Copper bar temperature sensing coulomb acquisition and switch control circuit of low-voltage motor home system

Abstract

The invention discloses a copper bar temperature sensing coulomb acquisition and switch control circuit of a low-voltage motor home system, which comprises a main control unit, a temperature sensor, a Hall current sensor, a contactor driving unit and a contactor, and is characterized in that the temperature sensor is used for acquiring the copper bar temperature of the low-voltage motor home system and transmitting the copper bar temperature to the main control unit in the form of an electric signal; the Hall current sensor is used for collecting copper bar current of the low-voltage motor home system and transmitting the copper bar current to the main control unit; the main control unit is used for judging the copper bar temperature collected by the temperature sensor and the copper bar current collected by the Hall current sensor, and if the copper bar temperature exceeds a set temperature value or the copper bar current exceeds a set current value, a disconnection instruction is sent to the contactor driving unit; the contactor driving unit is used for driving the switch end of the contactor to be disconnected according to the disconnection instruction. The device has multiple repeated overcurrent and over-temperature protection functions, and can realize automatic on-off control of the copper bar.

Description

Technical Field

[0001] The invention relates to a low-voltage RV system, in particular to a copper bar temperature sensing Coulomb acquisition and switch control circuit of the low-voltage RV system. Background Art

[0002] In traditional low-voltage RV systems, fuses are often used for overcurrent protection, and shunt resistors are used as coulomb meters to detect current. When used at high power, excessive current often causes excessive temperature rise. However, in actual applications, there is a lack of temperature detection, current detection, and temperature detection of the copper busbar and the terminal head. When the copper busbar is overcurrent or overtemperature and needs circuit breaker protection, it cannot be promptly alarmed and protected, which causes the fault to expand and even cause major disasters such as fire. Summary of the invention

[0003] The technical problem to be solved by the present invention is that, in view of the deficiencies in the prior art, a copper busbar temperature sensing Coulomb acquisition and switch control circuit for a low-voltage RV system is provided, which has multiple repeated over-current and over-temperature protection functions and can realize automatic on-off control of the copper busbar.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions.

[0005] A copper busbar temperature sensing coulomb acquisition and switch control circuit for a low-voltage RV system, comprising a main control unit, a temperature sensor, a Hall current sensor, a contactor drive unit and a contactor, wherein the temperature sensor, the Hall current sensor and the contactor drive unit are respectively connected to the main control unit, the output end of the contactor drive unit is connected to the control end of the contactor, the sensing end of the temperature sensor is in contact with the copper busbar of the low-voltage RV system and the two are insulated, the sensing end of the Hall current sensor is sleeved outside the copper busbar of the low-voltage RV system, and the switch end of the contactor is connected in series with the low-voltage RV system. The copper busbar of the system, wherein: the temperature sensor is used to collect the temperature of the copper busbar of the low-voltage RV system and transmit it to the main control unit in the form of an electrical signal; the Hall current sensor is used to collect the current of the copper busbar of the low-voltage RV system and transmit it to the main control unit; the main control unit is used to judge the copper busbar temperature collected by the temperature sensor and the copper busbar current collected by the Hall current sensor, and if the copper busbar temperature exceeds a set temperature value or the copper busbar current exceeds a set current value, a disconnection instruction is sent to the contactor drive unit; the contactor drive unit is used to drive the switch end of the contactor to disconnect according to the disconnection instruction.

[0006] Preferably, it comprises a voltage sampling unit connected to the main control unit, and the voltage sampling unit is used to collect the battery voltage of the low-voltage RV system and transmit it to the main control unit.

[0007] Preferably, it comprises an alarm unit connected to the main control unit, and the alarm unit issues an alarm prompt according to the alarm instruction output by the main control unit.

[0008] Preferably, it comprises a display unit and a communication interface connected to the main control unit.

[0009] Preferably, the main control unit includes an MCU controller U1 and peripheral circuits.

[0010] Preferably, a resistor R19 and a capacitor C14 are included, the temperature sensor includes a thermistor R18, the thermistor R18 and the resistor R19 are connected in series in sequence and connected between a 3.3V power supply terminal and ground, the capacitor C14 is connected in parallel with the resistor R19, and the connection point between the thermistor R18 and the resistor R19 is connected to the MCU controller U1.

[0011] Preferably, it includes a current interface CN3, a voltage follower U33 and an operational amplifier U34, the current interface CN3 is connected to a branch of the Hall current sensor and is connected to the in-phase end of the voltage follower U33, the inverting end and the output end of the voltage follower U33 are short-circuited, the output end of the voltage follower U33 is connected to the inverting end of the operational amplifier U34 through resistors R12 and R13 connected in series in sequence, and the output end of the operational amplifier U34 is connected to the MCU controller U1 through a resistor R7.

[0012] Preferably, the inverting terminal and the output terminal of the operational amplifier U34 are connected via a resistor R14 and a resistor R57 which are connected in series in sequence.

[0013] Preferably, a resistor R22, a resistor R54 and a resistor R55 are included, and the resistor R22, the resistor R54 and the resistor R55 are connected in series in sequence and connected between the 5V voltage terminal and the ground, and the connection point between the resistor R22 and the resistor R54 is connected to the in-phase terminal of the operational amplifier U34.

[0014] Preferably, the contactor drive unit includes an NPN tube Q2 and a diode D1, the base of the NPN tube Q2 is connected to the MCU controller U1 through a resistor R16, the emitter of the NPN tube Q2 is grounded, the collector of the NPN tube Q2 is connected to one end of the contactor coil, the other end of the contactor coil is connected to a 12V voltage terminal, the cathode of the diode D1 is connected to the 12V voltage terminal, and the anode of the diode D1 is connected to the collector of the NPN tube Q2.

[0015] The copper bar temperature sensing coulomb acquisition and switch control circuit of the low-voltage RV system disclosed in the present invention, during operation, the temperature sensor is used to collect the copper bar temperature of the low-voltage RV system, and the temperature data is transmitted to the main control unit in the form of an electrical signal. At the same time, the Hall current sensor collects the copper bar current of the low-voltage RV system and transmits it to the main control unit, and the voltage sampling unit is used to collect the battery voltage of the low-voltage RV system and transmit it to the main control unit. In the comparison and judgment process, the main control unit judges the copper bar temperature collected by the temperature sensor, the copper bar current collected by the Hall current sensor, and the battery voltage collected by the voltage sampling unit according to the set various thresholds. If the copper bar temperature exceeds the set temperature value or the copper bar current exceeds the set current value, the main control unit sends a disconnection instruction to the contactor drive unit, and uses the contactor drive unit to drive the switch end of the contactor to disconnect. When the battery is overcharged or over-discharged, an alarm prompt can be issued accordingly. Compared with the prior art, the present invention has repeated over-current and over-temperature protection functions, and can realize automatic on-off control of the copper bar. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a block diagram of the copper bar temperature sensing coulomb acquisition and switch control circuit of the low-voltage RV system of the present invention;

[0017] Figure 2 This is the schematic diagram of the main control unit;

[0018] Figure 3 This is the schematic diagram of the temperature acquisition unit;

[0019] Figure 4 is the schematic diagram of the current acquisition unit;

[0020] Figure 5 This is the schematic diagram of the contactor drive unit;

[0021] Figure 6 This is a flow chart of the copper bar temperature sensing Coulomb acquisition and switch control method of the low-voltage RV system of the present invention. DETAILED DESCRIPTION

[0022] The present invention is described in more detail below with reference to the accompanying drawings and embodiments.

[0023] The present invention discloses a copper bar temperature sensing coulomb acquisition and switch control circuit for a low voltage RV system, see Figure 1, which includes a main control unit 1, a temperature sensor 2, a Hall current sensor 3, a contactor drive unit 4 and a contactor 5, wherein the temperature sensor 2, the Hall current sensor 3 and the contactor drive unit 4 are respectively connected to the main control unit 1, the output end of the contactor drive unit 4 is connected to the control end of the contactor 5, the sensing end of the temperature sensor 2 is in contact with the copper busbar of the low-voltage RV system and the two are insulated, the sensing end of the Hall current sensor 3 is sleeved outside the copper busbar of the low-voltage RV system, and the switch end of the contactor 5 is connected in series to the copper busbar of the low-voltage RV system, wherein:

[0024] The temperature sensor 2 is used to collect the temperature of the copper bar of the low-voltage RV system and transmit it to the main control unit 1 in the form of an electrical signal;

[0025] The Hall current sensor 3 is used to collect the copper bus current of the low-voltage RV system and transmit it to the main control unit 1;

[0026] The main control unit 1 is used to judge the copper bar temperature collected by the temperature sensor 2 and the copper bar current collected by the Hall current sensor 3, and if the copper bar temperature exceeds the set temperature value or the copper bar current exceeds the set current value, a disconnection instruction is sent to the contactor drive unit 4;

[0027] The contactor driving unit 4 is used to drive the switch end of the contactor 5 to disconnect according to the disconnection instruction.

[0028] Furthermore, it also includes a voltage sampling unit 6 connected to the main control unit 1 , and the voltage sampling unit 6 is used to collect the battery voltage of the low-voltage RV system and transmit it to the main control unit 1 .

[0029] During the operation of the above circuit, please refer to Figure 1 and Figure 6, the temperature sensor 2 is used to collect the copper bar temperature of the low-voltage RV system, and the temperature data is transmitted to the main control unit 1 in the form of an electrical signal. At the same time, the Hall current sensor 3 collects the copper bar current of the low-voltage RV system and transmits it to the main control unit 1. The voltage sampling unit 6 collects the battery voltage of the low-voltage RV system and transmits it to the main control unit 1. In the comparison and judgment process, the main control unit 1 judges the copper bar temperature collected by the temperature sensor 2, the copper bar current collected by the Hall current sensor 3, and the battery voltage collected by the voltage sampling unit 6 according to the set various thresholds. If the copper bar temperature exceeds the set temperature value or the copper bar current exceeds the set current value, the main control unit 1 sends a disconnection instruction to the contactor drive unit 4, and the contactor drive unit 4 drives the switch end of the contactor 5 to disconnect. When the battery is overcharged or over-discharged, an alarm prompt can be issued accordingly. Compared with the prior art, the present invention has repeated over-current and over-temperature protection functions, which can realize automatic on-off control of the copper bar.

[0030] To facilitate the issuance of alarm prompts, please refer to Figure 1 This embodiment includes an alarm unit 7 connected to the main control unit 1, and the alarm unit 7 issues an alarm prompt according to the alarm instruction output by the main control unit 1. The alarm unit 7 can be a sound alarm unit or a sound and light combined alarm unit.

[0031] Furthermore, this embodiment includes a display unit 8 and a communication interface 9 connected to the main control unit 1. The display unit 8 and the communication interface 9 are provided to facilitate the realization of human-computer interaction and communication functions.

[0032] As a preferred method, see Figure 2 The main control unit 1 includes an MCU controller U1 and peripheral circuits. The MCU controller U1 is preferably a CH32V203C8T6 single chip microcomputer.

[0033] In this embodiment, see Figure 3 , the temperature acquisition unit includes a resistor R19 and a capacitor C14, the temperature sensor 2 includes a thermistor R18, the thermistor R18 and the resistor R19 are connected in series and connected between the 3.3V power supply terminal and the ground, the capacitor C14 is connected in parallel with the resistor R19, and the connection point between the thermistor R18 and the resistor R19 is connected to the MCU controller U1. The thermistor R18 is affected by the temperature of the copper bar and the resistance value changes. The MCU controller U1 calculates the temperature of the copper bar by calculating the resistance change of the thermistor R18. When the temperature of the copper bar exceeds the set temperature value, the alarm unit 7 can issue a corresponding alarm prompt, and the switch end of the contactor 5 can also be controlled to be disconnected.

[0034] See also Figure 4 In this embodiment, the current acquisition unit includes a current interface CN3, a voltage follower U33 and an operational amplifier U34. The current interface CN3 is connected to a branch of the Hall current sensor 3 and is connected to the in-phase end of the voltage follower U33. The inverting end and the output end of the voltage follower U33 are short-circuited. The output end of the voltage follower U33 is connected to the inverting end of the operational amplifier U34 through resistors R12 and R13 connected in series in sequence. The output end of the operational amplifier U34 is connected to the MCU controller U1 through a resistor R7. Among them, the inverting end and the output end of the voltage follower U33 are short-circuited, so that it has a voltage following effect, which can improve the stability of signal acquisition.

[0035] The operational amplifier U34 in this embodiment adopts an inverting proportional operational amplifier connection mode. Figure 4 The inverting terminal and the output terminal of the operational amplifier U34 are connected via a resistor R14 and a resistor R57 connected in series. Further, a resistor R22, a resistor R54 and a resistor R55 are included, and the resistor R22, the resistor R54 and the resistor R55 are connected in series in series and connected between the 5V voltage terminal and the ground, and the connection point between the resistor R22 and the resistor R54 is connected to the non-inverting terminal of the operational amplifier U34.

[0036] For the specific circuit principle of the contactor drive unit 4, please refer to Figure 5 , the contactor drive unit 4 includes an NPN tube Q2 and a diode D1, the base of the NPN tube Q2 is connected to the MCU controller U1 through a resistor R16, the emitter of the NPN tube Q2 is grounded, the collector of the NPN tube Q2 is connected to one end of the coil of the contactor 5, the other end of the coil of the contactor 5 is connected to the 12V voltage terminal, the cathode of the diode D1 is connected to the 12V voltage terminal, and the anode of the diode D1 is connected to the collector of the NPN tube Q2. Wherein, under normal working conditions, the MCU controller U1 controls the NPN tube Q2 to conduct at a high level so that the coil of the contactor 5 is powered on. When the temperature and current of the copper bar are abnormal and exceed the set value, the MCU controller U1 controls the NPN tube Q2 to disconnect at a low level, the coil of the contactor 5 is powered off and its switch end is disconnected, and the diode D1 plays a reverse cutoff role to prevent current backflow.

[0037] See also Figure 1 In addition to the above-mentioned function of automatically controlling the copper busbar disconnection, the present embodiment can also use the button 10 to manually send instructions to the MCU controller U1, and then the MCU controller U1 controls the on-off state of the contactor 5.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the technical scope of the present invention should be included in the scope of protection of the present invention.

Claims

1. A copper bar temperature sensing Coulomb acquisition and switch control circuit for a low-voltage RV system, characterized in that: The invention comprises a main control unit (1), a temperature sensor (2), a Hall current sensor (3), a contactor drive unit (4) and a contactor (5), wherein the temperature sensor (2), the Hall current sensor (3) and the contactor drive unit (4) are respectively connected to the main control unit (1), the output end of the contactor drive unit (4) is connected to the control end of the contactor (5), the sensing end of the temperature sensor (2) is in contact with the copper busbar of the low-voltage RV system and the two are insulated, the sensing end of the Hall current sensor (3) is sleeved outside the copper busbar of the low-voltage RV system, and the switch end of the contactor (5) is connected in series to the copper busbar of the low-voltage RV system, wherein: The temperature sensor (2) is used to collect the temperature of the copper bar of the low-voltage RV system and transmit it to the main control unit (1) in the form of an electrical signal; The Hall current sensor (3) is used to collect the copper bus current of the low-voltage RV system and transmit it to the main control unit (1); The main control unit (1) is used to judge the copper busbar temperature collected by the temperature sensor (2) and the copper busbar current collected by the Hall current sensor (3), and if the copper busbar temperature exceeds a set temperature value or the copper busbar current exceeds a set current value, a disconnection instruction is sent to the contactor drive unit (4); The contactor drive unit (4) is used to drive the switch end of the contactor (5) to disconnect according to the disconnection instruction.

2. The copper bar temperature sensing Coulomb acquisition and switch control circuit of the low-voltage RV system as claimed in claim 1, characterized in that: It comprises a voltage sampling unit (6) connected to the main control unit (1), and the voltage sampling unit (6) is used to collect the battery voltage of the low-voltage RV system and transmit it to the main control unit (1).

3. The copper bar temperature sensing Coulomb acquisition and switch control circuit of the low-voltage RV system as claimed in claim 1, characterized in that: It comprises an alarm unit (7) connected to the main control unit (1), and the alarm unit (7) issues an alarm prompt according to the alarm instruction output by the main control unit (1).

4. The copper bar temperature sensing Coulomb acquisition and switch control circuit of the low-voltage RV system as claimed in claim 1, characterized in that: It comprises a display unit (8) and a communication interface (9) connected to the main control unit (1).

5. The copper bar temperature sensing Coulomb acquisition and switch control circuit of the low-voltage RV system as claimed in claim 1, characterized in that: The main control unit (1) comprises an MCU controller U1 and peripheral circuits.

6. The copper bar temperature sensing Coulomb acquisition and switch control circuit of the low-voltage RV system as claimed in claim 5, characterized in that: The temperature sensor (2) comprises a resistor R19 and a capacitor C14, wherein the thermistor R18 and the resistor R19 are connected in series and connected between a 3.3V power supply terminal and ground, the capacitor C14 is connected in parallel with the resistor R19, and the connection point between the thermistor R18 and the resistor R19 is connected to the MCU controller U1.

7. The copper bar temperature sensing Coulomb acquisition and switch control circuit of the low-voltage RV system as claimed in claim 5, characterized in that: It comprises a current interface CN3, a voltage follower U33 and an operational amplifier U34, wherein the current interface CN3 is connected to a branch of the Hall current sensor (3) and is connected to the in-phase end of the voltage follower U33, the inverting end and the output end of the voltage follower U33 are short-circuited, the output end of the voltage follower U33 is connected to the inverting end of the operational amplifier U34 via resistors R12 and R13 which are connected in series in sequence, and the output end of the operational amplifier U34 is connected to the MCU controller U1 via a resistor R7.

8. The copper bar temperature sensing Coulomb acquisition and switch control circuit of the low-voltage RV system as claimed in claim 7, characterized in that: The inverting terminal and the output terminal of the operational amplifier U34 are connected via a resistor R14 and a resistor R57 which are connected in series in sequence.

9. The copper bar temperature sensing Coulomb acquisition and switch control circuit of the low-voltage RV system as claimed in claim 8, characterized in that: It includes a resistor R22, a resistor R54 and a resistor R55, which are connected in series in sequence and connected between a 5V voltage terminal and ground, and a connection point between the resistor R22 and the resistor R54 is connected to the in-phase terminal of the operational amplifier U34.

10. The copper bar temperature sensing Coulomb acquisition and switch control circuit of the low-voltage RV system as claimed in claim 5, characterized in that: The contactor drive unit (4) comprises an NPN tube Q2 and a diode D1, the base of the NPN tube Q2 is connected to the MCU controller U1 via a resistor R16, the emitter of the NPN tube Q2 is grounded, the collector of the NPN tube Q2 is connected to one end of the contactor (5) coil, the other end of the contactor (5) coil is connected to a 12V voltage terminal, the cathode of the diode D1 is connected to the 12V voltage terminal, and the anode of the diode D1 is connected to the collector of the NPN tube Q2.

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