Boost type motor home battery dual-power isolation switch circuit

Abstract

The utility model discloses a boost type motor home battery dual power supply isolation switch circuit, comprising an automobile generator, a DC-DC converter, a relay, a main battery, an auxiliary battery, a vibration sensor and a main control unit, the main battery, the input end of the DC-DC converter and the front switch end of the relay are connected with the output end of the automobile generator; the output end of the DC-DC converter and the rear switch end of the relay are both connected to the auxiliary battery, the vibration sensor is used for collecting the vibration state of the motor home and transmitting the vibration state to the main control unit in an electric signal mode, and a relay driving circuit is connected between a coil of the relay and the main control unit. And the main control unit is used for controlling the relay to be closed through the relay driving circuit when the main battery output voltage acquired by the main battery voltage sampling circuit is reduced and the motor home vibration state signal acquired by the vibration sensor is received. The charging state of the auxiliary battery can be automatically controlled, the motor home engine can be assisted to start, and the service life of the battery can be prolonged.

Description

Technical Field

[0001] The utility model relates to a RV battery switching control circuit, in particular to a boost type RV battery dual power supply isolation switch circuit. Background Art

[0002] At present, both all-in-one RVs and trailer RVs generally use batteries for energy storage. The stored energy in the batteries can be used for daily use in the RV. In terms of circuits, the battery needs to be isolated from the driving battery to achieve isolation between the daily use of the RV and the driving power of the RV, ensuring that the starting and travel of the RV are not affected. For this reason, existing RVs generally use a dual-battery system. In order to achieve power exchange between the driving battery and the daily use battery in certain specific environments, the driving battery (main battery) and the daily use battery (secondary battery) can be connected through a switch. When the car generator is needed to generate electricity to charge the daily use battery; or when the driving battery is low and cannot start the car, the connection switch is manually controlled to connect the main and secondary batteries, playing a parallel role; at the same time, the car generator can charge the daily use battery, or use the daily use battery to provide starting assistance for the driving battery.

[0003] However, the existing RV battery system has some obvious defects: first, when the car generator is charging the living battery, it cannot automatically disconnect the living battery connection, which can easily cause the driving battery to run out of power and affect the starting of the car; secondly, as the living electricity consumption of RVs increases, the capacity density of lithium-ion capacitors increases, and more and more RVs use lithium-ion batteries as living batteries. Under such coordination, the charging and discharging curves of the lithium battery living battery and the lead-acid battery of the driving battery are inconsistent, the internal resistance of the battery is inconsistent, and the cut-off voltage is inconsistent. The original switch direct connection mode cannot meet the application requirements. Utility Model Content

[0004] The technical problem to be solved by the present invention is to provide a boost-type RV battery dual power isolation switch circuit that can automatically control the charging state of the auxiliary battery, assist in starting the RV engine and extend the battery life in response to the shortcomings of the existing technology.

[0005] In order to solve the above technical problems, the present utility model adopts the following technical solutions.

[0006] A boost-type RV battery dual power isolation switch circuit includes an automobile generator, a DC-DC converter, a relay, a main battery, a secondary battery, a vibration sensor, and a main control unit. The main battery, the input end of the DC-DC converter, and the front switch end of the relay are all connected to the output end of the automobile generator. The output end of the DC-DC converter and the rear switch end of the relay are both connected to the secondary battery. A main battery voltage sampling circuit is connected between the main battery and the main control unit. The main battery voltage sampling circuit is used to collect the output voltage of the main battery and transmit it to the main control unit. A secondary battery voltage sampling circuit is connected between the secondary battery and the main control unit. The secondary battery voltage sampling circuit is used to collect the output voltage of the secondary battery and transmit it to the main control unit. The vibration sensor is used to collect the vibration status of the RV and transmit it to the main control unit in the form of an electrical signal. A relay drive circuit is connected between the coil of the relay and the main control unit. The main control unit is used to control the relay to close via the relay drive circuit when the main battery output voltage collected by the main battery voltage sampling circuit drops and the main control unit receives the RV vibration status signal collected by the vibration sensor.

[0007] Preferably, a charger drive circuit is connected between the DC-DC converter and the main control unit.

[0008] Preferably, a Hall current sensor is provided on the line between the output end of the DC-DC converter and the secondary battery, and the current signal collected by the Hall current sensor is transmitted to the main control unit.

[0009] Preferably, it includes a generator voltage sampling circuit connected between the automobile generator and the main control unit, and the generator voltage sampling circuit is used to collect the output voltage of the automobile generator and transmit it to the main control unit.

[0010] Preferably, the main control unit is also connected to a communication interface, a display unit and an alarm unit.

[0011] Preferably, the DC-DC converter includes a Boost circuit.

[0012] Preferably, the main control unit includes an MCU controller and peripheral circuits.

[0013] In the boost-type RV battery dual-power isolation switch circuit disclosed by the utility model, the DC-DC converter is connected between the main battery and the secondary battery, and the main control unit is used to control the boost state of the DC-DC converter to control the main battery to charge the secondary battery. At the same time, the switch end of the relay is connected between the main battery and the secondary battery, and the relay and the DC-DC converter are in a parallel relationship. The main control unit controls the switch state of the relay through the relay drive circuit, thereby realizing the use of the automobile generator to directly charge the secondary battery, or controlling the secondary battery to provide auxiliary power to the main battery based on a vibration state signal when the car is started, thereby assisting the RV engine starting, helping to reduce the discharge depth of the main battery, and effectively extending the battery life. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the circuit diagram of the boost type RV battery dual power supply isolation switch;

[0015] Figure 2 This is the circuit schematic diagram of the DC-DC converter;

[0016] Figure 3 This is the circuit schematic diagram of the main control unit;

[0017] Figure 4 This is a control flow chart of the dual power isolation switch circuit in the preferred embodiment of the present utility model. DETAILED DESCRIPTION

[0018] The present invention will be described in more detail below with reference to the accompanying drawings and embodiments.

[0019] This utility model discloses a boost type RV battery dual power supply isolation switch circuit, see Figure 1, which includes an automobile generator 1, a DC-DC converter 2, a relay 3, a main battery 4, a secondary battery 5, a vibration sensor 6 and a main control unit 7, wherein the main battery 4 is a driving battery, the secondary battery 5 is a life battery, the main battery 4, the input end of the DC-DC converter 2 and the front switch end of the relay 3 are all connected to the output end of the automobile generator 1, the output end of the DC-DC converter 2 and the rear switch end of the relay 3 are all connected to the secondary battery 5, a main battery voltage sampling circuit 8 is connected between the main battery 4 and the main control unit 7, the main battery voltage sampling circuit 8 is used to collect the output voltage of the main battery 4 and transmit it to the The main control unit 7, a secondary battery voltage sampling circuit 9 is connected between the secondary battery 5 and the main control unit 7, the secondary battery voltage sampling circuit 9 is used to collect the output voltage of the secondary battery 5 and transmit it to the main control unit 7, the vibration sensor 6 is used to collect the vibration state of the RV and transmit it to the main control unit 7 in the form of an electrical signal, and a relay drive circuit 10 is connected between the coil of the relay 3 and the main control unit 7, the main control unit 7 is used to control the relay 3 to close through the relay drive circuit 10 when the output voltage of the main battery 4 collected by the main battery voltage sampling circuit 8 drops and the RV vibration state signal collected by the vibration sensor 6 is received.

[0020] In the above circuit, the DC-DC converter 2 is connected between the main battery 4 and the secondary battery 5. The main control unit 7 is used to control the boost state of the DC-DC converter 2 to control the main battery 4 to charge the secondary battery 5. At the same time, the switch end of the relay 3 is connected between the main battery 4 and the secondary battery 5. The relay 3 and the DC-DC converter 2 are in parallel. The main control unit 7 controls the switch state of the relay 3 through the relay drive circuit 10, thereby realizing the use of the automobile generator 1 to directly charge the secondary battery 5, or controlling the secondary battery 5 to provide auxiliary power to the main battery 4 based on the vibration state signal when the car is started, thereby assisting the RV engine to start, helping to reduce the discharge depth of the main battery, and effectively extending the battery life.

[0021] As a preferred embodiment, a charger drive circuit 11 is connected between the DC-DC converter 2 and the main control unit 7. The main control unit 7 can drive and control the charger drive circuit 11 via a PWM signal. Furthermore, the provision of the charger drive circuit 11 in this embodiment can effectively improve the drive capability of the DC-DC converter 2, thereby helping the DC-DC converter 2 to stably and reliably perform boost conversion.

[0022] Furthermore, the DC-DC converter 2 includes a Boost circuit.

[0023] This embodiment also has a power supply loop current acquisition circuit, see Figure 1 and Figure 2 A Hall current sensor 12 is provided on the line between the output end of the DC-DC converter 2 and the secondary battery 5 , and the current signal collected by the Hall current sensor 12 is transmitted to the main control unit 7 .

[0024] As a preferred embodiment, a generator voltage sampling circuit 13 is included which is connected between the automobile generator 1 and the main control unit 7 . The generator voltage sampling circuit 13 is used to collect the output voltage of the automobile generator 1 and transmit it to the main control unit 7 .

[0025] In the above circuit, see Figure 4 When the RV's secondary battery voltage is low, the relay connects, allowing the generator to directly charge the utility battery. Once the driving battery is fully charged, the MCU automatically disconnects the relay. Because lithium-ion batteries have a high cutoff voltage, the DC-DC boost circuit is activated after the relay is disconnected to continue charging the secondary battery.

[0026] In actual applications, according to the characteristics of lithium-ion batteries, when the driving battery is fully charged, the lithium-ion secondary battery is charged to 85% of its capacity. For the remaining 15% of the battery capacity, the required charging power is relatively low. At the same time, at the end of the battery charging voltage, the charging current requirement is even smaller. Therefore, the DC-DC boost power does not need to be designed at full power to match the capacity of the lithium-ion household battery. At the same time, because the DC-DC only has a boost mode, the circuit design and control are relatively simple, and the cost is also low.

[0027] As a preferred method, this embodiment has a built-in vibration sensor. When it detects that the driving battery voltage drops rapidly and the engine vibration occurs simultaneously, it quickly closes the relay to connect the driving battery and the life battery, thereby helping to start the RV engine. At the same time, it can slow down the discharge depth of the starting battery and extend the battery life.

[0028] In addition, when the RV's secondary battery is more than 2V lower than the main battery, the DC-DC boost mode is started first to ensure the impact current of the parallel batteries, reduce the impact on the generator and main battery, and also extend the battery life.

[0029] As an extended function, in this embodiment, see Figure 1 and Figure 3 The main control unit 7 is also connected to a communication interface 14, a display unit 15 and an alarm unit 16. Specifically, the main control unit 7 includes an MCU controller and peripheral circuits.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements 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 boost type RV battery dual power supply isolation switch circuit, characterized in that: The invention comprises an automobile generator (1), a DC-DC converter (2), a relay (3), a main battery (4), a secondary battery (5), a vibration sensor (6) and a main control unit (7), wherein the main battery (4), the input end of the DC-DC converter (2) and the front switch end of the relay (3) are all connected to the output end of the automobile generator (1), the output end of the DC-DC converter (2) and the rear switch end of the relay (3) are all connected to the secondary battery (5), a main battery voltage sampling circuit (8) is connected between the main battery (4) and the main control unit (7), and the main battery voltage sampling circuit (8) is used to collect the output voltage of the main battery (4) and transmit it to the main control unit (7), and the secondary battery ( A secondary battery voltage sampling circuit (9) is connected between the secondary battery (5) and the main control unit (7), the secondary battery voltage sampling circuit (9) is used to collect the output voltage of the secondary battery (5) and transmit it to the main control unit (7), the vibration sensor (6) is used to collect the vibration state of the RV and transmit it to the main control unit (7) in the form of an electrical signal, and a relay driving circuit (10) is connected between the coil of the relay (3) and the main control unit (7), the main control unit (7) is used to control the relay (3) to close through the relay driving circuit (10) when the output voltage of the main battery (4) collected by the main battery voltage sampling circuit (8) drops and the RV vibration state signal collected by the vibration sensor (6) is received.

2. The boost type RV battery dual power supply isolation switch circuit according to claim 1, characterized in that: A charger drive circuit (11) is connected between the DC-DC converter (2) and the main control unit (7).

3. The boost type RV battery dual power supply isolation switch circuit according to claim 1, characterized in that: A Hall current sensor (12) is provided on the line between the output end of the DC-DC converter (2) and the auxiliary battery (5), and the current signal collected by the Hall current sensor (12) is transmitted to the main control unit (7).

4. The boost type RV battery dual power supply isolation switch circuit according to claim 1, characterized in that: The invention comprises a generator voltage sampling circuit (13) connected between the automobile generator (1) and the main control unit (7), wherein the generator voltage sampling circuit (13) is used to collect the output voltage of the automobile generator (1) and transmit it to the main control unit (7).

5. The boost type RV battery dual power supply isolation switch circuit according to claim 1, characterized in that: The main control unit (7) is also connected to a communication interface (14), a display unit (15) and an alarm unit (16).

6. The boost type RV battery dual power supply isolation switch circuit according to claim 1, characterized in that: The DC-DC converter (2) includes a Boost circuit.

7. The boost type RV battery dual power supply isolation switch circuit according to claim 1, characterized in that: The main control unit (7) includes an MCU controller and peripheral circuits.

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