice the AC input frequency and six times the AC input frequency. If the ripple frequency is twice the AC input frequency or less than the threshold frequency, then the processor 122 determines that single phase AC power is connected to the input 102. Conversely, if the ripple frequency is six times the AC input frequency or greater than the threshold frequency, then the processor 122 determines that three-phase AC power is connected to the input 102.”).
Anders does not explicitly disclose:
a reference node coupled to each winding of the three-phase input power via a corresponding impedance; and
the phase detection circuit coupled to the reference node
Evans teaches a device for detecting a fault in a three-phase system having a three-phase supply (Evans Fig.1, Evans on page 1 lines 19-20 teaches: “Figure 1 shows an example of a device for detecting a fault in a three-phase system”, and Evan on page 2 lines 18-23 teaches: “The sides of the capacitors and the sides of the resistors remote from their star points are connected respectively to the red, yellow and blue lines R, Y, and B of a three-phase supply, the device comprising an artificial load for the supply.”)
a reference node (reference node is the common junction of C1, C2, C3; see annotated Fig.1 of Evans below) (Evans on page 2 lines 14-16 teaches: “To the star point of the capacitors, there is connected a sensing lead 1”) coupled to each winding of the three-phase input power (each of red, yellow and blue lines R, Y, and B of “three-phase supply”, Evans Fig.1 & on page 2 lines 18-23) (Evans on page 2 lines 18-23 teaches: “The sides of the capacitors and the sides of the resistors remote from their star points are connected respectively to the red, yellow and blue lines R, Y, and B of a three-phase supply, the device comprising an artificial load for the supply.”) via a corresponding impedance (capacitors C1, C2, C3; Evans Fig.1); and
the phase detection circuit (phase-fault detection/tripping circuitry coupled to the capacitor star point via sensing lead 1, Evans Fig.1 & as explained in details from line 25 of page 1 to line 12 of page 4) coupled to the reference node (the reference node is the common junction of C1, C2, C3; see annotated Fig.1 of Evans below) (the phase-fault detection/tripping circuitry coupled to the capacitor star point via sensing lead 1 coupled to the reference node because Evans on page 2 lines 14-16 teaches: “To the star point of the capacitors, there is connected a sensing lead 1”, Evan teaches that, upon failure of one or two phases, the star point/reference node is no longer at zero potential and current flows through sensing lead 1, thereby enabling detection of the phase-failure condition, Evans from line 25 of page 1 to line 10 of page 2 teaches: “A triple pole, with or without a neutral, earth leakage circuit breaker detects and automatically isolates an earth fault in a circuit controlled by it, but does not detect a single phase fault. The examples to be described of devices in combinations according to the present invention enable the additional feature of detecting such a fault, so as to automatically isolate a circuit or part of a circuit in the event of one or two phases failing in a three-phase supply. The device could be an integral part of an earth leakage circuit breaker, or a completely separate device to work in conjunction with it. The device could be in a balanced or an unbalanced system and could be used, for example, with motors, overhead lines or feeder cables.”, and Evans on page 3 lines 7-24 teaches: “Under correct operating conditions, the star or neutral point of the device, comprising an artificial load for the supply is at zero potential and no current will flow through the sensing lead 1 when the neutral or star point is connected to the neutral or star point of the supply transformer. Should one or two phases fail, the neutral or star point of the device is no longer at zero potential, and current will now flow to the star or neutral point of the supply transformer and this current can be utilised to trip an earth leakage circuit breaker if the sensing lead 1 is connected to neutral at a point before the neutral enters the core balance transformer of the current-operated earth leakage circuit breaker. As mentioned above, the device could be separate from the earth leakage circuit breaker or an integral part of it.”)
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It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the three-phase input of Anders to include the common star-point sensing arrangement taught by Evans, wherein the common reference node coupled to each winding of the three-phase input power via corresponding impedance, and the phase detection circuit coupled to the reference node, as taught by Evans, in order to provide a common sensing point responsive to the collective electrical condition of the three input phases, thereby permitting a change in the phase condition, including loss of one or more phases, to produce a detectable change at a single sensing location and facilitating reliable determination of the condition of the three-phase input.
Regarding claim 2, Anders in view of Evans teaches the apparatus set forth in claim 1, and also teaches:
wherein the reference node (the reference node is the common junction of C1, C2, C3; see annotated Fig.1 of Evans below; as cited and incorporated in the rejection of claim 1 above) is coupled to each winding of the three-phase input power (each of red, yellow and blue lines R, Y, and B of “three-phase supply”, Evans Fig.1 & on page 2 lines 18-23) (Evans on page 2 lines 18-23 teaches: “The sides of the capacitors and the sides of the resistors remote from their star points are connected respectively to the red, yellow and blue lines R, Y, and B of a three-phase supply, the device comprising an artificial load for the supply.”) via a respective capacitor (capacitors C1, C2, C3, Evans Fig.1; as cited and incorporated in the rejection of claim 1 above).
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Regarding claim 4, Anders in view of Evans teaches the apparatus set forth in claim 1, Anders also discloses further comprising
control circuitry (control circuitry of the processor 122 [see the processor 122 in Anders Fig.1]) configured to control the power conversion circuitry (rectifier circuit 106, Anders Fig.1) based on whether single-phase power or three-phase power is detected on the input (input 102, Anders Fig.1) (Anders Par.0047 discloses: “If the filtered difference exceeds the threshold, then the processor 122 determines that single phase AC power is connected to the input. If the filtered difference is below the threshold, then the processor 122 determines that three-phase AC power is connected to the input. If three-phase AC power is connected to the input 102 (block 422), the welding-type power supply may continue normal operation. In some examples, the processor 122 may continue to monitor for a single phase AC input power condition even after determining that three-phase power AC is connected to the input. Therefore, the processor 122 may return to block 408 and repeat blocks 408-420. A welding-type power supply may continuously monitor for single phase AC input power because for example, a fault on an input line may cause three-phase AC power supplied to the input to become single phase AC power. Therefore, the processor 122 may be configured to continuously monitor for a single phase AC input power condition.”, and Anders Par.0048 discloses: “If at block 420, if the filtered difference exceeds the threshold, then the processor 122 determines that single phase AC power is connected to the input (block 424). Then at block 426, the processor 122 can take steps to protect the welding-type power supply or equipment connected to the welding type power supply from damage caused by a single phase AC input. For example, the processor 122 may power down the welding-type power supply in response to determining that single phase power is connected to the input of the welding-type power supply. In some examples, the processor 122 may disable the welding output 112 or the auxiliary output 118. In some examples, the processor 122 may limit the output of the welding inverter 110 to less than a threshold power level.”).
Regarding claim 5, Anders in view of Evans teaches the apparatus set forth in claim 4, Anders also discloses
wherein the control circuitry (control circuitry of the processor 122 [see the processor 122 in Anders Fig.1]) is configured to control at least one of an output current of the power conversion circuitry, an output voltage of the power conversion circuitry, an output power of the power conversion circuitry, a thermal shutdown limit, or output load shedding based on whether single- phase power or three-phase power is detected on the input (It is noted that the limitation “at least one of an output current of the power conversion circuitry, an output voltage of the power conversion circuitry, an output power of the power conversion circuitry, a thermal shutdown limit, or output load shedding” is in alternative form; therefore, only one these was required during examination. In this case, Anders discloses the control circuitry of the processor 122 is configured to control an output power of the power conversion circuitry based on whether single-phase power or three-phase power is detected on the input because Anders Par.0025 discloses: “When the processor 122 determines that single phase power is connected to the input, the processor 122 can take steps to protect the welding-type power supply, or equipment powered by the welding-type power supply from damage. In some examples, the processor 122 may power down the welding-type power supply 100 in response to determining that single phase power is connected to the input 102. Additionally or alternatively, the processor 122 may disable the welding output 112 and/or the auxiliary output 118, and/or may limit the output of the welding inverter 110 to less than a threshold power level. The threshold power level may be a threshold current, a threshold duty cycle, and/or any other threshold power level that limits the heat generated by the rectifier 106, the welding inverter 110, and/or the auxiliary inverter 116.”, Anders Par.0047 discloses: “If the filtered difference is below the threshold, then the processor 122 determines that three-phase AC power is connected to the input. If three-phase AC power is connected to the input 102 (block 422), the welding-type power supply may continue normal operation. In some examples, the processor 122 may continue to monitor for a single phase AC input power condition even after determining that three-phase power AC is connected to the input. Therefore, the processor 122 may return to block 408 and repeat blocks 408-420. A welding-type power supply may continuously monitor for single phase AC input power because for example, a fault on an input line may cause three-phase AC power supplied to the input to become single phase AC power. Therefore, the processor 122 may be configured to continuously monitor for a single phase AC input power condition.”, and Anders Par.0048 discloses: “If at block 420, if the filtered difference exceeds the threshold, then the processor 122 determines that single phase AC power is connected to the input (block 424). Then at block 426, the processor 122 can take steps to protect the welding-type power supply or equipment connected to the welding type power supply from damage caused by a single phase AC input. For example, the processor 122 may power down the welding-type power supply in response to determining that single phase power is connected to the input of the welding-type power supply. In some examples, the processor 122 may disable the welding output 112 or the auxiliary output 118. In some examples, the processor 122 may limit the output of the welding inverter 110 to less than a threshold power level.”).
Regarding claim 8, Anders in view of Evans teaches the apparatus set forth in claim 1, Anders also discloses:
wherein the power conversion circuitry (rectifier circuit 106, Anders Fig.1) is further configured to convert single-phase input power to the welding-type power (Anders discloses the rectifier circuit 106 is configured to convert single-phase input power to the welding-type powder because Anders Par.0019 discloses: “Disclosed methods of detecting whether single phase alternating current (AC) power is connected to an input of a welding-type power supply include providing AC input power to the input; converting, via a rectifier circuit, the AC input power to direct current (DC) power; and detecting whether single-phase AC power is coupled to the input by monitoring voltage samples of the DC power using a voltage sampling timing based on a frequency and voltage of AC power connected to the input.”).
Regarding claim 9, Anders in view of Evans teaches the apparatus set forth in claim 4, Anders also discloses:
wherein the control circuitry (control circuitry of the processor 122 [see the processor 122 in Anders Fig.1]) is configured to, in response to detecting single-phase input power via the phase detection circuit (detection circuit of the processor 122 [see the processor 122 in Anders Fig.1] because Anders Par.0029 discloses the processor 122 is configured to determine number of phases; thus, there is detection circuit associated with the processor 122, as cited and explained in the rejection of claim 1 above), at least one of output a notification, output an alarm, or disable output by the power conversion circuitry (It is noted that the limitation “at least one of output a notification, output an alarm, or disable output by the power conversion circuitry” is in alternative form; therefore, only one these was required during examination. In this case, Anders discloses output an alarm because Anders Par.0048 discloses: “the processor 122 may signal an alarm to indicate that single phase power is connected to the input 102”).
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Anders et al. (U.S. Pub. No. 2019/0337081 A1, previously cited) in view of Evans (EP 0041374 A1, newly cited, Reference is attached), and further in view of Kane (U.S. Pub. No. 2016/0164448 A1, newly cited).
Regarding claim 3, Anders in view of Evans teaches the apparatus set forth in claim 2, but does not explicitly teach:
wherein the respective capacitor is configured to perform filtering of the input to reduce electromagnetic emissions.
Kane teaches a three-phase input (Kane Fig.4 & Par.0030):
wherein the respective capacitor (Kane Fig.4 shows that phase A to a first capacitor to the common point 21, phase B to a second capacitor to the common point 21, and phase C to a third capacitor to the common point 21) is configured to perform filtering of the input to reduce electromagnetic emissions (Kane teaches the respective capacitor is configured to perform filtering of the input to reduce electromagnetic emissions because Kane Fig.4 shows “Wye connected capacitors act as short circuit at high frequency”, Kane teaches that EMI/RFI sources generated by active converter 202 are filtered by input filter 10, which includes capacitive three-phase filter element 20; Kane further explains that the line- and load- side inductors 26 and 28, respectively, and the capacitive filter element 20 are designed with inductance and capacitance values to provide a roll off of the EMI/RFI sources—i.e., high frequency switching components of the input current conducted by the converter 202, Kane also teaches that the filter operates to restrict or limit high frequency emissions from reflecting back to the AC power source 102, and Kane further teaches that the wye-connected capacitor bank provides a low-impedance path for switching frequency currents to earth for reducing common-mode current flow; specifically, Kane Par.0030 teaches: “EMI/RFI sources generated by the Active Converter 202 are filtered ahead of the converter 202 by splitting a three-phase AC input inductor 16 into a line-side inductor 26 and load-side inductor 28 per phase. The line-side inductors 26 and load-side inductors 28 are connected by inductor tap portions 18. A capacitive three-phase filter element 20 is wye-connected between the inductor tap portions 18. An optional earth connection 22 may be connected to a common point 21 of the wye-connected filter element 20. The earth connection 22 may alternately include a grounding capacitor 23. The line- and load- side inductors 26 and 28, respectively, and the capacitive filter element 20 are designed with inductance and capacitance values to provide a roll off of the EMI/RFI sources—i.e., high frequency switching components of the input current conducted by the converter 202. The input filter provides a high impedance via the differential mode inductive components of inductances 26 and 28 and a low impedance via the three-phase wye connected capacitance 20 to the EMI/RFI sources, while passing the fundamental component of the power current, e.g., 60 Hz, through the network with minimal impedance. By utilizing a four- or five-legged (4/5) input inductor 16, a common mode inductive component is formed via inductances 26 and 28 and together with the optional earth connection 22 or the grounding capacitor 23, increases to the capacity of the filter 10 acts to prevent common mode current generated by the converter 202 from flowing into the mains power source 102. The wye-connection point 21 of the input filter 10 may be directly earthed or alternately earthed through a separate capacitor 23 to provide greater shunting of high-frequency currents to earth.”, furthermore, Kane Par.0031 teaches: “Line-side inductors 26 provide impedance at a predetermined switching frequency of the VSD 104 between the wye-connected capacitors 20 and the AC power source 102. The impedance of the line-side inductors 26 is designed to allow the wye-connected capacitors 20 to be more effective than a system with no significant impedance between the input AC mains 102 and the VSD 104. Inductors 26 also provide high-frequency impedance in the reverse direction, to restrict the flow of high-frequency current from the converter 202 to the AC power source 102. Thus the inductors 26 restrict or limit high frequency emissions from reflecting back to the AC power source 102.”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Anders in view of Evans, by adding the teaching of the respective capacitor is configured to perform filtering of the input to reduce electromagnetic emissions, as taught by Kane, in order to provide a low-impedance path for high-frequency EMI/FRI components and thereby restrict or reduce high-frequency electromagnetic emissions from being conducted back toward the AC power source, while permitting the fundamental power-current component to pass with minimal impedance.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Anders et al. (U.S. Pub. No. 2019/0337081 A1, previously cited) in view of Evans (EP 0041374 A1, newly cited, Reference is attached), and further in view of Cripe (U.S. Patent No. 8,089,786 B1, newly cited).
Regarding claim 6, Anders in view of Evans teaches the apparatus set forth in claim 1, but does not explicitly teach:
wherein the signal comprises a ripple signal at the reference node.
Cripe teaches:
wherein the signal comprises a ripple signal at the reference node (Cripe Fig.3 & Col.7 lines 49-50 teaches a ripple voltage at an input star point (common/reference point/node) and an output star point (common/reference point/node), and Cripe Fig.3 & Col.8 lines 38-43 further teaches the amplitude and frequency of a ripple present at a transformer star point, and further teaches that the amplitude of the ripple voltage at the star point may be reduced through the reference multiphase configuration.).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Anders in view of Evans, by adding the teaching of the signal comprises a ripple signal at the reference node, as taught by Cripe, in order to permit the ripple condition at the common/star node to be identified and accounted for, thereby facilitating reduction of undesirable ripple and improving power-conversion performance since Cripe recognizes reducing input and output ripple signals as advantageous because doing so reduces the requirement for low-pass filtering and permits increased power-modulator bandwidth [Cripe, Col.4 lines 25-37].
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Anders et al. (U.S. Pub. No. 2019/0337081 A1, previously cited) in view of Evans (EP 0041374 A1, newly cited, Reference is attached), Cripe (U.S. Patent No. 8,089,786 B1, newly cited), and further in view of Smith (U.S. Patent No. 5,548,207 A, newly cited).
Regarding claim 7, Anders in view of Evans and Cripe teaches the apparatus set forth in claim 6, but does not explicitly teach:
wherein the ripple signal at the reference node is AC-coupled to the phase detection circuit.
Smith teaches a missing phase detector circuit (Smith Abstract & Fig.2):
wherein the ripple signal at the reference node is AC-coupled to the phase detection circuit (analyzer circuit 30, Smith Fig.2) (Smith Col.2 line 62 to Col.3 line 9 teaches: “The device comprises an isolation transformer 26, a three-phase rectifier 28, a voltage center reference circuit and an analyzer circuit 30 … The output of the rectifier 28 is connected to a termination resistor 31, producing a rectified signal waveform with respect to logic ground. This rectified signal, which has a ripple wave shape, is AC coupled to a voltage center reference circuit through a coupling capacitor 32, a resistor 35 and to a voltage reference (Vref) 34 terminating the resistor.”; therefore, Smith teaches the ripple signal is AC-coupled to the phase detection circuit. It is noted that Cripe already teaches the ripple signal at the reference node, as cited and incorporated in the rejection of claim 6 above; therefore, by adding the teaching of the ripple signal is AC-coupled to the phase detection circuit, as taught by Smith, in combination, Anders in view of Evans, Cripe and Smith teaches the ripple signal at the reference node is AC-coupled to the phase detection circuit.).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Anders in view of Evans and Cripe, by making the ripple signal is AC-coupled to the phase detection circuit, as taught by Smith, in order to couple the AC ripple component used for phase detection to the detection circuitry while establishing the ripple waveform about a suitable reference voltage for subsequent analysis, thereby facilitating reliable detection of a missing phase based on characteristics of the ripple waveform.
Conclusion
The following prior art(s) made of record and not relied upon is/are considered pertinent to Applicant’s disclosure.
Thomas (U.S. Pub. No. 2011/0011842 A1) discloses a method and apparatus for providing three-phase input to a welding type power source. The power source is capable of receiving wide range of three-phase input voltage and rectifies the AC input into a DC power capable for welding application.
Thommes (U.S. Patent No. 7,319,206 B2) discloses a method and apparatus for providing a welding current. A power source is capable of receiving any input voltage over a wide range of input voltages and includes an input rectifier that rectifies the AC input into a DC signal. A DC voltage stage converts the DC signal to a desired DC voltage and an inverter inverts the DC signal into a second AC signal. An output transformer receives the second AC signal and provides a third AC signal that has a current magnitude suitable for welding.
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.
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/THAO UYEN TRAN-LE/Examiner, Art Unit 3761 08/17/2026
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