DETAILED ACTION
This Office action is in response to the application filed on 12 February 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 .
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Rejections - 35 USC § 102
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.
Claim(s) 1-2 and 4 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Oh (US 2005/0207185).
In re claim 1, Oh discloses a power converter (Figs. 1-2) comprising:
a conversion circuit (100) configured to receive an input voltage (116) and output an output voltage (Vo),
a controller (U1) coupled to the conversion circuit, and the controller configured to control the conversion circuit to adjust the output voltage ([0021], [0026]),
a snubber circuit (104) coupled between the conversion circuit and the controller, and the snubber circuit configured to provide a snubber voltage (at node 112), and
an energy storage component (C2) configured to receive the snubber voltage (through D3, R1) as an operating voltage (Vcc) for the controller,
wherein the controller, the energy storage component, and the snubber circuit are coupled to a first node (Vcc node).
In re claim 2, Oh discloses wherein the conversion circuit comprises:
a transformer (T1) configured to convert the input voltage into the output voltage, and the transformer comprising a leakage inductance (leakage inductance is understood to be an inherent property of a transformer), and
a switch unit (Q1) configured to be controlled to adjust the output voltage of the conversion circuit ([0029]),
wherein the transformer, the switch unit, and the snubber circuit are coupled to a second node (node between Q1, C1, and N1),
wherein when the switch unit is turned on, a current flows through the leakage inductance, and the leakage inductance is in an energy storage stage ([0028]).
In re claim 4, Oh discloses wherein the snubber circuit comprises:
a first capacitor (C1) coupled to the second node,
an energy release unit (D2, L1) coupled between the first capacitor and the switch unit (via ground), and
a second diode (D3) coupled between the first node and the first capacitor,
wherein the first capacitor, the energy release unit, and the second diode are coupled to a third node (node 112),
wherein when the switch unit is turned on, a releasing path is formed by the first capacitor, the switch unit, and the energy release unit, and a current with a first current value flows through the releasing path (Figs. 3-4: current ic1 during, e.g., times t1-t2: see Fig. 5A and [0034]).
Claim(s) 1 and 3 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Jitaru (US 2020/0169180).
In re claim 1, Jitaru discloses a power converter (Fig. 16) comprising:
a conversion circuit (2300) configured to receive an input voltage (Vin from 10) and output an output voltage (Vo at 24),
a controller (90) coupled to the conversion circuit, and the controller configured to control the conversion circuit to adjust the output voltage ([0046], [0106]),
a snubber circuit (Dc1, Cr, D1, D2, Rs) coupled between the conversion circuit and the controller, and the snubber circuit configured to provide a snubber voltage (voltage between Cr, D1, D2), and
an energy storage component (CB1) configured to receive the snubber voltage (through D1) as an operating voltage (VBias 60) for the controller ([0101]),
wherein the controller, the energy storage component, and the snubber circuit are coupled to a first node (VBias node).
In re claim 3, Jitaru discloses an auxiliary circuit comprising:
an auxiliary winding (N3/L3/166) configured to induce magnetic energy of the transformer to provide an auxiliary voltage (voltage across aux winding L3/N3/166), and
a first diode (synchronous rectifier 68 may instead be a simple diode: [0101]) coupled between the first node and the auxiliary winding,
wherein the energy storage component is configured to receive the auxiliary voltage as the operating voltage for the controller through the first diode ([0101]).
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.
Claim(s) 5-7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Oh in view of Jitaru.
In re claim 5, Oh discloses wherein the energy release unit comprises:
a third diode (Figs. 1-2: D2) coupled to the switch unit (Q1).
Oh does not disclose a first resistor coupled to the third node and connected to the third diode in series.
Whereas Jitaru discloses the use of a damping resistor (Fig. 16: Rs, 70) in a snubber circuit for the purpose of damping ringing oscillations caused by the switching of the main converter switch ([0084], [0100], [0134]).
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 circuit of Oh by including a first resistor coupled to the third node and connected to the third diode in series for damping resonant ringing in the circuit as taught by Jitaru.
Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Oh and Jitaru as applied to claim 6 above, and further in view of Irissou et al. (US Patent 6,233,165; hereinafter “Irissou”).
In re claim 8, Oh and Jitaru disclose the claimed invention as explained above except for wherein the snubber circuit further comprises a third resistor coupled between the second node and the first capacitor, wherein when the switch unit is turned on, the releasing path is formed by the first capacitor, the third resistor, the switch unit, and the energy release unit, and a current with a fourth current value flows through the releasing path, and the first current value is greater than the fourth current value; when the switch unit is turned off, the charging path is formed by the third resistor, the first capacitor, and the second diode, and a current with a fifth current value flows through the charging path, and the second current value is greater than the fifth current value.
Whereas Irissou discloses the use of a dissipation resistor (Fig. 3: R2) in series with the clamping capacitor (C3) of a snubber circuit for dissipation of energy to limit magnitude of the voltage spike when main switch turns off (col. 4: last paragraph).
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 circuit of Oh by including a resistor in series with the first capacitor for dissipation of energy to limit magnitude of the voltage spike when main switch turns off as shown and taught by Irissou. Based on Ohm’s Law, the inclusion of such resistor in the energy releasing path would necessarily reduce the energy releasing current magnitude and therefore the second current value would be greater than the fifth current value.
Allowable Subject Matter
Claims 9-12 are 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:
With respect to claim 9, the closest prior art in Oh, as modified in view of Jitaru, discloses the invention according to claim 6 as explained above, but does not further disclose wherein the snubber circuit further comprises a second capacitor coupled to the first resistor in parallel; when the switch unit is turned on, the releasing path is formed by the first capacitor, the switch unit, the third diode, the first resistor, and the second capacitor, and a current with a sixth current value flows through the releasing path, and the first current value is less than the sixth current value.
Furthermore, the additional prior art on record does not suggest an obvious modification to Oh that would have resulted in the claimed features.
Claim 12 depends from claim 9 and therefore would be allowable for the same reasons.
Claims 10 and 11 both recite substantially similar features as claim 9 and thus would be allowable for the same reasons as well.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
US 2015/0207422 discloses an ISOLATED POWER CONVERTER AND SWITCHING POWER SUPPLY USING THE SAME including a snubber circuit for generating an auxiliary supply voltage.
US 2018/0309358 discloses a VOLTAGE CONVERTER CIRCUIT AND METHOD FOR OPERATING A VOLTAGE CONVERTER CIRCUIT in which a supply voltage (Vcc), for example to supply a control circuit (11) controlling a switch (Q1), is generated using an additional current path (16) and a snubber circuit (12).
US 2021/0257923 discloses an INDUCTIVE CHARGING CIRCUIT TO PROVIDE OPERATIVE POWER FOR A CONTROLLER.
US Patent 11,165,351 discloses a Conversion Apparatus With Oscillation Reduction Control And Method Of Operating The Same.
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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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Monica Lewis can be reached at (571) 272-1838. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/FRED E FINCH III/Primary Examiner, Art Unit 2838
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