DETAILED ACTION
This Office action is in response to the amendment filed on 03 December 2025.
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
Applicant’s arguments with respect to claims 1-11 have been considered but are moot because the new grounds of rejection do not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claim Objections
Claim 6 is objected to because of the following informalities:
In claim 6, the amendment to delete “each of” at line 1 in response to the previous rejection under 35 U.S.C. 112(b) is noted. However, another instance of this phrasing appears at line 3. The scope of the claim is considered to be definite given the apparently bona fide attempt to correct the issues raised in the rejection, however the instance at line 3 must be similarly corrected to that at line 1. Appropriate correction is required.
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.
Claims 1-9 are rejected under 35 U.S.C. 103 as being unpatentable over Nishikawa (US Patent 9,379,617; “Nishikawa”) in view of Chen et al. (US 2018/0234028; “Chen” – previously made of record in the 26 September 2023 IDS).
In re claim 1, Nishikawa discloses a power converter (Fig. 1), comprising:
an isolated DC-DC converter (100) comprising:
a first stage (Q1-Q4) capable of converting a DC voltage (Vin) into a first high frequency AC voltage (Vuv) having an amplitude Vi (amplitude of Vuv);
an intermediary stage (Tr) having a high frequency transformer (Tr), wherein a turns ratio (Col. 2:8-11 , n=NP:NS) of the high frequency transformer equals a ratio of the high frequency AC voltage and a second high frequency AC voltage (as understood to a person of ordinary skill in the art from the estimated voltage conversion rate given at id. as well routine circuit analysis for a transformer circuit, the ratio of the primary voltage Vuv to the voltage across secondary winding NS (hereinafter “VNS”) may also be expressed or estimated as the ratio n);
a resonant tank (Lr, Cr, and the inherent magnetizing inductance of primary winding NP) operably connected to the first stage (Q1-Q4) and a primary winding (NP) of the high frequency transformer (TR) of the intermediary stage, wherein the resonant tank when excited by a square waveform (Vuv; see bottom graph of Fig. 7) generated by the first stage (Q1-Q4) outputs a resonant sinusoidal current that is scaled by the high frequency transformer (see Fig. 8 and Col. 9: 58-67); and
a second stage (Fig. 1: D1-D4), electrically coupled to a secondary winding (NS) of the high frequency transformer (TR) of the intermediary stage, comprising four diodes (D1-D4), and a capacitor (Co), electrically coupled to one another (see Fig. 1), wherein the second stage selectively converts the second high frequency AC voltage of an amplitude V2 (amplitude of VNS) into a DC voltage (Vout) of amplitude equaling V2 (i.e., based on the expression given at Col. 2:8-11, of conversion ratio M=n*Vo/Vin which is understood to be an approximation when the voltage drops across any conducting switches/diodes are neglected, and is approximately equal to the similar expression, as explained above, for an ideal transformer circuit, that n=NP/NS=VUV/VNS).
Nishikawa does not disclose the second stage as further comprising a power conversion switch having a diode connected in parallel across the power conversion switch, separate from the four diodes, and two or more capacitors, and where the second stage may also selectively convert the second high frequency AC voltage of amplitude V2 into a DC voltage of amplitude equaling 2V2.
Whereas Chen discloses a hybrid full bridge-voltage doubler rectifier topology (Fig. 3A), in addition to four diodes in a full-bridge structure (D1-D4), a power conversion switch (S) having a diode connected in parallel across the power conversion switch (see Fig. 3A), separate from the four diodes (as shown), and two capacitors (C1, C2), connected and controlled such that the rectifier may selectively produce an output voltage (Vo_FBVD_1) with amplitude approximately equal to the input AC voltage amplitude ([0111]-[0115] and Fig. 6: in full bridge mode with switch S turned OFF, Vo_FBVD_1 approximately equals amplitude of Vac) or two times the input voltage amplitude ([[0105]-[0109] and Fig. 4: with switch S turned ON, the circuit operates as a voltage doubler to produce an output Vo_FBVD_1 that is approximately twice the amplitude of the AC input voltage VAC). The ability to select between these modes enables the rectifier to accommodate a wider range of input voltages ([0098]).
Therefore it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the power converter of Nishikawa by including, in the second stage, a power conversion switch having a diode connected in parallel across the power conversion switch, separate from the four diodes, and two or more capacitors, connected in the manner shown by Chen, and controlling the power conversion switch such that the second stage may also selectively perform a voltage doubling function to convert the second high frequency AC voltage of amplitude V2 into a DC voltage of amplitude equaling 2V2, as taught by Chen, in order to enable the second stage rectifier to operate across a wider input voltage range produced by the first stage and the transformer, and thus enabling the power converter as a whole to accommodate a larger range of voltages input to the first stage.
In re claim 2, Nishikawa discloses wherein the first stage (see Fig. 1) comprises four power conversion switches (Q1-Q4) electrically coupled to the resonant tank (Lr, Cr, magnetizing inductance of NP) such that:
a second terminal of a first power conversion switch is connected to a first terminal of a second power conversion switch and a first end of a resonant inductor of the resonant tank (source of Q1 connected to drain of Q2 and first end of Lr);
a first terminal of the first power conversion switch is connected to a first terminal of a third power conversion switch (drain of Q1 connected to drain of Q3), and
a second terminal of the second power conversion switch is connected to a second terminal of a fourth power conversion switch (source of Q2 connected to source of Q4); and
a second terminal of the third power conversion switch is connected to a first terminal of the fourth power conversion switch, and a first end of a resonant capacitor of the resonant tank (source of Q3 connected to drain of Q4 and first end of Cr).
In re claim 3, Nishikawa discloses wherein the resonant tank (see Fig. 1) comprises a resonant inductor (Lr), a resonant capacitor (Cr), and a transformer magnetizing inductor (not explicitly shown, but it is understood by one of ordinary skill to be an inherent inductance associated with transformer Tr and specifically its primary winding NP) operably connected to one another such that:
a second end of the resonant inductor is connected to a first end of the transformer magnetizing inductor (not explicitly shown, but see above explanation and the connection of Lr to primary winding NP),
wherein a first end of the resonant inductor is connected to a second terminal of a first power conversion switch and a first terminal of a second power conversion switch of the first stage (Lr connected to Q1 and Q2);
a second end of the resonant capacitor is connected to a second end of the transformer magnetizing inductor (see explanations above and connection of Cr to NP),
wherein a first end of the resonant capacitor is connected to a second terminal of a third power conversion switch and a first terminal of a fourth power conversion switch of the first stage (Cr connected to Q3 and Q4); and
the first end of the transformer magnetizing inductor is connected to a first end of the primary winding of the high frequency transformer of the intermediary stage and a second end of the transformer magnetizing inductor is connected to a second end of the primary winding of the high frequency transformer (see explanations above: the magnetizing inductor or inductance is understood as being an inductance that is at least a portion of the physical primary winding’s inductance and/or is analyzed as being a parallel inductance to the primary winding).
In re claim 4, the proposed modifications of Nishikawa in view of Chen would further result in that in the second stage (see Fig. 1 of Nishikawa, as modified in view of Fig. 3A of Chen as proposed), the power conversion switch (Chen: switch S), the four diodes (Nishikawa or Chen: D1-D41), and the two or more capacitors (Chen: C1, C2) are arranged across a secondary winding of the high frequency transformer (that is, the modification, as proposed, is made to Nishikawa’s circuit, resulting in the additional rectifier components incorporated from Chen also being connected across winding NS of transformer Tr in Nishikawa’s Fig. 1) such that:
a first terminal of a first diode is connected to a second terminal of a second diode and a first end of the secondary winding (Nishikawa: D1 connected to D2 and NS);
a first terminal of the second diode is connected to a first terminal of a fourth diode and a negative terminal of a second capacitor (Nishikawa: D2 connected to D4, and Chen: D2 connected to D4 and C2);
a second terminal of the fourth diode is connected to a second terminal of the power conversion switch (Chen: D4 connected to S;
a first terminal of the power conversion switch is connected to a first terminal of a third diode (Chen: S connected to D3), (Chen: S connected to D3, C2, and C1); and
a second terminal of the first diode is connected to a second terminal of the third diode (Nishikawa and Chen: D1 connected to D3) and to a positive terminal of the first capacitor (Chen: D1 and D3 also connected to C1).
The modification of Nishikawa in view of Chen as proposed would not have resulted in the second terminal of the power conversion switch connected to a second end of the secondary winding, and the first terminal of the power conversion switch connected to a positive terminal of the second capacitor and a negative terminal of a first capacitor (essentially, Chen has these connections flipped with respect to the two terminals of switch S).
However, through basic circuit analysis of Chen’s rectifier, which is well within the ordinary level of skill in the art, it can be seen that when switch S is turned ON in full bridge mode, the two terminals of switch S are effectively short circuited, resulting in the connections as claimed; on the other hand, when switch S is turned OFF in voltage doubler mode, the only difference between Chen’s circuit and the flipped connections of claim 4 is that an additional diode drop, across the parallel diode of S, is either part of the upper bridge arm with D3 (in Chen’s circuit), or part of the lower bridge arm with D4 (in the claimed circuit).
Therefore, before the effective filing date of the claimed invention, the person of ordinary skill in the art would have found the connections recited in claim 4 to produce almost identical circuit operation through use of basic circuit analysis. The difference would have been a matter of obvious design choice, in selecting whether the additional diode drop is made in the upper or lower bridge arm of the rectifier based on which half cycle of the input AC voltage that the switch’s parallel diode conducts. The obvious variant in the design could be chosen, for instance, based on layout considerations of the four diodes, the power conversion switch, and the two capacitors of the second stage on a printed circuit board, as well as their connections to any power, ground, or mid-point node conductive traces or planes. That is, the choice in variants could be envisioned the ordinary artisan to result in longer or shorter copper traces for these connections, producing a routine engineering trade-off in power loss, size, and/or thermal characteristics of the circuitry.
In re claim 5, the proposed modifications of Nishikawa in view of Chen would further result in that in the second stage (see Fig. 1 of Nishikawa, as modified in view of Fig. 3A of Chen as proposed), the power conversion switch (Chen: switch S), the four diodes (Nishikawa and Chen: D1-D4; see supra note 1), and the two or more capacitors (Chen C1, C2) are arranged across a secondary winding of the high frequency transformer (that is, the modification, as proposed, is made to Nishikawa’s circuit, resulting in the additional rectifier components incorporated from Chen also being connected across winding NS of transformer Tr in Nishikawa’s Fig. 1) such that:
a first terminal of a first diode is connected to a second terminal of a second diode and a first end of the secondary winding (Nishikawa: D1 connected to D2 and NS);
a first terminal of the second diode is connected to a first terminal of a fourth diode and a negative terminal of a second capacitor (Nishikawa: D2 connected to D4, and Chen: D2 connected to D4 and C2);
a second terminal of the fourth diode is connected to a second terminal of the power conversion switch, a positive terminal of the second capacitor and a negative terminal of a first capacitor (Chen: D4 connected to S, C1, and C2);
a first terminal of the power conversion switch is connected to a first terminal of a third diode and a second end of the secondary winding (Chen: S connected to D3 at the second (lower) input terminal, and in Nishikawa, the lower input terminal of the second stage is the second end of winding NS); and
a second terminal of the first diode is connected to a second terminal of the third diode and to a positive terminal of the first capacitor (Nishikawa: D1 connected to D3 and in Chen: D1 connected to D3 and to C1).
In re claim 6, the proposed modifications of Nishikawa in view of Chen would further result in that the power conversion switch (Chen, Fig. 3A: switch S), when in an off state, blocks a positive DC voltage applied across the first terminal and the second terminal of the power conversion switch (due to presence of the parallel diode as shown in Chen).
In re claim 7, the proposed modifications of Nishikawa in view of Chen would further result in that: the power conversion switch when in a closed state enables the second stage to generate the DC voltage having the amplitude 2V2 corresponding to the second high frequency AC voltage of the amplitude V2 (see Chen at [0105]-[0109] and Figs. 3A, 4: with switch S turned ON, the circuit operates as a voltage doubler to produce an output Vo_FBVD_1 that is approximately twice the amplitude of the AC input voltage VAC); and
the power conversion switch when in an open state enables the second stage to generate the DC voltage having the amplitude V2 corresponding to the second high frequency AC voltage having the amplitude V2 (see Chen at [0111]-[0115] and Fig. 6: in full bridge mode with switch S turned OFF, Vo_FBVD_1 approximately equals amplitude of Vac).
In re claim 8, the proposed modifications of Nishikawa in view of Chen would further include a control unit (Nishikawa at Fig. 1: control device Cont; it is noted that the proposed modification of Nishikawa’s converter would necessitate modification to the control device Cont to produce the functional operation of the power conversion switch taught by Chen) controlling the power converter according to claim 1 (see explanation of claim 1, above in this Office action) wherein the control unit comprises one or more controllers (see Chen at [0059], teaching the controllers which form the basis for modifying Nishikawa’s control device as explained above) configured to selectively switch the power conversion switch, of the second stage of the isolated DC-DC converter of the power converter, between a closed state and an open state (as taught in Chen and cited above in this Office action). Furthermore, Nishikawa teaches the intended use of the power converter is to charge a battery of an electric vehicle when connected to a vehicle-side module connectable to the power converter (see Nishikawa at col. 12:24-28).
However, neither Nishikawa nor Chen explicitly disclose controlling the power conversion switch based on a voltage requirement of the battery. Nonetheless, based on the teachings in Chen that he power conversion switch is operable to selectively cause the second stage to either output a voltage substantially equal to its input voltage or to output a voltage substantially equal to twice its input voltage, it would have been obvious to the person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the control unit of Nishikawa in view of Chen to control the operation of the switch to produce different output voltages based on the voltage required by load of the power converter, being the battery of the electric vehicle as taught in Nishikawa.
In re claim 9, the proposed modifications of Nishikawa in view of Chen would further include a charging device for transferring power to an electric vehicle from a power grid (see Nishikawa at Fig. 1 and at col. 12:24-28), wherein the charging device comprises: the control unit according to claim 8 (see explanation of claim 8, above); the power converter, being controlled by the control unit (see Nishikawa at Fig. 1, as modified according to Chen as proposed with respect to claim 1, above in this Office action); a grid-side module (for instance, including the primary-side circuitry and the connections to the source circuit Ed as shown in Nishikawa) capable of receiving one of an AC voltage and a DC voltage from the power grid (the electrical connections are inherently capable of the function of receiving a voltage); a vehicle-side module (for instance, including the secondary-side circuitry and connection to the vehicle battery at Vout in Nishikawa) capable of delivering the DC voltage to the electric vehicle (the electrical connections are inherently capable of the function of delivering a voltage), and wherein the vehicle-side module is electrically coupled to the grid-side module via the power converter (as shown in Fig. 1 of Nishikawa).
Claims 10-11 are rejected under 35 U.S.C. 103 as being unpatentable over Nishikawa and Chen as applied to claims 1 and 8-9 above, and further in view of DE 102017120298 A1, having the named inventor H.J. Pfisterer (hereinafter “Pfisterer”; see the machine translation into English of Pfisterer, cited and provided with the Office action dated 19 August 2025).
In re claim 10, the modification of Nishikawa in view of Chen, as proposed above in this Office action, would necessarily further include a method for transferring power between an electric vehicle and a power grid using the charging device according to claim 9 (that is, the functional operation of the device in the combined prior art, as described above, would necessarily perform the claimed method). However, Nishikawa and Chen do not disclose the method comprising detecting a physical connection of the electric vehicle to the vehicle-side module of the charging device; and selectively operating the bi-directional power converter of the charging device in one of a power conversion mode and a power inversion mode.
Whereas Pfisterer discloses methods for operating an electric vehicle charging station (Fig. 1) in which vehicles connecting to the charging columns (2) to be charged are detected by a main controller (8) through various communication protocols as well as through a user interface (see paragraphs (31), (79) in machine translation; Fig. 5), and the charging column with switching power converter (2; see Figs. 2, 4 as examples) are controlled through appropriate selection to operate in any of various modes, including modes for rectification (i.e., conversion) and inversion (see Abstract, paragraphs (14), (19)). The charging station can thus operate in a flexible manner to control transfer of power as needed, both to and from the vehicles as well as other associated power networks, loads, or sources connected to the charging station (paragraphs (19)-(22)).
Therefore it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the apparatus and method from the combination of Nishikawa and Chen to include detecting a physical connection of the electric vehicle to the vehicle-side module of the charging device; and selectively operating the bi-directional power converter of the charging device in one of a power conversion mode and a power inversion mode as taught by Pfisterer, in order to enable a flexible operation of the system through its bidirectional power flow capabilities.
In re claim 11, the combination of Nishikawa, Chen, and Pfisterer would necessarily further result in that the power conversion switch when in the closed state enables the second stage to generate the DC voltage having an amplitude 2V2 corresponding to a high frequency AC voltage of the amplitude V2, and when in an open state enables the second stage to generate the DC voltage having an amplitude V2 corresponding to the high frequency AC voltage having the amplitude V2 (see citations to Nishikawa and Chen as well as examiner’s explanations provided above with respect to the same limitations of claim 7).
Conclusion
Applicant's amendment necessitated the new grounds 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 FRED E FINCH III whose telephone number is (571)270-7883. The examiner can normally be reached Monday-Friday, 8:00 AM - 4:30 PM ET.
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/FRED E FINCH III/Primary Examiner, Art Unit 2838
1 For cross-referencing the cited figures, it is noted that the four diodes D1-D4 in Nishikawa are equivalent to the corresponding four diodes D1-D4, respectively, in Chen