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 .
Priority
Acknowledgment is made of applicant’s claim for foreign priority under 35 U.S.C. 119(a)-(d).
Information Disclosure Statement
The information disclosure statement (IDS)’s submitted on 3/30/2023, 3/5/2025 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Preliminary Amendment
The preliminary amendment to the claims received on 3/30/2023 is acceptable and made of record in accordance with MPEP 714.01 (e). Applicant’s statement of “no new matter entered” is acknowledged.
Specification
The title of the invention is not descriptive. A new title is required that is clearly indicative of the invention to which the claims are directed.
The following title is suggested: Energy Harvesting System with Capacitor-Based DC-DC Converter.
Claim Objections
Claim 12 is objected to because of the following informalities: Line 2 recites, “… comprise an or the operating …”. This appears to be a missing limitation, or extraneous words. 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) 1-2, 4-7 and 12 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Zamparette et al. “A 90% Efficiency 60 mW MPPT Switched Capacitor DC-DC Converter for Photovoltaic Energy Harvesting Aiming for IoT Applications.” (See IDS documents of record, NPL 3/30/2023).
Regarding claim 1, Zamparette et al. discloses a circuit portion comprising:
an energy harvesting device producing a DC output [abstract, photovoltaic energy harvesting. Fig. 2, solar panel. Page 1 Section II];
an inductor-less capacitor-based DC-DC converter [abstract, switched capacitor DC-DC converter. Figs. 2 and 3, 6x Time Interleaved 1:2 switched capacitor converter], having an input connected to said DC output of the energy harvesting device [Fig. 2, solar panel. Page 2 Section III];
an output connected to a battery [abstract, Fig. 2, LiFePO4 battery];
a voltage limiting module [abstract, output overvoltage protection. Fig. 2, Hyst. Comparator with feedback loop], comprising a voltage sensor [Fig. 2, voltage divider nR, mR] arranged to measure a voltage representative of a voltage at the battery [Fig. 2, LiFePO4 battery]; wherein
the voltage limiting module is arranged to limit a voltage provided by the DC-DC converter if said voltage representative of the voltage at the battery exceeds a threshold [abstract, output overvoltage protection of 3.6v. Page 2 Section III, output protection circuit composed of hysteric comparator plus a band-gap voltage reference that limits the output voltage at 3.6v].
Regarding claim 2, Zamparette discloses the circuit portion as claimed in claim 1, wherein the inductor-less capacitor-based DC-DC converter comprises a plurality of capacitors [page 2 Section III].
Regarding claim 4, Zamparette discloses the circuit portion as claimed in claim 1, wherein the voltage sensor comprises a comparator [Fig. 2, Hyst. Comp.] with a first input comprising the voltage representing the voltage at the battery [Fig. 2, LiFePO4] and a second input comprising a reference voltage [Fig. 2, bandgap REF. Page 2 Section III].
Regarding claim 5, Zamparette discloses the circuit portion as claimed in claim 1, wherein the DC-DC converter comprises an oscillator [controlled ring oscillator] which determines an operating frequency of the DC-DC converter [Page 2 Section III].
Regarding claim 6, Zamparette discloses the circuit portion as claimed in claim 5, wherein the voltage limiting module is configured to reduce the operating frequency of the DC-DC converter based on a measurement obtained by the voltage sensor [Page 2 Section III].
Regarding claim 7, Zamparette discloses the circuit portion as claimed in claim 1 wherein the voltage limiting module is configured to halt operation of the DC-DC converter if the voltage measured by the voltage sensor is above the threshold voltage [Page 2 Section III protection circuit and timer can generate disable pulses to stop the converter].
Regarding claim 12, Zamparette discloses the circuit portion as claimed in claim 9, wherein the one or more parameters of the DC-DC converter comprise an or the operating frequency and/or input impedance [Page 2 Section III].
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) 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zamparette et al. “A 90% Efficiency 60 mW MPPT Switched Capacitor DC-DC Converter for Photovoltaic Energy Harvesting Aiming for IoT Applications.” (See IDS documents of record, NPL 3/30/2023) as applied to claim 1 above, and further in view of McMorrow US 20200119561.
Regarding claim 3, Zamparette discloses the circuit portion as claimed in claim 1, but does not disclose: a switch between the DC-DC converter and the battery.
McMorrow discloses: a switch [Figs. 1 and 2, switch 114/214] between the DC-DC converter [DC-DC converter 104] and the battery [Fig. 1, Energy Storage Source 108; par. 0117].
Zamparette and McMorrow are analogous dc converters supplied by solar panels controlled with MPPT and used to supply charging power to a battery. It would have been obvious to one of ordinary skill in the art at the time of the filing to incorporate a switch, as disclosed by McMorrow, into Zamparette’s circuit for the benefit of isolating the battery from the converter as desired.
Claim(s) 8, 9, 10, 11, 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zamparette et al. “A 90% Efficiency 60 mW MPPT Switched Capacitor DC-DC Converter for Photovoltaic Energy Harvesting Aiming for IoT Applications.” (See IDS documents of record, NPL 3/30/2023) as applied to claim 1 above, and further in view of Liu et al. US 20080012542.
Regarding claim 8, Zamparette discloses the circuit portion as claimed in claim 7, but does not disclose: comprising a by-pass circuit arranged to route current from the energy harvesting device or the DC-DC converter to ground if the voltage measured by the voltage sensor is above the threshold voltage.
Liu discloses: comprising a by-pass circuit [Fig. 4, 64] arranged to route current from the energy harvesting device [connected at Vin] or the DC-DC converter [converter 80; par. 0035] to ground if the voltage measured by the voltage sensor [Fig. 4, over-voltage monitoring circuit 43] is above the threshold voltage [pars. 0028, 0033, 0039].
Zamparette and Liu are analogous dc-dc converters which supply power for connected loads. It would have been obvious to one of ordinary skill in the art at the time of the filing to incorporate the over-voltage arrangement as recited for the benefit of clamping the output voltage to safe level, thus protecting any connected load(s) [see, Liu, par. 0040].
Regarding claim 9, Zamparette discloses the circuit portion as claimed in claim 1 further comprising a monitoring module arranged to monitor an output voltage of the DC-DC converter and to adjust one or more parameters of the DC-DC converter based on information relating to the DC-DC converter output voltage [page 2 Section III].
Liu discloses monitoring the current [Fig. 4, resistor 30 + current sensing circuit 44; par. 0026].
Zamparette and Liu are analogous dc-dc converters which supply power for connected loads. It would have been obvious to one of ordinary skill in the art at the time of the filing to incorporate the current monitoring arrangement as recited for the benefit of more accurately controlling the output of the converter to the required level and as well as helping to protect any connected load(s) [see, Liu, par. 0040].
Regarding claim 10, Liu discloses: wherein the monitoring module is arranged to derive the information relating to the DC-DC converter output current by measuring current through a sense arrangement [Fig. 4, resistor 30, par. 0036].
Regarding claim 11, the combination of Zamparette and Liu disclose the circuit portion as claimed in claim 10, but is silent regarding: wherein the sense arrangement comprises a non-ohmic semiconductor element.
Examiner takes Official Notice, IAW MPEP 2144.03, as to the common knowledge of the recited subject matter.
Non-ohmic current sensors such as current mirrors or hall-sensors used for determining battery charging current are well-known in the art of battery charging. It would have been obvious to one of ordinary skill in the art at the time of filing to utilize such a senor with Zamparette and Liu’s combined converter for the benefit of using a current sensing solution that does not impose an additional current drain on the dc converter or its load.
Regarding claim 13 the combination of Zamparette and Liu disclose the circuit portion as claimed in claim 9, but is silent regarding: comprising two or more power paths, wherein said monitoring module is configured to monitor a sum of currents for the two or more power paths.
Examiner takes Official Notice, IAW MPEP 2144.03, as to the common knowledge of the recited subject matter.
DC Converters that supply power to multiple load paths are well-known in the art of battery charging. It would have been obvious to one of ordinary skill in the art at the time of filing to utilize additional load path(s) with Zamparette and Liu’s combined converter for the benefit of being able to simultaneously supply a load and charging a battery, whilst having the converter respond to the combined current output in order to maintain output regulation for the total load.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US 11063440 discloses a system and method for combining power from DC power sources. Each power source is coupled to a converter. Each converter converts input power to output power by monitoring and maintaining the input power at a maximum power point. Substantially all input power is converted to the output power, and the controlling is performed by allowing output voltage of the converter to vary. The converters are coupled in series. An inverter is connected in parallel with the series connection of the converters and inverts a DC input to the inverter from the converters into an AC output. The inverter maintains the voltage at the inverter input at a desirable voltage by varying the amount of the series current drawn from the converters. The series current and the output power of the converters, determine the output voltage at each converter.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to RICHARD V MURALIDAR whose telephone number is (571)272- 8933. The examiner can normally be reached M - W 9:30 am to 6:30 PM.
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/RICHARD V MURALIDAR/Primary Examiner, Art Unit 2859