DETAILED ACTION
This Office action is in response to the application filed on 09 January 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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Objections
Claim 1 is objected to because of the following informalities:
At line 2, “and converter the DC” should be changed to “and convert the DC”.
Appropriate correction is required.
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) 1-3 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Lim et al. (US 2018/0123461; hereinafter “Lim”).
In re claim 1, Lim discloses a dual-stage DC power converter (Fig. 8), comprising:
a first-stage DC converter (8) configured to receive a DC input voltage (from 6), and convert the DC voltage into a first output voltage (across capacitor 42),
a second-stage DC converter (10,12) configured to receive the first output voltage (from 8/across 42), and convert the first output voltage into a second output voltage (to load 14),
a first controller (180, 182) configured to provide a control signal to control the first-stage DC converter (Signal from 182 to 8; see [0066]), and
a second controller (16, 4) configured to provide a frequency signal to control the second-stage DC converter (outputs GD1, GD2; see Fig. 7 and [0030]),
wherein the first controller is configured to receive the second output voltage, and provide a mode signal to the second controller (to signal VS at pin 24 of 4) according to the second output voltage so that the second controller is configured to control the second-stage DC converter operating in a fixed-frequency mode or a variable-frequency mode according to the frequency signal (see [0030] and Fig. 7 showing variable and fixed frequency modes).
In re claim 2, Lim discloses wherein the first-stage DC converter is a non-isolated DC converter (PFC 8 is non-isolated PFC converter; see Fig. 8, [0032], [0088]), and the second-stage DC converter is an isolated DC converter (see Fig. 2, [0035]).
In re claim 3, Lim discloses wherein the first-stage DC converter is a boost converter, a buck converter, or a buck-boost converter ([0032], [0088]: as PFC 8 is operated “to correct the DC signal level” when the rectified input voltage is “too low”, PFC 8 is understood to have a boosting operation).
Allowable Subject Matter
Claims 4-17 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 4, the closest prior art in Lin discloses the invention according to claim 1 as explained above, but does not further disclose wherein when the first controller is configured to determine that the DC input voltage is greater than an input minimum voltage and is less than an input maximum voltage according to the second output voltage, the first controller is configured to output the mode signal so that the second controller is configured to control the second-stage DC converter operating in the fixed-frequency mode according to the frequency signal. That is, in Lim, the first controller does not determine the DC input voltage according to the second output voltage, and does not control the second-stage DC converter to operate in fixed-frequency mode in the manner being claimed.
Furthermore, the additional prior art on record does not suggest an obvious modification to the dual-stage DC power converter of Lim that would have resulted in the features of the claimed invention.
Claims 5-8 depend, either directly or indirectly, from claim 4 and would thus be allowable for the same reasons.
Claims 9 and 14 both depend from claim 1 and recite substantially similar subject matter as found in claim 4. As such, these claims would be allowable in view of the prior art for substantially similar reasons as explained above.
Claims 10-13 and 15-17 depend from claim s9 and 14, respectively, and thus would also be allowable for the same reasons.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
US 2010/0225289 discloses a TWO-STAGE SWITCHING POWER SUPPLY that controls gains of the first and second stages including a fixed- and variable frequency modes of the second stage.
US 2014/0160799 discloses a DC/DC CONVERTER WITH RESONANT CONVERTER STAGE AND BUCK STAGE AND METHOD OF CONTROLLING THE SAME, configured to perform one of: (a) fixing a switching frequency of the bridge circuit to a predetermined maximum switching frequency and controlling the output voltage by controlling a duty cycle of the buck switch, and (b) fixing the duty cycle of the buck switch to a predetermined duty cycle and controlling the output voltage by controlling the switching frequency of the bridge circuit.
US 2015/0198634 discloses a CONTROLLER FOR USE WITH A POWER CONVERTER AND METHOD OF OPERATING THE SAME, including a dual-stage architecture and frequency control of the second stage.
US 2022/0158548 discloses a dual-stage power supply in a display apparatus including fixed- and variable-frequency operation modes of the second stage converter.
US 2023/0134040 discloses a dual stage POWER CONVERSION DEVICE, CONTROL DEVICE FOR POWER CONVERSION DEVICE, AND POWER CONVERSION CONTROL METHOD configured to switch between frequency modulation control and phase shift control.
US Patent 11,737,189 discloses a dual-stage power converter including variable on-time, fixed on-time, and variable frequency control modes.
US 2025/0055372 discloses a control circuit for a power conversion system having a first-stage power conversion circuit and a second-stage power conversion circuit.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to FRED E FINCH III whose telephone number is (571)270-7883. The examiner can normally be reached Monday-Friday, 8:00 AM - 4:30 PM ET.
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/FRED E FINCH III/Primary Examiner, Art Unit 2838
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