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 § 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.
Claims 1–19 are rejected under 35 U.S.C. 103 as being unpatentable over Yu (US 2021/0028712 A1 hereinafter “Yu”) in view of Umetani (US 2014/0218012 A1 hereinafter “Umetani”).
As to claim 1, Yu discloses in Figs. 1, 2 and 3: a switching power supply (power conversion system 200 / power converter 210 as shown in Fig. 2) comprising:
an energy transfer element comprising a primary winding, a secondary winding, and a core (transformer T1 328 as shown in Fig. 3) that has a first winding and a second winding (“having a first winding and a second winding”);
a primary switch electrically coupled to the primary winding and configured to generate a magnetic flux within the core according to a switching cycle (switches of converter 210, including fifth switch 336 and eighth switch 342 as shown in Fig. 3) that generates magnetic flux (“time-varying current that generates magnetic flux that couples to the Rogowski coil”, para 0046);
a magnetic flux probe (Rogowski coil 100 as shown in Fig. 1; coil 214 as shown in Fig. 2; Rogowski coil 314 as shown in Fig. 3) configured to form a loop enclosing the magnetic flux and to provide a probe signal in proportion to a time derivative of the magnetic flux (“a Rogowski coil, or a coil having windings on a toroid coil (e.g., an air core), is disposed, placed, and/or otherwise arranged around a SR current loop of a power converter”; “the Rogowski coil generates a voltage signal having a phase that is different (e.g., a 90 degree phase difference; para 0066) from the SR current”; “the Rogowski coil utilizes magnetic flux for current sensing”); and
a synchronous rectifier (SR) electrically coupled to the secondary winding and configured to receive a control signal based, at least in part, upon the probe signal (SR control logic 216 as shown in Fig. 2) that has a control output coupled to a switch (“the control output adapted to be coupled to a switch”).
Yu does not disclose a magnetic flux probe comprising a first resistor and a second resistor.
However, Umetani discloses a first resistor and a second resistor (voltage divider resistors 51 and 52 as shown in Fig. 3) (“The voltage divider resistors 51 and 52 divide an induction voltage induced by the reference winding 50.”).
Therefore, it would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to modify the system of Yu and implement the magnetic flux probe as comprising a first resistor and a second resistor, as taught by Umetani, to divide the probe signal and set its magnitude for Yu’s SR control logic 216.
As to claim 2, Yu discloses the switching power supply of claim 1.
Yu does not disclose wherein the switching power supply is a flyback converter.
However, Umetani discloses a flyback converter (flyback transformer 80, primary circuit 85, switching element 85a, primary winding 82, secondary winding 83, rectifier circuit 86 as shown in Fig. 32) (“The primary circuit 85 supplies a primary winding 82 of the flyback transformer 80 with a DC voltage generated from a DC power supply 85b.”).
Therefore, it would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to modify the system of Yu and implement the switching power supply as a flyback converter, as taught by Umetani, because both references are isolated switching converters that transfer energy through a transformer.
As to claim 3, Yu discloses wherein the energy transfer element is a magnetic component (transformer T1 328 as shown in Fig. 3).
As to claim 4, Yu in view of Umetani discloses the switching power supply of claim 3.
Yu does not disclose wherein the magnetic component is an embedded transformer.
However, Umetani discloses a planar transformer (planar transformer 60, magnetic core 61 as shown in Figs. 26 and 29).
Therefore, it would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to modify the system of Yu and implement the magnetic component as an embedded transformer, as taught by Umetani, to integrate the transformer in a planar magnetic structure.
As to claim 5, Yu discloses wherein the synchronous rectifier is an N-type field effect transistor (NFET) (switches 316, 318, 320, 322 as shown in Fig. 3) (“The first switch (316), the second switch (318), the third switch (320), and the fourth switch (322) are N-channel metal-oxide-semiconductor field-effect transistors (MOSFETs)”).
As to claim 6, Umetani discloses wherein the magnetic flux probe comprises a first node electrically coupled to the first resistor (a node of voltage divider resistor 51 as shown in Fig. 3) (“The voltage divider resistors 51 and 52 divide an induction voltage induced by the reference winding 50.”).
As to claim 7, Umetani discloses wherein the probe signal is determined, at least in part, by an electromotive force (emf) of the first resistor (voltage divider resistors 51 and 52 as shown in Fig. 3) (“The voltage divider resistors 51 and 52 divide an induction voltage induced by the reference winding 50.”).
As to claim 8, Umetani discloses wherein the probe signal is proportional to a resistance of the first resistor and inversely proportional to a total resistance of the magnetic flux probe (voltage divider resistors 51 and 52 as shown in Fig. 3) (“The voltage divider resistors 51 and 52 divide an induction voltage induced by the reference winding 50.”).
As to claim 9, Umetani discloses wherein the total resistance of the magnetic flux probe comprises the resistance of the first resistor and a resistance of the second resistor (voltage divider resistors 51 and 52 as shown in Fig. 3) (“The voltage divider resistors 51 and 52 divide an induction voltage induced by the reference winding 50.”).
As to claim 10, Yu and Umetani disclose the switching power supply of claim 1, including a second resistor (resistor 52 as shown in Fig. 3 of Umetani).
Yu does not disclose wherein the second resistor is a variable resistor.
Umetani does not disclose wherein the second resistor is a variable resistor.
However, it would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to modify the system of Yu as modified by Umetani and implement the second resistor as a variable resistor, to adjust the divided probe-signal magnitude taught by Umetani (“The voltage divider resistors 51 and 52 divide an induction voltage induced by the reference winding 50.”).
As to claim 11, Yu and Umetani disclose the switching power supply of claim 1, including a second resistor (resistor 52 as shown in Fig. 3 of Umetani).
Yu does not disclose wherein the second resistor is a trimmable resistor.
Umetani does not disclose wherein the second resistor is a trimmable resistor.
However, it would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to modify the system of Yu as modified by Umetani and implement the second resistor as a trimmable resistor, to calibrate the divided probe-signal magnitude taught by Umetani (“The voltage divider resistors 51 and 52 divide an induction voltage induced by the reference winding 50.”).
As to claim 12, Yu discloses wherein the magnetic flux probe comprises a first node electrically coupled to the secondary winding (Rogowski coil 314 and current path 348 as shown in Fig. 3) (“the current path in circuit with an output terminal coupled to the second winding”).
As to claim 13, Yu discloses wherein the first node is electrically coupled to the synchronous rectifier (current path 348 and switches 336, 342 as shown in Fig. 3; SR control logic 216 as shown in Fig. 2) (“the control output adapted to be coupled to a switch”).
As to claim 14, Yu discloses a flux detection circuit configured to provide a detection signal in response to the probe signal, wherein the synchronous rectifier is configured to receive a control signal based, at least in part, upon the detection signal (SR control logic 216, integrator logic 218, gain amplifier logic 220, and comparator logic 224 as shown in Fig. 2) (“The comparator logic (224) to compare a voltage (e.g., an amplified integrated voltage), which corresponds to the time-varying current generated by the coil (214), to a threshold.”; “the control output adapted to be coupled to a switch”).
As to claim 15, Yu discloses wherein the flux detection circuit comprises a comparator configured to provide the detection signal in response to a comparison of the probe signal to a reference voltage (comparator logic 224 and reference voltage V_REF 407 as shown in Fig. 2) (“The comparator logic (224) to compare a voltage (e.g., an amplified integrated voltage), which corresponds to the time-varying current generated by the coil (214), to a threshold.”).
As to claim 16, Yu discloses a reference voltage (V_REF 407 as shown in Fig. 2).
Yu does not disclose wherein the reference voltage has a magnitude of zero-point one volts (0.1V) to zero-point five volts (0.5V).
Umetani does not disclose wherein the reference voltage has a magnitude of zero-point one volts (0.1V) to zero-point five volts (0.5V).
However, it would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to modify the system of Yu as modified by Umetani and implement the reference voltage as having a magnitude of zero-point one volts (0.1V) to zero-point five volts (0.5V), as a routine selection of Yu’s threshold / V_REF 407 for a divided probe voltage.
As to claim 17, Umetani discloses at least one interconnect electrically coupled between the first resistor and the second resistor (the connection between voltage divider resistors 51 and 52 as shown in Fig. 3) (“The voltage divider resistors 51 and 52 divide an induction voltage induced by the reference winding 50.”).
As to claim 18, Yu and Umetani disclose the switching power supply of claim 17.
Yu does not disclose wherein the at least one interconnect comprises a printed circuit board trace.
Umetani does not disclose wherein the at least one interconnect comprises a printed circuit board trace.
However, it would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to modify the system of Yu as modified by Umetani and implement the at least one interconnect as a printed circuit board trace, as a conventional interconnect for the divider of resistors 51 and 52.
As to claim 19, Umetani discloses wherein the at least one interconnect comprises a wire (“The detection winding includes a wire, the wire inserted into the hole of the magnetic core and surrounding a periphery of a detection region.”).
Claims 20–29 are rejected under 35 U.S.C. 103 as being unpatentable over Yu (US 2021/0028712 A1 hereinafter “Yu”) in view of Umetani (US 2014/0218012 A1 hereinafter “Umetani”).
As to claim 20, Yu discloses in Figs. 1, 2 and 3: A method of controlling a synchronous rectifier during a switching cycle (SR control logic 216 as shown in Fig. 2; switches 336, 342 as shown in Fig. 3) comprising:
using a magnetic flux probe to measure a time varying magnetic flux (Rogowski coil 100 as shown in Fig. 1; coil 214 as shown in Fig. 2; Rogowski coil 314 as shown in Fig. 3) (“time-varying current that generates magnetic flux that couples to the Rogowski coil”);
receiving a probe signal from the magnetic flux probe (voltage output of coil 214 as shown in Fig. 2) (“the Rogowski coil generates a voltage signal having a phase that is different (e.g., a 90 degree phase difference) from the SR current”);
using a flux detection circuit to provide a detection signal in response to the probe signal (SR control logic 216, integrator logic 218, gain amplifier logic 220, and comparator logic 224 as shown in Fig. 2) (“The comparator logic (224) to compare a voltage (e.g., an amplified integrated voltage), which corresponds to the time-varying current generated by the coil (214), to a threshold.”); and
driving the synchronous rectifier in response to the detection signal (SR control logic 216 as shown in Fig. 2) (“the control output adapted to be coupled to a switch”).
Yu does not disclose receiving a probe signal from a first resistor of the magnetic flux probe.
However, Umetani discloses receiving a probe signal from a first resistor (voltage divider resistor 51 as shown in Fig. 3) (“The voltage divider resistors 51 and 52 divide an induction voltage induced by the reference winding 50.”).
Therefore, it would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to modify the method of Yu and receive a probe signal from a first resistor of the magnetic flux probe, as taught by Umetani, to divide the probe signal and set its magnitude for Yu’s flux detection circuit.
As to claim 21, Yu and Umetani disclose the method of claim 20.
Yu does not disclose adjusting a variable resistor to determine a magnitude of the probe signal.
Umetani does not disclose adjusting a variable resistor to determine a magnitude of the probe signal.
However, it would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to modify the method of Yu as modified by Umetani and adjust a variable resistor to determine a magnitude of the probe signal, to set the divided magnitude taught by Umetani (“The voltage divider resistors 51 and 52 divide an induction voltage induced by the reference winding 50.”).
As to claim 22, Yu discloses wherein the synchronous rectifier is an N-type field effect transistor (NFET) (switches 316, 318, 320, 322 as shown in Fig. 3) (“The first switch (316), the second switch (318), the third switch (320), and the fourth switch (322) are N-channel metal-oxide-semiconductor field-effect transistors (MOSFETs)”).
As to claim 23, Yu discloses using a comparator to compare the probe signal to a reference voltage (comparator logic 224 and reference voltage V_REF 407 as shown in Fig. 2) (“The comparator logic (224) to compare a voltage (e.g., an amplified integrated voltage), which corresponds to the time-varying current generated by the coil (214), to a threshold.”).
As to claim 24, Yu discloses a reference voltage (V_REF 407 as shown in Fig. 2).
Yu does not disclose wherein the reference voltage has a magnitude between zero point one volts (0.1V) and zero point five volts (0.5V).
Umetani does not disclose wherein the reference voltage has a magnitude between zero point one volts (0.1V) and zero point five volts (0.5V).
However, it would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to modify the method of Yu as modified by Umetani and implement the reference voltage as having a magnitude between zero point one volts (0.1V) and zero point five volts (0.5V), as a routine selection of Yu’s threshold / V_REF 407.
As to claim 25, Yu discloses wherein the switching cycle is a power converter switching cycle (power converter 210 as shown in Fig. 2; switches 336, 342 as shown in Fig. 3).
As to claim 26, Yu discloses a power converter (power converter 210 as shown in Fig. 2).
Yu does not disclose wherein the power converter is a flyback converter.
However, Umetani discloses a flyback converter (flyback transformer 80, primary circuit 85, switching element 85a as shown in Fig. 32) (“The primary circuit 85 supplies a primary winding 82 of the flyback transformer 80 with a DC voltage generated from a DC power supply 85b.”).
Therefore, it would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to modify the method of Yu and implement the power converter as a flyback converter, as taught by Umetani.
As to claim 27, Yu discloses a magnetic flux probe that encloses magnetic flux (Rogowski coil 314 as shown in Fig. 3) (“time-varying current that generates magnetic flux that couples to the Rogowski coil”).
Yu does not disclose wherein the magnetic flux probe encloses the time varying magnetic flux of a core.
However, Umetani discloses wherein the magnetic flux probe encloses the time varying magnetic flux of a core (detection winding 21, 22 as shown in Fig. 1; magnetic core 11 as shown in Fig. 1) (“The detection winding includes a wire, the wire inserted into the hole of the magnetic core and surrounding a periphery of a detection region.”).
Therefore, it would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to modify the method of Yu and implement the magnetic flux probe to enclose the time varying magnetic flux of a core, as taught by Umetani.
As to claim 28, Umetani discloses wherein the core is an energy transfer element core (magnetic core 11, primary winding 12, secondary winding 13 of transformer 10 as shown in Fig. 1).
As to claim 29, Yu and Umetani disclose the method of claim 27.
Yu does not disclose wherein the core is an embedded transformer core.
However, Umetani discloses a planar transformer core (planar transformer 60, magnetic core 61 as shown in Figs. 26 and 29).
Therefore, it would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to modify the method of Yu as modified by Umetani and implement the core as an embedded transformer core, as taught by Umetani.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TUNG X NGUYEN whose telephone number is (571)272-1967. The examiner can normally be reached 10:30AM-6:30PM M-F.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Judy Nguyen can be reached at 571-272-2258. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/TUNG X NGUYEN/Primary Examiner, Art Unit 2858 9/4/26
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