DETAILED ACTION
This office action is in response to the remarks filed on 12/26/2025.
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 .
Specification
The lengthy specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant’s cooperation is requested in correcting any errors of which applicant may become aware in the specification.
Claim Interpretation
In re to claim 11, method claim 11 is rejected based on the following case law, note that under MPEP 2112.02, the principles of inherency, if a prior art device, in its normal and usual operation, would necessarily perform the method claimed, then the method claimed will be considered to be anticipated by the prior art device. When the prior art device is the same as a device described in the specification for carrying out the claimed method, it can be assumed the device inherently performs the claimed process. In re King, 801 F.2d 1324, 231 USPQ 136 (Fed Cir. 1986). Therefore the previous rejections based on the apparatus will not be repeated.
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.
Claim(s) 1-2, 7-8 and 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Radic US2019/0245 in view of Young US 2015/0097600.
Regarding Claims 1 and 11, Radic teaches (Figures 2-8) A switching power converter (Fig. 2), comprising: a main switch (M1); an auxiliary circuit (C3 and M3), wherein the auxiliary circuit comprises an auxiliary switch and an auxiliary capacitor electrically connected in series (C3 and M3); and a control module (118 and control circuitry of 214), configured to detect a load state of the switching power converter and control an operation state of the auxiliary switch according to the load state (par. 23 and 34-35), wherein when the load state of the switching power converter is light, the control module controls the auxiliary switch to turn off (M3 is off, par. 34-35) so that a capacitance of a first equivalent capacitor (equivalent capacitance as seen by the nodes at the terminals of the switch) between a drain and a source of the main switch is maintained at a first threshold (due to the non-switching of the switch, Fig. 8, par. 41 and 45 in the order of picoF, the equivalent capacitance will be in the range of picoF), and when the load state of the switching power converter is heavy, the control module controls the auxiliary switch to turn on so (normal operation) that the capacitance of the first equivalent capacitor (equivalent capacitance) is maintained at a second threshold (due to the switching of the switch, Fig. 7, Par. 41 and 44 in the order of nanoF, the equivalent capacitance will have a value int the order of nanoF), and the second threshold is higher than the first threshold (nanoF is greater than picoF). (For Example: Par. 33-38 and 41-46)
Radic does not teach an auxiliary circuit, electrically connected in parallel to the main switch.
Young teaches (Fig. 15b) an auxiliary circuit (Cc and Sa), electrically connected in parallel to the main switch (Sw). (For Example: Par. 52)
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the circuit of Radic to include an auxiliary circuit, electrically connected in parallel to the main switch as taught by Young to improve efficiency under light-load conditions.
Regarding Claim 2, Radic teaches (Figures 2-8) wherein the switching power converter is a flyback conversion circuit (Fig. 2), and the switching power converter further comprises: a positive input terminal and a negative input terminal (Vin and Gnd), wherein the positive input terminal and the negative input terminal are configured to receive an input power (Vin); a positive output terminal and a negative output terminal (at 112), wherein the positive output terminal and the negative output terminal are configured to provide an output voltage (Vout); a transformer (102) comprising a primary winding and a secondary winding (104-106) magnetically coupled to each other, wherein a first terminal of the primary winding is electrically connected to the positive input terminal (at 108), two terminals of the secondary winding are electrically connected to the positive output terminal and the negative output terminal respectively (at 112); the main switch (M1), electrically connected between a second terminal of the primary winding of the transformer and the negative input terminal (See fig. 6), wherein the main switch has a first parasitic capacitor (CossM1); the auxiliary capacitor (C3), electrically connected to the second terminal of the primary winding (at 110); and the auxiliary switch electrically connected between the auxiliary capacitor and the negative input terminal (gnd), wherein the auxiliary switch has a second parasitic capacitor (CossM3). (For Example: Par. 33-38 and 41-46)
Regarding Claim 7, Radic teaches (Figures 2-8) wherein when the load state of the switching power converter is light, the capacitance of the first equivalent capacitor is a sum of a capacitance of a first parasitic capacitor of the main switch and a capacitance of a second parasitic capacitor of the auxiliary switch (Fig. 8); and when the load state of the switching power converter is heavy, the capacitance of the first equivalent capacitor is a sum of the capacitance of the first parasitic capacitor of the main switch and a capacitance of the auxiliary capacitor (Fig. 7). (For Example: Par. 41-46)
Regarding Claim 8, Radic teaches (Figures 2-8)wherein a capacitance of a first parasitic capacitor of the main switch (M1) is greater than or equal to a capacitance of a second parasitic capacitor of the auxiliary switch (M3). (For Example: Par. 45)
Claim(s) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Radic US2019/0245 in view of Young US 2015/0097600 and further in view of Shimura US 2017/0005585.
Regarding Claim 4, Radic teaches (Figures 2-8) the converter.
Radic does not teach wherein the control module comprises an optocoupler unit and a control unit, the optocoupler unit converts a voltage across the secondary winding into a feedback signal through optical coupling and transmits the feedback signal to the control unit, wherein the control unit comprises a feedback signal port, a main switch control port and an auxiliary switch control port, the control unit reflects information of the feedback signal through the feedback signal port, the control unit controls an operation state of the main switch through the main switch control port, the control unit controls the operation state of the auxiliary switch through the auxiliary switch control port, and the control unit determines if the load state of the switching power converter is light or heavy according to the information of the feedback signal reflected by the feedback signal port and the control unit controls the operation state of the auxiliary switch through the auxiliary switch control port.
Shimura teaches (Figures 1-4 and 6) wherein the control module (101-103 and 115) comprises an optocoupler unit (at 115) and a control unit (101-103), the optocoupler unit converts a voltage across the secondary winding (S1) into a feedback signal through optical coupling and transmits the feedback signal to the control unit (FB), wherein the control unit comprises a feedback signal port (at FB), a main switch control port (at 102) and an auxiliary switch control port (at 102), the control unit reflects information of the feedback signal through the feedback signal port (at FB, par. 48-49 and 59-60), the control unit controls an operation state of the main switch through the main switch control port (with 102), the control unit controls the operation state of the auxiliary switch through the auxiliary switch control port (with 102), and the control unit determines if the load state of the switching power converter is light or heavy (low or high load state, par. 49) according to the information of the feedback signal reflected by the feedback signal port and the control unit controls the operation state of the auxiliary switch (FET2) through the auxiliary switch control port (at 102). (For Example: Par. 33-38 and 82-88)
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the circuit of Radic to include a control module, wherein the control module comprises an optocoupler unit and a control unit, the optocoupler unit converts a voltage across the secondary winding into a feedback signal through optical coupling and transmits the feedback signal to the control unit, wherein the control unit comprises a feedback signal port, a main switch control port and an auxiliary switch control port, the control unit reflects information of the feedback signal through the feedback signal port, the control unit controls an operation state of the main switch through the main switch control port, the control unit controls the operation state of the auxiliary switch through the auxiliary switch control port, and the control unit determines if the load state of the switching power converter is light or heavy according to the information of the feedback signal reflected by the feedback signal port and the control unit controls the operation state of the auxiliary switch through the auxiliary switch control port, as taught by Shimura to improve power efficiency during low load in a power supply apparatus of an active clamp system.
Claim(s) 5-6 and 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Radic US2019/0245 in view of Young US 2015/0097600 and further in view of Jang US 6051961.
Regarding Claim 5, Radic teaches (Figures 2-8) the converter.
Radic does not teach wherein the switching power converter is a boost circuit, and the switching power converter comprises: a positive input terminal and a negative input terminal, wherein the positive input terminal and the negative input terminal are configured to receive an input power; a positive output terminal and a negative output terminal, wherein the positive output terminal and the negative output terminal are configured to provide an output voltage; an inductor, wherein a first terminal of the inductor is electrically connected to the positive input terminal; the main switch, electrically connected between a second terminal of the inductor and the negative input terminal, wherein the main switch has a first parasitic capacitor; the auxiliary capacitor, electrically connected to the second terminal of the inductor; the auxiliary switch, electrically connected between the auxiliary capacitor and the negative input terminal, wherein the auxiliary switch has a second parasitic capacitor; and a diode, electrically connected between the second terminal of the inductor and the positive output terminal.
Jang teaches (Figure 4) wherein the switching power converter is a boost circuit (Fig. 4), and the switching power converter comprises: a positive input terminal and a negative input terminal (with 409), wherein the positive input terminal and the negative input terminal are configured to receive an input power (from 409); a positive output terminal and a negative output terminal (at Vo), wherein the positive output terminal and the negative output terminal are configured to provide an output voltage (Vo); an inductor (L), wherein a first terminal of the inductor is electrically connected to the positive input terminal; the main switch (S), electrically connected between a second terminal of the inductor (L) and the negative input terminal, wherein the main switch has a first parasitic capacitor (of 402, Col. 4 lines 60-62); the auxiliary capacitor (Cc), electrically connected to the second terminal of the inductor (L); the auxiliary switch (S1), electrically connected between the auxiliary capacitor (Cc) and the negative input terminal, wherein the auxiliary switch has a second parasitic capacitor (of 404, Col. 4 lines 60-62); and a diode (D), electrically connected between the second terminal of the inductor and the positive output terminal. (For Example: Col. 4 lines 39-67)
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the circuit of Radic to include wherein the switching power converter is a boost circuit, and the switching power converter comprises: a positive input terminal and a negative input terminal, wherein the positive input terminal and the negative input terminal are configured to receive an input power; a positive output terminal and a negative output terminal, wherein the positive output terminal and the negative output terminal are configured to provide an output voltage; an inductor, wherein a first terminal of the inductor is electrically connected to the positive input terminal; the main switch, electrically connected between a second terminal of the inductor and the negative input terminal, wherein the main switch has a first parasitic capacitor; the auxiliary capacitor, electrically connected to the second terminal of the inductor; the auxiliary switch, electrically connected between the auxiliary capacitor and the negative input terminal, wherein the auxiliary switch has a second parasitic capacitor; and a diode, electrically connected between the second terminal of the inductor and the positive output terminal, as taught by Jang to improve the performance of a PWM converter by eliminating switching losses.
Regarding Claim 6, Radic teaches (Figures 2-8) the converter.
Radic does not teach wherein the switching power converter is a buck conversion circuit, and the switching power converter comprises: a positive input terminal and a negative input terminal, wherein the positive input terminal and the negative input terminal are configured to receive an input power; a positive output terminal and a negative output terminal, wherein the positive output terminal and the negative output terminal are configured to provide an output voltage; the main switch, electrically connected to the positive input terminal, wherein the main switch has a first parasitic capacitor; an inductor, electrically connected between the main switch and the positive output terminal, wherein the inductor and the main switch is electrically connected to a junction node; the auxiliary capacitor, electrically connected between the positive input terminal and the auxiliary switch; the auxiliary switch, electrically connected between the auxiliary capacitor and the junction node, wherein the auxiliary switch has a second parasitic capacitor; and a diode, electrically connected between the junction node and the negative output terminal.
Jang teaches (Figure 14) wherein the switching power converter is a buck conversion circuit (Fig. 14), and the switching power converter comprises: a positive input terminal and a negative input terminal (at 409), wherein the positive input terminal and the negative input terminal are configured to receive an input power (from 409); a positive output terminal and a negative output terminal (at Vo), wherein the positive output terminal and the negative output terminal are configured to provide an output voltage (Vo); the main switch (S), electrically connected to the positive input terminal, wherein the main switch has a first parasitic capacitor (of 402, Col. 4 lines 60-62); an inductor (L), electrically connected between the main switch (S) and the positive output terminal (at Vo), wherein the inductor and the main switch is electrically connected to a junction node (node between 403 and 402); the auxiliary capacitor (Cc), electrically connected (when S1 is in the off state and S is in the on state) between the positive input terminal (at 409) and the auxiliary switch (S1); the auxiliary switch, electrically connected between the auxiliary capacitor (Cc) and the junction node (node between 403 and 402), wherein the auxiliary switch has a second parasitic capacitor (of 404, Col. 4 lines 60-62); and a diode (D), electrically connected between the junction node and the negative output terminal. (For Example: Col. 11 lines 5-10)
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the circuit of Radic to include wherein the switching power converter is a buck conversion circuit, and the switching power converter comprises: a positive input terminal and a negative input terminal, wherein the positive input terminal and the negative input terminal are configured to receive an input power; a positive output terminal and a negative output terminal, wherein the positive output terminal and the negative output terminal are configured to provide an output voltage; the main switch, electrically connected to the positive input terminal, wherein the main switch has a first parasitic capacitor; an inductor, electrically connected between the main switch and the positive output terminal, wherein the inductor and the main switch is electrically connected to a junction node; the auxiliary capacitor, electrically connected between the positive input terminal and the auxiliary switch; the auxiliary switch, electrically connected between the auxiliary capacitor and the junction node, wherein the auxiliary switch has a second parasitic capacitor; and a diode, electrically connected between the junction node and the negative output terminal, as taught by Jang to improve the performance of a PWM converter by eliminating switching losses.
Regarding Claim 9, Radic teaches (Figures 2-8) the converter.
Radic does not teach a wherein a capacitance of the auxiliary capacitor is greater than or equal to a capacitance of a second parasitic capacitor of the auxiliary switch.
Jang teaches (Figures 4 and 6) wherein a capacitance of the auxiliary capacitor (Cc) is greater than or equal to a capacitance of a second parasitic capacitor of the auxiliary switch (capacitance of 402). (For Example: Col. 6)
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the circuit of Radic to include wherein a capacitance of the auxiliary capacitor is greater than or equal to a capacitance of a second parasitic capacitor of the auxiliary switch, as taught by Jang to improve the performance of a PWM converter by eliminating switching losses.
Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Radic US2019/0245 in view of Young US 2015/0097600 and further in view of Sato US 2019/0207522.
Regarding Claim 10, Radic teaches (Figures 2-8) a fourth port, the control unit controls the operation state of the auxiliary switch through the fourth port and the control unit controls the operation state of the auxiliary switch through the fourth port.
Radic does not teach wherein the control module comprises a control unit, an auxiliary winding, an auxiliary diode, a first divider resistor and a second divider resistor, and the control unit comprises a first port, a second port, a third port, wherein the control unit reflects information of the output voltage through the first port, the control unit reflects information of a voltage across the auxiliary winding through the second port, the control unit controls an operation state of the main switch through the third port, wherein the auxiliary winding and the auxiliary diode are electrically connected in series between the negative input terminal and the first port, the auxiliary winding and the auxiliary diode is electrically connected to a first branch connection node, and the first divider resistor and the second divider resistor are electrically connected in series between the negative input terminal and the first branch connection node, the first divider resistor and the second divider resistor is electrically connected to a second branch connection node, and the second branch connection node is connected to the second port, wherein the control unit determines if the load state of the switching power converter is light or heavy according to the information of the voltage across the auxiliary winding reflected by the second port.
Sato teaches (Figures 1-4) wherein the control module (at 20) comprises a control unit (100), an auxiliary winding (L3), an auxiliary diode (d1), a first divider resistor and a second divider resistor (R1-R2), and the control unit comprises a first port (t6), a second port (t1), a third port (t5), wherein the control unit reflects information of the output voltage through the first port (with Vp, par. 35-39), the control unit reflects information of a voltage across the auxiliary winding through the second port (with Vm), the control unit controls an operation state of the main switch through the third port (control of n1), wherein the auxiliary winding and the auxiliary diode are electrically connected in series between the negative input terminal(gnd1) and the first port (t6), the auxiliary winding and the auxiliary diode is electrically connected to a first branch connection node (node Vp), and the first divider resistor and the second divider resistor are electrically connected in series between the negative input terminal (gnd1) and the first branch connection node (node vp), the first divider resistor and the second divider resistor is electrically connected to a second branch connection node (node Vm), and the second branch connection node is connected to the second port (T1), wherein the control unit (100) determines if the load state of the switching power converter is light or heavy according to the information of the voltage across the auxiliary winding reflected by the second port (with 102, par. 62). (For Example: Par. 60-63 and 73)
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the circuit of Radic to include wherein the control module comprises a control unit, an auxiliary winding, an auxiliary diode, a first divider resistor and a second divider resistor, and the control unit comprises a first port, a second port, a third port, wherein the control unit reflects information of the output voltage through the first port, the control unit reflects information of a voltage across the auxiliary winding through the second port, the control unit controls an operation state of the main switch through the third port, wherein the auxiliary winding and the auxiliary diode are electrically connected in series between the negative input terminal and the first port, the auxiliary winding and the auxiliary diode is electrically connected to a first branch connection node, and the first divider resistor and the second divider resistor are electrically connected in series between the negative input terminal and the first branch connection node, the first divider resistor and the second divider resistor is electrically connected to a second branch connection node, and the second branch connection node is connected to the second port, wherein the control unit determines if the load state of the switching power converter is light or heavy according to the information of the voltage across the auxiliary winding reflected by the second port, as taught by Sato to provide a power control device with reduced power consumption under a light or no load.
Allowable Subject Matter
Claim 3 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.
Reasons for Indicating Allowable Subject Matter
The following is an examiner’s statement of reasons for indicating Allowable Subject Matter:
Claim 3; prior art of record fails to disclose either by itself or in combination: “…wherein the control module comprises a control unit, an auxiliary winding, an auxiliary diode and an extended branch circuit, the control unit comprises a first port, a second port and a third port, wherein the control unit reflects information of the output voltage through the first port, the control unit reflects information of a voltage across the auxiliary winding through the second port, and the control unit controls an operation state of the main switch through the third port, wherein the auxiliary winding and the auxiliary diode are electrically connected in series between the negative input terminal and the first port, the extended branch circuit comprises a first Zener diode, a first extended resistor, a second Zener diode and a second extended resistor, and the first Zener diode, the first extended resistor and the second Zener diode are electrically connected in series between the first port and the negative input terminal sequentially, the second extended resistor is electrically connected in parallel to the second Zener diode, the first extended resistor and the second Zener diode is electrically connected to a third branch connection node, and the third branch connection node is connected to the auxiliary switch for controlling the operation state of the auxiliary switch”.
These features taken alone or in combination are neither disclosed nor suggested by the prior art of record.
Response to Arguments
Applicant's arguments filed 12/26/2025 have been fully considered but they are not persuasive.
Applicant argued that “However, the capacitors identified by the Office Action in FIGS. 7 and 8 as having capacitance values at the order of nano-farads and pico-farads are the parasitic capacitance CossM3 of the active clamp switch M3 and the active clamp capacitor C3, but not the parasitic capacitance CossM1 of the main switch M1. In fact, as shown in paragraphs [0044]-[0045] of Radic, the parasitic capacitance CossM1 of the main switch M1 in FIGS. 7-8 of Radic is on the order of pico-farads, without any apparent difference in magnitude. Accordingly, Applicant respectfully disagrees with the reasoning set forth in the Office Action”. However, the examiner is entitled to the broadest reasonable interpretation. In this case, claim 1 mentions “so that a capacitance of a first equivalent capacitor between a drain and a source of the main switch”. The claims do not read that the parasitic capacitor of the main switch changes values, the claim mentions that the equivalent capacitor between the source and drain of the main switch changes value. Radic paragraph 35 mentions that during light load the clamping circuitry with M3 and C3 is not used, so when the switch is off the nodes where the main switch is connected do not see the capacitance of CossM3 and M3 and the equivalent capacitance present between the nodes of the main switch is smaller, when in light load. In heavy state when the switch is being used the nodes between the main switch will see the capacitance of M3 and C3 and the value of the capacitance as seen by said nodes will increase, See figure below. The equivalent capacitance during heavy load will be the combination of CmosM3 and C3 and this combination will be added to capacitance Cossm1 providing a higher value of capacitance.
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Conclusion
THIS ACTION IS MADE FINAL. 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 GUSTAVO A ROSARIO-BENITEZ whose telephone number is (571)270-7888. The examiner can normally be reached M-F 9AM-5PM.
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/GUSTAVO A ROSARIO-BENITEZ/Primary Examiner, Art Unit 2838