Utility meters with solar-powered real-time clocks

Abstract

The utility meter includes a real-time clock (RTC), a supercapacitor, a power supply, and a set of photodiodes. The RTC keeps time used to timestamp events that occur during an alternating current (AC) power outage to the utility meter, and the supercapacitor powers the RTC. The power supply operates in an active mode in response to an AC line voltage that meets a threshold, and in the active mode, charges the supercapacitor to power the RTC. The set of photodiodes absorb energy from ambient light and charge the supercapacitor to power the RTC. Thus, the supercapacitor is configured to be charged based on the power supply and based on the set of photodiodes.

Description

Technical Field

[0001] The various embodiments described herein relate to utility meters, and more particularly to utility meters having a real-time clock that operates on solar power.

Background Art

[0002] A utility meter measures the consumption of resources within an associated premise. To maintain its internal operations, the utility meter utilizes alternating current (AC) power provided to the utility meter. During an AC power outage in the utility meter, some critical operations of the utility meter still need to be performed. For example, the utility meter operates a low-power real-time clock (RTC) that provides time stamps for events occurring during an AC power outage. Such events include attempts at tampering and service flags, and for each of these, for example, the utility meter associates a time stamp based on the output from the RTC.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Typically, when the AC line voltage received in the internal power supply is sufficient, the RTC is powered by the DC power provided by the internal power supply. When the AC line voltage meets at least a threshold value, the power supply is active, powers the RTC, and further charges the supercapacitor for use during a potential AC power outage. When an AC power outage occurs (i.e., when the AC line voltage drops below the threshold value), the power supply becomes inactive, and the supercapacitor powers only the RTC until there is not enough energy stored in the supercapacitor itself to do so. In some cases, the supercapacitor can store enough energy to power the RTC for 24 hours during an AC power outage. In some cases, the supercapacitor also powers anti-tamper sensors such as a cover removal sensor or a vibration sensor. In that case, the energy of the supercapacitor is drawn out more rapidly, and then the RTC and the anti-tamper sensors stop operating.

[0004] The present disclosure provides a demand meter equipped with a real-time clock operating on solar power.

Means for Solving the Problem

[0005] In one embodiment, the demand meter includes a real-time clock (RTC), a supercapacitor, a power supply, and a set of photodiodes. The RTC measures the time used for a time stamp applicable to an event occurring during an AC power outage of the demand meter, and the supercapacitor powers the RTC. The power supply operates in an active mode in response to an AC line voltage meeting a threshold value, and when in the active mode, powers the RTC by charging the supercapacitor. A set of photodiodes absorbs energy from ambient light and powers the RTC by charging the supercapacitor. Therefore, the supercapacitor is configured to be charged based on the power supply and also based on a set of photodiodes.

[0006] Another embodiment is a method of powering the RTC of a demand meter. The method includes operating, by the demand meter, an RTC configured to time the time utilized for a time stamp applicable to an event occurring during an AC power outage of the demand meter. The method further includes charging, by the power supply, a supercapacitor configured to power the RTC when the power supply of the demand meter is active due to the demand meter receiving a sufficient AC line voltage. The method further includes powering the RTC by the supercapacitor based on energy provided by the power supply. The method further includes charging the supercapacitor based on energy absorbed from ambient light by a set of photodiodes. Further, the method includes powering the RTC by the supercapacitor based on energy provided by the photodiodes when the power supply is inactive.

[0007] In yet another embodiment, the method includes incorporating into the device an RTC configured to time the time utilized for a time stamp applicable to an event occurring during an AC power outage of the device. The method further includes incorporating into the device a supercapacitor configured to power the RTC. The method further includes incorporating into the device a power supply configured to operate in an active mode in response to an AC line voltage meeting a threshold and, when in the active mode, further configured to power the RTC by charging the supercapacitor. Further, the method includes incorporating into the device a set of photodiodes configured to absorb energy from ambient light and power the RTC by charging the supercapacitor. The supercapacitor is configured to be charged based on the power supply and the set of photodiodes, and the device is usable as a demand meter.

[0008] These exemplary aspects and features are not intended to limit or define the subject matter described herein, but are referred to in order to provide examples that assist in understanding the concepts described in the present application. Other aspects, advantages, and features of the subject matter described herein will become apparent by reading the entire present application.

Brief Description of the Drawings

[0009]

Figure 1

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Mode for Carrying Out the Invention

[0010] These and other features, aspects, and advantages of the present disclosure will be further understood when the following detailed description is read with reference to the accompanying drawings.

[0011] There are several techniques for extending the time during which a real-time clock (RTC) can operate during an alternating current (AC) power outage, but these techniques have significant drawbacks. For example, to extend the operation of the RTC during an AC power outage, a demand meter may include a lithium battery in addition to a supercapacitor. In that case, the lithium battery is OR-connected to the output of the supercapacitor, thereby enabling both the supercapacitor and the lithium battery to be used as direct current (DC) power to the RTC. However, lithium batteries are relatively expensive, and thus including a lithium battery in a demand meter increases the cost of manufacturing the meter. Further, lithium batteries require periodic inspection or replacement after several years. This results in additional costs for maintaining the demand meter. Another option is to increase the size (i.e., capacitance) of the supercapacitor, either as an alternative to or in addition to including a lithium battery. However, this option is sometimes not possible due to space limitations on the printed circuit board (PCB) of the demand meter.

[0012] Some of the embodiments described in this application extend the operation of the supercapacitor, thereby enabling the supercapacitor to power the RTC for an extended time period, e.g., for several days or indefinitely. Specifically, some embodiments incorporate a micropower solar charger to charge the supercapacitor in a cost - effective manner. In ambient light, the micropower solar charger absorbs energy, thus enabling the micropower solar charger to charge the supercapacitor and the supercapacitor to continue powering the RTC. By incorporating a micropower solar charger, also referred to herein as a solar charger, the demand meter can eliminate the lithium battery for powering the RTC. In some embodiments, when ambient light is available, the solar charger absorbs energy to charge the supercapacitor while the supercapacitor powers the RTC, and when ambient light is not available, the supercapacitor continues to power the RTC using its stored charge. Additionally or alternatively, the supercapacitor may power the RTC and, for an extended period, one or more sensors such as an anti - tamper sensor.

[0013] Figure 1 is a diagram of the various subsystems of a demand meter 100, also referred to as a meter 100, according to some of the embodiments described in this application. The exemplary demand meter 100 shown in Figure 1 is a power meter, but it will be understood that the embodiments described in this application are not limited to power meters and may be other types of meters that utilize AC power. Generally, the demand meter 100 measures the consumption of resources associated with the premises, such as electricity.

[0014] As shown in FIG. 1, the supply-demand meter 100 includes various subsystems that all operate together to form the supply-demand meter 100. For example, the supply-demand meter 100 may include one or more of the following subsystems: a measurement engine 110, a host 120, an interface 130, a zero-crossing device 140, a sensor 170, and a power supply 150. Each subsystem may operate as a functional block. Dividing the operations into subsystems is for illustrative purposes only, and it will be understood that the various subsystems, or components of the subsystems, may be combined or divided in ways different from those shown in FIG. 1 or described in this application. Each of the subsystems of the supply-demand meter 100 may be implemented as hardware, software, or a combination of both. For example, each subsystem may be implemented as an integrated circuit, as a software function, or as some combination of hardware and software.

[0015] In some embodiments, the measurement engine 110 measures the consumption of resources and generates consumption data indicating this consumption. For example, in the case of a power meter as shown in FIG. 1, the measurement engine 110 processes samples from the AC line voltage and current sensors, thereby calculating the amount of power, reactive power, power outages, and other related AC service information. In some embodiments, the measurement engine 110 is implemented as an integrated circuit.

[0016] In some embodiments, host 120 processes data received from measurement engine 110, such as consumption data, and interfaces with an automatic meter reading (AMR) device and other peripheral devices, for example via interface 130. Host 120 may communicate with flash memory, which operates as a non-volatile mass memory for the supply-demand meter 100. Additionally or alternatively, host 120 may communicate with a general user interface (GUI), which operates as a user interface to enable a user (e.g., a technician) to communicate with the supply-demand meter 100. In some embodiments, host 120 includes an RTC 160, which maintains the time utilized by host 120 or other subsystems and applies a time stamp to events. Host 120 may be implemented as a microcontroller. However, in some embodiments, both host 120 and measurement engine 110 are implemented as a common integrated circuit, for example, this may be the case for a residential supply-demand meter 100.

[0017] In some embodiments, interface 130 provides the logic and buffering required by one or more peripheral devices. Such peripheral devices may include, for example, AMR, wireless, wireless fidelity (WiFi (registered trademark)) card, Bluetooth (registered trademark) card, Ethernet (registered trademark) card, or an isolated load control system. In other words, interface 130 facilitates communication between host 120 and one or more peripheral devices.

[0018] Additionally or alternatively, in some embodiments, the zero-crossing device 140 provides AC line detection. In one embodiment, the alternating current received at the demand meter 100 includes a single phase, in which case the zero-crossing device 140 may include a single zero-crossing circuit that detects the presence of the alternating current. In another embodiment, the received alternating current includes a plurality of phases (e.g., three phases), in which case the zero-crossing device 140 may include a zero-crossing circuit for each phase such that each zero-crossing circuit detects the alternating current corresponding to its respective phase. In an exemplary embodiment, the zero-crossing device 140 is integrated into the measurement engine 110 rather than implemented as a separate one or more circuits.

[0019] The power supply 150 receives the AC line voltage and may then provide DC power to various components of the demand meter 100. In some embodiments, at a given time, the power supply 150 is either in an active mode (i.e., active) or in an inactive mode (i.e., inactive). Specifically, for example, when the AC line voltage meets (i.e., equals or exceeds) a threshold value and is thus sufficient for the power supply 150 to generate the DC voltage required by various subsystems and other components of the demand meter 100, the power supply 150 becomes active. As shown in FIG. 1, for example, the power supply 150 provides voltage to other subsystems including the measurement engine 110, the host 120, the interface 130, and the zero-crossing device 140. The power supply 150 may also provide a voltage for charging the supercapacitor 155 and for powering the RTC 160. Additionally or alternatively, the power supply 150 provides a voltage for powering one or more sensors 170. The sensors 170 may be low-power anti-tamper sensors such as the cover removal sensor 172 and the vibration sensor 174.

[0020] In some embodiments, in the event of an AC power outage, the supercapacitor 155 may provide a DC voltage (e.g., 3.3 volts) to the RTC 160 in the host 120 and also provide a DC voltage to the sensor 170. However, in some embodiments, to ensure that the supercapacitor 155 can supply power to the RTC 160 over an extended period, the supercapacitor 155 supplies power to the RTC 160 and not to the sensor 170 during an AC power outage, thereby allowing the power to the sensor to be turned off. Although the present disclosure repeatedly refers to the supercapacitor 155 supplying power to the RTC 160 during an AC power outage, it will be understood that the supercapacitor 155 may supply power to the sensor 170 during a power outage. In other words, when the power supply 150 is inactive, the supercapacitor takes over the role of supplying power to the RTC 160 and, in some embodiments, also to the sensor 170.

[0021] Furthermore, as shown in FIG. 1, the solar charger 190 is connected to the supercapacitor 155 such that, when the power supply 150 is inactive, the DC voltage output from the solar charger 190 is input to the supercapacitor 155, charging the supercapacitor 155 and enabling the supercapacitor 155 to supply power to the RTC 160 or the sensor 170 or both. Specifically, in some embodiments, a linear regulator receives a DC voltage (e.g., 12 volts DC) from the power supply 150 when the power supply 150 is active and generates an appropriate voltage to charge the supercapacitor 155 and supply power to the RTC 160 and the sensor 170. The output from the solar charger 190 may be OR-connected to the output of the linear regulator, where the output from the OR connection is input to the supercapacitor 155, thereby enabling the supercapacitor 155 to be charged based on either the power supply 150 or the solar charger 190.

[0022] In existing demand meters that do not incorporate such a solar charger 190, the output from the lithium battery is OR-connected to the output of a linear regulator that charges the supercapacitor 155. However, as described above, this approach requires periodic inspection and replacement of the lithium battery. However, according to some of the embodiments described in the present application, the solar charger 190 is used in place of the lithium battery. The solar charger 190 may have a longer lifespan and may require less service, and can supply power to the supercapacitor 155 to devices such as the RTC 160 or the sensor 170 for a longer period of time than the period during which the lithium battery can supply power during an AC power outage.

[0023] Figure 2 is a diagram of an example of a solar charger 190 that can be used in the demand meter 100 according to some of the embodiments described in the present application. In some embodiments, the solar charger 190 is implemented as an integrated circuit, although it will be understood that other implementations are within the scope of the present disclosure. As shown, the solar charger 190 may include a Schottky diode 210 in addition to one or more photodiodes 220. In some embodiments, the Schottky diode 210 has a low leakage current and a low forward voltage (i.e., a low voltage drop), however, the Schottky diode 210 may be replaced with other diodes having a low leakage current and a low forward voltage. The solar charger 190 may include a plurality of photodiodes 220, which may be connected in series with each other additively. In some embodiments, the photodiodes 220 operate in their solar cell mode. Specifically, the photodiodes 220 absorb energy in the presence of ambient light and use that energy to output a voltage to charge the supercapacitor 155.

[0024] As shown in FIG. 2, an example of the solar charger 190 includes seven photodiodes 220 connected in series to a Schottky diode 210, and the Schottky diode 210 is connected to a supercapacitor charger that charges the supercapacitor 155. In this embodiment, each photodiode 220 generates 400 millivolts. Thus, the seven photodiodes 220 together generate 2.8 volts, which is appropriate to charge the supercapacitor 155. The Schottky diode 210 may result in only a small voltage drop (e.g., a forward voltage of DC 0.21 volts) at an acceptable level of leakage current (e.g., less than 1 μA DC). In some embodiments, a low leakage current is required so that the solar charger 190 does not draw charge from the supercapacitor 155. One or more additional photodiodes 220 may be added to increase the voltage output of the solar charger 190 to the supercapacitor 155 based on the requirements of the supercapacitor 155 being used, or to charge the supercapacitor 155 more quickly.

[0025] When there is no AC power and no ambient light (e.g., at night), the supercapacitor 155 supplies power to the RTC 160 based on the charge stored in it, which was obtained from the power supply 150 or from the photodiode 220 while previously receiving ambient light. In some embodiments, the size of the supercapacitor 155 is determined such that it can maintain the operation of the devices receiving power supply (e.g., the RTC 160 and the sensor 170) for 24 hours. During the interruption of AC power, the supercapacitor 155 recharges using the sunlight charger 190 in ambient light while supplying power to the RTC 160. If ambient light is not available, the supercapacitor 155 may supply power to the RTC until ambient light becomes available again. Thus, the photodiode 220 and the supercapacitor 155 may form a cycle where, while receiving ambient light (e.g., sunlight), the supercapacitor 155 is charged based on the photodiode 220 and supplies power to the RTC 160, and during darkness, the supercapacitor 155 uses its stored energy to supply power to the RTC 160. In some embodiments, this cycle may continue indefinitely during an extended interruption of AC power. For example, the RTC 160 or the sensor 170, or both, may continue to operate for days, weeks, or months when powered by the supercapacitor 155.

[0026] When the demand meter 100 is placed in a location where it has access to ambient light, it will be understood that the various embodiments operate as described in the present application. For example, if the demand meter is installed underground where there is no light source and no window, the photodiode 220 cannot absorb energy and output a voltage to the supercapacitor 155. However, if ambient light is available, the supercapacitor 155 may continue to supply power to the RTC or the sensor 170 for an extended period.

[0027] FIG. 3 is a diagram of an example of a solar charger 190 connected to a supercapacitor charger 310 implemented as a supercapacitor charging circuit according to some embodiments described in the present application. The supercapacitor charger 310 may be, for example, a part of the power supply 150, charge the supercapacitor 155, and supply power to the RTC 160 and the sensor 170. The supercapacitor charger 310 includes a linear regulator 320. As described above, when the power supply 150 is active, the linear regulator 320 receives DC power from the power supply 150 and generates an appropriate voltage to charge the supercapacitor 155 and supply power to the RTC 160 and the sensor 170. Specifically, for example, the linear regulator 320 has an input connected to the power supply 150 and an output connected to the supercapacitor charger 310, the RTC 160, and the sensor 170. In FIG. 3, the voltage from the power supply 150 to the linear regulator 310 has the symbol V12, and the voltage from the linear regulator 310 to the RTC 160 and the sensor 170 has the symbol VBB.

[0028] As shown in FIG. 3, the output from the solar charger 190 may be connected (e.g., OR-connected) to the output from the linear regulator 320 to charge the supercapacitor 155. Therefore, when the power supply 150 is active due to the sufficient AC line voltage, the supercapacitor 155 receives voltage from the power supply 150 by the linear regulator 310, and when ambient light reaches the solar charger 190, the supercapacitor 155 receives voltage from the solar charger 190.

[0029] FIG. 4 shows the printed circuit board 400 of the supply-demand meter 100 according to some embodiments described in the present application. In some embodiments, various subsystems of the supply-demand meter 100 are present on the PCB 400, which electrically connects the various subsystems as needed for the operation of the supply-demand meter 100. As shown in FIG. 4, the solar charger 190 may be attached to the surface of the PCB 400 facing the cover or housing of the supply-demand meter 100. For example, this may be the soldering side of the PCB 400, specifically, the soldering side of the measurement electronic assembly operating as the measurement engine 110.

[0030] FIG. 5 shows the cover 500 or housing of the supply-demand meter 100 according to some embodiments described in the present application. The cover 500 may accommodate at least a portion of the PCB 400 and thus may cover at least a portion thereof. For example, the cover 500 may provide a protective layer for the electronic circuit of the supply-demand meter 100. In some embodiments, as shown in FIG. 5, the cover 500 defines an opening 510 through which ambient light can pass through the cover 500, thereby exciting the photodiode 220 of the solar charger 190. Further, in some embodiments, the lens 520 fills the opening of the cover 500. The lens 520 may be transparent and has an appropriate curvature for focusing ambient light on the photodiode 220. For example, if there is no lens 520 located at the opening 510, the photodiode 220 may have an output of 300 millivolts, but if there is a lens 520 that focuses ambient light, the photodiode 220 may have an output of 500 millivolts. Those skilled in the art will understand how to calculate an appropriate curvature for the lens 520. Such a lens 520 can improve the efficiency of the photodiode 220 when charging the supercapacitor 155 by allowing an increased amount of light to reach the photodiode 220.

[0031] Figure 6 is a flowchart of a method 600 executed in the demand meter 100 to supply power to the RTC 160, according to some embodiments described in the present application. Although this method 600 specifically refers to supplying power to the RTC 160, it will be understood that the same or similar method may be used to supply power to one or more sensors 170, additionally or alternatively to the RTC 160. Further, this method 600 is provided for illustrative purposes only, and it will be understood that various activities need not be performed in the order described. For example, various activities described hereinafter as part of this method 600 may be performed simultaneously while the demand meter 100 is operating.

[0032] In block 605, the demand meter 100 is operating and the power supply 150 of the demand meter is active. Accordingly, the power supply 150 supplies a DC voltage to power various subsystems of the demand meter 100. In block 610, due to being active, the power supply 150 charges the supercapacitor 155 via the linear regulator 320 and supplies power to the RTC 160. Although not shown in FIG. 6, while the power supply 150 is active, the solar charger 190 may still contribute to the charging of the supercapacitor 155. In block 615, the AC line voltage drops below a threshold value and the power supply 150 becomes inactive.

[0033] In block 620, the supercapacitor 155 begins to supply power to the RTC 160 from the stored capacity in the supercapacitor 155. In block 625, when ambient light reaches the solar charger 190, the photodiode 220 is excited and the solar charger 190 charges the supercapacitor 155, which continues to supply power to the RTC 160. In block 630, when the ambient light is no longer present, the supercapacitor 155 continues to supply power to the RTC 160 from the stored capacity in the supercapacitor 155. As shown in FIG. 6, blocks 625 and 630 repeat the cycle over an extended time period, for example, as long as the power supply 150 is inactive.

[0034] In block 635, the AC line voltage increases to at least a threshold value, thereby reactivating power supply 150. Thus, in block 640, power supply 150 returns to charging supercapacitor 155 by linear regulator 320 and powering RTC 160.

[0035] FIG. 7 is a flowchart of a method 700 of making (e.g., manufacturing) a demand meter 100 incorporating a solar charger 190 for charging supercapacitor 155, according to some embodiments described herein. This method 700 or the like may be performed by one or more people, by one or more machines, or by a combination of people and machines. It is understood that this method 700 is provided for illustrative purposes only and that the various activities of this method 700 do not limit the activities that may be performed to manufacture demand meter 100 and that the various activities need not be performed in the order described.

[0036] As shown in FIG. 7, in block 705, method 700 includes incorporating into the device an RTC 160 configured to time the time utilized by a time stamp applicable to an event occurring during AC power stoppage of demand meter 100. According to the present disclosure, the phrase "install" indicates establishing for use. The device into which RTC 160 is incorporated is demand meter 100 or will become demand meter 100 during or after its manufacture. For example, in this case, the incorporation of RTC 160 may include electrically connecting RTC 160 to host 120 or to various other components of demand meter 100.

[0037] In block 710, method 700 includes incorporating into the device a supercapacitor 155 configured to power RTC 160 during AC power stoppage. For example, the incorporation of supercapacitor 155 may include electrically connecting the input of supercapacitor 155 to supercapacitor charger 310 and electrically connecting the output of supercapacitor 155 to RTC 160.

[0038] In block 715, method 700 includes incorporating into the device a power supply 150 configured to operate in an active mode in response to an AC line voltage that meets a threshold, and further configured to power the RTC 160 by charging the supercapacitor 155 when in the active mode. For example, incorporating the power supply 150 may include electrically connecting the output of the power supply 150 to various subsystems of the supercapacitor 155, the RTC 160, and the demand meter 100.

[0039] In block 720, method 700 includes incorporating into the device a set of photodiodes 200 configured to absorb energy from ambient light and power the RTC 160 by charging the supercapacitor 155. For example, incorporating the photodiodes 220 may include connecting a series of photodiodes 220 to a Schottky diode 210 and connecting the Schottky diode 210 to the input of the supercapacitor charger 310. Thus, in some embodiments, the supercapacitor 155 is configured to be charged based on the power supply 150 and also based on a set of photodiodes 220.

[0040] FIG. 8 is a diagram of a demand meter 100 according to some embodiments described in the present application. For example, the demand meter 100 may be an electricity meter or another type of meter that measures the consumption of a resource 810. The demand meter 100 as illustrated may include a solar charger 190 that charges the supercapacitor 155, and the supercapacitor 155 powers the RTC 160 or one or more sensors 170 as described in the present application.

[0041] As shown in FIG. 8, an example of the supply-demand meter 100 measures the consumption amount of the resource 810 that occurs in the premises 820. For this purpose, the supply-demand meter 100 may include a measurement engine 110 that detects a signal indicating the use of the resource 810 and determines the use of the resource 810 in the premises 820 based on that signal. The supply-demand meter 100 may further include a communication device such as a processing device 830, a volatile memory 840, a non-volatile storage device 850, and a wireless device 860. The processing device 830, the volatile memory 840, the non-volatile storage device 850, and the wireless device 860 may communicate with each other and with the measurement engine 110 via a system bus 870. The processing device 830, the volatile memory 840, and the non-volatile storage device 850 are illustrated and described herein as separate components, but it will be understood that this distinction is for illustrative purposes only and does not limit the scope of the present disclosure. For example, the processing device 830, the volatile memory 840, and the non-volatile storage device 850 may all be integrated into a single chip, such as a microcontroller unit, that operates as all or part of the host 120 described above.

[0042] In some embodiments, the logical operations of the supply-demand meter 100 are embodied as program instructions stored in a computer-readable medium, such as the non-volatile storage device 850 or the volatile memory 840 of the supply-demand meter 100. In some embodiments, the computer-readable medium is a non-transitory computer-readable medium. The processing device 830 may perform operations as described herein by executing the program instructions. Additionally or alternatively, certain operations of the supply-demand meter 100, such as charging the supercapacitor 155 by the power supply 150 or the solar charger 190, may be implemented as hardware rather than as computer-readable instructions.

[0043] Numerous specific details are set forth in this specification in order to provide a thorough understanding of the subject matter claimed herein. However, one of ordinary skill in the art will understand that the subject matter claimed may be practiced without these specific details. In other instances, well-known methods, devices, or systems known to those of ordinary skill in the art have not been described in detail so as not to obscure the subject matter claimed.

[0044] The features described in this application are not limited to any particular hardware architecture or configuration. A computing device may include any suitable device consisting of components that provide results conditional on one or more inputs. A suitable computing device includes a computer system based on a general-purpose microprocessor that accesses stored software (i.e., computer-readable instructions stored on the memory of a computer system), and this software programs or configures the computing system to become a special computing device that implements one or more aspects of the subject matter of this application from a general-purpose computing device. In the software used to program or configure the computing device, any suitable programming, scripting, other type of language, or combination of languages may be used to implement the disclosure contained in this application.

[0045] Aspects of the methods disclosed in this application may be executed in the operation of such a computing device. The order of the blocks presented in the above examples may be changed, for example, the blocks may be rearranged, combined, and / or divided into sub-blocks. A plurality of given blocks or a plurality of processes may be executed in parallel.

[0046] The use of "adapted to" or "configured to" in this application is intended to be an open and inclusive term that does not exclude an apparatus adapted or configured to perform additional tasks or steps. Further, the use of "based on" is intended to be open and inclusive in that a process, step, calculation, or other operation "based on" one or more recited conditions or values may in fact be based on additional conditions or values beyond those recited. Headings, lists, and numbers included in this application are for purposes of simplicity of explanation only and are not intended to be limiting.

[0047] While the subject matter of this application has been described in detail with respect to its particular embodiments, those skilled in the art will recognize that, by understanding the foregoing, it is readily possible to make changes, variations, and equivalents of such embodiments. Accordingly, it should be understood that this disclosure is presented for purposes of illustration and not limitation and does not exclude such changes, variations, and / or additions to the subject matter of this application as would be readily apparent to those skilled in the art.

Claims

1. a real-time clock (RTC) configured to measure a time utilized for time stamping applicable events occurring during an alternating current (AC) power outage of the utility meter; a supercapacitor configured to power the RTC; a power source configured to operate in an active mode in response to an AC line voltage satisfying a threshold, and further configured to power the RTC by charging the supercapacitor when in the active mode; a set of photodiodes configured to absorb energy from ambient light and charge the supercapacitor to power the RTC; the supercapacitor is configured to charge based on the power source and based on the set of photodiodes; Supply and demand meter.

2. the set of photodiodes comprises two or more photodiodes connected in series; 2. The utility meter of claim 1.

3. the utility meter further comprising a linear regulator connected to an output of the power supply; an output of the linear regulator is connected to a supercapacitor charger for charging the supercapacitor; the set of photodiodes is connected to the supercapacitor charger which charges the supercapacitor; 3. A utility meter as claimed in claim 2.

4. a Schottky diode connecting the pair of photodiodes to the supercapacitor charger.

4. A utility meter as claimed in claim 3.

5. the utility meter further comprises a metering electronic assembly configured to measure a consumption of a resource; the set of photodiodes is mounted on a printed circuit board of the utility meter on a side of the measurement electronics assembly; 2. The utility meter of claim 1.

6. a cover over a printed circuit board of the utility meter, the cover defining an opening configured to allow the ambient light to reach the set of photodiodes.

2. The utility meter of claim 1.

7. a lens fitted in an opening in a cover of the utility meter and configured to focus light onto the set of photodiodes.

7. A utility meter as claimed in claim 6.

8. The supercapacitor is configured to power the RTC for two or more days while the power source is inactive.

2. The utility meter of claim 1.

9. the supercapacitor is configured to power one or more sensors while the power source is inactive; 2. The utility meter of claim 1.

10. 1. A method of powering a real-time clock (RTC) of a utility meter, the method comprising: operating, by the utility meter, an RTC configured to time a time utilized for time stamping applicable events occurring during an alternating current (AC) power outage of the utility meter; charging, by the utility meter's power supply, a supercapacitor configured to power the RTC when the power supply is active due to receiving sufficient AC line voltage; powering the RTC based on energy provided by the power source through the supercapacitor; charging the supercapacitor based on energy absorbed from ambient light by a set of photodiodes; and powering the RTC based on energy provided by the photodiode by the supercapacitor when the power source is inactive. method.

11. the set of photodiodes comprises two or more photodiodes connected in series; The method of claim 10.

12. the utility meter includes a linear regulator connected to an output of the power supply; an output of the linear regulator is connected to a supercapacitor charger for charging the supercapacitor; the set of photodiodes is connected to the supercapacitor charger which charges the supercapacitor; The method of claim 11.

13. the utility meter including a Schottky diode connecting the pair of photodiodes to the supercapacitor charger; 13. The method of claim 12.

14. The method further comprises measuring the consumption of the resource by a measurement electronic assembly; the set of photodiodes is mounted on a printed circuit board of the utility meter on a side of the measurement electronics assembly; The method of claim 10.

15. the utility meter comprising a housing covering at least a portion of a printed circuit board of the utility meter, the housing defining an opening configured to allow the ambient light to reach the set of photodiodes. The method of claim 10.

16. the utility meter including a lens fitted in an opening in the housing and configured to focus light onto the set of photodiodes.

16. The method of claim 15.

17. The supercapacitor is configured to power the RTC for two or more days while the power source is inactive. The method of claim 10.

18. incorporating a real-time clock (RTC) into the device, the RTC being configured to time a time utilized for time stamping applicable events occurring during an alternating current (AC) power outage of the device; incorporating a supercapacitor into the device configured to power the RTC; incorporating in the apparatus a power supply configured to operate in an active mode in response to an AC line voltage satisfying a threshold, and further configured to power the RTC by charging the supercapacitor when in the active mode; incorporating into the device a set of photodiodes configured to absorb energy from ambient light and charge the supercapacitor to power the RTC; the supercapacitor is configured to charge based on the power source and based on the set of photodiodes; The device can be used as a utility meter. method.

19. connecting an input of a linear regulator to an output of the power supply; connecting an output of the linear regulator to an input of a supercapacitor charger for charging the supercapacitor; and charging the supercapacitor by connecting the set of photodiodes to the supercapacitor charger using a Schottky diode.

20. The method of claim 18.

20. providing said set of photodiodes on a printed circuit board of said device adjacent to a measurement electronics assembly; Fitting a lens into a housing of the device; and mounting the housing with the lens on the printed circuit board on a side of the measurement electronics assembly.

20. The method of claim 18.

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