Voltage stability monitoring circuit and voltage stability monitoring method

Abstract

The embodiment of the invention provides a voltage stability monitoring circuit and a voltage stability monitoring method. The voltage stability monitoring circuit comprises a voltage comparator, a double-pole double-throw relay and a monitoring indicator lamp, the normal-phase input end of the voltage comparator is used for receiving threshold voltage, and the inverted-phase input end of the voltage comparator is used for receiving eMMC working voltage; the output end of the voltage comparator is connected with a first coil terminal of the double-pole double-throw relay, and a second coil terminal of the double-pole double-throw relay is connected with a reference ground; the monitoring indicating lamp is connected in parallel with the double-pole double-throw relay. Wherein under the condition that the working voltage of the eMMC is lower than the threshold voltage, the voltage comparator outputs a high level, and the double-pole double-throw relay is powered on and enters a self-locking state, so that the monitoring indicating lamp is switched from a lightening state to an extinguishing state. According to the scheme of the embodiment of the invention, the voltage stability can be monitored and processed sensitively and quickly in real time.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage monitoring, and particularly relates to a voltage stability monitoring circuit and a voltage stability monitoring method. Background Art

[0002] When an embedded Multi Media Card (eMMC) verification platform device tests the eMMC, the power supply voltage of the eMMC may be unstable; the unstable power supply voltage will directly interfere with the normal reading and writing process of the eMMC, resulting in data access delay, error transmission, data corruption, etc.; in order to ensure the continuous and stable operation of the verification platform device and the reliability of data detection, it is particularly important to adopt appropriate voltage stability monitoring. Currently, a multimeter is generally used to detect the voltage of the eMMC, but due to the accuracy limitation of the instrument itself, large errors may occur during the voltage stability test, and the change of the voltage cannot be monitored in real time. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art.

[0004] To this end, the present invention provides a voltage stability monitoring circuit, which can monitor and process the voltage stability in real time, sensitively and quickly.

[0005] The present invention also provides a voltage stability monitoring method based on the above voltage stability monitoring circuit.

[0006] According to the voltage stability monitoring circuit of the first aspect embodiment of the present invention, it includes:

[0007] A voltage comparator, the positive input terminal of the voltage comparator is used to receive a threshold voltage, and the negative input terminal of the voltage comparator is used to receive the operating voltage of the embedded multi-media card eMMC;

[0008] A double-pole double-throw relay, the output terminal of the voltage comparator is connected to the first coil terminal of the double-pole double-throw relay, and the second coil terminal of the double-pole double-throw relay is connected to the reference ground;

[0009] A monitoring indicator light, the monitoring indicator light is connected in parallel with the double-pole double-throw relay;

[0010] Wherein, when the operating voltage of the eMMC is lower than the threshold voltage, the voltage comparator outputs a high level, the double-pole double-throw relay is energized and enters a self-locking state, so that the monitoring indicator light switches from the lit state to the extinguished state.

[0011] According to some embodiments of the present invention, it further includes an anti-reverse diode, the positive electrode of the anti-reverse diode is connected to the output terminal of the voltage comparator, and the negative electrode of the anti-reverse diode is connected to the first coil terminal of the double-pole double-throw relay.

[0012] According to some embodiments of the present invention, it further includes a freewheeling diode, the negative electrode of the freewheeling diode is respectively connected to the first coil terminal of the double-pole double-throw relay and the first normally closed contact of the double-pole double-throw relay, and the positive electrode of the freewheeling diode is connected to the reference ground.

[0013] According to some embodiments of the present invention, it further includes a current-limiting resistor and a switch. One end of the switch is connected to the power supply, and the other end of the switch is respectively connected to the power input terminal of the voltage comparator, the first common terminal of the double-pole double-throw relay, and one end of the current-limiting resistor. The other end of the current-limiting resistor is respectively connected to the second common terminal of the double-pole double-throw relay and one end of the monitoring indicator light, and the other end of the monitoring indicator light is connected to the reference ground. The second normally closed contact of the double-pole double-throw relay is connected to the reference ground; wherein, when the first coil terminal and the second coil terminal of the double-pole double-throw relay are energized, the first moving contact of the double-pole double-throw relay connects the first common terminal to the first normally open contact, and the second moving contact of the double-pole double-throw relay connects the second common terminal to the second normally closed contact, so that the double-pole double-throw relay is in a self-locking state.

[0014] According to some embodiments of the present invention, it further includes a first adjusting resistor and a second adjusting resistor. One end of the first adjusting resistor is connected to the other end of the switch, the adjusting end of the first adjusting resistor is respectively connected to the positive-phase input terminal of the voltage comparator and one end of the second adjusting resistor, and the adjusting end of the second adjusting resistor is connected to the reference ground.

[0015] According to some embodiments of the present invention, the voltage comparator is an operational amplifier.

[0016] According to the voltage stability monitoring method of the second aspect embodiment of the present invention, which is applied to the above voltage stability monitoring circuit, the method includes:

[0017] Receiving the threshold voltage through the positive-phase input terminal of the voltage comparator, and receiving the eMMC operating voltage through the inverting input terminal of the voltage comparator;

[0018] When the eMMC operating voltage is lower than the threshold voltage, the output terminal of the voltage comparator outputs a high level to the double-pole double-throw relay, so that the double-pole double-throw relay is energized into a self-locking state, and the monitoring indicator light switches from the lit state to the extinguished state.

[0019] According to some embodiments of the present invention, after the monitoring indicator light switches from the lit state to the extinguished state, the method further includes:

[0020] When the operating voltage of the eMMC is higher than or equal to the threshold voltage, control the switch to close so that the double-pole double-throw relay is in a self-locking state, and the monitoring indicator light remains in the extinguished state.

[0021] According to some embodiments of the present invention, after the monitoring indicator light switches from the lit state to the extinguished state, the method further includes:

[0022] When the operating voltage of the eMMC is higher than or equal to the threshold voltage, control the switch to open so that the double-pole double-throw relay exits the self-locking state, and control the switch to close so that the monitoring indicator light switches from the extinguished state to the lit state.

[0023] According to some embodiments of the present invention, the threshold voltage is calculated by the first adjusting resistor and the second adjusting resistor.

[0024] The voltage stability monitoring circuit according to the embodiments of the present invention has at least the following beneficial effects: the positive input terminal of the voltage comparator receives the threshold voltage, and the negative input terminal of the voltage comparator receives the operating voltage of the eMMC; when the operating voltage of the eMMC is lower than the threshold voltage, the voltage comparator outputs a high level, and the double-pole double-throw relay is energized, causing the moving contact to switch from the normally closed contact to the normally open contact, and further causing the monitoring indicator light to be in a short-circuited state and switch from the lit state to the extinguished state; and since the double-pole double-throw relay is also in a self-locking state, when the operating voltage of the eMMC is not lower than the threshold voltage subsequently, the moving contact of the double-pole double-throw relay is still connected to the normally open contact, and the monitoring indicator light is still in the extinguished state; through the above technical solutions, the voltage comparator can flexibly capture the voltage change situation, and the voltage abnormality during the test can be intuitively reflected through the monitoring indicator light; and due to the self-locking state of the double-pole double-throw relay, any abnormality during the test will be recorded and reflected, making the voltage stability monitoring more reliable.

[0025] Other features and advantages of the present invention will be described in the following specification, and in part, will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained by the structures specifically pointed out in the specification, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are used to provide a further understanding of the technical solutions of the present disclosure, and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the technical solutions of the present disclosure, and do not constitute a limitation to the technical solutions of the present disclosure.

[0027] Figure 1 is the circuit schematic diagram of the voltage stability monitoring circuit provided by an embodiment of the present invention;

[0028] Figure 2 is the flowchart of the voltage stability monitoring method provided by an embodiment of the present invention;

[0029] Figure 3 is the flowchart of the voltage stability monitoring method provided by another embodiment of the present invention;

[0030] Figure 4 is the flowchart of the voltage stability monitoring method provided by another embodiment of the present invention. Detailed Embodiments

[0031] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0032] In the description of the present invention, the meaning of "a number of" is one or more, the meaning of "a plurality of" is two or more, and understandings such as "greater than", "less than", "exceeding", etc. do not include the present number, and understandings such as "above", "below", "within", etc. include the present number. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0033] In the description of the present invention, unless otherwise clearly defined, words such as "set", "installed", "connected", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0034] The present invention provides a voltage stability monitoring circuit and a voltage stability monitoring method. The positive input terminal of a voltage comparator receives a threshold voltage, and the negative input terminal of the voltage comparator receives the eMMC operating voltage. When the eMMC operating voltage is lower than the threshold voltage, the voltage comparator outputs a high level, and a double-pole double-throw relay is energized, causing the moving contact to switch from the normally closed contact to the normally open contact. As a result, the monitoring indicator light is in a short-circuited state and switches from the lit state to the extinguished state. Moreover, since the double-pole double-throw relay is in a self-locking state, when the eMMC operating voltage is not lower than the threshold voltage subsequently, the moving contact of the double-pole double-throw relay remains connected to the normally open contact, and the monitoring indicator light remains in the extinguished state. Through the above technical solution, the voltage comparator can flexibly capture voltage changes, and the voltage anomalies during the test can be visually reflected through the monitoring indicator light. Additionally, due to the self-locking state of the double-pole double-throw relay, any anomalies that occur during the test are recorded and reflected, making the voltage stability monitoring more reliable.

[0035] The following further elaborates on the embodiments of the present invention with reference to the accompanying drawings.

[0036] Refer to Figure 1 As shown in [figure reference], a voltage stability monitoring circuit provided by an embodiment of the present invention includes a voltage comparator U1, a double-pole double-throw relay RL1, and a monitoring indicator light D1. The positive input terminal of the voltage comparator U1 is used to receive a threshold voltage Vth, and the negative input terminal of the voltage comparator U1 is used to receive the eMMC operating voltage Vin. The output terminal of the voltage comparator U1 is connected to the first coil terminal of the double-pole double-throw relay RL1, and the second coil terminal of the double-pole double-throw relay RL1 is connected to the reference ground. The monitoring indicator light D1 is connected in parallel with the double-pole double-throw relay RL1. When the eMMC operating voltage Vin is lower than the threshold voltage Vth, the voltage comparator U1 outputs a high level, and the double-pole double-throw relay RL1 is energized, causing the moving contact to switch from the normally closed contact to the normally open contact. As a result, the monitoring indicator light D1 is in a short-circuited state and switches from the lit state to the extinguished state. Moreover, since the double-pole double-throw relay RL1 is in a self-locking state, when the eMMC operating voltage Vin is not lower than the threshold voltage Vth subsequently, the moving contact of the double-pole double-throw relay RL1 remains connected to the normally open contact, and the monitoring indicator light D1 remains in the extinguished state. Through the above technical solution, the voltage comparator U1 can flexibly capture voltage changes, and the voltage anomalies during the test can be visually reflected through the monitoring indicator light D1. Additionally, due to the self-locking state of the double-pole double-throw relay RL1, any anomalies that occur during the test are recorded and reflected, making the voltage stability monitoring more reliable.

[0037] It should be noted that the non-inverting input terminal of the voltage comparator U1 is used to receive the threshold voltage Vth, and the inverting input terminal of the voltage comparator U1 is used to receive the eMMC operating voltage Vin; when the threshold voltage Vth is not higher than the eMMC operating voltage Vin, the voltage comparator U1 outputs a low level, and at this time, the double-pole double-throw relay RL1 is not energized, and the moving contact of the double-pole double-throw relay RL1 is connected to the normally closed contact; when the threshold voltage Vth is higher than the eMMC operating voltage Vin, the voltage comparator U1 outputs a high level, and at this time, the double-pole double-throw relay RL1 is energized, and the moving contact of the double-pole double-throw relay RL1 is connected to the normally open contact, so that the monitoring indicator D1 is short-circuited and switches from the lit state to the extinguished state. Exemplarily, the eMMC operating voltage Vin generally needs to be greater than 1.7V, so the threshold voltage Vth can be set to 1.7V. Therefore, when the eMMC operating voltage Vin is lower than 1.7V, the double-pole double-throw relay RL1 will be energized so that the monitoring indicator D1 is short-circuited and switches from the lit state to the extinguished state, and thus it can intuitively and quickly reflect that the eMMC operating voltage Vin has an abnormal situation.

[0038] It should be noted that the voltage stability monitoring circuit can monitor the voltage changes in the circuit in real time, display through the monitoring indicator D1, has high-precision characteristics, can capture tiny voltage fluctuations, and ensure the accuracy of data; when the threshold voltage Vth is higher than the eMMC operating voltage Vin, the voltage stability monitoring circuit can react quickly, providing the possibility for timely handling of abnormal situations; the voltage stability monitoring circuit can operate stably for a long time, continuously monitor the situation of the eMMC operating voltage Vin, and ensure the stability and reliability of the circuit.

[0039] It should be noted that the voltage comparator U1 can be an operational amplifier. An operational amplifier is a high-performance direct-coupled amplifier, which is widely used in circuit designs such as signal processing, amplification, filtering, and comparison. An operational amplifier is an amplifier with high gain, high input impedance, and low output impedance.

[0040] It should be noted that the double-pole double-throw relay RL1 includes a first coil terminal, a second coil terminal, a first common terminal, a second common terminal, a first normally open contact, a second normally open contact, a first normally closed contact, a second normally closed contact, a first moving contact, and a second moving contact; one end of the first moving contact is connected to the first common terminal, and the other end of the first moving contact switches between the first normally open contact and the first normally closed contact. One end of the second moving contact is connected to the second common terminal, and the other end of the second moving contact switches between the second normally open contact and the second normally closed contact; and when the first moving contact is connected to the first normally open contact, the second moving contact will be connected to the second normally open contact; when the first moving contact is connected to the first normally closed contact, the second moving contact will be connected to the second normally closed contact. Among them, only when there is current conduction between the first coil terminal and the second coil terminal, the double-pole double-throw relay RL1 will be in a self-locking state, and the level output by the voltage comparator U1 will not affect the working state of the double-pole double-throw relay RL1.

[0041] It should be noted that when the working voltage Vin of the eMMC is normal, the monitoring indicator D1 will be in the lit state; when the working voltage Vin of the eMMC is abnormal, the monitoring indicator D1 will be converted to the extinguished state due to a short circuit.

[0042] Refer to Figure 1 , in some embodiments, the voltage stability monitoring circuit further includes an anti-reverse diode D3. The positive electrode of the anti-reverse diode D3 is connected to the output terminal of the voltage comparator U1, and the negative electrode of the anti-reverse diode D3 is connected to the first coil terminal of the double-pole double-throw relay RL1. Based on the anti-reverse diode D3, the current flowing through the double-pole double-throw relay RL1 cannot flow back to the output terminal of the voltage comparator U1, thereby protecting the voltage comparator U1 well and preventing the voltage comparator U1 from being damaged.

[0043] Refer to Figure 1 , in some embodiments, the voltage stability monitoring circuit further includes a freewheeling diode D2. The negative electrode of the freewheeling diode D2 is respectively connected to the first coil terminal of the double-pole double-throw relay RL1 and the first normally closed contact of the double-pole double-throw relay RL1, and the positive electrode of the freewheeling diode D2 is connected to the reference ground. Based on the freewheeling diode D2, the current and voltage on the coil of the double-pole double-throw relay RL1 are released, so that when the double-pole double-throw relay RL1 exits the self-locking state, it can prevent the coil of the double-pole double-throw relay RL1 and the external power supply VCC from being damaged due to the coil high voltage.

[0044] Refer to Figure 1, in some embodiments, the voltage stability monitoring circuit further includes a current-limiting resistor R1 and a switch K1. One end of the switch K1 is connected to the power supply VCC. The other end of the switch K1 is respectively connected to the power input terminal of the voltage comparator U1, the first common terminal of the double-pole double-throw relay RL1, and one end of the current-limiting resistor R1. The other end of the current-limiting resistor R1 is respectively connected to the second common terminal of the double-pole double-throw relay RL1 and one end of the monitoring indicator D1. The other end of the monitoring indicator D1 is connected to the reference ground. The second normally-closed contact of the double-pole double-throw relay RL1 is connected to the reference ground. Wherein, when the first coil terminal and the second coil terminal of the double-pole double-throw relay RL1 are energized, the first moving contact of the double-pole double-throw relay RL1 connects the first common terminal to the first normally-open contact, and the second moving contact of the double-pole double-throw relay RL1 connects the second common terminal to the second normally-open contact, so that the double-pole double-throw relay RL1 is in a self-locking state.

[0045] It should be noted that, at the initial stage of monitoring, when the switch K1 is closed, the monitoring indicator D1 will be lit due to being energized. The current-limiting resistor R1 is connected in series with the monitoring indicator D1, which can well prevent excessive current from damaging the monitoring indicator D1 and well protect the monitoring indicator D1. When the threshold voltage Vth is higher than the eMMC operating voltage Vin, the voltage comparator U1 will output a high level to energize the double-pole double-throw relay RL1. The first moving contact of the double-pole double-throw relay RL1 will switch from the first normally-closed contact to the first normally-open contact, and the second moving contact of the double-pole double-throw relay RL1 will switch from the second normally-closed contact to the second normally-open contact. Since the first common terminal is connected to the power supply VCC, therefore, when the switch K1 is closed, the coil of the double-pole double-throw relay RL1 is always in an energized state, and the double-pole double-throw relay RL1 will enter a self-locking state, making the monitoring indicator D1 always in an off state and not changing due to the output of the voltage comparator U1. When the switch K1 is opened, since the power supply VCC does not supply power to the double-pole double-throw relay RL1, the double-pole double-throw relay RL1 will exit the self-locking state. When the switch K1 is closed again, the monitoring indicator D1 is lit again, and a new round of voltage stability monitoring processing can be carried out again.

[0046] Refer to Figure 1, in some embodiments, the voltage stability monitoring circuit further includes a first adjustable resistor R2 and a second adjustable resistor R3. One end of the first adjustable resistor R2 is connected to the other end of the switch K1. The adjustable end of the first adjustable resistor R2 is respectively connected to the non-inverting input terminal of the voltage comparator U1 and one end of the second adjustable resistor R3. The adjustable end of the second adjustable resistor R3 is connected to the reference ground. It should be noted that, since one end of the first adjustable resistor R2 is connected to the other end of the switch K1, the adjustable end of the first adjustable resistor R2 is respectively connected to the non-inverting input terminal of the voltage comparator U1 and one end of the second adjustable resistor R3, and the adjustable end of the second adjustable resistor R3 is connected to the reference ground. Therefore, the threshold voltage Vth can be determined according to the magnitudes of the first adjustable resistor R2 and the second adjustable resistor R3. Exemplarily, the first adjustable resistor R2 is 3.3 KΩ, the second adjustable resistor R3 is 1.7 KΩ, and the voltage of the power supply VCC is 5V. Therefore, the threshold voltage Vth = 5V * 1.7 / (1.7 + 3.3) = 1.7V. During the actual monitoring process, the resistance values of the first adjustable resistor R2 and the second adjustable resistor R3 can also be adjusted according to actual needs.

[0047] In some embodiments of the present invention, referring to Figure 2 , an embodiment of the present invention further provides a voltage stability monitoring method, which is implemented based on the voltage stability monitoring circuit of the above embodiment. The method may include but is not limited to the following steps.

[0048] Step S100, receiving the threshold voltage through the non-inverting input terminal of the voltage comparator, and receiving the eMMC operating voltage through the inverting input terminal of the voltage comparator;

[0049] Step S200, when the eMMC operating voltage is lower than the threshold voltage, the output terminal of the voltage comparator outputs a high level to the double-pole double-throw relay, so that the double-pole double-throw relay is energized and enters the self-locking state, and the monitoring indicator light switches from the lit state to the extinguished state.

[0050] It should be noted that when the operating voltage of the eMMC is lower than the threshold voltage, the voltage comparator outputs a high level, and the double-pole double-throw relay is energized, causing the moving contact to switch from the normally closed contact to the normally open contact. As a result, the monitoring indicator light is in a short-circuited state and switches from the lit state to the extinguished state. Moreover, since the double-pole double-throw relay is also in a self-locking state, when the operating voltage of the eMMC is not lower than the threshold voltage subsequently, the moving contact of the double-pole double-throw relay remains connected to the normally open contact, and the monitoring indicator light remains in the extinguished state. Through the above technical solution, the voltage comparator can flexibly capture the voltage change situation, and the voltage abnormality during the test process can be intuitively reflected through the monitoring indicator light. And due to the self-locking state of the double-pole double-throw relay, any abnormality during the test process will be recorded and reflected, making the voltage stability monitoring more reliable.

[0051] In some embodiments of the present invention, referring to Figure 3 , after step S200 is executed, it may further include but is not limited to step S310.

[0052] Step S310, when the operating voltage of the eMMC is higher than or equal to the threshold voltage, control the switch to close to make the double-pole double-throw relay in a self-locking state, and the monitoring indicator light remains extinguished.

[0053] It should be noted that when the first coil terminal and the second coil terminal of the double-pole double-throw relay are energized, the first moving contact of the double-pole double-throw relay connects the first common end to the first normally open contact, and the second moving contact of the double-pole double-throw relay connects the second common end to the second normally open contact, so that the double-pole double-throw relay is in a self-locking state, and the monitoring indicator light remains extinguished due to being short-circuited.

[0054] In some embodiments of the present invention, referring to Figure 4 , after step S200 is executed, it may further include but is not limited to step S410.

[0055] Step S410, when the operating voltage of the eMMC is higher than or equal to the threshold voltage, control the switch to open to make the double-pole double-throw relay exit the self-locking state, and control the switch to close to make the monitoring indicator light switch from the extinguished state to the lit state.

[0056] It should be noted that when the switch is closed, the coil of the double-pole double-throw relay is always in the energized state, and the double-pole double-throw relay will enter the self-locking state, making the monitoring indicator always in the off state and not changing due to the output of the voltage comparator; when the switch is opened, since the power supply does not supply power to the double-pole double-throw relay, the double-pole double-throw relay will exit the self-locking state. When the switch is closed again, the monitoring indicator is re-lit, and a new round of voltage stability monitoring processing can be carried out again.

[0057] In some embodiments of the present invention, the threshold voltage is calculated through the first adjustment resistor and the second adjustment resistor; since one end of the first adjustment resistor is connected to the other end of the switch, the adjustment end of the first adjustment resistor is respectively connected to the positive-phase input terminal of the voltage comparator and one end of the second adjustment resistor, and the adjustment end of the second adjustment resistor is connected to the reference ground, the threshold voltage can be determined according to the magnitudes of the first adjustment resistor and the second adjustment resistor.

[0058] The above is a specific description of the preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included within the scope defined by the claims of the present invention.

Claims

1. A voltage stability monitoring circuit, characterized in that: include: A voltage comparator, wherein a positive input terminal of the voltage comparator is used to receive a threshold voltage, and an inverting input terminal of the voltage comparator is used to receive an operating voltage of an embedded multimedia card eMMC; A double-pole double-throw relay, wherein the output end of the voltage comparator is connected to a first coil terminal of the double-pole double-throw relay, and the second coil terminal of the double-pole double-throw relay is connected to a reference ground; A monitoring indicator light, the monitoring indicator light being connected in parallel with the double-pole double-throw relay; Among them, when the eMMC operating voltage is lower than the threshold voltage, the voltage comparator outputs a high level, the double-pole double-throw relay is energized and enters a self-locking state, so that the monitoring indicator light switches from a lit state to an off state.

2. The voltage stability monitoring circuit according to claim 1, characterized in that: It also includes an anti-reverse diode, the positive electrode of the anti-reverse diode is connected to the output end of the voltage comparator, and the negative electrode of the anti-reverse diode is connected to the first coil terminal of the double-pole double-throw relay.

3. The voltage stability monitoring circuit according to claim 2, characterized in that: It also includes a freewheeling diode, the cathode of which is respectively connected to the first coil terminal of the double-pole double-throw relay and the first normally closed contact of the double-pole double-throw relay, and the anode of which is connected to the reference ground.

4. The voltage stability monitoring circuit according to claim 3, characterized in that: It also includes a current limiting resistor and a switch, one end of the switch is connected to the power supply, the other end of the switch is respectively connected to the power input end of the voltage comparator, the first common end of the double-pole double-throw relay and one end of the current limiting resistor, the other end of the current limiting resistor is respectively connected to the second common end of the double-pole double-throw relay and one end of the monitoring indicator light, the other end of the monitoring indicator light is connected to the reference ground, and the second normally closed contact of the double-pole double-throw relay is connected to the reference ground; wherein, when power is supplied between the first coil terminal and the second coil terminal of the double-pole double-throw relay, the first moving contact of the double-pole double-throw relay connects the first common end with the first normally open contact, and the second moving contact of the double-pole double-throw relay connects the second common end with the second normally closed contact, so that the double-pole double-throw relay is in a self-locking state.

5. The voltage stability monitoring circuit according to claim 4, characterized in that: It also includes a first regulating resistor and a second regulating resistor, one end of the first regulating resistor is connected to the other end of the switch, the regulating end of the first regulating resistor is respectively connected to the non-phase input end of the voltage comparator and one end of the second regulating resistor, and the regulating end of the second regulating resistor is connected to the reference ground.

6. The voltage stability monitoring circuit according to claim 1, characterized in that: The voltage comparator is an operational amplifier.

7. A voltage stability monitoring method, characterized in that: Applied to the voltage stability monitoring circuit of claim 5, the method comprising: Receiving the threshold voltage through the positive input terminal of the voltage comparator, and receiving the eMMC operating voltage through the negative input terminal of the voltage comparator; When the eMMC operating voltage is lower than the threshold voltage, the output end of the voltage comparator outputs a high level to the double-pole double-throw relay, so that the double-pole double-throw relay is energized to enter a self-locking state, and the monitoring indicator light is switched from a lit state to an off state.

8. The voltage stability monitoring method according to claim 7, characterized in that: After the monitoring indicator light is switched from the on state to the off state, the method further includes: When the eMMC operating voltage is higher than or equal to the threshold voltage, the switch is controlled to close so that the double-pole double-throw relay is in a self-locking state, and the monitoring indicator light remains off.

9. The voltage stability monitoring method according to claim 7, characterized in that: After the monitoring indicator light is switched from the on state to the off state, the method further includes: When the eMMC operating voltage is higher than or equal to the threshold voltage, the switch is controlled to be opened so that the double-pole double-throw relay exits the self-locking state, and the switch is controlled to be closed so that the monitoring indicator light switches from the off state to the on state.

10. The voltage stability monitoring method according to claim 7, characterized in that: The threshold voltage is calculated by using the first adjustment resistor and the second adjustment resistor.

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