Three-phase meter cover opening detection and power supply control circuit and electric energy meter

Abstract

This invention discloses a three-phase meter cover opening detection and power control circuit, including a main control MCU, a backup power supply circuit, a clock power supply circuit, a controlled low-power power supply circuit, a single-phase RC pulse trigger circuit, a programmable integral sustaining circuit, and a limit switch circuit. The main control MCU is electrically connected to the clock power supply circuit, the limit switch circuit, the controlled low-power power supply circuit, and the programmable integral sustaining circuit. The limit switch circuit is electrically connected to the clock power supply circuit, the single-phase RC pulse trigger circuit, and the controlled low-power power supply circuit. The clock power supply circuit is electrically connected to the backup power supply circuit and the controlled low-power power supply circuit. The programmable integral sustaining circuit is electrically connected to the single-phase RC pulse trigger circuit and the controlled low-power power supply circuit. This invention also discloses an energy meter. This invention solves the technical problem of cover opening event monitoring and clock battery power consumption control in a three-phase energy meter during a power outage and when the backup battery fails.

Description

Technical Field

[0001] This invention relates to the field of electronic information technology, and in particular to a three-phase meter cover opening detection and power control circuit and an energy meter. Background Technology

[0002] Currently, three-phase electricity meters sold by the State Grid and China Southern Power Grid generally employ a dual power supply scheme consisting of a replaceable backup battery and a non-replaceable clock battery. The backup battery primarily powers the MCU for low-power operation, supporting functions such as button display and cover opening detection; the clock battery maintains the correct operation of the RTC when the backup battery is low on voltage or replaced. With technological advancements, the latest technical specifications require that electricity meters, even after a power outage due to a low-voltage or removed backup battery, and after two days of power outage followed by cover opening, should still accurately record the cover opening event. This requirement sets a higher standard for the power management and event detection capabilities of electricity meters.

[0003] Traditional three-phase smart meter cover-opening detection circuits suffer from the following technical defects: First, insufficient power consumption control. When the cover is open, the clock battery continuously powers the entire detection circuit, leading to unnecessary power consumption. Even when the cover is closed, there is still static power consumption, affecting the lifespan of the clock battery. Second, poor event recording reliability. When a cover-closing event occurs, the MCU may not be able to record the event in time due to the delay in the power cut-off process, resulting in event loss. Third, low intelligence. Lacking an effective power management mechanism, it cannot dynamically adjust the power supply strategy according to actual needs and cannot automatically enter a low-power mode under prolonged cover-opening conditions. Patent document CN223651079U discloses a three-phase smart meter cover-opening detection circuit and energy meter, but it also fails to solve the above problems. These defects seriously affect the reliability and lifespan of the energy meter, failing to meet the technical requirements of the next generation of smart meters. Therefore, it is urgent to propose a three-phase smart meter cover-opening detection and power control circuit and energy meter to solve the technical problems of cover-opening event monitoring and clock battery power consumption control in the event of a power outage and backup battery failure. Summary of the Invention

[0004] The main objective of this invention is to propose a three-phase meter cover opening detection and power control circuit and an energy meter, aiming to solve the technical problems of cover opening event monitoring and clock battery power consumption control in a three-phase energy meter when there is a power outage and the backup battery fails.

[0005] To achieve the above objectives, the present invention provides a three-phase meter cover opening detection and power control circuit, wherein the three-phase meter cover opening detection and power control circuit includes: a main control MCU, a backup power supply circuit, a clock power supply circuit, a controlled low-power power supply circuit, a unidirectional RC pulse trigger circuit, a programmable integral sustaining circuit, and a limit switch circuit.

[0006] The main control MCU is electrically connected to the clock power supply circuit, the limit switch circuit, the controlled low-power power supply circuit, and the programmable integral sustain circuit, respectively. The limit switch circuit is electrically connected to the clock power supply circuit, the unidirectional RC pulse trigger circuit, and the controlled low-power power supply circuit, respectively. The clock power supply circuit is electrically connected to the backup power supply circuit and the controlled low-power power supply circuit, respectively. The programmable integral sustain circuit is electrically connected to the unidirectional RC pulse trigger circuit and the controlled low-power power supply circuit, respectively.

[0007] In one preferred embodiment, the backup power supply circuit includes diode D1, diode D2, resistor R2, and second battery BT2; the negative terminal of the second battery BT2 is grounded, the positive terminal of the second battery is connected to resistor R2, the other end of resistor R2 is connected to the anode of diode D2, the cathode of diode D2 is connected to the cathode of diode D1, the clock power supply circuit, and the controlled low-power power supply circuit, and the anode of diode D1 is connected to the regulated power supply VPP.

[0008] In one preferred embodiment, the clock power supply circuit includes a first battery BT1, a resistor R1, a diode D3, a resistor R4, a capacitor C3, a capacitor C1, a voltage regulator VR1, a capacitor C2, a diode D4, and a capacitor C10. The positive terminal of the first battery BT1 is connected to the resistor R1, and the other end of the resistor R1 is connected to the anode of the diode D3. The cathode of the diode D3 is connected to the resistor R4, the limit switch circuit, the capacitor C10, the cathode of the diode D4, and the clock power supply PRTC. The other end of the resistor R4 is connected to the main control MCU and the capacitor C3. The anode of the diode D4 is connected to the capacitor C2 and pin 3 of the voltage regulator VR1. Pin 1 of the voltage regulator VR1 is connected to the backup power supply circuit and the capacitor C1. The negative terminal of the first battery BT1, pin 2 of the voltage regulator VR1, and the other ends of the capacitors C3, C10, C2, and C1 are grounded.

[0009] In one preferred embodiment, the limit switch circuit includes a limit switch K1, resistors R3 and R5, and a capacitor C4. Pin 1 of the limit switch K1 is connected to a unidirectional RC pulse trigger circuit and a controlled low-power power supply circuit, pin 2 of the limit switch K1 is connected to a clock power supply circuit, pin 3 of the limit switch K1 is connected to resistor R3, the other end of resistor R3 is connected to the controlled low-power power supply circuit, pin 4 of the limit switch K1 is connected to resistor R5, capacitor C4, and the main control MCU, and the other ends of resistor R5 and capacitor C4 are grounded.

[0010] In one preferred embodiment, the unidirectional RC pulse trigger circuit includes a diode D8, a resistor R6, a capacitor C9, a resistor R8, and a capacitor C8; the anode of the diode D8 is connected to the limit switch circuit, the cathode of the diode D8 is connected to the resistor R6 and the capacitor C9, the other end of the resistor R6 is connected to the other end of the capacitor C9, the resistor R8, the capacitor C8, the controlled low-power power supply circuit, and the programmable integral sustaining circuit, and the other end of the resistor R8 is connected to the other end of the capacitor C8 and ground.

[0011] In one preferred embodiment, the controlled low-power power supply circuit includes diodes D5, D6, and D7, capacitor C6, voltage regulator VR2, and capacitor C7. Pin 1 of voltage regulator VR2 is connected to capacitor C6, the cathodes of diodes D5 and D6, respectively. The anode of diode D5 is connected to a limit switch circuit. Pin 3 of voltage regulator VR2 is connected to the cathode of diode D7 and a unidirectional RC pulse trigger circuit, respectively. The anodes of diodes D7 and D6 are both connected to a clock power supply circuit. Pin 5 of voltage regulator VR2 is connected to the limit switch circuit, capacitor C7, low-power power supply VBB, and the main control MCU, respectively. Pin 2 of voltage regulator VR2, and the other ends of capacitors C6 and C7 are grounded.

[0012] In one preferred embodiment, the programmable integral sustaining circuit includes a diode D9, a capacitor C11, and a resistor R9; the cathode of the diode D9 is connected to a unidirectional RC pulse trigger circuit, the anode of the diode R9 is connected to both the capacitor C11 and the resistor R9, the other end of the resistor R9 is connected to the main control MCU, and the other end of the capacitor C11 is grounded.

[0013] In one preferred embodiment, the interrupt port INT of the main control MCU is connected to the limit switch circuit.

[0014] An electricity meter, the electricity meter including the aforementioned three-phase meter cover opening detection and power control circuit.

[0015] In the above-described technical solution of the present invention, the three-phase meter cover opening detection and power control circuit includes: a main control MCU, a backup power supply circuit, a clock power supply circuit, a controlled low-power power supply circuit, a unidirectional RC pulse trigger circuit, a programmable integral sustaining circuit, and a limit switch circuit. The main control MCU is electrically connected to the clock power supply circuit, the limit switch circuit, the controlled low-power power supply circuit, and the programmable integral sustaining circuit. The limit switch circuit is electrically connected to the clock power supply circuit, the unidirectional RC pulse trigger circuit, and the controlled low-power power supply circuit. The clock power supply circuit is electrically connected to the backup power supply circuit and the controlled low-power power supply circuit. The programmable integral sustaining circuit is electrically connected to the unidirectional RC pulse trigger circuit and the controlled low-power power supply circuit. This invention solves the technical problem of cover opening event monitoring and clock battery power consumption control in a three-phase energy meter during a power outage and when the backup battery fails. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a first schematic diagram of a three-phase meter cover opening detection and power control circuit according to an embodiment of the present invention;

[0018] Figure 2 This is a second schematic diagram of a three-phase meter cover opening detection and power control circuit according to an embodiment of the present invention.

[0019] The realization of the objective, functional characteristics and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0022] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0023] See Figures 1-2 According to one aspect of the present invention, a three-phase meter cover opening detection and power control circuit is provided, wherein the three-phase meter cover opening detection and power control circuit includes: a main control MCU, a backup power supply circuit, a clock power supply circuit, a controlled low-power power supply circuit, a unidirectional RC pulse trigger circuit, a programmable integral sustaining circuit, and a limit switch circuit; the main control MCU is electrically connected to the clock power supply circuit, the limit switch circuit, the controlled low-power power supply circuit, and the programmable integral sustaining circuit respectively; the limit switch circuit is electrically connected to the clock power supply circuit, the unidirectional RC pulse trigger circuit, and the controlled low-power power supply circuit respectively; the clock power supply circuit is electrically connected to the backup power supply circuit and the controlled low-power power supply circuit respectively; and the programmable integral sustaining circuit is electrically connected to the unidirectional RC pulse trigger circuit and the controlled low-power power supply circuit respectively.

[0024] Specifically, in this embodiment, the backup power circuit includes diode D1, diode D2, resistor R2, and second battery BT2; the negative terminal of the second battery BT2 is grounded, the positive terminal of the second battery is connected to resistor R2, the other end of resistor R2 is connected to the anode of diode D2, the cathode of diode D2 is connected to the cathode of diode D1, the clock power supply circuit, and the controlled low-power power supply circuit, respectively, and the anode of diode D1 is connected to the regulated power supply VPP; the second battery is a replaceable battery.

[0025] Specifically, in this embodiment, the clock power supply circuit includes a first battery BT1, a resistor R1, a diode D3, a resistor R4, a capacitor C3, a capacitor C1, a voltage regulator VR1, a capacitor C2, a diode D4, and a capacitor C10. The positive terminal of the first battery BT1 is connected to the resistor R1, and the other end of the resistor R1 is connected to the anode of the diode D3. The cathode of the diode D3 is connected to the resistor R4, the limit switch circuit, the capacitor C10, the cathode of the diode D4, and the clock power supply PRTC. The other end of the resistor R4 is connected to the main control MCU and the capacitor C3. The anode of the diode D4 is connected to the capacitor C2 and the 3rd pin of the voltage regulator VR1. The 1st pin of the voltage regulator VR1 is connected to the backup power supply circuit and the capacitor C1. The negative terminal of the first battery BT1, the 2nd pin of the voltage regulator VR1, the capacitors C3, C10, C2, and the other end of the capacitor C1 are grounded.

[0026] Specifically, in this embodiment, the limit switch circuit includes a limit switch K1, a resistor R3, a resistor R5, and a capacitor C4; pin 1 of the limit switch K1 is connected to a unidirectional RC pulse trigger circuit and a controlled low-power power supply circuit, pin 2 of the limit switch K1 is connected to a clock power supply circuit, pin 3 of the limit switch K1 is connected to a resistor R3, the other end of the resistor R3 is connected to the controlled low-power power supply circuit, pin 4 of the limit switch K1 is connected to a resistor R5, a capacitor C4, and a main control MCU, and the other ends of the resistor R5 and the capacitor C4 are grounded.

[0027] Specifically, in this embodiment, the unidirectional RC pulse trigger circuit includes a diode D8, a resistor R6, a capacitor C9, a resistor R8, and a capacitor C8; the anode of the diode D8 is connected to the limit switch circuit, the cathode of the diode D8 is connected to the resistor R6 and the capacitor C9, the other end of the resistor R6 is connected to the other end of the capacitor C9, the resistor R8, the capacitor C8, the controlled low-power power supply circuit, and the programmable integral sustaining circuit, and the other end of the resistor R8 is connected to the other end of the capacitor C8 and the ground terminal.

[0028] Specifically, in this embodiment, the controlled low-power power supply circuit includes diodes D5, D6, and D7, capacitor C6, voltage regulator VR2, and capacitor C7. Pin 1 of voltage regulator VR2 is connected to capacitor C6, the cathode of diode D5, and the cathode of diode D6, respectively. The anode of diode D5 is connected to a limit switch circuit. Pin 3 of voltage regulator VR2 is connected to the cathode of diode D7 and a unidirectional RC pulse trigger circuit, respectively. The anodes of diode D7 and diode D6 are both connected to a clock power supply circuit. Pin 5 of voltage regulator VR2 is connected to the limit switch circuit, capacitor C7, low-power power supply VBB, and the main control MCU, respectively. Pin 2 of voltage regulator VR2, and the other ends of capacitors C6 and C7 are grounded.

[0029] Specifically, in this embodiment, the programmable integral sustaining circuit includes a diode D9, a capacitor C11, and a resistor R9; the cathode of the diode D9 is connected to a unidirectional RC pulse trigger circuit, the anode of the diode R9 is connected to both the capacitor C11 and the resistor R9, the other end of the resistor R9 is connected to the main control MCU, and the other end of the capacitor C11 is grounded.

[0030] Specifically, in this embodiment, the interrupt port INT of the main control MCU is connected to the limit switch circuit.

[0031] Specifically, in this embodiment, when the cover is open, the button of limit switch K1 is in the pop-up state, and both sets of contacts of the limit switch are closed simultaneously; when the cover is closed, the button of limit switch K1 is in the pressed state, and both sets of contacts of limit switch K1 are open simultaneously; the RC time constant T1 of resistor R6 and capacitor C9 is set greater than the RC time constant T2 of resistor R8 and capacitor C8, the resistance value of resistor R8 is set less than the resistance value of resistor R6, the capacitance value of capacitor C8 is set less than the capacitance value of capacitor C9, and the resistance value of resistor R9 is set less than the resistance value of resistor R8. In the steady-state equilibrium state where the backup power supply VBB_IN is de-energized, the cover is open, and there is no programmable integral maintenance circuit, the voltage drop across resistor R8 is less than the low-level threshold voltage VTHL input to the enable pin of voltage regulator VR2 in the controlled low-power power supply circuit, so that voltage regulator VR2 can be kept in the off state; when the backup power supply VBB_IN is de-energized, the cover is open, and there is programmable integral maintenance circuit... In the steady-state equilibrium state where the POWR output of the main control MCU is high, the voltage across resistor R8 is greater than the high-level threshold voltage VTHH input to the enable pin of regulator VR2 in the controlled low-power power supply circuit, ensuring that regulator VR2 remains constantly in the on state. When the backup power supply VBB_IN is de-energized and the contacts of limit switch K1 change from open to closed, the differential, integral, and voltage-dividing effects of the RC series-parallel circuit in the unidirectional RC pulse trigger circuit are utilized. After time T3, the voltage across capacitor C8 and resistor R8 is greater than the high-level threshold voltage VTHH input to the enable pin of regulator VR2, and regulator VR2 is in the on state. Furthermore, the window time T4 during which the voltage across capacitor C8 and resistor R8 is greater than the high-level threshold voltage VTHH input to the enable pin of regulator VR2 is much longer than T3. Therefore, regulator VR2 remains in the on state for time T4.

[0032] Specifically, in this embodiment, when the backup power supply VBB_IN is active, the backup power supply VBB_IN supplies power to pin 1 of the regulator VR2 through diode D6 in the controlled low-power power supply circuit, and provides a high level to pin 3 of the enabled regulator VR2 through diode D7 in the controlled low-power power supply circuit. This high level is greater than the input high-level threshold voltage VTHH of pin 3 of the regulator VR2, so the regulator VR2 is in the on state, and the low-power power supply VBB is continuously powered. When the backup power supply VBB_IN is active, due to the reverse cutoff function of diodes D5 and D8, the backup power supply VBB_IN will not supply power to the clock power supply PRTC in reverse, and due to the reverse cutoff function of diode D9, the backup power supply VBB_IN will not supply power to the control port POWR of the main control MCU in reverse.

[0033] Specifically, in this embodiment, the three-phase meter cover opening detection and power control circuit described in this invention enables the meter to detect when the cover is opened in a power outage and when the replaceable backup battery is undervoltage or removed. If an opening event occurs, the button of limit switch K1 pops up, and both sets of contacts of limit switch K1 close simultaneously. The clock power supply PRTC is connected to the unidirectional RC pulse trigger circuit and the controlled low-power power supply circuit through the first set of contacts of limit switch K1. The voltage regulator VR2 is in the open state during time T4. At this time, the clock power supply PRTC supplies power to the low-power power supply VBB through the controlled low-power power supply circuit, enabling the main control MCU to be powered on and restart. During the open window time T4 of the voltage regulator VR2, the main control MCU sets the control port POWR to a high level. Through the programmable integral sustain circuit, capacitors C8 and C9 in the unidirectional RC pulse trigger circuit are recharged and discharged. The voltage regulator in the controlled low-power power supply circuit... The enable pin level of VR2 gradually changes to a stable level, keeping the regulator VR2 on and the power meter in a power-on hold state. The main control MCU can then detect the closed state of the second group of contacts of limit switch K1, i.e., detect the open state and record the event. If a closed event occurs, the button of limit switch K1 is pressed, and both groups of contacts of limit switch K1 open simultaneously. The first group of contacts of limit switch K1 disconnects the loop between the clock power supply PRTC and the controlled low-power supply circuit. The clock power supply PRTC stops supplying power to the controlled low-power supply circuit, equivalent to stopping the supply of power to the low-power supply VBB. However, the main control MCU does not immediately stop running because the remaining charge stored in capacitors C5 and C7 allows the MCU to continue running for a period of time. During this time, the main control MCU can detect the open state of the second group of contacts of limit switch K1, thus detecting the closed state and recording the event. In the closed state, only the real-time clock of the main control MCU is powered.If the meter remains open for an extended period, the main control MCU can monitor this duration and, after a preset time, set the control port POWR to a low level. During this time, capacitor C11 discharges through resistor R9, and capacitors C9 and C8 recharge and discharge. The enable pin level of voltage regulator VR2 in the controlled low-power power supply circuit gradually decreases. After a certain time delay (T5), the voltage across resistor R8 causes the enable pin of voltage regulator VR2 to detect a low level, shutting off its output. This interrupts the power supply to the low-power power supply VBB, and related circuits powered by VBB stop consuming power. The RC network formed by resistor R9 and capacitor C11... It can effectively suppress the weak voltage output generated by the POWR control port of the main control MCU during the power-down reset process of the main control MCU, and prevent the enable pin level of the voltage regulator VR2 from being raised again, causing the voltage regulator VR2 to be turned on again; the clock power supply PRTC still supplies power to the unidirectional RC pulse trigger circuit and the controlled low-power power supply circuit. Since the voltage across the resistor R8 eventually tends to stabilize and is less than the low-level threshold voltage VTHL of the enable pin of the voltage regulator VR2, the controlled low-power power supply circuit is in a stable off state, the low-power power supply VBB is interrupted, and the main control MCU only runs the real-time clock, reducing the power consumption of the clock battery.

[0034] According to another aspect of the present invention, the present invention provides an electricity meter, the electricity meter including the aforementioned three-phase meter cover opening detection and power control circuit.

[0035] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A three-phase meter cover opening detection and power control circuit, characterized in that, include: Main control MCU, backup power supply circuit, clock power supply circuit, controlled low power supply circuit, unidirectional RC pulse trigger circuit, programmable integral sustain circuit and limit switch circuit; The main control MCU is electrically connected to the clock power supply circuit, the limit switch circuit, the controlled low-power power supply circuit, and the programmable integral sustain circuit, respectively. The limit switch circuit is electrically connected to the clock power supply circuit, the unidirectional RC pulse trigger circuit, and the controlled low-power power supply circuit, respectively. The clock power supply circuit is electrically connected to the backup power supply circuit and the controlled low-power power supply circuit, respectively. The programmable integral sustain circuit is electrically connected to the unidirectional RC pulse trigger circuit and the controlled low-power power supply circuit, respectively.

2. The three-phase meter cover opening detection and power control circuit according to claim 1, characterized in that, The backup power circuit includes diode D1, diode D2, resistor R2, and second battery BT2; the negative terminal of the second battery BT2 is grounded, the positive terminal of the second battery is connected to resistor R2, the other end of resistor R2 is connected to the anode of diode D2, the cathode of diode D2 is connected to the cathode of diode D1, the clock power supply circuit, and the controlled low-power power supply circuit, and the anode of diode D1 is connected to the regulated power supply VPP.

3. A three-phase meter cover opening detection and power control circuit according to any one of claims 1-2, characterized in that, The clock power supply circuit includes a first battery BT1, a resistor R1, a diode D3, a resistor R4, a capacitor C3, a capacitor C1, a voltage regulator VR1, a capacitor C2, a diode D4, and a capacitor C10. The positive terminal of the first battery BT1 is connected to the resistor R1, and the other end of the resistor R1 is connected to the anode of the diode D3. The cathode of the diode D3 is connected to the resistor R4, the limit switch circuit, the capacitor C10, the cathode of the diode D4, and the clock power supply PRTC. The other end of the resistor R4 is connected to the main control MCU and the capacitor C3. The anode of the diode D4 is connected to the capacitor C2 and the 3rd pin of the voltage regulator VR1. The 1st pin of the voltage regulator VR1 is connected to the backup power supply circuit and the capacitor C1. The negative terminal of the first battery BT1, the 2nd pin of the voltage regulator VR1, and the other ends of the capacitors C3, C10, C2, and C1 are grounded.

4. A three-phase meter cover opening detection and power control circuit according to any one of claims 1-2, characterized in that, The limit switch circuit includes limit switch K1, resistor R3, resistor R5, and capacitor C4. Pin 1 of limit switch K1 is connected to a unidirectional RC pulse trigger circuit and a controlled low-power power supply circuit, pin 2 of limit switch K1 is connected to a clock power supply circuit, pin 3 of limit switch K1 is connected to resistor R3, the other end of resistor R3 is connected to the controlled low-power power supply circuit, pin 4 of limit switch K1 is connected to resistor R5, capacitor C4, and the main control MCU, and the other ends of resistor R5 and capacitor C4 are grounded.

5. A three-phase meter cover opening detection and power control circuit according to any one of claims 1-2, characterized in that, The unidirectional RC pulse trigger circuit includes a diode D8, a resistor R6, a capacitor C9, a resistor R8, and a capacitor C8; the anode of the diode D8 is connected to the limit switch circuit, the cathode of the diode D8 is connected to the resistor R6 and the capacitor C9, the other end of the resistor R6 is connected to the other end of the capacitor C9, the resistor R8, the capacitor C8, the controlled low-power power supply circuit, and the programmable integral sustaining circuit, and the other end of the resistor R8 is connected to the other end of the capacitor C8 and the ground terminal.

6. A three-phase meter cover opening detection and power control circuit according to any one of claims 1-2, characterized in that, The controlled low-power power supply circuit includes diodes D5, D6, and D7, capacitor C6, voltage regulator VR2, and capacitor C7. Pin 1 of voltage regulator VR2 is connected to capacitor C6, the cathode of diode D5, and the cathode of diode D6. The anode of diode D5 is connected to a limit switch circuit. Pin 3 of voltage regulator VR2 is connected to the cathode of diode D7 and a unidirectional RC pulse trigger circuit. The anodes of diode D7 and D6 are both connected to a clock power supply circuit. Pin 5 of voltage regulator VR2 is connected to the limit switch circuit, capacitor C7, low-power power supply VBB, and the main control MCU. Pin 2 of voltage regulator VR2, and the other ends of capacitors C6 and C7 are grounded.

7. A three-phase meter cover opening detection and power control circuit according to any one of claims 1-2, characterized in that, The programmable integral sustaining circuit includes a diode D9, a capacitor C11, and a resistor R9; the cathode of the diode D9 is connected to a unidirectional RC pulse trigger circuit, the anode of the diode R9 is connected to both the capacitor C11 and the resistor R9, the other end of the resistor R9 is connected to the main control MCU, and the other end of the capacitor C11 is grounded.

8. A three-phase meter cover opening detection and power control circuit according to any one of claims 1-2, characterized in that, The interrupt port INT of the main control MCU is connected to the limit switch circuit.

9. An electricity meter, characterized in that, The electricity meter includes a three-phase meter opening detection and power control circuit as described in any one of claims 1-8.

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