Low voltage shut-off system and apparatus therefor

Abstract

The application discloses a low-voltage shutdown and power grid activation system and equipment thereof, and relates to the technical field of battery protection, in particular to a low-voltage shutdown and power grid activation system and equipment thereof. The first voltage signal of a target battery is acquired through a battery sampling circuit; the controller performs voltage judgment on the first voltage signal, and when the first voltage signal is lower than a preset voltage threshold, a shutdown signal is delivered to the low-voltage shutdown circuit; then the low-voltage shutdown circuit performs shutdown processing on the auxiliary source of the transformer according to the shutdown signal of the controller; and the low-voltage protection circuit and the activation circuit perform start processing or clamping processing on the auxiliary source of the transformer according to the second voltage signal of the power grid. The application can realize low-voltage protection of the battery, prevent the continuous operation of the inverter from causing the battery to be empty, and based on the low-voltage protection of the battery, the inverter can be charged by the power grid when the power grid is powered, without artificially adding a power supply to the battery for charging, thereby saving the equipment maintenance cost, and can be widely applied to the technical field of battery protection.

Description

Technical Field

[0001] This invention relates to the field of battery protection technology, and in particular to a low-voltage shutdown system and device. Background Technology

[0002] An AC coupler system consists of a battery system and an inverter. The inverter's auxiliary power input comes from the battery, and when there is no grid power, the inverter's auxiliary power supply comes from the battery. However, when the battery's charge is depleted to its minimum, the inverter's continued operation will cause the battery to discharge completely. When grid power is restored, the inverter cannot start normally because the battery is discharged. The current mainstream solution is to charge the battery with an external power source when the battery is low until it reaches the voltage required for the inverter to start, allowing the system to operate. The disadvantages of this existing technology include: the need for an external power source to replenish the battery; and the impact of prolonged battery discharge on battery life. Summary of the Invention

[0003] In view of this, the present invention provides a low-voltage shutdown system and device for low-voltage protection of the battery, so that the inverter can be automatically charged by the grid when the grid power is restored.

[0004] In a first aspect, embodiments of the present invention provide a low-voltage shutdown system, including a transformer, a battery sampling circuit, a controller, a low-voltage shutdown circuit, a low-voltage protection circuit, and an activation circuit;

[0005] The battery sampling circuit is used to acquire the first voltage signal of the target battery;

[0006] The controller is used to determine the voltage of the first voltage signal, and when the first voltage signal is lower than a preset voltage threshold, it sends a shutdown signal to the low-voltage shutdown circuit.

[0007] The low-voltage shutdown circuit is used to shut down the auxiliary power supply of the transformer according to the shutdown signal from the controller.

[0008] The low-voltage protection circuit and activation circuit are used to start or clamp the auxiliary power source of the transformer according to the second voltage signal of the power grid.

[0009] Optionally, the system further includes a power grid sampling circuit; the power grid sampling circuit is used to acquire a third voltage signal from the power grid and transmit it to the controller.

[0010] Optionally, the controller is a DSP, the controller is electrically connected to the battery sampling circuit via an AD port, and the controller is connected to the low-voltage shutdown circuit via GPIO.

[0011] Optionally, the battery sampling circuit includes an operational amplifier U19D, resistors R279, R280, R281, R283, and R284; one end of resistor R279 is electrically connected to the inverting input terminal of operational amplifier U19D, and the other end is electrically connected to the output terminal of operational amplifier U19D; one end of resistor R280 is electrically connected to the positive terminal of the target battery, and the other end is electrically connected to the inverting input terminal of operational amplifier U19D; one end of resistor R283 is electrically connected to the negative terminal of the target battery, and the other end is electrically connected to the non-inverting input terminal of operational amplifier U19D; one end of resistor R281 is electrically connected to the output terminal of operational amplifier U19D, and the other end is electrically connected to the controller; one end of resistor R284 is electrically connected to the non-inverting input terminal of operational amplifier U1A, and the other end is electrically connected to the GND terminal;

[0012] The battery sampling circuit obtains the first voltage signal by performing differential operational amplifier processing on the sampled voltage of the target battery, and then sends the first voltage signal to the controller.

[0013] Optionally, the low-voltage shutdown circuit includes an optocoupler PC3, resistors R51, R154, R312, and transistor Q74; one end of resistor R51 is electrically connected to pin 1 of the optocoupler PC3, and the other end is electrically connected to the auxiliary power supply terminal; one end of resistor R154 is electrically connected to the auxiliary power supply, and the other end is electrically connected to pin 3 of the optocoupler PC3; one end of resistor R312 is electrically connected to the base of transistor Q74, and the other end is electrically connected to the controller; the collector of transistor Q74 is electrically connected to pin 2 of the optocoupler PC3, and the emitter of transistor Q74 is electrically connected to the GND terminal; pin 4 of the optocoupler PC3 is electrically connected to the chip power supply terminal.

[0014] The low-voltage shutdown circuit responds to the shutdown signal from the controller by connecting the on-state voltage to the shutdown pin of the auxiliary source to shut down the auxiliary source.

[0015] Optionally, the low-voltage protection circuit and activation circuit include an optocoupler PC2, a transistor Q73, and an external circuit.

[0016] When the voltage signal of the low-voltage protection circuit and the activation circuit is not connected to the power grid, the auxiliary source is grounded through the conduction of the transistor Q73, and the auxiliary source is clamped.

[0017] When the voltage signal of the low-voltage protection circuit and activation circuit connected to the power grid is turned on through the optocoupler PC2, the grounding of the transistor Q73 to the auxiliary power source is turned off, and the auxiliary power source is started.

[0018] Optionally, the external circuit includes transistor Q19, Zener diode Z1, Zener diode Z27, voltage regulator U26, capacitor C91, diode D25, diode D26, resistors R3, R19, R21, R306, R311, R313, R129, R150, R142, R147, R155, and R156; one end of resistor R3 is electrically connected to the collector of transistor Q73, and the other end is electrically connected to the auxiliary power source; one end of resistor R21 is electrically connected to the base of transistor Q73, and the other end is electrically connected to the emitter of transistor Q73. Connections are made as follows: One end of resistor R19 is electrically connected to the base of transistor Q73, and the other end is electrically connected to the anode of Zener diode Z1 and the collector of transistor Q73; One end of resistor R306 is electrically connected to the cathode of Zener diode Z1 and pin 3 of voltage regulator U26, and the other end is electrically connected to the positive terminal of the target battery; One end of resistor R311 is electrically connected to pin 1 of voltage regulator U26, and the other end is electrically connected to the positive terminal of the target battery; One end of resistor R313 is electrically connected to pin 1 of voltage regulator U26, and the other end is electrically connected to the negative terminal of the target battery; Pin 2 of voltage regulator U26 is connected to... The negative terminal of the target battery is electrically connected; one end of resistor R129 is electrically connected to the positive terminal of the target battery, and the other end is electrically connected to the negative terminal of the Zener diode Z27; one end of resistor R150 is electrically connected to the base of transistor Q19 and pin 3 of optocoupler PC2, and the other end is electrically connected to the negative terminal of the target battery; the emitter of transistor Q19 is electrically connected to the negative terminal of the target battery; the anode of Zener diode Z27 is electrically connected to pin 4 of optocoupler PC2; one end of resistor R147 is electrically connected to pin 1 of optocoupler PC2, and the other end is electrically connected to pin 4 of optocoupler PC2. Pin 2 is electrically connected; one end of resistor R142 is electrically connected to pin 1 of optocoupler PC2, and the other end is electrically connected to the positive terminal of capacitor C91; the negative terminal of capacitor C91 is electrically connected to pin 2 of optocoupler PC2; one end of resistor R155 is electrically connected to the positive terminal of capacitor C91, and the other end is electrically connected to the negative terminal of diode D25; one end of resistor R156 is electrically connected to pin 2 of optocoupler PC2, and the other end is electrically connected to the positive terminal of diode D26; the negative terminal of diode D26 is electrically connected to the neutral wire of the power grid, and the positive terminal of diode D25 is electrically connected to the live wire of the power grid.

[0019] Secondly, embodiments of the present invention provide a device with a low-voltage shutdown system, including the low-voltage shutdown system as described in the first aspect of the present invention.

[0020] The beneficial effects of this invention are as follows: A first voltage signal of the target battery is obtained through a battery sampling circuit; the controller performs voltage judgment on the first voltage signal, and when the first voltage signal is lower than a preset voltage threshold, a shutdown signal is sent to the low-voltage shutdown circuit; then, the low-voltage shutdown circuit shuts down the auxiliary power supply of the transformer according to the shutdown signal from the controller; and the low-voltage protection circuit and activation circuit start or clamp the auxiliary power supply of the transformer according to the second voltage signal from the power grid. This invention can achieve low-voltage protection for the battery, preventing the battery from being discharged due to continuous operation of the inverter. Based on the low-voltage protection of the battery, the inverter can automatically charge itself through the power grid when the grid power is restored, without the need for manual external power supply to charge the battery, thus saving equipment maintenance costs. Attached Figure Description

[0021] Figure 1 This is a schematic diagram illustrating the overall architecture of a low-voltage shutdown system provided in an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the overall circuit of a low-voltage shutdown system provided in an embodiment of the present invention. Detailed Implementation

[0023] The following will describe the concept, specific structure and technical effects of the present invention clearly and completely with reference to the embodiments and accompanying drawings, so as to fully understand the purpose, features and effects of the present invention.

[0024] Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the protection scope of the present invention.

[0025] Furthermore, all the connection relationships mentioned in this article do not refer to direct connection between components, but rather to the ability to form a better connection structure by adding or removing connecting accessories according to specific implementation conditions. The various technical features in this invention can be combined interactively without contradicting each other.

[0026] In a first aspect, embodiments of the present invention provide a low-voltage shutdown system, including a transformer, a battery sampling circuit, a controller, a low-voltage shutdown circuit, a low-voltage protection circuit, and an activation circuit;

[0027] A battery sampling circuit is used to acquire the first voltage signal of the target battery.

[0028] The controller is used to determine the voltage of the first voltage signal. When the first voltage signal is lower than the preset voltage threshold, it sends a shutdown signal to the low-voltage shutdown circuit.

[0029] The low-voltage shutdown circuit is used to shut down the auxiliary power supply of the transformer according to the shutdown signal from the controller.

[0030] The low-voltage protection circuit and activation circuit are used to start or clamp the auxiliary power supply of the transformer according to the second voltage signal of the power grid.

[0031] It should be noted that when the controller detects that the battery voltage is lower than the set threshold through the battery voltage sampling circuit, the controller sends a high level as a shutdown signal to the low-voltage shutdown circuit.

[0032] Optionally, the system also includes a power grid sampling circuit; the power grid sampling circuit is used to acquire the third voltage signal of the power grid and send it to the controller.

[0033] Optionally, the controller uses a DSP, and is electrically connected to the battery sampling circuit via an AD port, and is connected to the low-voltage shutdown circuit via GPIO.

[0034] Optionally, the battery sampling circuit includes an operational amplifier U19D, resistors R279, R280, R281, R283, and R284; one end of resistor R279 is electrically connected to the inverting input terminal of operational amplifier U19D, and the other end is electrically connected to the output terminal of operational amplifier U19D; one end of resistor R280 is electrically connected to the positive terminal of the target battery, and the other end is electrically connected to the inverting input terminal of operational amplifier U19D; one end of resistor R283 is electrically connected to the negative terminal of the target battery, and the other end is electrically connected to the non-inverting input terminal of operational amplifier U19D; one end of resistor R281 is electrically connected to the output terminal of operational amplifier U19D, and the other end is electrically connected to the controller; one end of resistor R284 is electrically connected to the non-inverting input terminal of operational amplifier U1A, and the other end is electrically connected to the GND terminal.

[0035] The battery sampling circuit obtains a first voltage signal by performing differential operational amplifier processing on the sampled voltage of the target battery, and then sends the first voltage signal to the controller.

[0036] Optionally, the low-voltage shutdown circuit includes an optocoupler PC3, resistors R51, R154, R312, and transistor Q74; one end of resistor R51 is electrically connected to pin 1 of optocoupler PC3, and the other end is electrically connected to the auxiliary power supply terminal; one end of resistor R154 is electrically connected to the auxiliary power supply, and the other end is electrically connected to pin 3 of optocoupler PC3; one end of resistor R312 is electrically connected to the base of transistor Q74, and the other end is electrically connected to the controller; the collector of transistor Q74 is electrically connected to pin 2 of optocoupler PC3, and the emitter of transistor Q74 is electrically connected to the GND terminal; pin 4 of optocoupler PC3 is electrically connected to the chip power supply terminal.

[0037] The low-voltage shutdown circuit responds to the shutdown signal from the controller by connecting the on-state voltage to the shutdown pin of the auxiliary power source to shut down the auxiliary power source.

[0038] Optionally, the low-voltage protection circuit and activation circuit include optocoupler PC2, transistor Q73 and external circuitry;

[0039] Among them, when the voltage signal of the low voltage protection circuit and the activation circuit is not connected to the power grid, the auxiliary source is grounded through the conduction of transistor Q73, and the auxiliary source is clamped.

[0040] When the voltage signal of the low-voltage protection circuit and activation circuit is connected to the power grid, the optocoupler PC2 turns off the grounding of the transistor Q73 to the auxiliary power source, and the auxiliary power source is started.

[0041] Optionally, the external circuit includes transistor Q19, Zener diode Z1, Zener diode Z27, voltage regulator U26, capacitor C91, diode D25, diode D26, resistors R3, R19, R21, R306, R311, R313, R129, R150, R142, R147, R155, and R156; one end of resistor R3 is electrically connected to the collector of transistor Q73, and the other end is electrically connected to the auxiliary power source; one end of resistor R21 is electrically connected to the base of transistor Q73, and the other end is electrically connected to the base of transistor Q73. The emitter of transistor Q73 is electrically connected; one end of resistor R19 is electrically connected to the base of transistor Q73, and the other end is electrically connected to the anode of Zener diode Z1 and the collector of transistor Q73; one end of resistor R306 is electrically connected to the cathode of Zener diode Z1 and pin 3 of voltage regulator U26, and the other end is electrically connected to the positive terminal of the target battery; one end of resistor R311 is electrically connected to pin 1 of voltage regulator U26, and the other end is electrically connected to the positive terminal of the target battery; one end of resistor R313 is electrically connected to pin 1 of voltage regulator U26, and the other end is electrically connected to the negative terminal of the target battery; voltage regulator U2... Pin 2 of resistor R129 is electrically connected to the negative terminal of the target battery; one end of resistor R129 is electrically connected to the positive terminal of the target battery, and the other end is electrically connected to the negative terminal of Zener diode Z27; one end of resistor R150 is electrically connected to the base of transistor Q19 and pin 3 of optocoupler PC2, and the other end is electrically connected to the negative terminal of the target battery; the emitter of transistor Q19 is electrically connected to the negative terminal of the target battery; the anode of Zener diode Z27 is electrically connected to pin 4 of optocoupler PC2; one end of resistor R147 is electrically connected to pin 1 of optocoupler PC2, and the other end is electrically connected to pin 2 of optocoupler PC2. Pin 2 of the resistor is electrically connected; one end of resistor R142 is electrically connected to pin 1 of optocoupler PC2, and the other end is electrically connected to the positive terminal of capacitor C91; the negative terminal of capacitor C91 is electrically connected to pin 2 of optocoupler PC2; one end of resistor R155 is electrically connected to the positive terminal of capacitor C91, and the other end is electrically connected to the negative terminal of diode D25; one end of resistor R156 is electrically connected to pin 2 of optocoupler PC2, and the other end is electrically connected to the positive terminal of diode D26; the negative terminal of diode D26 is electrically connected to the neutral wire of the power grid, and the positive terminal of diode D25 is electrically connected to the live wire of the power grid.

[0042] It should be noted that the voltage regulator U26 can be a TL431 (controllable precision voltage regulator).

[0043] Secondly, embodiments of the present invention provide a device with a low-voltage shutdown system, including the low-voltage shutdown system as described in the first aspect of the present invention.

[0044] The present invention will be further described in detail below using a specific low-voltage shutdown system as an example, in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0045] Reference Figure 1 and Figure 2 A low-voltage shutdown system includes a sampling circuit, an auxiliary power source, a low-voltage protection circuit and activation circuit, a low-voltage shutdown circuit, and a controller. The auxiliary power source is connected to the energy storage battery (i.e., the target battery), the low-voltage protection circuit and activation circuit, and the low-voltage shutdown circuit, respectively. The sampling circuit, controller, and low-voltage shutdown circuit are connected sequentially. The sampling circuit is also connected to the energy storage battery, and the low-voltage protection circuit and activation circuit are connected to the power grid. Specifically, the working principle of the low-voltage shutdown system is as follows:

[0046] It should be noted that the sampling circuit includes a battery voltage sampling circuit and a mains voltage sampling circuit.

[0047] R280, R283, R279, R284, R281 and U19D form a battery voltage sampling circuit. The battery voltage sampling circuit converts the battery voltage into a low voltage and sends it to the controller. This circuit is a differential operational amplifier.

[0048] R1, R2, R5, R6, R4, and U18D form a mains voltage sampling circuit. This circuit converts the mains voltage into a low voltage and sends it to the controller. This circuit is a differential operational amplifier.

[0049] R51, R154, R312, R314, Q74, and PC3 form a low-voltage shutdown circuit.

[0050] When the controller detects that the battery voltage is lower than the set threshold through the battery voltage sampling circuit, the controller sends a high level to Q74 through the GPIO port. Q74 turns on, current flows through the primary side of the PC3 optocoupler, the secondary side turns on, and the voltage is supplied to pin 7 of the auxiliary power chip. U25 stops working, and the inverter shuts down without consuming battery power.

[0051] It should be noted that in the low-voltage shutdown circuit, when the controller detects that the battery voltage is lower than the threshold, the controller sends a signal to the low-voltage shutdown circuit, Q74 conducts, current flows through the primary side of the PC3 optocoupler, the secondary side conducts, and the chip's power supply terminal ( Figure 2 When the auxiliary power source (represented by U16-VCC) is turned off, the inverter shuts down and stops consuming battery power.

[0052] R3, R19, R21, R306, R311, R313, R129, R150, R142, R147, R155, R156, Q73, Z1, U26, Z27, Q19, PC2, C91, D25, and D26 form a low-voltage protection circuit and activation circuit;

[0053] After the inverter is turned off, U26 is turned off by voltage division through R311 and R313. The BAT+ voltage is applied to Z1 (Zenyl Zener diode, transient voltage suppressor diode), and the leakage current of Z1, Q73, is turned on, pulling the VCC (chip power supply terminal) voltage of the auxiliary power chip U25 to 0V, so the auxiliary power does not start.

[0054] When the grid is powered, the current is rectified by D25 and D26, and current is limited by R155 and R156. Current flows through the primary side of optocoupler PC2, and the secondary side is turned on. The voltage of BAT+ is applied to Z27. The leakage current of Z27 flows through Q19, and Q19 turns on, pulling the voltage at point a to 0V. At this time, Q73 is turned off, the auxiliary power chip U25 starts, the inverter starts, and the grid energy is used to charge the battery.

[0055] It should be noted that in the low-voltage protection circuit and activation circuit, BAT+ is connected to the positive terminal of the battery. When the inverter is turned off, this circuit pulls the auxiliary power source's VCC (auxiliary power supply terminal) to ground through R306, R311, R313, U26, Z1, R19, R21, Q73, and R3 to prevent the auxiliary power source from starting. The threshold voltage can be adjusted through R306, R311, and R313. Pin 1 of U26 is divided into 2.5V through R311 and R313 and compared with the internal reference voltage of U26. When BAT+ is less than the shutdown threshold, the voltage divided from pin 1 of U26 is less than the internal reference voltage of U26. At this time, pins 2 and 3 of U26 are not conducting. The BAT+ voltage is supplied to Q73 through Z1. Q73 conducts and pulls the auxiliary power source's VCC (auxiliary power supply terminal) to ground, and the inverter is in the shutdown state.

[0056] When the grid is powered, the auxiliary power source is activated via D25, D26, R3, R19, R21, R155, R142, R150, R147, R156, C91, PC2, Z2, Q19, and Q73, thus starting the inverter. After the grid power is restored, D25 and D26 rectify the AC power from the grid into DC power, C91 filters, R155 and R156 current limit, PC2 conducts, and the BAT+ voltage is supplied to Q19 through PC2. Q19 conducts, pulling the gate of Q73 to ground, and Q73 turns off. At this time, the auxiliary power source's VCC (auxiliary power supply terminal) is no longer clamped, the inverter starts, and uses grid energy to charge the battery.

[0057] Figure 1 This is a low-voltage shutdown system diagram. When the system is working normally, the battery can discharge to the grid to supply the load. When the battery is low, the grid can charge the battery.

[0058] When the grid is without power, the inverter will continuously consume battery power. The controller monitors the battery voltage in real time through the sampling circuit to determine the battery power. When the battery voltage is lower than the set threshold, the controller will send a signal to the low-voltage shutdown circuit. The low-voltage shutdown circuit will shut down the auxiliary power source, the inverter will shut down, and stop consuming battery power, thereby protecting the battery.

[0059] After the inverter is turned off, the battery still has a certain voltage because it still stores electricity. At this time, a low-voltage protection circuit is needed to prevent the inverter from starting.

[0060] When the grid power is restored, the activation circuit will use the grid voltage to activate the auxiliary power source, use battery energy to start the inverter, and the inverter will use grid energy to charge the battery.

[0061] It should be noted that the symbols of the circuit elements mentioned above, such as R155, R156, D25, PC2, etc., are only for the purpose of indicating the circuit elements and should not be regarded as limiting the circuit elements of the system of the present invention.

[0062] In summary, the embodiments of the present invention disclose a low-voltage shutdown system and device. The present invention achieves anti-howling by combining a notch filter circuit parameter adjustment circuit with a notch filter circuit through a simple circuit design. It does not require a DSP processor and only uses a simple circuit structure combined with the function of a mainstream notch filter to achieve anti-howling. The circuit is simple to debug, modular and low cost.

[0063] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A low-voltage shutdown system, characterized in that, Includes transformer, battery sampling circuit, controller, low-voltage shutdown circuit, low-voltage protection circuit, and activation circuit; The battery sampling circuit is used to acquire the first voltage signal of the target battery; The controller is used to determine the voltage of the first voltage signal, and when the first voltage signal is lower than a preset voltage threshold, it sends a shutdown signal to the low-voltage shutdown circuit. The low-voltage shutdown circuit is used to shut down the auxiliary power supply of the transformer according to the shutdown signal from the controller. The low-voltage protection circuit and activation circuit are used to start or clamp the auxiliary power source of the transformer according to the second voltage signal of the power grid. The battery sampling circuit includes an operational amplifier U19D, resistors R279, R280, R281, R283, and R284. One end of resistor R279 is electrically connected to the inverting input of operational amplifier U19D, and the other end is electrically connected to the output of operational amplifier U19D. One end of resistor R280 is electrically connected to the positive terminal of the target battery, and the other end is electrically connected to the inverting input of operational amplifier U19D. One end of resistor R283 is electrically connected to the negative terminal of the target battery, and the other end is electrically connected to the non-inverting input of operational amplifier U19D. One end of resistor R281 is electrically connected to the output of operational amplifier U19D, and the other end is electrically connected to the controller. One end of resistor R284 is electrically connected to the non-inverting input of operational amplifier U19D, and the other end is electrically connected to the GND terminal. The battery sampling circuit obtains the first voltage signal by performing differential operational amplifier processing on the sampled voltage of the target battery, and then sends the first voltage signal to the controller.

2. The low-voltage shutdown system according to claim 1, characterized in that, It also includes a power grid sampling circuit; the power grid sampling circuit is used to acquire the third voltage signal of the power grid and transmit it to the controller.

3. A low-voltage shutdown system according to claim 1, characterized in that, The controller uses a DSP, is electrically connected to the battery sampling circuit via an AD port, and is connected to the low-voltage shutdown circuit via GPIO.

4. A low-voltage shutdown system according to claim 1, characterized in that, The low-voltage shutdown circuit includes an optocoupler PC3, resistors R51, R154, R312, and transistor Q74. One end of resistor R51 is electrically connected to pin 1 of the optocoupler PC3, and the other end is electrically connected to the auxiliary power supply terminal. One end of resistor R154 is electrically connected to the auxiliary power supply, and the other end is electrically connected to pin 3 of the optocoupler PC3. One end of resistor R312 is electrically connected to the base of transistor Q74, and the other end is electrically connected to the controller. The collector of transistor Q74 is electrically connected to pin 2 of the optocoupler PC3, and the emitter of transistor Q74 is electrically connected to the GND terminal. Pin 4 of the optocoupler PC3 is electrically connected to the chip power supply terminal. The low-voltage shutdown circuit responds to the shutdown signal from the controller by connecting the on-state voltage to the shutdown pin of the auxiliary source to shut down the auxiliary source.

5. A low-voltage shutdown system according to claim 1, characterized in that, The low-voltage protection circuit and activation circuit include an optocoupler PC2, a transistor Q73, and external circuitry. When the voltage signal of the low-voltage protection circuit and the activation circuit is not connected to the power grid, the auxiliary source is grounded through the conduction of the transistor Q73, and the auxiliary source is clamped. When the voltage signal of the low-voltage protection circuit and activation circuit connected to the power grid is turned on through the optocoupler PC2, the grounding of the transistor Q73 to the auxiliary power source is turned off, and the auxiliary power source is started.

6. A low-voltage shutdown system according to claim 5, characterized in that, The external circuit includes transistor Q19, Zener diode Z1, Zener diode Z27, voltage regulator U26, capacitor C91, diode D25, diode D26, resistors R3, R19, R21, R306, R311, R313, R129, R150, R142, R147, R155, and R156; one end of resistor R3 is electrically connected to the collector of transistor Q73, and the other end is electrically connected to the auxiliary power source; one end of resistor R21 is electrically connected to the base of transistor Q73, and the other end is electrically connected to the emitter of transistor Q73. One end of resistor R19 is electrically connected to the base of transistor Q73, and the other end is electrically connected to the anode of Zener diode Z1 and the collector of transistor Q73; one end of resistor R306 is electrically connected to the cathode of Zener diode Z1 and pin 3 of voltage regulator U26, and the other end is electrically connected to the positive terminal of the target battery; one end of resistor R311 is electrically connected to pin 1 of voltage regulator U26, and the other end is electrically connected to the positive terminal of the target battery; one end of resistor R313 is electrically connected to pin 1 of voltage regulator U26, and the other end is electrically connected to the negative terminal of the target battery; pin 2 of voltage regulator U26 is connected to... The negative terminal of the target battery is electrically connected; one end of resistor R129 is electrically connected to the positive terminal of the target battery, and the other end is electrically connected to the negative terminal of the Zener diode Z27; one end of resistor R150 is electrically connected to the base of transistor Q19 and pin 3 of optocoupler PC2, and the other end is electrically connected to the negative terminal of the target battery; the emitter of transistor Q19 is electrically connected to the negative terminal of the target battery; the anode of Zener diode Z27 is electrically connected to pin 4 of optocoupler PC2; one end of resistor R147 is electrically connected to pin 1 of optocoupler PC2, and the other end is electrically connected to pin 4 of optocoupler PC2. Pin 2 is electrically connected; one end of resistor R142 is electrically connected to pin 1 of optocoupler PC2, and the other end is electrically connected to the positive terminal of capacitor C91; the negative terminal of capacitor C91 is electrically connected to pin 2 of optocoupler PC2; one end of resistor R155 is electrically connected to the positive terminal of capacitor C91, and the other end is electrically connected to the negative terminal of diode D25; one end of resistor R156 is electrically connected to pin 2 of optocoupler PC2, and the other end is electrically connected to the positive terminal of diode D26; the negative terminal of diode D26 is electrically connected to the neutral wire of the power grid, and the positive terminal of diode D25 is electrically connected to the live wire of the power grid.

7. A device with a low-voltage shutdown system, characterized in that, Includes the low-voltage shutdown system as described in any one of claims 1 to 6.

Images