Power failure detection circuit, power failure control method and smart meter
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- QINGDAO ITECHENE TECH CO LTD
- Filing Date
- 2026-03-30
- Publication Date
- 2026-05-29
Smart Images
Figure CN122109600A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of smart meter technology, specifically to a power failure detection circuit, a power failure control method, and a smart meter. Background Technology
[0002] Smart meters need to perform power outage detection in order to effectively respond to power outages. However, existing power outage detection technologies have the following problems: 1. Traditional power failure detection mechanisms have a slow response: Many existing power failure detection circuits cannot respond quickly to voltage drops, resulting in the inability to trigger protection measures in a timely manner in practical applications.
[0003] 2. Insufficient detection accuracy: Some power failure detection circuits are too sensitive to voltage fluctuations, which can easily lead to misjudgments and affect the normal operation of the system.
[0004] 3. Improper timing of reset: If the reset occurs at an inappropriate time, it may result in data loss or system crash.
[0005] Accordingly, there is a need in the field for a new power failure detection solution to address the above problems. Summary of the Invention
[0006] In order to overcome the above-mentioned deficiencies, this application is made to solve, or at least partially solve, the technical problem of how to achieve more accurate, timely and reliable power failure detection.
[0007] In a first aspect, a power-down detection circuit is provided, comprising: The voltage sampling module is used to sample voltage and obtain voltage sampling results. The power failure detection module is used to compare thresholds based on voltage sampling results to determine the power failure detection result. The output driver module is used to output a power-down control signal based on the power-down detection result.
[0008] In one technical solution of the above-mentioned power failure detection circuit, the power failure detection module includes a reference voltage source and a voltage divider circuit; The reference voltage source is used to generate a reference voltage for threshold comparison. The voltage divider circuit is used to divide the reference voltage to generate a corresponding threshold for threshold comparison.
[0009] In one technical solution of the above-mentioned power failure detection circuit, the voltage divider circuit includes a first resistor and a second resistor; The first terminal of the first resistor is connected to the voltage sampling module; The second end of the first resistor is connected to the first end of the power failure detection module; The first end of the second resistor is connected to the second end of the first resistor; The second terminal of the second resistor is grounded.
[0010] In one technical solution of the above-mentioned power failure detection circuit, the power failure detection module further includes a hysteresis comparison unit; The hysteresis comparator unit is used to generate hysteresis voltage.
[0011] In one technical solution of the above-mentioned power failure detection circuit, the output driving module includes a CMOS driving circuit; The CMOS driving circuit is used to convert the level signal corresponding to the power-down detection result into a power-down control signal.
[0012] In one technical solution of the above-mentioned power failure detection circuit, the power failure detection circuit further includes a first capacitor and a second capacitor; The first terminal of the first capacitor is connected to the first terminal of the power failure detection module; the second terminal of the first capacitor is grounded. The first terminal of the second capacitor is connected to the second terminal of the power failure detection module; the second terminal of the second capacitor is grounded.
[0013] In one technical solution of the above-mentioned power failure detection circuit, the power failure detection circuit further includes a third resistor; The first end of the third resistor is connected to the power supply; the second end of the third resistor is connected to the second end of the power failure detection module.
[0014] In a second aspect, a power-down control method is provided, the method being applied to a controller, the controller being connected to the power-down detection circuit in the aforementioned power-down detection circuit technical solution; the method includes: Obtain the power-down control signal output by the power-down detection circuit; The controller is powered down according to the power-down control signal.
[0015] In one technical solution of the above power-down control method, the step of performing power-down control on the controller according to the power-down control signal includes: If the power-down control signal is a high-level signal, the controller will operate normally. If the power-down control signal is a low-level signal, the controller is interrupted, and the controller is controlled to execute critical data.
[0016] In a third aspect, a smart meter is provided, which includes a power failure detection circuit and a controller as described in the above-mentioned power failure detection circuit technical solution, the controller including at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program, and when the computer program is executed by the at least one processor, it implements the method described in any of the above-mentioned technical solutions of the power failure control method.
[0017] The above-described technical solutions of this application have at least one or more of the following beneficial effects: In implementing the power failure detection technology solution provided in this application, the power failure detection circuit includes a voltage sampling module, a power failure detection module, and an output driving module. The voltage sampling module is used to sample the voltage and obtain the voltage sampling result. The power failure detection module is used to compare a threshold based on the voltage sampling result to determine the power failure detection result. The output driving module is used to output a power failure control signal based on the power failure detection result. Through the above settings, this application can achieve high-precision voltage monitoring and a rapid response mechanism for power failures, ensuring that a power failure control signal can be effectively output at the moment of power failure, thereby enabling timely protective measures to be taken in response to power failures. Furthermore, the output driving module of this application can output a power failure control signal based on the power failure detection result, and then, based on the power failure control signal, achieve effective power failure control of the controller, thereby realizing an effective power failure protection mechanism for the controller and ensuring the stable operation of the system.
[0018] Furthermore, the power failure detection module of this application is equipped with a voltage divider circuit. By setting different voltage divider resistors, it is possible to achieve voltage monitoring of multiple voltage thresholds, which can effectively improve the stability of the system under various working conditions. Attached Figure Description
[0019] The disclosure of this application will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this application. Wherein: Figure 1 This is a schematic diagram of the main components of a power-down detection circuit according to an embodiment of this application; Figure 2 This is a schematic diagram of the main components of a power-down detection circuit according to one embodiment of the present application. Figure 3 This is a schematic flowchart of the main steps of a power-off control method according to an embodiment of this application; Figure 4 This is a schematic flowchart of the main steps of a power-off control method according to one embodiment of the present application.
[0020] Figure label: 11: Voltage sampling module; 12: Power failure detection module; 13: Output drive module. Detailed Implementation
[0021] Some embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application.
[0022] In the description of this application, "module" and "processor" can include hardware, software, or a combination of both. A module can include hardware circuitry, various suitable sensors, communication ports, and memory, and may also include software components, such as program code, or a combination of software and hardware. The term "A and / or B" means all possible combinations of A and B, such as only A, only B, or A and B. The terms "at least one A or B" or "at least one of A and B" have a similar meaning to "A and / or B" and can include only A, only B, or A and B. The singular forms of the terms "a" and "this" can also include plural forms.
[0023] See appendix Figure 1 , Figure 1 This is a schematic diagram of the main structural components of a power-down detection circuit according to an embodiment of this application. Figure 1 As shown, the power failure detection circuit of this application embodiment mainly includes a voltage sampling module 11, a power failure detection module 12, and an output driving module 13.
[0024] In this embodiment, the voltage sampling module 11 can be used to perform voltage sampling and obtain voltage sampling results. The power-down detection module 12 can be used to perform threshold comparison based on the voltage sampling results and determine the power-down detection result. The output drive module 13 can be used to output a power-down control signal based on the power-down detection result.
[0025] In one implementation, the voltage of the power bus requiring power-down detection can be sampled using a voltage sampling module to obtain voltage sampling results. The voltage sampling process can employ a continuous loop detection method, such as sampling at a preset sampling frequency, to obtain voltage sampling results.
[0026] In one implementation, an RC filter circuit can be set to filter out the ripple of the sampled voltage, thereby improving the anti-interference capability of the voltage sampling module and thus improving the accuracy of the voltage sampling results.
[0027] In one implementation, the power failure detection module may include a reference voltage source and a voltage divider circuit.
[0028] In this embodiment, a reference voltage source can be used to generate a reference voltage for threshold comparison. A voltage divider circuit can be used to divide the reference voltage to generate the corresponding threshold for threshold comparison.
[0029] In one implementation, the power failure detection module can compare the voltage sampling result with a threshold. If the voltage sampling result is greater than or equal to the threshold, the power failure detection result can be determined to be that the voltage is stable; if the voltage sampling result is less than the threshold, the power failure detection result can be determined to be that a power failure has occurred.
[0030] In one implementation, when the power-down detection result indicates that the voltage is stable, a high-level signal can be output as a power-down control signal. When the power-down detection result indicates that a power-down has occurred, a low-level signal can be output as a power-down control signal.
[0031] In one embodiment, the voltage divider circuit may include a first resistor and a second resistor. A first terminal of the first resistor may be connected to a voltage sampling module, a second terminal of the first resistor may be connected to a first terminal of a power-down detection module, and a first terminal of the second resistor may be connected to the second terminal of the first resistor; the second terminal of the second resistor is grounded. The threshold value can be precisely adjusted by regulating the resistance ratio of the first and second resistors.
[0032] In some specific examples, the threshold adjustment accuracy can reach ±1%.
[0033] In one embodiment, the reference voltage source can be a high-precision reference voltage source, with a detection accuracy of ±1%. The high-precision reference voltage source, combined with a voltage divider circuit consisting of a first resistor and a second resistor, enables power-down detection processes for different power supply specifications.
[0034] In one embodiment, the power failure detection circuit may further include a first capacitor and a second capacitor.
[0035] In this embodiment, the first terminal of the first capacitor can be connected to the first terminal of the power failure detection module; the second terminal of the first capacitor can be grounded; the first terminal of the second capacitor can be connected to the second terminal of the power failure detection module; the second terminal of the second capacitor can be grounded. The first and second capacitors can serve as decoupling capacitors to achieve the filtering function of the power failure detection circuit.
[0036] In one embodiment, the power failure detection circuit may further include a third resistor.
[0037] In this embodiment, the first end of the third resistor can be connected to the power supply, and the second end of the third resistor can be connected to the second end of the power failure detection module.
[0038] In one embodiment, the power failure detection module may further include a hysteresis comparison unit, which can be used to generate a hysteresis voltage.
[0039] In this embodiment, the hysteresis comparator can be set with a hysteresis voltage to avoid frequent level switching caused by power supply voltage fluctuations. In some specific examples, the hysteresis voltage set for the hysteresis comparator can be 20–50 mV.
[0040] In one implementation, the power-down detection circuit can be a low temperature coefficient design circuit.
[0041] In some specific examples, the low temperature coefficient is designed to be ±10mV / ℃, which can effectively avoid false detections caused by factors such as resistance temperature drift, power supply jitter and temperature fluctuations in a wide temperature range of -40℃ to +125℃, and can effectively ensure that the threshold has higher stability.
[0042] In one implementation, the output driving module may include a CMOS (Complementary Metal Oxide Semiconductor) driving circuit.
[0043] In this embodiment, the CMOS driving circuit can be used to convert the level signal corresponding to the power failure detection result into a power failure control signal. Specifically, the CMOS driving circuit receives the power failure detection signal output by the power failure detection module and can convert the power failure detection signal into a power failure control signal that the controller can recognize, thereby realizing the controller's power failure alarm or triggering the controller to execute the power failure save process.
[0044] In some specific examples, the output driver module can support open collectors and can implement multi-channel power failure detection through wired-AND logic expansion.
[0045] In one implementation, the output driver module may include an optocoupler isolation circuit to achieve optocoupler-based interference isolation.
[0046] In one implementation, the power-down detection module may have a built-in noise suppression circuit.
[0047] In this embodiment, a two-stage anti-interference system can be constructed by building a built-in noise suppression circuit to effectively withstand the effects of power bus surges, ripples, and electromagnetic interference. Combined with the design of the optocoupler isolation circuit of the output drive module, it can fully meet the EMC (Electromagnetic Compatibility) standards of industrial-grade equipment, effectively solving the problem of traditional voltage divider schemes being susceptible to interference.
[0048] In one implementation, the output drive module can be connected to a signal conditioning module. The signal conditioning module can be used to filter the power-down control signal, thereby ensuring the stability and accuracy of the power-down control signal.
[0049] In a specific example, the power failure detection module can use the BD4823 series voltage comparator chip. For example... Figure 2 As shown, Figure 2 U1 in the diagram refers to the voltage comparator chip. The voltage divider circuit of the voltage comparator chip may include a first resistor (i.e., Figure 2 R1 in the middle) and the second resistor (i.e., Figure 2 R3 in the middle). The third resistor (i.e., Figure 2 R2 in the first capacitor is connected to VCC at one end and to the OUT pin of the voltage comparator chip at the other end. By adjusting the resistance ratio of R1 and R3, the detection threshold can be precisely adjusted. Figure 2 C1 in the middle), the second capacitor (i.e., Figure 2 C2) in the diagram is used for filtering and is connected to the VDD and OUT pins of the voltage comparator chip, respectively. The BD4823 series voltage comparator chip has a typical operating current of only 1μA, and its power-down detection module can trigger the output of a power-down control signal only when the power supply voltage is below a threshold. This enables the controller to enter a deep sleep state when no power-down control signal is output, eliminating the need for continuous power-down control signal detection and significantly reducing standby power consumption. This is particularly suitable for scenarios requiring long-term low-power operation, such as smart meters. Furthermore, the power-down detection module can be packaged using industrial-grade technology, enabling maintenance-free operation for over 10 years. This avoids threshold drift issues caused by resistor aging in resistor divider schemes, reducing long-term maintenance costs and meeting the long-life design requirements of industrial equipment such as smart meters.
[0050] The power-down detection circuit of this application embodiment includes a voltage sampling module, a power-down detection module, and an output driving module. The voltage sampling module performs voltage sampling to obtain the voltage sampling result. The power-down detection module performs a threshold comparison based on the voltage sampling result to determine the power-down detection result. The output driving module outputs a power-down control signal based on the power-down detection result. Through the above configuration, this application embodiment can achieve high-precision voltage monitoring and a rapid response mechanism for power-down situations, ensuring effective output of a power-down control signal at the moment of power failure, thereby enabling timely protective measures to be taken in response to power failure.
[0051] Furthermore, the power-down detection module in this embodiment is equipped with a voltage divider circuit. By setting different voltage divider resistors, voltage monitoring of multiple voltage thresholds can be achieved, which can effectively improve the stability of the system under various working conditions.
[0052] Furthermore, this application also provides a power-off control method.
[0053] See appendix Figure 3 , Figure 3This is a schematic flowchart illustrating the main steps of a power-down control method according to an embodiment of this application. The power-down control method of this embodiment is applied to a controller, which is connected to the power-down detection circuit in the above-described power-down detection circuit embodiment. Figure 3 As shown, the power-down control method in this application embodiment mainly includes the following steps S101 to S102.
[0054] Step S101: Obtain the power-down control signal output by the power-down detection circuit.
[0055] In this embodiment, the output of the power failure detection circuit can be connected to the controller, and the controller can acquire the power failure control signal output by the power failure detection circuit.
[0056] In one implementation, the controller may be an MCU (Microcontroller Unit). In some other implementations, the controller may be other controllers commonly used in the art.
[0057] Step S102: Perform power-down control on the controller according to the power-down control signal.
[0058] In this embodiment, power-down control of the controller can be achieved based on the power-down control signal.
[0059] In one embodiment, step S102 may further include steps S1021 and S1022: Step S1021: If the power-down control signal is a high-level signal, the controller will operate normally.
[0060] Step S1022: If the power-down control signal is a low-level signal, trigger the controller interrupt and control the controller to execute key data.
[0061] In this embodiment, if the power-down control signal is detected to be high, the controller can maintain normal operation. If the power-down control signal is detected to be low, a controller interrupt can be triggered, and the controller can execute only critical data to preserve power.
[0062] In one implementation, if the controller triggers an interrupt, it can continue to acquire the power-down control signal to determine whether the power bus voltage has recovered to the power-on voltage; if so, the controller can resume normal operation; if not, the controller can continue to maintain the interrupt state.
[0063] In one implementation, see Appendix Figure 4 ,like Figure 4 As shown, the power-down control method may include the following steps S201 to S209: Step S201: Power supply to the power bus to be tested.
[0064] Step S202: The power failure detection circuit performs continuous loop detection.
[0065] Step S203: The power failure detection circuit determines whether the power supply voltage is lower than the threshold; if yes, proceed to step S204; if no, proceed to step S206.
[0066] Step S204: The power-down detection circuit outputs a high level.
[0067] Step S205: The controller is working normally.
[0068] Step S206: The power-down detection circuit outputs a low level.
[0069] Step S207: Trigger a controller interrupt.
[0070] Step S208: The controller executes critical data (power saving).
[0071] Step S209: Determine whether the power supply voltage has recovered to the power-on voltage; if yes, proceed to step S205; if no, proceed to step S208.
[0072] Based on the methods described in steps S101 to S102 above, in the power-down control method of this application embodiment, the controller acquires the power-down control signal from the power-down detection circuit, and performs power-down control on the controller according to the power-down control signal. Through the above configuration, this application embodiment can achieve effective power-down control of the controller based on the power-down control signal output by the power-down detection circuit, thereby realizing an effective power-down protection mechanism for the controller and improving the operational stability of the system.
[0073] It should be noted that although the steps in the above embodiments are described in a specific order, those skilled in the art will understand that in order to achieve the effect of this application, different steps do not necessarily have to be executed in such an order. They can be executed simultaneously (in parallel) or in other orders. These adjusted solutions are equivalent to the technical solutions described in this application and therefore will also fall within the protection scope of this application.
[0074] Those skilled in the art will understand that all or part of the processes in the method of the above-described embodiment can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form. The computer-readable storage medium can include any entity or device capable of carrying the computer program code, a medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory, a random access memory, an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.
[0075] Another aspect of this application provides a computer-readable storage medium.
[0076] In one embodiment of a computer-readable storage medium according to this application, the computer-readable storage medium can be configured to store a program that performs the power-down control method of the above-described method embodiments. This program can be loaded and run by a processor to implement the power-down control method. For ease of explanation, only the parts related to the embodiments of this application are shown; for specific technical details not disclosed, please refer to the method section of the embodiments of this application. The computer-readable storage medium can be a storage device including various electronic devices, such as magnetic disks, hard disks, optical disks, flash memory, read-only memory, random access memory, etc. Optionally, in the embodiments of this application, the computer-readable storage medium is a non-transitory computer-readable storage medium.
[0077] Another aspect of this application provides a smart meter.
[0078] In one embodiment of a smart meter according to this application, the smart meter may include the power failure detection circuit and controller described in the above-described power failure detection circuit embodiments. The controller may be connected to the power failure detection circuit. The controller may include at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program that, when executed by the at least one processor, implements the method described in any of the above-described power failure control method embodiments.
[0079] In some embodiments of this application, the processor may be a central processing unit, a microprocessor, a graphics processor, a digital signal processor, or any other suitable processor. The processor has data and / or signal processing capabilities. The processor may be implemented in software, in hardware, or a combination of both.
[0080] The technical solution of this application has been described above with reference to one embodiment shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.
Claims
1. A power-down detection circuit, characterized in that, include: The voltage sampling module is used to sample voltage and obtain voltage sampling results. The power failure detection module is used to compare thresholds based on voltage sampling results to determine the power failure detection result. The output driver module is used to output a power-down control signal based on the power-down detection result.
2. The power failure detection circuit according to claim 1, characterized in that, The power failure detection module includes a reference voltage source and a voltage divider circuit; The reference voltage source is used to generate a reference voltage for threshold comparison. The voltage divider circuit is used to divide the reference voltage to generate a corresponding threshold for threshold comparison.
3. The power failure detection circuit according to claim 2, characterized in that, The voltage divider circuit includes a first resistor and a second resistor; The first terminal of the first resistor is connected to the voltage sampling module; The second end of the first resistor is connected to the first end of the power failure detection module; The first end of the second resistor is connected to the second end of the first resistor; The second terminal of the second resistor is grounded.
4. The power failure detection circuit according to claim 2, characterized in that, The power failure detection module also includes a hysteresis comparison unit; The hysteresis comparator unit is used to generate hysteresis voltage.
5. The power failure detection circuit according to claim 1, characterized in that, The output driving module includes a CMOS driving circuit; The CMOS driving circuit is used to convert the level signal corresponding to the power-down detection result into a power-down control signal.
6. The power failure detection circuit according to claim 1, characterized in that, The power failure detection circuit also includes a first capacitor and a second capacitor. The first terminal of the first capacitor is connected to the first terminal of the power failure detection module; the second terminal of the first capacitor is grounded. The first terminal of the second capacitor is connected to the second terminal of the power failure detection module; the second terminal of the second capacitor is grounded.
7. The power failure detection circuit according to claim 1, characterized in that, The power failure detection circuit also includes a third resistor; The first end of the third resistor is connected to the power supply; the second end of the third resistor is connected to the second end of the power failure detection module.
8. A power-off control method, characterized in that, The method is applied to a controller, the controller being connected to the power failure detection circuit according to any one of claims 1 to 7; the method includes: Obtain the power-down control signal output by the power-down detection circuit; The controller is powered down according to the power-down control signal.
9. The power-off control method according to claim 8, characterized in that, The step of performing power-down control on the controller according to the power-down control signal includes: If the power-down control signal is a high-level signal, the controller will operate normally. If the power-down control signal is a low-level signal, the controller is interrupted, and the controller is controlled to execute critical data.
10. A smart meter, characterized in that, The device includes a power-down detection circuit and a controller as described in any one of claims 1 to 7, the controller being connected to the power-down detection circuit and the controller including at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program that, when executed by the at least one processor, implements the power-down control method as described in any one of claims 8 to 9.