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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 12 Jan 2026 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Response to Arguments
Applicant’s arguments with respect to the claims have been considered but are moot because the new ground of rejection does 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 5 is objected to because of the following informalities:
Claim 5, line 2: “a bias current” should be changed to “the bias current”.
Appropriate correction is required.
Claim Rejections - 35 USC § 102
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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1, 3-5, 17-18, & 29-30 are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Knoedgen (US 20150244248 A1).
Regarding Claim 1, Knoedgen teaches a controller (306, [0050]) for use in a power converter ("flyback converter of FIG. 3", [0046]) having an energy transfer element (307, Fig 3a), the controller comprising: a primary drive circuit ("202 … which is controlled via a gate control signal 232 generated by the controller 306", U2/232, Fig 2/3a, [0046]) configured to control operation of a primary switch (202, Fig 3a) coupled to a primary winding associated with the energy transfer element (primary coil P1 of 307, Fig 3a), the primary drive circuit causing the primary switch to transition between a conducting state during a first portion of a switching cycle ("The flyback converter may be configured to store energy coming from an input of the flyback converter (with an input voltage 230) in an inductor during an on-state of the switch 202.", Fig 3a, [0046]) and a nonconducting state during a second portion of the switching cycle (" the flyback converter is configured to transfer the stored energy from the primary coil 314 to the secondary coil 315 during an off-state of the switch 202" Fig 3a, [0046]); a bias switch (350, Fig 3a) coupled to a bypass capacitor ("The supply voltage switch 350 may be used to couple and/or to decouple the auxiliary coil 313 from the supply voltage circuitry 352 of FIG. 3a of the controller 306, e.g. from the supply voltage capacitor 310 of FIG. 2", [0050]); and a bias drive circuit (351, Fig 3a) configured to control operation of a bias switch (350, Fig 3a) coupled to an auxiliary winding (313/S2, Fig 3a) associated with the energy transfer element to drive a bias current ("the energy provided via the flyback converter may be used to recharge the supply voltage capacitor 310, thereby maintaining the supply voltage Vcc.", Fig 3a) through the bias switch to a bypass capacitor ("The supply voltage switch 350 may be used to couple and/or to decouple the auxiliary coil 313 from the supply voltage circuitry 352 of FIG. 3a of the controller 306, e.g. from the supply voltage capacitor 310 of FIG. 2", [0050]) coupled to the bias drive circuit for providing a bias supply to the controller ("The supply voltage switch 350 may be used to couple and/or to decouple the auxiliary coil 313 from the supply voltage circuitry 352 of FIG. 3a of the controller 306, e.g. from the supply voltage capacitor 310 of FIG. 2. As such, the energy provided via the flyback converter may be used to recharge the supply voltage capacitor 310, thereby maintaining the supply voltage Vcc.", Fig 2/3a).
Regarding Claim 3, Knoedgen teaches a controller according to claim 1, wherein the bias drive circuit (351, Fig 3a) is further configured to cause the bias switch (350, Fig 3a) to transition between a conducting state (350 on, Fig 3a) and a nonconducting state (350 off, Fig 3a) based on a bias voltage ("The supply voltage switch 350 of FIG. 3a may be opened and/or closed such that the supply voltage Vcc is maintained within a pre-determined voltage interval.", [0050]) across the bypass capacitor (310, Fig 3a).
Regarding Claim 4, Knoedgen teaches a controller according to claim 1, wherein the bias drive circuit is further configured to control the operation of the bias switch to drive the bias current through the bias switch (351 controls 350, Fig 3a) during at least part of the second portion of the switching cycle (" the energy provided via the flyback converter may be used to recharge the supply voltage capacitor 310, thereby maintaining the supply voltage Vcc. ", 202 off, Fig 3, [0050]).
Regarding Claim 5, Knoedgen teaches a controller of claim 4, wherein the bias drive circuit is further configured to cause conduction of a->the bias current in the auxiliary winding (when 350 is closed, current flows through it from 313, Fig 3a) during the at least part of the second portion of the switching cycle ("the energy provided via the flyback converter may be used to recharge the supply voltage capacitor 310, thereby maintaining the supply voltage Vcc. ", 202 off, Fig 3, [0050]) with the bias switch in the conducting state (when 350 is on, Fig 3a) and substantially no current is conducted in the auxiliary winding during the first portion of the switching cycle with the bias switch in the nonconducting state (no current can flow in 313 when 350 is open, Fig 3a).
Regarding Claim 17, Knoedgen teaches a controller of claim 1, wherein the controller (306, Fig 3a) comprises the bias switch ("The supply voltage switch 350 may e.g. be an internal power switch 350 of the controller 306 of FIG. 2.", [0050]).
Regarding Claim 18, Knoedgen teaches a controller (306, [0050]) for use in a power converter ("flyback converter of FIG. 3", [0046]) having an energy transfer element (307, Fig 3a), the controller comprising: a primary drive circuit ("202 … which is controlled via a gate control signal 232 generated by the controller 306", U2/232, Fig 2/3a, [0046]) configured to control operation of a primary switch (202, Fig 3a) coupled to a primary winding associated with the energy transfer element (primary coil P1 of 307, Fig 3a), the primary drive circuit causing the primary switch to transition between a conducting state during a first portion of a switching cycle (202 on, Fig 3a, [0046]) and a nonconducting state during a second portion of the switching cycle (202 off, Fig 3a, [0046]); a bias switch (350, Fig 3a) coupled to a bypass capacitor ("The supply voltage switch 350 may be used to couple and/or to decouple the auxiliary coil 313 from the supply voltage circuitry 352 of FIG. 3a of the controller 306, e.g. from the supply voltage capacitor 310 of FIG. 2", [0050]); and a bias drive circuit (351, Fig 3a) configured to control operation of the bias switch (351 controls 350, Fig 3a) to drive a bias current ("the energy provided via the flyback converter may be used to recharge the supply voltage capacitor 310, thereby maintaining the supply voltage Vcc.", Fig 3a) from an auxiliary winding associated with the energy transfer element (S2/313 is part of transformer 307, Fig 3a) through the bias switch to charge the bypass capacitor coupled to the bias switch ("The supply voltage switch 350 may be used to couple and/or to decouple the auxiliary coil 313 from the supply voltage circuitry 352 of FIG. 3a of the controller 306, e.g. from the supply voltage capacitor 310 of FIG. 2", [0050]) for providing a bias supply to the controller ("the controller may be coupled to a supply voltage capacitor 310 configured to provide the supply voltage Vcc to the controller 306", [0045]).
Regarding Claim 29, Knoedgen teaches a controller (306, [0050]) for use in a power converter ("flyback converter of FIG. 3", [0046]) having an energy transfer element (307, Fig 3a), the controller comprising: a primary drive circuit ("202 … which is controlled via a gate control signal 232 generated by the controller 306", U2/232, Fig 2/3a, [0046]) configured to control operation of a primary switch (202, Fig 3a) coupled to a primary winding associated with the energy transfer element (primary coil P1 of 307, Fig 3a), the primary drive circuit causing the primary switch to transition between a conducting state during a first portion of a switching cycle (202 on, Fig 3a, [0046]) and a nonconducting state during a second portion of the switching cycle (202 off, Fig 3a, [0046]); a bias switch (350, Fig 3a) coupled to a bypass capacitor ("The supply voltage switch 350 may be used to couple and/or to decouple the auxiliary coil 313 from the supply voltage circuitry 352 of FIG. 3a of the controller 306, e.g. from the supply voltage capacitor 310 of FIG. 2", [0050]); and a bias drive circuit (351, Fig 3a) is configured to control operation of a bias switch (350, Fig 3a) connected in series between an auxiliary winding associated with the energy transfer element (350 connected in series with auxiliary winding 313 of transformer 307, Fig 3a) and a bypass capacitor (350 connected in series with auxiliary winding 313 of transformer 307, Fig 3a) that provides a bias voltage to the controller ("The supply voltage switch 350 may be used to couple and/or to decouple the auxiliary coil 313 from the supply voltage circuitry 352 of FIG. 3a of the controller 306, e.g. from the supply voltage capacitor 310 of FIG. 2", [0050]), and wherein the bias drive circuit is further configured to connect the auxiliary winding (351 drives 350 to connect to 313 to 352/310, Fig 3a, [0050]).
Regarding Claim 30, Knoegden teaches the controller of claim 29, wherein the bias drive circuit (351, Fig 3a) is further configured to connect the auxiliary winding to the bypass capacitor (351 drives 350 to connect to 313 to 352/310, Fig 3a, [0050]) during at least a portion of the second portion of the switching cycle ("the energy provided via the flyback converter may be used to recharge the supply voltage capacitor 310, thereby maintaining the supply voltage Vcc. ", when 202 is off, Fig 3, [0050]).
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 6-7 are rejected under 35 U.S.C. 103 as being unpatentable over Knoedgen (US 20150244248 A1) in view of Chen (US 20220393603 A1).
Regarding Claim 6, Knoedgen teaches all of the limitations of Claim 1 above.
Knoedgen does not teach wherein the bias drive circuit is further configured to cause the bias switch to transition into a conducting state based on a comparison between a bias voltage across the bypass capacitor and a reference.
Chen teaches a conventional power supply circuit for a switching mode power supply (see Fig 6) wherein the bias drive circuit (606, Fig 6) is further configured to cause the bias switch (S1, Fig 6) to transition into a conducting state (S1 on, Fig 6) based on a comparison (501 compares Vcc to Vref1, Fig 6) between a bias voltage (Vcc, Fig 6) across the bypass capacitor (Cc, Fig 4) and a reference (if Vcc<Vref1, then Vccl/Aon/Ga-1 are high, which causes S1 to turn on, Fig 6).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have optionally included the power supply circuit in Knoedgen, as taught by Chen, as it provides the advantage of ensuring the power supply capacitor maintains enough charge to guarantee sufficient power is supplied to the control circuit ([0005-6] of Chen).
Regarding Claim 7, Knoedgen teaches all of the limitations of Claim 1 above.
Knoedgen does not teach wherein the bias drive circuit is further configured to cause the bias switch to transition into a conducting state during at least part of the second portion of the switching cycle based on a signal representative of the nonconducting state of the primary switch from the primary drive circuit.
Chen teaches a conventional power supply circuit for a switching mode power supply (see Fig 6) wherein the bias drive circuit (606, Fig 6) is further configured to cause the bias switch (S1, Fig 4) to transition into a conducting state (S1 on, Fig 4) during at least part of the second portion of the switching cycle (when PM1 is off, Fig 4) based on a signal representative of the nonconducting state (EN, [0039]) of the primary switch (PM1, Fig 6) from the primary drive circuit (401, 402, G1).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have optionally included the power supply circuit in Knoedgen, as taught by Chen, as it provides the advantage of ensuring the power supply capacitor maintains enough charge to guarantee sufficient power is supplied to the control circuit ([0005-6] of Chen).
Claims 8-11 & 15 are rejected under 35 U.S.C. 103 as being unpatentable over Knoedgen (US 20150244248 A1) in view of Chen (US 20220393603 A1) and further in view of Bianco (US 20210351707 A1).
Regarding Claim 8, the combination of Knoedgen and Chen teaches all of the limitations of claim 1, and further teaches wherein the bias drive circuit (e.g. 606, Fig 6) is further configured to drive a bias drive signal to the bias switch (Gs drives S1, Fig 4 of Chen) to cause the bias switch (S1, Fig 4 ) to transition between a conducting state (S1 on, Fig 4) and a nonconducting state (S1 off, Fig 4) based on a bias voltage (Vcc, Fig 6) across the bypass capacitor (Cc, Fig 4)
wherein the bias switch (Gs drives S1, Fig 4) in the conducting state (S1 on, Fig 4).
The combination of Knoedgen and Chen does not teach causes a bias current through the auxiliary winding instead of through a secondary winding associated with the energy transfer element, and wherein the bias switch in the nonconducting state allows a secondary current to flow through the secondary winding.
Bianco teaches a conventional power supply circuit for use in a power converter (see Fig 8) that causes a bias current (current path illustrated by II, Fig 8) through the auxiliary winding (123, Fig 8) instead of through a secondary winding ("charging VCCpri while the impact on Vout is limited, notionally nil", [0091]) associated with the energy transfer element (12, Fig 8), and wherein the bias switch in the nonconducting state (VCCpri is equal to or greater than Vout, Fig 9, [0085]) allows a secondary current (current path illustrated by III, Fig 9) to flow through the secondary winding (122, Fig 9).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have optionally included the power supply circuit in Knoedgen, as taught by Bianco, as it provides the advantage of charging the bias/power supply capacitor while having a low impact on the output voltage, ([0079] of Bianco).
Regarding Claim 9, the combination of Knoedgen, Chen, and Bianco teaches all of the limitations of claim 8, and further teaches wherein the bias drive circuit (e.g. 606, Fig 6 of Chen) is further configured to: compare the bias voltage (Vcc, Fig 6 of Chen) to a first reference (Vref1, Fig 6 of Chen) and a second reference (Vref2, Fig 6 of Chen) greater than the first reference (Vref1 is the low voltage threshold and Vref2 is the sufficient voltage threshold so Vref2 is greater than Vref1, [0035] of Chen), drive the bias drive signal (Gs, Fig 6 of Chen) to a first value (Gs=1, Fig 6 of Chen) that causes the bias switch (S1, Fig 4 of Chen) to transition into the conducting state (S1 on/high, Fig 6 of Chen) when the bias voltage (Vcc, Fig 6 of Chen) is lower than the first reference (Vref1, Fig 6 of Chen), the bias drive signal (Gs, Fig 6 of Chen) being driven to the first value (Gs=1, Fig 6 of Chen) for a duration (when Vcc is lower than Vref1, Vccl triggers 502 to generate a pulse Aon to drive S1 on for a duration, [0029] of Chen) ("duration of the pulses of a forced burst suited to be defined (as programmable parameters, for instance)", [0108] of Bianco) during which the bias voltage is increased (VCCpri, Fig 12 of Bianco) towards the second reference (Vref2, Fig 6 of Chen), and drive the bias drive signal (Gs, Fig 6 of Chen) to a second value smaller than the first value (Gs=0, Fig 6 of Chen) that causes the bias switch (S1, Fig 4 of Chen) to transition into the nonconducting state (S1 off, Fig 6 of Chen) when the bias voltage (Vcc, Fig 6 of Chen) reaches the second reference (Vref2, Fig 6 of Chen).
Regarding Claim 10, the combination of Knoedgen, Chen, and Bianco teaches all of the limitations of claim 8, and further teaches wherein the bias drive circuit (e.g. 606, Fig 6 of Chen) is further configured to cause the bias switch (Gs drives S1, Fig 6 of Chen) to transition into the conducting state (S1 on, Fig 4 of Chen) during at least part of the second portion of the switching cycle based (S1 is on while PM1 is off, Fig 4 of Chen) on a duration threshold ("duration of the pulses of a forced burst suited to be defined (as programmable parameters, for instance)", [0108] of Bianco) corresponding to the at least part of the second portion of the switching cycle (second phase/II when VCCPRI is less than Vout, Fig 8, [0082] of Bianco).
Regarding Claim 11, the combination of Knoedgen, Chen, and Bianco teaches all of the limitations of claim 10, and further teaches wherein the bias drive circuit (e.g. 606, Fig 6 of Chen) (the voltage on the auxiliary winding and VCCpri determine if diode 20b is on or off, Fig 1, [0084] of Bianco) is further configured to: compare the bias voltage (Vcc, Fig 6 of Chen) (VCCPRI , Fig 1 of Bianco) to a first reference (Vref1, Fig 6 of Chen) and a second reference (Vref2, Fig 6 of Chen) greater than the first reference (Vref1 is the low voltage threshold and Vref2 is the sufficient voltage threshold so Vref2 is greater than Vref1, [0035] of Chen), drive the bias drive signal (Gs, Fig 6 of Chen) to a first value (Gs=1, Fig 6 of Chen) that causes the bias switch to transition into the conducting state (S1 on, Fig 4 of Chen) when the bias voltage (Vcc, Fig 6 of Chen) is lower than the first reference (Vref1, Fig 6 of Chen), the bias drive signal (Gs, Fig 6 of Chen) being driven to the first value for a duration ("duration of the pulses of a forced burst suited to be defined (as programmable parameters, for instance)", [0108] of Bianco) during which the bias voltage (VCCPRI , Fig 1 of Bianco) is increased towards the second reference and the duration does not exceed the duration threshold ("duration of the pulses of a forced burst suited to be defined (as programmable parameters, for instance)", [0108] of Bianco) and drive the bias drive signal (Gs, Fig 6 of Chen) to a second value smaller than the first value (Gs=0, Fig 6 of Chen) that causes the bias switch to transition into the nonconducting state (S1 off, Fig 4 of Chen) when the bias voltage (Vcc, Fig 6 of Chen) reaches the second reference (Vref2, Fig 6 of Chen), a signal representative of the conducting state of the primary switch (EN=0, [0039] of Chen) from the primary drive circuit (401, 402, G1 of Chen) indicates that the primary switch is in the conducting state (PM1 is on, Fig 4 of Chen) or the duration exceeds the duration threshold ("duration of the pulses of a forced burst suited to be defined (as programmable parameters, for instance)", [0108] of Bianco).
Regarding Claim 15, the combination of Knoedgen, Chen, and Bianco teaches all of the limitations of claim 8, and further teaches wherein a first ratio (Vout:1 where Vout is the output voltage on the secondary side and is equal to the voltage on the auxiliary winding, [0083, 85] of Bianco) of an auxiliary voltage across the auxiliary winding ("the same voltage (under the 1:1 turn ratio assumption discussed previously) is generated at the auxiliary winding 123 and the secondary winding 122", [0083] of Bianco) to a number of turns in the auxiliary winding ("assuming a turn ratio 1:1 of the auxiliary winding 123 to the secondary winding", [0080] of Bianco) is lesser than or equal to a second ratio (Vout:1, [0083, 85] of Bianco) of an output voltage (Vout, Fig 1 of Bianco) across the secondary winding (122, Fig 1 of Bianco) of the energy transfer element (12, Fig 1 of Bianco) to a number of turns in the secondary winding ("assuming a turn ratio 1:1 of the auxiliary winding 123 to the secondary winding", [0080] of Bianco).
Claims 19-23 are rejected under 35 U.S.C. 103 as being unpatentable over Bianco (US 20210351707 A1) in view of Knoedgen (US 20150244248 A1).
Regarding Claim 19, Bianco teaches a power converter (10, Fig 1) for providing power to a load (LD, Fig 1) the power converter comprising: an energy transfer element (12, Fig 1) comprising a primary winding (121, Fig 1) and a secondary winding (122, Fig 1), the primary winding being coupled to an input voltage (Vin, Fig 1) during a first portion of a switching cycle (first phase/I, Fig 7, [0082]) and configured to generate a secondary current through the secondary winding ("energy is transferred to secondary side (only) ", Fig 9, [0085]) during a second portion of the switching cycle (16 is off in phases II and III, and secondary current is generated in phase III when VCCpri greater than or equal to Vout, Figs 8&9, [0083-85]); an output capacitor (Csec charges in phase III, Fig 9) coupled to the secondary winding (122, Fig 1); and a controller (14 & 20, Fig 1) configured to control transfer of energy between the primary winding (121, Fig 1) and the secondary winding (122, Fig 1), the controller, configured to control conduction of a bias current (current path illustrated by II, Fig 8) through a bias switch (20b, Fig 1) instead of ("charging VCCpri while the impact on Vout is limited, notionally nil", [0091]) through the output capacitor (Csec, Fig 1) during at least part of the second portion of the switching cycle (second phase/II when VCCPRI is less than Vout, Fig 8, [0084]) for providing a bias supply (VCCPRI, Fig 8) to the controller ("the supply voltage VCCpri provided to the controller", [0059]) for the power converter (10, Fig 1).
Bianco does not teach the controller comprising a bias drive circuit.
Knoedgen teaches a conventional driver circuit (see Fig 3a) including a bias drive circuit ("The supply voltage switch 350 may be controlled via a switch driver 351", 351, [0050]) and a bias switch (350, Fig 4a).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have optionally included the driver circuit in Bianco, as taught by Knoedgen, as it provides the advantage of more precise control of the charging circuit.
Regarding Claim 20, the combination of Bianco and Knoedgen teaches all of the limitations of Claim 19 above and further teaches wherein the bias drive circuit (351, [0050] of Knoedgen) is further configured to control operation of the bias switch (350, Fig 4a of Knoedgen) during the at least part of the second portion of the switching cycle (second phase/II when VCCPRI is less than Vout, Fig 8, [0082]) to drive the bias current (current path illustrated by II, Fig 8) to a bypass capacitor (CAPVCC, Fig 1) coupled to the bias switch (350, Fig 4a of Knoedgen).
Regarding Claim 21, the combination of Bianco and Knoedgen teaches all of the limitations of Claim 20 above and further teaches wherein the bias drive circuit (351, [0050] of Knoedgen) is further configured to control operation of the bias switch (350, Fig 4a of Knoedgen) to drive the bias current (current path illustrated by II, Fig 8 of Bianco) to the bypass capacitor (CAPVCC, Fig 1 of Bianco) during the at least part of the second portion of the switching cycle (second phase/II when VCCPRI is less than Vout, Fig 8, [0082] of Bianco) by causing the bias switch (350, Fig 4a of Knoedgen) to transition between a conducting state (20b conducts when VCCPRI is less than Vout, [0084] of Bianco) and a nonconducting state (20b stops conducting when VCCPRI reaches Vout, [0085] of Bianco) based on a bias voltage (VCCPRI , Fig 1 of Bianco) across the bypass capacitor (CAPVCC, Fig 1 of Bianco).
Regarding Claim 22, the combination of Bianco and Knoedgen teaches all of the limitations of Claim 21 above and further teaches wherein the bias switch (350, Fig 4a of Knoedgen) is coupled to an auxiliary winding (123, Fig 11 of Bianco) having a same input return (Ground symbol shown attached to the secondary winding 123 is connected to 140, which is connected to controller 14 (or can be inside of it) which is connected to the primary winding 121, Fig 11, [0108] of Bianco) as the primary winding (121, Fig 11 of Bianco).
Regarding Claim 23, the combination of Bianco and Knoedgen teaches all of the limitations of Claim 21 above and further teaches wherein the bias switch (350, Fig 4a of Knoedgen) is coupled to the secondary winding (122, Fig 1 of Bianco).
Claims 24-27 are rejected under 35 U.S.C. 103 as being unpatentable over Bianco (US 20210351707 A1) in view of Knoedgen (US 20150244248 A1) and further in view of Yee (CN 115113670 A).
Regarding Claim 24, the combination of Bianco and Knoedgen teaches all of the limitations of Claim 21, and further teaches wherein the controller further comprises: a first controller (14, Fig 1 of Bianco) associated with the primary winding (121, Fig 1 of Bianco); the secondary winding (20b controls whether current will be conducted through the auxiliary or secondary winding, Fig 8 & 9, [0084-85] of Bianco), wherein the first controller and the second controller are configured to communicate via a communication link between the first controller and the second controller (output of 140 shows arrow to 14 establishing communication between second controller and first controller, Fig 11 of Bianco).
The combination of Bianco and Knoedgen does not teach a second controller, the second controller having the bias drive circuit and the bias switch.
Yee teaches a conventional secondary side controller for use in a power converter (see Fig 5) including a second controller (102, Fig 5) associated with the secondary winding (202, Fig 5), the second controller having the bias drive circuit (gate signal of 102, Fig 5) and the bias switch (S2, Fig 5).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have optionally included the secondary side controller in Bianco, as taught by Yee, as it provides the advantage of "precisely controlling an output voltage in a converter." (Col 3, lines 54-55 of Yee).
Regarding Claim 25, the combination of Bianco, Knoedgen, and Yee teaches all of the limitations of Claim 24 above and further teaches further comprising an output rectifier (18, Fig 1 of Bianco) coupled between the secondary winding (122, Fig 1 of Bianco) and the output capacitor (Csec, Fig 1 of Bianco).
Regarding Claim 26, the combination of Bianco, Knoedgen, and Yee teaches wherein the output rectifier (312, Fig 4a of Knoedgen) is reversed biased when the bias switch is in the nonconducting state (in Fig 4b from 25-30 .mu.s 202 is of while S3 and 312 are off, Fig 4b of Knoedgen) and is forward biased when the bias switch is in the conducting state ("In the forward mode, the diode 312 and the coil 313 are arranged such that a current through the primary coil 314 is directly translated into a current through the secondary coil 313 (when the switch 202 is closed)", and in Fig 4b from 20-25 .mu.s 202 is on while S3 is on, Fig 4b, [0053] of Knoedgen).
Regarding Claim 27, the combination of Bianco, Knoedgen, and Yee teaches all of the limitations of Claim 25 above and further teaches wherein the bias drive circuit (351, [0050] of Knoedgen) is further configured to drive a bias drive signal (output signal from 351, Fig 3a of Knoedgen) to the bias switch (350, Fig 4a of Knoedgen)(20b, Fig 1 of Bianco) to cause the bias switch to transition between the conducting state and the nonconducting state (350 on/off, Fig 3a of Knoedgen) (20b on/off, Fig 1 of Bianco) based on the bias voltage (VCCPRI , Fig 1 of Bianco) across the bypass capacitor (CAPVCC, Fig 1 of Bianco) and a signal representative of a voltage across the secondary winding (20b conducts if 16 is off, which transfers Vout to 122 or 123 based on if VCCpri is less than Vout, [0083-85] of Bianco), wherein the bias switch in the conducting state (350 on, Fig 3a of Knoedgen)(20b on, Fig 1 of Bianco) redirects current to the bypass capacitor (CAPVCC, Fig 8 of Bianco) instead of to the output rectifier (no current flowing through 18 when 20b and Q3 are conducting and charging CAPvcc, Fig 8 of Bianco), and wherein the bias switch in the nonconducting state (350 off, Fig 3a of Knoedgen) (20b off, Fig 9 of Bianco) allows the current to flow (phase III shows current flowing through 18 when 20b is reverse biased, Fig 9 of Bianco) to the output rectifier (18, Fig 1 of Bianco).
Claims 31, 33 & 35 are rejected under 35 U.S.C. 103 as being unpatentable over Knoedgen (US 20150244248 A1) in view of Li (US 20230188046 A1).
Regarding Claim 31, Knoedgen teaches wherein the bias drive circuit (351, Fig 3a) is configured to disconnect the auxiliary winding (313, Fig 3a) from the bypass capacitor (capacitor 310 is disconnected from 313 by the controller 306, Fig 3a) during the first portion of the switching cycle.
Knoedgen does not teach during the first portion of the switching cycle.
Li teaches a conventional switching converter (see Fig 3) wherein the bias drive circuit (206, Fig 3) is configured to disconnect the auxiliary winding from the bypass capacitor during the first portion of the switching cycle (when MP is on and MA is off it disconnects the grounded end of the auxiliary winding from the grounded end of the capacitor, Fig 3).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have optionally included the switching converter in Knoedgen, as taught by Li, as it provides the advantage of using a soft switching technique to improve the efficiency of the converter ([0005] of Li).
Regarding Claim 33, the combination of Knoedgen and Li teaches all of the limitations of Claim 29 above, and further teaches wherein the bias drive circuit (206, Fig 3 of Li) is further configured to disconnect the auxiliary winding from the bypass capacitor (disabled when MA off, Fig 3 of Li) during a part of the second portion of the switching cycle (DRVA/MA off when DRVP/MP is off {t1-t2}, Fig 3/6 of Li).
Regarding Claim 35, the combination of Knoedgen and Li teaches wherein the bias drive circuit (351, Fig 3a of Knoedgen) is further configured to connect the auxiliary winding to the bypass capacitor (351 turns on 350 to connect 313 to capacitor 352/310, Fig 3a of Knoedgen) after a delay (t3 to t6, Fig 6 of Li) following the transition from the first portion of the switching cycle to the second portion of the switching cycle (MP goes from on to off at t3, Fig 6 of Li).
Claim 34 is rejected under 35 U.S.C. 103 as being unpatentable over Knoedgen (US 20150244248 A1) in view of Li (US 20230188046 A1), and further in view of Fan (US 20120133348 A1).
Regarding Claim 34, the combination of Knoedgen and Li teaches all of the limitations of Claim 29 above, and further teaches wherein the bias drive circuit (351, Fig 3a of Knoedgen) is further configured to disconnect the auxiliary winding from the bypass capacitor (351 turns off 350 to disconnect 313 from capacitor 352/310, Fig 3a of Knoedgen).
The the combination of Knoedgen and Li does not teach in response to detection of a zero current condition.
Fan teaches a conventional zero detection circuit for use in a power converter (see Fig 4) including in response to detection of a zero current condition (“thereby pulling high a signal S6 to delay the signal Sc that is generated by the zero current detector 30 to turn off the low-side switch Q2.”, [0021]).
Before the effective filing date, it would have been obvious to one having ordinary skill in the art to configure Chen’s system such that it comprises: in response to detection of a zero current condition, as taught at least in part by Fan. The reason for doing so would have been to improve efficiency under light or zero load conditions ([0019, 21] of Fan).
Claims 37 & 38 are rejected under 35 U.S.C. 103 as being unpatentable over Knoedgen (US 20150244248 A1) in view of Chen (US 20220393603 A1) and further in view of Bianco (US 20210351707 A1) and further in view of Li (US 20230188046 A1).
Regarding Claim 37, the combination of Knoedgen, Chen, and Bianco teaches all of the limitations of claim 8.
The combination of Knoedgen, Chen, and Bianco does not teach wherein the bias drive circuit is further configured to provide the bias drive signal to the bias switch to force the bias switch into the conducting state during a first part of the second portion of the switching cycle and the nonconducting state during a second part of the second portion of the switching cycle, wherein the first part of the secondportion of the switching cycle precedes the second part of the second portion of the switching cycle.
Li teaches a conventional zero voltage control method for a power converter (see Fig 3, and also Fig 6 reproduced below with additional reference characters added) wherein the bias drive circuit (206, Fig 3) is further configured to provide the bias drive signal (DRVA, Fig 3) to the bias switch (MA, Fig 3) to force the bias switch into the conducting state (MA is on when DRVA is high, Fig 6 below) during a first part (t3-tA, see Fig 6 below) of the second portion of the switching cycle (t3-tA is the first part of the second portion t3-tB that DRVP/MP is off and DRVA/MA is on t6-tA, see Fig 6 below) and the nonconducting state (MA is off when DRVA is low, Fig 6 below) during a second part of the second portion of the switching cycle (tA-tB is the second part of the second portion t3-tB that DRVP/MP is off and DRVA/MA is off tA-tB, see Fig 6 below), wherein the first part of the second portion of the switching cycle precedes the second part of the second portion of the switching cycle (t3-tA precedes tA-tB, see Fig 6 below). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have optionally included the zero voltage control method in Knoedgen, as taught by Li, as it provides the advantage of using a soft switching technique to improve the efficiency of the converter ([0005] of Li).
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Regarding Claim 38, the combination of Knoedgen, Chen, and Bianco teaches all of the limitations of claim 8.
The combination of Knoedgen, Chen, and Bianco does not teach wherein the bias drive circuit is further configured to provide the bias drive signal to the bias switch to force the bias switch into the nonconducting state during a first part of the second portion of the switching cycle and the conducting state during a second part of the second portion of the switching cycle, wherein the first part of the second portion of the switching cycle precedes the second part of the second portion of the switching cycle.
Li teaches a conventional zero voltage control method for a power converter (see Fig 3, and also Fig 6 reproduced above with additional reference characters added) wherein the bias drive circuit (206, Fig 3) is further configured to provide the bias drive signal (DRVA, Fig 3) to the bias switch (MA, Fig 3) to force the bias switch into the nonconducting state during a first part (t3-t6, see Fig 6 above) of the second portion of the switching cycle (t3-t6 is the first part of the second portion t3-tB that DRVP/MP is off and DRVA/MA is off t3-t6, see Fig 6 above)
and the conducting state during a second part of the second portion of the switching cycle (t6-tB is the second part of the second portion t3-tB that DRVP/MP is off and DRVA/MA is on t6-tA, see Fig 6 above), wherein the first part of the second portion of the switching cycle precedes the second part of the second portion of the switching cycle (t3-t6 precedes t6-tB, see Fig 6 above).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have optionally included the zero voltage control method in Knoedgen, as taught by Li, as it provides the advantage of using a soft switching technique to improve the efficiency of the converter ([0005] of Li).
Allowable Subject Matter
Claim 36 is 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.
The following is a statement of reasons for the indication of allowable subject matter:
Regarding Claim 36, the prior art made of record fails to disclose or suggest the controller for use in a power converter having the claimed structural features in combination with the recited functionality wherein, “wherein the auxiliary voltage across the auxiliary winding is greater than the output voltage across the secondary winding.”
Conclusion
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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/J.C.C./Examiner, Art Unit 2838
/CRYSTAL L HAMMOND/Supervisory Primary Examiner, Art Unit 2838