A meter detection circuit

Abstract

This application relates to the field of battery management technology and discloses a meter detection circuit. Specifically, the meter detection circuit includes a control unit (MCU) with a power supply port, a first sampling port, and a second sampling port; a first power supply branch having an internal battery and an output circuit connected in sequence, the output terminal of the output circuit being electrically connected to the power supply port; a first sampling circuit connected between the internal battery and the first sampling port; and a second power supply branch connected to the output circuit, having an external battery and a second sampling circuit, the external battery being connected to the output circuit, and the second sampling circuit being connected between the output terminal of the external battery and the output circuit. This invention enables the control unit (MCU) to run a low-power sleep mode program when the internal battery has power but the external battery voltage is insufficient, thereby greatly reducing the power consumption of the internal battery and increasing its service life.

Description

Technical Field

[0001] This application relates to the field of battery management technology, and more specifically, to a meter detection circuit. Background Technology

[0002] When the electricity meter is disconnected from the mains power and is in a power-off state, it is usually powered by the meter's internal battery and a replaceable external battery. The two batteries are connected to the power supply port of the control unit MCU through some peripheral circuits to ensure the operation of the clock circuit. In this circuit design, the internal and external batteries will play the same role and can both provide power to the electricity meter to enable the meter to work normally.

[0003] The internal battery is usually fixedly soldered inside the meter. It is used to ensure that the meter can detect and record events when the meter cover is opened and that the meter's LCD screen can be woken up. The external battery is detachably installed on the outside of the meter and works with the internal battery to power the meter. However, when the voltage of the external battery is low, the internal battery will become the main power source for the meter and will need to output higher power than the external battery. Over time, the lifespan of the internal battery will be greatly reduced, and thus the overall lifespan of the meter will be directly affected. Summary of the Invention

[0004] This invention provides a meter detection circuit that can overcome some or all of the defects of the prior art.

[0005] To achieve the above objectives, this utility model provides the following technical solution, which includes:

[0006] The control unit (MCU) has a power supply port, a first sampling port, and a second sampling port.

[0007] The first power supply branch has an internal battery BAT2 and an output circuit connected in sequence, and the output terminal of the output circuit is electrically connected to the power supply port.

[0008] A first sampling circuit is connected between the internal battery BAT2 and the first sampling port;

[0009] The second power supply branch connected to the output circuit has a removable external battery BAT1 and a second sampling circuit. The output terminal of the external battery BAT1 is connected to the output circuit, and the input terminal of the second sampling circuit is connected between the output terminal of the external battery BAT1 and the output circuit. The output terminal of the second sampling circuit is electrically connected to the second sampling port.

[0010] This invention enables the control unit MCU to run a low-power sleep mode program when the first sampling port samples a high level and the second sampling port samples a low level, i.e., when the internal battery BAT2 has power and the external battery BAT1 has insufficient voltage. This greatly reduces the power consumption of the internal battery and increases its service life.

[0011] Preferably, the first sampling circuit includes voltage divider resistors R200, AR2, and BR1 connected in sequence, with one end of voltage divider resistor R200 connected to the positive terminal of the internal battery BAT2; the first sampling port is connected between voltage divider resistors AR2 and BR1; the first sampling circuit also includes voltage divider resistors R201, AR3, and AR4 connected in sequence, with one end of voltage divider resistor R201 connected to the positive terminal of the external battery BAT1; the second sampling port is connected between voltage divider resistors AR3 and AR4.

[0012] By setting up the above multiple voltage divider resistors, the voltages at both ends of the internal and external batteries can be converted into level signals that can be recognized by the control unit MCU, thereby effectively detecting the battery voltage status and better enabling the control unit MCU to select the program to run.

[0013] Preferably, the output circuit is equipped with an isolation device D6. The isolation device D6 has a first input interface for connecting to the output circuit and an output interface for connecting to the output terminal of the output circuit. It also has a second input interface for connecting to the second power supply branch. The isolation device D6 can output the power of the internal battery BAT2 and the external battery BAT1 to the control unit MCU through the two input interfaces respectively. At the same time, the isolation device D6 has two reverse-connected anti-reverse diodes to prevent the current of the two batteries from flowing back to each other.

[0014] Preferably, an anti-reverse diode D3 is connected in series at the output circuit. The anti-reverse diode D3 can further prevent the current from the external battery BAT1 from flowing back into the internal battery BAT2 and causing damage.

[0015] As a preferred option, a voltage regulator chip U2 is connected in series at the output circuit. The voltage regulator chip U2 can convert the fluctuating voltage of the internal battery BAT2 into a stable voltage. The model of the voltage regulator chip U2 is MD8230A.

[0016] Preferably, the grounding side of the internal battery BAT2 is provided with a shorting point JD1. When the meter is not installed and in use, the shorting point JD1 is equivalent to a switch in an open circuit state, and the internal battery BAT2 does not work to extend the service life of the meter.

[0017] As a preferred option, the control unit MCU model is FM33A06EV.

[0018] Preferably, the second sampling port is equipped with filter capacitors C67 and C68, which can effectively prevent interference signal level states.

[0019] Preferably, a filter capacitor AC12 is provided at the power supply port, which can effectively improve the stability of the power supply to the control unit MCU by the two batteries. Attached Figure Description

[0020] Figure 1 This is the electrical schematic diagram of the control unit MCU in the embodiments of this application;

[0021] Figure 2 This is an electrical schematic diagram of a meter detection circuit according to an embodiment of this application. Detailed Implementation

[0022] To further understand the content of this utility model, a detailed description of the utility model is provided in conjunction with the embodiments. It should be understood that the embodiments are merely illustrative and not limiting of the utility model.

[0023] In existing technologies, electricity meters with both internal and external replaceable batteries connect to the power supply port of the control unit MCU via a single port after passing through some peripheral circuits. In this circuit design, both the internal and external batteries provide the same auxiliary power supply. The internal battery is typically fixedly soldered inside the meter, and its lifespan directly affects the overall lifespan of the meter; currently, most markets require a lifespan of 10 or even 15 years. When the meter is disconnected from mains power and the external battery is not installed or has a low voltage, operations such as waking up the LCD screen and detecting power failures consume the internal battery, severely impacting its lifespan. Therefore, this application proposes a meter detection circuit and method to solve the above problems, as detailed below:

[0024] like Figure 1 and Figure 2 As shown, this application provides a meter detection circuit, which includes:

[0025] The control unit (MCU) has a power supply port, a first sampling port, and a second sampling port.

[0026] The first power supply branch has an internal battery BAT2 and an output circuit connected in sequence, and the output terminal of the output circuit is electrically connected to the power supply port.

[0027] A first sampling circuit is connected between the internal battery BAT2 and the first sampling port;

[0028] The second power supply branch connected to the output circuit has a removable external battery BAT1 and a second sampling circuit. The output terminal of the external battery BAT1 is connected to the output circuit, and the input terminal of the second sampling circuit is connected between the output terminal of the external battery BAT1 and the output circuit. The output terminal of the second sampling circuit is electrically connected to the second sampling port.

[0029] Please see Figure 1 and Figure 2 When the meter is disconnected from the mains power, the control unit MCU configures the first sampling port VBAT_RTC_ADC and the second sampling port EXTERRNAL_BAT_ADC as general-purpose I / O inputs, and the meter enters a low-power sleep mode. Subsequently, if the meter is pressed to wake up the display, the control unit MCU is awakened. The first step of its internal program is to detect the high and low levels of the first sampling port VBAT_RTC_ADC and the second sampling port EXTERRNAL_BAT_ADC. If both the first sampling port VBAT_RTC_ADC and the second sampling port EXTERRNAL_BAT_ADC are sampled at a high level, that is, both the internal battery BAT2 and the external battery BAT1 are powered, the control unit MCU runs the program normally to complete the operation of waking up the display by pressing the button. If the first sampling port VBAT_RTC_ADC is sampled at a high level and the second sampling port EXTERRNAL_BAT_ADC is sampled at a low level, that is, the internal battery BAT2 is powered but the external battery BAT1 has insufficient voltage, the control unit MCU runs the program of low-power sleep mode, thereby greatly reducing the power consumption of the internal battery and increasing its service life.

[0030] In some specific embodiments, the first sampling circuit includes voltage divider resistors R200, AR2, and BR1 connected in sequence, with one end of voltage divider resistor R200 connected to the positive terminal of the internal battery BAT2; the first sampling port is connected between voltage divider resistors AR2 and BR1; the first sampling circuit also includes voltage divider resistors R201, AR3, and AR4 connected in sequence, with one end of voltage divider resistor R201 connected to the positive terminal of the external battery BAT1; and the second sampling port is connected between voltage divider resistors AR3 and AR4.

[0031] By setting up the above multiple voltage divider resistors, the voltages at both ends of the internal and external batteries can be converted into level signals that can be recognized by the control unit MCU, thereby effectively detecting the battery voltage status and better enabling the control unit MCU to select the program to run.

[0032] In some specific embodiments, an isolation device D6 is provided at the output circuit. The isolation device D6 has a first input interface for connecting to the output circuit and an output interface for connecting to the output terminal of the output circuit. It also has a second input interface for connecting to the second power supply branch. The isolation device D6 can output the power of the internal battery BAT2 and the external battery BAT1 from the output interface to the control unit MCU for power supply through the two input interfaces respectively. At the same time, the isolation device D6 has two reverse-connected anti-reverse diodes to prevent the current of the two batteries from flowing back to each other.

[0033] In some specific embodiments, a reverse protection diode D3 is connected in series at the output circuit. The reverse protection diode D3 can further prevent the current from the external battery BAT1 from flowing back into the internal battery BAT2 and causing damage.

[0034] In some specific embodiments, a voltage regulator chip U2 is connected in series at the output circuit. The voltage regulator chip U2 can convert the fluctuating voltage of the internal battery BAT2 into a stable voltage. The model of the voltage regulator chip U2 is MD8230A.

[0035] In some specific embodiments, the grounding side of the internal battery BAT2 is provided with a shorting point JD1. When the meter is not installed and in use, the shorting point JD1 is equivalent to a switch in an open circuit state, and the internal battery BAT2 does not work to extend the service life of the meter.

[0036] In some specific embodiments, the control unit MCU is model FM33A06EV.

[0037] In some specific embodiments, the second sampling port is equipped with filter capacitors C67 and C68, which can effectively prevent interference signal level states; the power supply port is equipped with filter capacitor AC12, which can effectively improve the stability of the power supply of the two batteries to the control unit MCU.

[0038] This application also provides a method for powering an electricity meter, which uses any of the electricity meter detection circuits described above to power the electricity meter.

[0039] It is readily understood that those skilled in the art can combine, split, or reorganize the embodiments provided in this application to obtain other embodiments, all of which do not exceed the protection scope of this application.

[0040] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the embodiments shown are only part of the embodiments of the present invention. The actual structure is not limited to this. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A meter detection circuit, characterized in that, include: The control unit (MCU) has a power supply port, a first sampling port, and a second sampling port. The first power supply branch has an internal battery BAT2 and an output circuit connected in sequence, and the output terminal of the output circuit is electrically connected to the power supply port. A first sampling circuit is connected between the internal battery BAT2 and the first sampling port; The second power supply branch connected to the output circuit has a removable external battery BAT1 and a second sampling circuit. The output terminal of the external battery BAT1 is connected to the output circuit, and the input terminal of the second sampling circuit is connected between the output terminal of the external battery BAT1 and the output circuit. The output terminal of the second sampling circuit is electrically connected to the second sampling port.

2. The meter detection circuit according to claim 1, characterized in that: The first sampling circuit includes voltage divider resistors R200, AR2, and BR1 connected in sequence. One end of voltage divider resistor R200 is connected to the positive terminal of the internal battery BAT2. The first sampling port is connected between voltage divider resistors AR2 and BR1.

3. The meter detection circuit according to claim 1, characterized in that: An isolation device D6 is provided at the output circuit. The isolation device D6 has a first input interface for connecting to the output circuit and an output interface for connecting to the output terminal of the output circuit. It also has a second input interface for connecting to the second power supply branch.

4. The meter detection circuit according to claim 1, characterized in that: The first sampling circuit includes voltage divider resistors R201, AR3, and AR4 connected in sequence. One end of voltage divider resistor R201 is connected to the positive terminal of external battery BAT1. The second sampling port is connected between voltage divider resistors AR3 and AR4.

5. The meter detection circuit according to claim 1, characterized in that: An anti-reverse diode D3 is connected in series at the output circuit.

6. The meter detection circuit according to claim 5, characterized in that: A voltage regulator chip U2 is connected in series at the output circuit. The model of voltage regulator chip U2 is MD8230A.

7. The meter detection circuit according to claim 1, characterized in that: The internal battery BAT2 has a shorting point JD1 on its ground side.

8. The meter detection circuit according to claim 1, characterized in that: The control unit MCU model is FM33A06EV.

9. A meter detection circuit according to claim 1, characterized in that: Both the second sampling port and the power supply port are equipped with filter capacitors.

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