Dual battery hardware switching circuit and dual battery power supply system

Abstract

The embodiment of the application discloses a double-battery hardware switching circuit and a double-battery power supply system, which are used for controlling a main battery or a secondary battery to supply power to a power-using device. The double-battery hardware switching circuit comprises a hysteresis comparison module, a first switch module, a first control module, a second switch module, a second control module and a level inversion module. When the voltage of the main battery is greater than or equal to the voltage of the secondary battery, the first level output by the hysteresis comparison module controls the first control module to work, the first control module controls the first switch module to be turned on, and the main battery independently supplies power to the power-using device. When the voltage of the main battery is less than the voltage of the secondary battery and the voltage difference exceeds a preset value, the fourth level output by the level inversion module controls the second control module to work, the second switch module is turned on, and the secondary battery independently supplies power to the power-using device. The automatic switching of the main battery and the secondary battery is realized, the response action is rapid, and stable and reliable electric energy is provided to the power-using device.

Description

Technical Field

[0001] This invention relates to the field of circuit technology, and in particular to a dual-battery hardware switching circuit and a dual-battery power supply system. Background Technology

[0002] In the field of automotive electronics, to ensure the safe operation of the vehicle's control systems, two batteries are typically used to power the system simultaneously. One is a primary battery that provides priority power, while the other is a backup secondary battery that switches to power when the primary battery fails or becomes low on voltage.

[0003] However, the common method for switching between the main and secondary batteries is to use the analog-to-digital converter of the microcontroller unit (MCU) to detect the voltage of the main and secondary batteries. When the voltage of the main battery is insufficient, the MCU controls the power supply path to switch from the main battery to the secondary battery, which then provides power. This method suffers from slow response or even failure to switch. Summary of the Invention

[0004] This invention provides a dual-battery hardware switching circuit and a dual-battery power supply system to achieve automatic switching between the main battery and the auxiliary battery, with rapid response, so as to provide stable and reliable power to electrical equipment.

[0005] According to one aspect of the present invention, a dual-battery hardware switching circuit is provided for controlling a main battery or a secondary battery to supply power to an electrical device. The dual-battery hardware switching circuit includes a hysteresis comparison module, a first switch module, a first control module, a second switch module, a second control module, and a level inversion module.

[0006] The first input terminal of the hysteresis comparator module and the first terminal of the first switch module are both electrically connected to the positive terminal of the main battery. The second input terminal of the hysteresis comparator module and the first terminal of the second switch module are both electrically connected to the positive terminal of the auxiliary battery. The shutdown signal control terminal of the first control module and the control terminal of the level inversion module are both electrically connected to the output terminal of the hysteresis comparator module. The output terminal of the level inversion module is electrically connected to the shutdown signal control terminal of the second control module. The control terminal of the first switch module is electrically connected to the output terminal of the first control module. The control terminal of the second switch module is electrically connected to the output terminal of the second control module. The second terminals of the first switch module and the second terminals of the second switch module are both electrically connected to the electrical equipment.

[0007] When the voltage of the main battery is greater than or equal to the voltage of the auxiliary battery, the first level output by the hysteresis comparison module controls the first control module to work, the first control module controls the first switch module to turn on, the second level output by the level inversion module controls the second control module to turn off, the second switch module to turn off, and the main battery independently supplies power to the electrical equipment.

[0008] When the voltage of the main battery is less than the voltage of the secondary battery and the voltage difference exceeds a preset value, the third level output by the hysteresis comparison module controls the first control module to shut down and the first switch module to turn off. The fourth level output by the level inversion module controls the second control module to operate and the second switch module to turn on, and the secondary battery independently supplies power to the electrical equipment.

[0009] Optionally, when the voltage of the main battery recovers from being lower than the voltage of the secondary battery and the voltage difference exceeding a preset value to being higher than the voltage of the secondary battery, the hysteresis comparison module outputs the first level to restore the main battery to independently power the electrical device.

[0010] Optionally, the hysteresis comparison module includes an operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor;

[0011] The first end of the first resistor is electrically connected to the positive terminal of the main battery, the second end of the first resistor is electrically connected to the first end of the second resistor, the second end of the second resistor is grounded, and the non-inverting input terminal of the operational amplifier is electrically connected to the second end of the first resistor.

[0012] The first end of the third resistor is electrically connected to the positive terminal of the auxiliary battery, the second end of the third resistor is electrically connected to the first end of the fourth resistor, the second end of the fourth resistor is grounded, and the inverting input terminal of the operational amplifier is electrically connected to the second end of the third resistor.

[0013] The first end of the fifth resistor is electrically connected to the second end of the first resistor, and the second end of the fifth resistor is electrically connected to the output end of the operational amplifier.

[0014] The output terminal of the operational amplifier is directly electrically connected to the shutdown signal control terminal of the first control module, and the output terminal of the operational amplifier is electrically connected to the shutdown signal control terminal of the second control module through the level inversion module.

[0015] Optionally, the first resistor and the third resistor have the same resistance value, and the second resistor has a greater resistance value than the fourth resistor.

[0016] Optionally, both the first control module and the second control module include a MAX16141 chip.

[0017] Optionally, the first switching module includes a first MOSFET and a second MOSFET. The drain of the first MOSFET is electrically connected to the positive terminal of the main battery, the gate of the first MOSFET is electrically connected to the output terminal of the first control module, the source of the first MOSFET is electrically connected to the source of the second MOSFET, the gate of the second MOSFET is electrically connected to the output terminal of the first control module, the drain of the second MOSFET is electrically connected to the electrical device, and the source of the second MOSFET is also electrically connected to the overcurrent detection output terminal of the first control module.

[0018] The second switching module includes a third MOSFET and a fourth MOSFET. The drain of the third MOSFET is electrically connected to the positive terminal of the secondary battery, the gate of the third MOSFET is electrically connected to the output terminal of the second control module, the source of the third MOSFET is electrically connected to the source of the fourth MOSFET, the gate of the fourth MOSFET is electrically connected to the output terminal of the second control module, the drain of the fourth MOSFET is electrically connected to the electrical device, and the source of the fourth MOSFET is also electrically connected to the overcurrent detection output terminal of the second control module.

[0019] Optionally, a sixth resistor is also included, wherein the first end of the sixth resistor is electrically connected to the positive terminal of the main battery, and the second end of the sixth resistor is electrically connected to the shutdown signal control terminal of the first control module.

[0020] Optionally, the level inversion module includes a fifth MOSFET and a seventh resistor;

[0021] The first end of the seventh resistor is electrically connected to the positive terminal of the auxiliary battery, the second end of the seventh resistor is electrically connected to the drain of the fifth MOS transistor, the gate of the fifth MOS transistor is electrically connected to the output terminal of the hysteresis comparator module, the source of the fifth MOS transistor is grounded, and the drain of the fifth MOS transistor is also electrically connected to the turn-off signal control terminal of the second control module.

[0022] Optionally, the first level is equal to the fourth level, and the second level is equal to the third level.

[0023] According to another aspect of the present invention, a dual-battery power supply system is provided, including a main battery, a secondary battery, an electrical device, and a dual-battery hardware switching circuit as described in any embodiment of the present invention.

[0024] The technical solution provided by this invention, by setting a hysteresis comparison module, can compare the voltages of the main battery and the auxiliary battery and output corresponding levels. When the voltage of the main battery is greater than or equal to the voltage of the auxiliary battery, meaning the main battery can meet the normal power needs of the electrical equipment, the hysteresis comparison module outputs a first level to control the first control module to operate, thereby controlling the first switch module to conduct. The second level output by the level inversion module controls the second control module to shut down, and the second switch module to turn off, allowing the main battery to independently power the electrical equipment. When the voltage of the main battery is less than the voltage of the auxiliary battery and the voltage difference exceeds a preset value, meaning the main battery has an undervoltage or other fault, the hysteresis comparison module outputs a third level to control the first control module to shut down, and the first switch module to turn off. The level inversion module outputs a fourth level to control the second control module to operate, and the second switch module to conduct, allowing the auxiliary battery to independently power the electrical equipment. This achieves automatic switching between the main and auxiliary batteries, with rapid response, to provide stable and reliable power to the electrical equipment.

[0025] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A circuit block diagram of a dual-battery hardware switching circuit provided in an embodiment of the present invention;

[0028] Figure 2 A circuit diagram of a dual-battery hardware switching circuit provided in an embodiment of the present invention;

[0029] Figure 3 A circuit diagram of another dual-battery hardware switching circuit provided in an embodiment of the present invention;

[0030] Figure 4 This is a circuit diagram of another dual-battery hardware switching circuit provided in an embodiment of the present invention. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0032] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0033] Figure 1 This invention provides a circuit block diagram of a dual-battery hardware switching circuit, used to control the main battery 11 or the auxiliary battery 12 to supply power to the device 700, such as... Figure 1As shown, the dual-battery hardware switching circuit includes a hysteresis comparator module 100, a first switch module 200, a first control module 300, a second switch module 400, a second control module 500, and a level inversion module 600. The first input terminal of the hysteresis comparator module 100 and the first terminal of the first switch module 200 are both electrically connected to the positive terminal of the main battery 11. The second input terminal of the hysteresis comparator module 100 and the first terminal of the second switch module 400 are both electrically connected to the positive terminal of the auxiliary battery 12. The shutdown signal control terminal SHDN of the first control module 300 and the control terminal of the level inversion module 600 are both electrically connected to the output terminal of the hysteresis comparator module 100. The output terminal of the level inversion module 600 is electrically connected to the shutdown signal control terminal SHDN of the second control module 500. The control terminal of the first switch module 200 is electrically connected to the output terminal of the first control module 300. The control terminal of the second switch module 400 is electrically connected to the output terminal of the second control module 500. The second terminals of both the first switch module 200 and the second switch module 400 are electrically connected to the electrical device 700. When the voltage of the main battery 11 is greater than or equal to the voltage of the secondary battery 12, the first level output by the hysteresis comparator module 100 controls the first control module 300 to operate, the first control module 300 controls the first switch module 200 to turn on, and the second level output by the level inversion module 600 controls the second control module 500 to turn off, and the second switch module 400 to turn off, so the main battery 11 independently supplies power to the device 700. When the voltage of the main battery 11 is less than the voltage of the secondary battery 12 and the voltage difference exceeds a preset value, the third level output by the hysteresis comparator module 100 controls the first control module 300 to turn off, the first switch module 200 to turn off, and the fourth level output by the level inversion module 600 controls the second control module 500 to operate, the second switch module 400 to turn on, so the secondary battery 12 independently supplies power to the device 700.

[0034] The dual-battery hardware switching circuit can be used in the automotive electronics field. The electrical device 700 can be a car's electric windshield wipers, windshield washer, air conditioning system, car audio-visual equipment, electric window regulators, electric seats, electric sunroof, electric rearview mirrors, etc. The first input terminal of the hysteresis comparison module 100 is electrically connected to the positive terminal of the main battery 11, and the second input terminal is electrically connected to the positive terminal of the auxiliary battery 12, preventing the hysteresis comparison module 100 from failing to operate if either the main battery 11 or the auxiliary battery 12 malfunctions or has no remaining power. The first terminal of the first switching module 200 is electrically connected to the positive terminal of the main battery 11, and the main battery 11 supplies power to the first switching module 200 to enable its normal operation. The first terminal of the second switching module 400 is electrically connected to the positive terminal of the auxiliary battery 12, and the auxiliary battery 12 supplies power to the second switching module 400 to enable its normal operation.

[0035] It is understood that, in specific implementations, in the first control module 300, when the electrical signal received by the shutdown signal control terminal SHDN is high, the first control module 300 outputs an electrical signal to control the first switch module 200 to turn on; when the electrical signal received by the shutdown signal control terminal SHDN is low, the first control module 300 outputs an electrical signal to control the first switch module 200 to turn off. Alternatively, in the first control module 300, when the electrical signal received by the shutdown signal control terminal SHDN is low, the first control module 300 outputs an electrical signal to control the first switch module 200 to turn on; when the electrical signal received by the shutdown signal control terminal SHDN is high, the first control module 300 outputs an electrical signal to control the first switch module 200 to turn off. The second control module 500 operates in the same manner as the first control module 300, and this embodiment of the invention does not limit this. Optionally, the first level and the fourth level are equal, and the second level and the third level are equal.

[0036] Specifically, when the voltage of the main battery 11 is greater than or equal to the voltage of the auxiliary battery 12, the hysteresis comparator module 100 compares the voltages of the main battery 11 and the auxiliary battery 12 according to its internal comparison circuit or comparison logic and outputs a first level. This first level is input to the shutdown signal control terminal SHDN of the first control module 300, which then controls the first control module 300 to operate. The first control module 300 then controls the first switch module 200 to turn on, so that the electrical energy from the main battery 11 can supply power to the electrical device 700 through the first switch module 200. Figure 1 The direction indicated by the dotted arrow in the diagram is the power supply direction. The level inversion module 600 inverts the first level output by the hysteresis comparator module 100 and outputs a second level; for example, the first level is high and the second level is low. The second level controls the second control module 500 to turn off. The second switch module 400 cannot receive the electrical signal from the second control module 500, and the second switch module 400 is turned off. The auxiliary battery 12 cannot supply power to the electrical device 700 through the second switch module 400, and all the power required by the electrical device 700 is provided by the main battery 11.

[0037] Correspondingly, when the voltage of the main battery 11 is less than the voltage of the secondary battery 12 and the voltage difference exceeds a preset value, it indicates that the main battery 11 has an undervoltage fault. The hysteresis comparison module 100 compares the voltage of the main battery 11 and the voltage of the secondary battery 12 according to the internal comparison circuit or comparison logic and outputs a third level. The third level is input to the shutdown signal control terminal SHDN of the first control module 300 to control the first control module 300 to shut down. The first switch module 200 is turned off. The first switch module 200 cannot receive the electrical signal from the first control module 300. The main battery 11 cannot supply power to the electrical device 700 through the first switch module 200. The level inversion module 600 inverts the third level output by the hysteresis comparison module 100 and outputs a fourth level. For example, the third level is a low level and the fourth level is a high level. After the fourth level input is applied to the shutdown signal control terminal SHDN of the second control module 500, the second control module 500 is controlled to work. The second control module 500 then controls the second switch module 400 to turn on, so that the power of the auxiliary battery 12 can be used to independently power the electrical equipment 700 through the second switch module 400.

[0038] It is understood that the preset value can be set according to actual needs. This embodiment of the invention does not impose specific limitations on this. For example, in one embodiment, the preset value can be 4V.

[0039] The technical solution of this invention, by setting a hysteresis comparison module, can compare the voltages of the main battery and the auxiliary battery and output corresponding levels. When the voltage of the main battery is greater than or equal to the voltage of the auxiliary battery, meaning the main battery can meet the normal power needs of the electrical device, the hysteresis comparison module outputs a first level to control the first control module to operate, thereby controlling the first switch module to conduct. The second level output by the level inversion module controls the second control module to shut down, and the second switch module to turn off, allowing the main battery to independently power the electrical device. When the voltage of the main battery is less than the voltage of the auxiliary battery and the voltage difference exceeds a preset value, meaning the main battery has an undervoltage fault, the hysteresis comparison module outputs a third level to control the first control module to shut down, and the first switch module to turn off. The level inversion module outputs a fourth level to control the second control module to operate, and the second switch module to conduct, allowing the auxiliary battery to independently power the electrical device. This achieves automatic switching between the main battery and the auxiliary battery, with rapid response, to provide stable and reliable power to the electrical device.

[0040] In an optional embodiment, when the voltage of the main battery 11 recovers from being less than the voltage of the secondary battery 12 and the voltage difference exceeds a preset value to being greater than the voltage of the secondary battery 12, the hysteresis comparison module 100 outputs a first level to restore the main battery 11 to independently supply power to the electrical device 700.

[0041] Specifically, when the voltage of the main battery 11 recovers from being lower than the voltage of the secondary battery 12 and the voltage difference exceeds a preset value to being higher than the voltage of the secondary battery 12, that is, when the main battery 11 recovers from a fault state such as undervoltage to a state where it can normally supply power to the electrical device 700, the hysteresis comparison module 100 outputs the first level, which allows the main battery 11 to supply power to the electrical device 700 alone, avoiding the secondary battery 12 and the main battery 11 consuming power at the same time and failing to play the role of a backup battery.

[0042] It is understood that the specific structures of the hysteresis comparison module 100, the first switch module 200, the second switch module 400, the first control module 300, the second control module 500, and the level inversion module 600 can be designed according to actual needs. Provided that their respective functions are met, this embodiment of the invention does not limit the specific structures of the hysteresis comparison module 100, the first switch module 200, the second switch module 400, the first control module 300, the second control module 500, and the level inversion module 600. The following uses typical examples to exemplify the specific structures of each circuit in this embodiment of the invention.

[0043] Optional, Figure 2 A circuit diagram of a dual-battery hardware switching circuit provided in an embodiment of the present invention is shown below. Figure 2 As shown, the hysteresis comparator module 100 includes an operational amplifier T1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, and a fifth resistor R5. The first terminal of the first resistor R1 is electrically connected to the positive terminal of the main battery 11. The second terminal of the first resistor R1 is electrically connected to the first terminal of the second resistor R2, and the second terminal of the second resistor R2 is grounded. The non-inverting input terminal A1 of the operational amplifier T1 is electrically connected to the second terminal of the first resistor R1. The first terminal of the third resistor R3 is electrically connected to the positive terminal of the auxiliary battery 12. The second terminal of the third resistor R3 is electrically connected to the first terminal of the fourth resistor R4, and the second terminal of the fourth resistor R4 is grounded. The inverting input terminal A2 of the operational amplifier T1 is electrically connected to the second terminal of the third resistor R3. The first terminal of the fifth resistor R5 is electrically connected to the second terminal of the first resistor R1, and the second terminal of the fifth resistor R5 is electrically connected to the output terminal of the operational amplifier T1. The output terminal of operational amplifier T1 is directly electrically connected to the shutdown signal control terminal SHDN of the first control module 300, and the output terminal of operational amplifier T1 is electrically connected to the shutdown signal control terminal SHDN of the second control module 500 through the level inversion module 600.

[0044] Thus, the potential at the non-inverting input terminal A1 of the operational amplifier T1 is U1*R2 / (R1+R2), where U1 is the current voltage of the main battery 11. That is, the potential at the non-inverting input terminal A1 is related to the current voltage U1 of the main battery 11, the resistance values ​​of the first resistor R1 and the second resistor R2. By setting the resistance values ​​of the first resistor R1 and the second resistor R2, the magnitude of the potential at the non-inverting input terminal A1 can be adaptively adjusted.

[0045] Correspondingly, the potential at the inverting input terminal A2 of operational amplifier T1 is U2*R4 / (R3+R4), where U2 is the current voltage of the secondary battery 12. That is, the potential at the inverting input terminal A2 is related to the current voltage U2 of the secondary battery 12, the resistance values ​​of the third resistor R3 and the fourth resistor R4. By setting the resistance values ​​of the third resistor R3 and the fourth resistor R4, the magnitude of the potential at the inverting input terminal A2 can be adaptively adjusted.

[0046] The VCC port of operational amplifier T1 can be electrically connected to the positive terminal of the main battery 11, and the GND port of operational amplifier T1 can be electrically connected to the ground terminal GND to enable amplifier T1 to operate. The fifth resistor R5 can limit the current of the electrical signal output by operational amplifier T1.

[0047] In an optional embodiment, the first resistor R1 and the third resistor R3 have the same resistance value, and the second resistor R2 has a greater resistance value than the fourth resistor R4.

[0048] For example, the resistance of the first resistor R1 and the third resistor R3 is 300kΩ, the resistance of the second resistor R2 is 36kΩ, the resistance of the fourth resistor R4 is 24kΩ, and the resistance of the fifth resistor R5 is 820kΩ. When the voltage U1 of the main battery 11 is greater than or equal to the voltage U2 of the secondary battery 12, the potential at the non-inverting input terminal A1 of the operational amplifier T1 is U1*36 / (300+36)=0.107*U1, and the potential at the inverting input terminal A2 is U2*24kΩ. / (300+24)=0.074*U2, the potential at the non-inverting input terminal A1 is greater than the potential at the inverting input terminal A2, the first level output by operational amplifier T1 is high. After the first level is input to the shutdown signal control terminal SHDN of the first control module 300, it controls the first control module 300 to work. The first control module 300 then controls the first switch module 200 to turn on, so that the power of the main battery 11 can supply power to the device 700 through the first switch module 200. The level inversion module 600 inverts the high level first level and outputs a low level second level. The second level controls the second control module 500 to turn off, the second switch module 400 to turn off, and the auxiliary battery 12 cannot supply power to the device 700 through the second switch module 400. All the power required by the device 700 is provided by the main battery 11.

[0049] Correspondingly, when the voltage U1 of the main battery 11 is less than the voltage U2 of the secondary battery 12 and the voltage difference exceeds a preset value, the potential at the non-inverting input terminal A1 of the operational amplifier T1 is U1*36 / (300+36)=0.107*U1, and the potential at the inverting input terminal A2 is U2*24 / (300+24)=0.074*U2. Since the potential at the non-inverting input terminal A1 is less than the potential at the inverting input terminal A2, the third level output by the operational amplifier T1 is low, and the third level is input to the first control... After the shutdown signal control terminal SHDN of the control module 300 is activated, the first control module 300 is shut down, and the first switch module 200 is turned off. The main battery 11 cannot supply power to the device 700 through the first switch module 200. After the third level is input to the shutdown signal control terminal SHDN of the second control module 500, the first control module 300 is activated. The first control module 300 then controls the first switch module 200 to turn on, allowing the main battery 11 to supply power to the device 700 through the first switch module 200. The level inversion module 600 inverts the low-level third level and outputs a high-level fourth level. This fourth level controls the second control module 500 to operate, and the second switch module 400 is turned on. The auxiliary battery 12 then supplies power to the device 700 through the second switch module 400. All the power required by the device 700 is provided by the auxiliary battery 12. At this time, since the third level output by operational amplifier T1 is low, the potential at the non-inverting input terminal A1 of operational amplifier T1 is U1*(R2 / / R5) / ((R2 / / R5)+R1)=U1*(36 / / 820) / ((36 / / 820)+300)=0.103*U1. Only when the voltage of the main battery 11 recovers to a relatively high level can the potential at the non-inverting input terminal A1, 0.103*U1, be greater than the potential at the inverting input terminal A2, 0.074*U2, thereby enabling the main battery 11 to supply power to the device 700 independently again.

[0050] Based on the above embodiments, Figure 3 A circuit diagram of another dual-battery hardware switching circuit provided in an embodiment of the present invention is shown below. Figure 3 As shown, both the first control module 300 and the second control module 500 include a MAX16141 chip.

[0051] The MAX16141 chip includes a shutdown signal control terminal SHDN, an output terminal GATE, an input terminal IN, a power supply terminal VCC, a ground terminal GND, and an overcurrent detection output terminal SRC. The power supply terminal VCC and the ground terminal GND are connected to the external power supply and ground terminal respectively to power the MAX16141 chip. The input terminal IN is also used to connect an external power signal to enable the MAX16141 chip. The shutdown signal control terminal SHDN is used to control the MAX16141 chip to work or shut down. The output terminal GATE is used to output an electrical signal. The overcurrent detection output terminal SRC is used to detect whether there is an overcurrent in the input electrical signal.

[0052] Specifically, the MAX16141 chip features various system fault protection characteristics, such as reverse current protection, overcurrent protection, input overvoltage / undervoltage protection, and overheat protection. The MAX16141 chip employs low-power shutdown, reducing battery consumption.

[0053] In an alternative embodiment, reference continues. Figure 3 The first switching module 200 includes a first MOSFET Q1 and a second MOSFET Q2. The drain d1 of the first MOSFET Q1 is electrically connected to the positive terminal of the main battery 11. The gate g1 of the first MOSFET Q1 is electrically connected to the output terminal GATE of the first control module 300. The source s1 of the first MOSFET Q1 is electrically connected to the source s2 of the second MOSFET Q2. The gate g2 of the second MOSFET Q2 is electrically connected to the output terminal of the first control module 300. The drain d2 of the second MOSFET Q2 is electrically connected to the electrical device 700. The source s2 of the second MOSFET Q2 is also electrically connected to the overcurrent detection output terminal SRC of the first control module 300.

[0054] The second switching module 400 includes a third MOSFET Q3 and a fourth MOSFET Q4. The drain d3 of the third MOSFET Q3 is electrically connected to the positive terminal of the secondary battery 12. The gate g3 of the third MOSFET Q3 is electrically connected to the output terminal GATE of the second control module 500. The source s3 of the third MOSFET Q3 is electrically connected to the source s4 of the fourth MOSFET Q4. The gate g4 of the fourth MOSFET Q4 is electrically connected to the output terminal GATE of the second control module 500. The drain d4 of the fourth MOSFET Q4 is electrically connected to the electrical device 700. The source s4 of the fourth MOSFET Q4 is also electrically connected to the overcurrent detection output terminal SRC of the second control module 500.

[0055] Because MOSFETs have high impedance when off and extremely low impedance when on, the first MOSFET Q1, the second MOSFET Q2, the third MOSFET Q3, and the fourth MOSFET Q4 possess characteristics such as high efficiency, low heat loss, low noise, small size, low cost, and long lifespan. The first MOSFET Q1, the second MOSFET Q2, the third MOSFET Q3, and the fourth MOSFET Q4 can be N-channel depletion-mode, P-channel depletion-mode, N-channel enhancement-mode, or P-channel enhancement-mode, etc. Figure 3 The example provided only uses the first MOSFET Q1, the second MOSFET Q2, the third MOSFET Q3, and the fourth MOSFET Q4 as N-channel enhancement-mode transistors. Other configurations can be made according to actual needs.

[0056] Specifically, the drain d1 of the first MOSFET Q1 is electrically connected to the positive terminal of the main battery 11 to supply power to the first MOSFET Q1. This ensures that the first MOSFET Q1 conducts when the voltage Ugs between its gate g1 and source s1 reaches its turn-on voltage, and is turned off when the voltage Ugs does not reach its turn-on voltage. Furthermore, since the source s1 of the first MOSFET Q1 is electrically connected to the source s2 of the second MOSFET Q2, and the drain d2 of the second MOSFET Q2 is electrically connected to the device 700, if the device 700 reverse-transmits power to the second switching module 200, the diode (not shown in the figure) in the second MOSFET Q2 is reverse-biased and cut off. The reverse-transmitted power from the device 700 will not pass through the second MOSFET Q2 or the first MOSFET Q1, preventing the device 700 from reverse-transmitting power to the main battery 11 through the first switching module 200.

[0057] It is understandable that the working principle of the third MOSFET Q3 and the fourth MOSFET Q4 is similar to that of the first MOSFET Q1 and the second MOSFET Q2, which will not be elaborated here. That is, to prevent the electrical device 700 from transmitting electrical energy to the main battery 11 in reverse through the second switch module 400.

[0058] Optional, see reference Figure 3 The dual-battery hardware switching circuit also includes a sixth resistor R6. The first end of the sixth resistor R6 is electrically connected to the positive terminal of the main battery 11, and the second end of the sixth resistor R6 is electrically connected to the shutdown signal control terminal SHDN of the first control module 300.

[0059] The resistance value of the sixth resistor R6 can be set according to actual needs, and this embodiment of the invention does not impose a specific limitation on it. For example, the sixth resistor R6 can be 10kΩ.

[0060] Specifically, if the first level output by the hysteresis comparator module 100 is high, the sixth resistor R6 will limit the current. If the third level output by the hysteresis comparator module 100 is low, the sixth resistor R6 will divide the voltage to prevent the current input to the SHDN terminal of the MAX16141 chip from being too large and affecting the operation of the MAX16141 chip.

[0061] Based on the above embodiments, Figure 4 A circuit diagram of another dual-battery hardware switching circuit provided in an embodiment of the present invention is shown below. Figure 4 As shown, the level inversion module 600 includes a fifth MOSFET Q5 and a seventh resistor R7. The first terminal of the seventh resistor R7 is electrically connected to the positive terminal of the secondary battery 12, the second terminal of the seventh resistor R7 is electrically connected to the drain d5 of the fifth MOSFET Q5, the gate g5 of the fifth MOSFET Q5 is electrically connected to the output terminal of the hysteresis comparator module 100, the source s5 of the fifth MOSFET Q5 is grounded, and the drain d5 of the fifth MOSFET Q5 is also electrically connected to the turn-off signal control terminal SHDN of the second control module 500.

[0062] Because the MOSFET has a high impedance when off and an extremely low impedance when on, the fifth MOSFET Q5 exhibits characteristics such as high efficiency, low heat loss, low noise, small size, and long lifespan. The fifth MOSFET Q5 can be an N-channel depletion-mode, P-channel depletion-mode, N-channel enhancement-mode, or P-channel enhancement-mode MOSFET. Figure 4 The example given is only the fifth MOSFET Q5, which is an N-channel enhancement type. Other configurations can be made according to actual needs.

[0063] Specifically, if the first level output by the hysteresis comparator module 100 is high, when the voltage Ugs between the gate g5 and source s5 of the fifth MOSFET Q5 reaches the turn-on voltage of the fifth MOSFET Q5, the fifth MOSFET Q5 turns on. Since the source s5 of the fifth MOSFET Q5 is grounded, the third level output by the fifth MOSFET Q5 is basically consistent with the ground terminal voltage. After inputting the turn-off signal control terminal SHDN of the second control module 500, the second control module 500 is controlled to turn off.

[0064] Correspondingly, if the second level output by the hysteresis comparator module 100 is low, and the voltage Ugs between the gate g5 and source s5 of the fifth MOSFET Q5 does not reach the turn-on voltage of the fifth MOSFET Q5, the fifth MOSFET Q5 is turned off. The voltage of the secondary battery 12 is divided by the seventh resistor R7 and outputs a high-level fourth-level signal. After being input to the turn-off signal control terminal SHDN of the second control module 500, the second control module 500 is controlled to work.

[0065] Based on the same inventive concept, embodiments of the present invention also provide a dual-battery power supply system. This system includes a main battery, a secondary battery, electrical devices, and a dual-battery hardware switching circuit according to any embodiment of the present invention. It has the same beneficial effects as the aforementioned dual-battery hardware switching circuit, and will not be repeated here. The dual-battery power supply system can be used in automobiles, and the electrical devices include, but are not limited to, audio equipment, air conditioning equipment, and lighting equipment. In other embodiments, the dual-battery power supply system can be used in other situations requiring dual-battery power supply; the specific implementation can be designed according to actual conditions.

[0066] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A dual-battery hardware switching circuit, characterized in that, The dual-battery hardware switching circuit, used to control the main battery or auxiliary battery to supply power to electrical equipment, includes a hysteresis comparison module, a first switch module, a first control module, a second switch module, a second control module, and a level inversion module. The first input terminal of the hysteresis comparator module and the first terminal of the first switch module are both electrically connected to the positive terminal of the main battery. The second input terminal of the hysteresis comparator module and the first terminal of the second switch module are both electrically connected to the positive terminal of the auxiliary battery. The shutdown signal control terminal of the first control module and the control terminal of the level inversion module are both electrically connected to the output terminal of the hysteresis comparator module. The output terminal of the level inversion module is electrically connected to the shutdown signal control terminal of the second control module. The control terminal of the first switch module is electrically connected to the output terminal of the first control module. The control terminal of the second switch module is electrically connected to the output terminal of the second control module. The second terminals of the first switch module and the second terminals of the second switch module are both electrically connected to the electrical equipment. When the voltage of the main battery is greater than or equal to the voltage of the auxiliary battery, the first level output by the hysteresis comparison module controls the first control module to work, the first control module controls the first switch module to turn on, the second level output by the level inversion module controls the second control module to work, the second control module controls the second switch module to turn off, and the main battery independently supplies power to the electrical equipment. When the voltage of the main battery is less than the voltage of the secondary battery and the voltage difference exceeds a preset value, the third level output by the hysteresis comparison module controls the first control module to work, the first control module controls the first switch module to turn off, the fourth level output by the level inversion module controls the second control module to work, the second control module controls the second switch module to turn on, and the secondary battery independently supplies power to the electrical equipment. The hysteresis comparison module includes an operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor; The first end of the first resistor is electrically connected to the positive terminal of the main battery, the second end of the first resistor is electrically connected to the first end of the second resistor, the second end of the second resistor is grounded, and the non-inverting input terminal of the operational amplifier is electrically connected to the second end of the first resistor. The first end of the third resistor is electrically connected to the positive terminal of the auxiliary battery, the second end of the third resistor is electrically connected to the first end of the fourth resistor, the second end of the fourth resistor is grounded, and the inverting input terminal of the operational amplifier is electrically connected to the second end of the third resistor. The first end of the fifth resistor is electrically connected to the second end of the first resistor, and the second end of the fifth resistor is electrically connected to the output end of the operational amplifier. The output terminal of the operational amplifier is directly electrically connected to the shutdown signal control terminal of the first control module, and the output terminal of the operational amplifier is electrically connected to the shutdown signal control terminal of the second control module through the level inversion module.

2. The dual-battery hardware switching circuit according to claim 1, characterized in that, When the voltage of the main battery recovers from being lower than the voltage of the secondary battery and the voltage difference exceeding a preset value to being higher than the voltage of the secondary battery, the hysteresis comparison module outputs the first level, restoring the main battery to independently power the electrical device.

3. The dual-battery hardware switching circuit according to claim 1, characterized in that, The first resistor and the third resistor have the same resistance value, and the second resistor has a greater resistance value than the fourth resistor.

4. The dual-battery hardware switching circuit according to claim 1, characterized in that, Both the first control module and the second control module include the MAX16141 chip.

5. The dual-battery hardware switching circuit according to claim 4, characterized in that, The first switching module includes a first MOSFET and a second MOSFET. The drain of the first MOSFET is electrically connected to the positive terminal of the main battery. The gate of the first MOSFET is electrically connected to the output terminal of the first control module. The source of the first MOSFET is electrically connected to the source of the second MOSFET. The gate of the second MOSFET is electrically connected to the output terminal of the first control module. The drain of the second MOSFET is electrically connected to the electrical device. The source of the second MOSFET is also electrically connected to the overcurrent detection output terminal of the first control module. The second switching module includes a third MOSFET and a fourth MOSFET. The drain of the third MOSFET is electrically connected to the positive terminal of the secondary battery, the gate of the third MOSFET is electrically connected to the output terminal of the second control module, the source of the third MOSFET is electrically connected to the source of the fourth MOSFET, the gate of the fourth MOSFET is electrically connected to the output terminal of the second control module, the drain of the fourth MOSFET is electrically connected to the electrical device, and the source of the fourth MOSFET is also electrically connected to the overcurrent detection output terminal of the second control module.

6. The dual-battery hardware switching circuit according to claim 4, characterized in that, It also includes a sixth resistor, the first end of which is electrically connected to the positive terminal of the main battery, and the second end of which is electrically connected to the shutdown signal control terminal of the first control module.

7. The dual-battery hardware switching circuit according to claim 1, characterized in that, The level inversion module includes a fifth MOSFET and a seventh resistor; The first end of the seventh resistor is electrically connected to the positive terminal of the auxiliary battery, the second end of the seventh resistor is electrically connected to the drain of the fifth MOS transistor, the gate of the fifth MOS transistor is electrically connected to the output terminal of the hysteresis comparator module, the source of the fifth MOS transistor is grounded, and the drain of the fifth MOS transistor is also electrically connected to the turn-off signal control terminal of the second control module.

8. The dual-battery hardware switching circuit according to claim 1, characterized in that, The first level is equal to the fourth level, and the second level is equal to the third level.

9. A dual-battery power supply system, characterized in that, It includes a main battery, a secondary battery, electrical equipment, and a dual-battery hardware switching circuit as described in any one of claims 1 to 8.

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