Circuit capable of preventing power supply fluctuation of automobile electronic product

Abstract

The utility model discloses a circuit capable of preventing power supply fluctuation of an automobile electronic product, and belongs to the field of power supply of vehicle-mounted electronic products. The vehicle machine power supply module is used for providing a vehicle machine voltage signal; the automobile storage battery power supply module is used for providing an automobile storage battery voltage signal; the host power supply control module is used for controlling and managing the power supply of the electronic product; and the vehicle machine power supply module and the vehicle storage battery power supply module are connected into the host power supply control module. Compared with the prior art, under the condition that a lithium battery or a super capacitor is not arranged in the electronic product, the voltage signal output by the vehicle-mounted terminal is used as a standby power supply to supply power to the electronic product, and when an automobile storage battery is powered down, the vehicle-mounted terminal can provide stable 5V output voltage through interfaces such as a USB (Universal Serial Bus) and the like; therefore, power supply fluctuation of the automobile electronic product can be avoided.

Description

Technical Field

[0001] This utility model belongs to the field of power supply for automotive electronic products, and specifically relates to a circuit that can prevent power fluctuations in automotive electronic products. Background Technology

[0002] With the increasing intelligence of automobiles, the use of in-vehicle electronic products is becoming more and more common, such as smart car boxes, which usually have functions such as in-vehicle navigation and screen projection. They need to communicate with the car via a USB interface and draw power from the car battery via a power cord.

[0003] Generally, automotive electronic products operate at 5V, while car batteries typically output around 12V. However, in vehicles with automatic start-stop systems and plug-in hybrids, battery degradation occurs after a certain number of years of use. During engine startup or switching between battery-driven and engine-driven operation, battery voltage fluctuates, causing unstable power supply to subsequently installed automotive products. The supply voltage may drop sharply to around 2V, affecting the normal operation of the products.

[0004] As attached Figure 1 By measuring the battery voltage of the Lexus ES hybrid vehicle with an oscilloscope, it was found that at a certain moment, the vehicle's battery voltage dropped to 2V (line 3935), which would affect the power supply of electronic products.

[0005] To address the aforementioned issues, most automotive electronic products currently employ a method of adding a backup lithium battery or supercapacitor within the device to handle fluctuations in car battery power. This method provides continuous power to the device during power fluctuations, but it presents the following main problems:

[0006] 1. Currently, both of these methods incur additional costs and increase the size of the equipment;

[0007] 2. Both methods require a full charge before power can be supplied, which will affect the device's startup time;

[0008] 3. Lithium batteries are unstable in high-temperature environments in summer, and their capacity will continuously decrease as the usage time increases.

[0009] 4. The continuous power supply time and cycle life of supercapacitors are both limited; moreover, the cycle life of supercapacitors is limited. Utility Model Content

[0010] To address the aforementioned issues, the primary objective of this invention is to provide a circuit capable of preventing power fluctuations in automotive electronic products. This circuit allows the vehicle's infotainment system to add a backup power supply via a USB interface to the device, even when the car battery loses power, without requiring a lithium battery or supercapacitor within the electronic product. This ensures a stable power supply voltage for the electronic product, thus preventing power fluctuations.

[0011] To achieve the above objectives, the technical solution of this utility model is as follows:

[0012] This utility model provides a circuit capable of preventing power fluctuations in automotive electronic products, comprising:

[0013] Vehicle power supply module used to provide vehicle system voltage signals;

[0014] Automotive battery power supply module used to provide voltage signals to automotive batteries;

[0015] A host power control module used for controlling and managing the power supply to electronic products;

[0016] The vehicle power supply module and the car battery power supply module are connected to the host power control module.

[0017] Furthermore, the circuit also includes a step-down module, which is located between the car battery power supply module and the host power control module.

[0018] Furthermore, the host power control module includes a power supply signal switching unit and a switch control unit. The vehicle power supply module and the car battery power supply module are connected in parallel and then connected to the switch control unit. The vehicle power supply module, the car battery power supply module, and the switch control unit are all connected to the power supply signal switching unit.

[0019] Furthermore, the power supply signal switching unit includes a MOSFET QE1, whose three pins are respectively connected to the vehicle power supply module, the car battery power supply module, and the switch control unit.

[0020] Furthermore, the host power control module includes a resistor R141, and the switch control unit includes a transistor Q13, a resistor R143, a resistor R16, and a capacitor C89. One end of the resistor R141 is connected to the car battery power supply module, and the other end forms a common terminal with the MOSFET QE1 and is connected to the transistor Q13. The resistors R16 and R143 are connected in series and then in parallel with the capacitor C89 and connected to the transistor Q13. The capacitor C89 and the transistor Q13 form a common terminal and are grounded. The end of the resistor R16 away from the resistor R143 is grounded.

[0021] Furthermore, the host power control module also includes a filter unit and a diode D3. The filter unit includes a resistor R40, a capacitor C174, and a capacitor CE1. The vehicle power supply module, resistor R40, capacitor C174, and capacitor CE1 form a common terminal connected to one end of diode D3, and the other end of diode D3 is connected to MOSFET QE1.

[0022] Furthermore, the host power control module also includes resistors R45, R42, and R17, which are connected in parallel to a common terminal formed by resistors R143 and R16.

[0023] Compared with the prior art, the beneficial effects of this utility model are: without setting up lithium batteries or supercapacitors in electronic products, the voltage signal output by the vehicle's infotainment system is used as a backup power source to power the electronic products. When the car battery loses power, the infotainment system can provide a stable 5V output voltage through interfaces such as USB, thereby avoiding power fluctuations in the car's electronic products. Attached Figure Description

[0024] Figure 1 This is a data table used in the background technology to measure the battery voltage of a Lexus ES hybrid vehicle using an oscilloscope.

[0025] Figure 2 This is the block diagram of this circuit.

[0026] Figure 3 This is the schematic diagram of the vehicle's infotainment system outputting 5V voltage via USB.

[0027] Figure 4 This is the circuit schematic diagram of this circuit. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0029] To achieve the above objectives, the technical solution of this utility model is as follows:

[0030] See Figure 2-4 As shown, this embodiment provides a circuit capable of preventing power fluctuations in automotive electronic products, including:

[0031] Vehicle power supply module used to provide vehicle system voltage signals;

[0032] Automotive battery power supply module used to provide voltage signals to automotive batteries;

[0033] A host power control module used for controlling and managing the power supply to electronic products;

[0034] The vehicle power supply module and the car battery power supply module are connected to the host power control module.

[0035] Furthermore, the circuit also includes a step-down module, which is located between the car battery power supply module and the host power control module.

[0036] In this application, the main unit of the electronic product is connected to the car battery via a power cable and to the vehicle's infotainment system via a USB-TYPE-C data cable. The vehicle's infotainment system can provide 5V backup power through the USB-TYPE-C interface. The car battery can provide a 12V voltage signal, which is stepped down to 5V by a voltage reduction module and then connected in parallel with the 5V voltage signal provided by the vehicle's infotainment system. This output is then processed by the main unit's power control module to power the main unit. This eliminates the need for a lithium battery or supercapacitor within the electronic product. Even if the car battery's power supply is unstable, the vehicle's infotainment system can provide a stable 5V output voltage through the USB interface, thus preventing power fluctuations in the automotive electronic product.

[0037] Furthermore, the host power control module includes a power supply signal switching unit and a switch control unit. The vehicle power supply module and the car battery power supply module are connected in parallel and then connected to the switch control unit. The vehicle power supply module, the car battery power supply module, and the switch control unit are all connected to the power supply signal switching unit.

[0038] Furthermore, the power supply signal switching unit includes a MOSFET QE1, whose three pins are connected to the vehicle power supply module, the car battery power supply module, and the switch control unit, respectively. When the DC-IN signal output by the car battery power supply module fluctuates and drops below 5V, the USB 5V (5V_TYPEC-DECT) can control the MOSFET QE1. After QE1 is turned on, the USB_5V is directly connected to DC_IN, which can continue to supply power to the device, thereby ensuring stable power supply.

[0039] Furthermore, the host power control module includes a resistor R141, and the switch control unit includes a transistor Q13, a resistor R143, a resistor R16, and a capacitor C89. One end of the resistor R141 is connected to the car battery power supply module, and the other end forms a common terminal with the MOSFET QE1 and is connected to the transistor Q13. The resistors R16 and R143 are connected in series and then in parallel with the capacitor C89 and connected to the transistor Q13. The capacitor C89 and the transistor Q13 form a common terminal and are grounded. The end of the resistor R16 furthest from the resistor R143 is grounded. The resistor R141 is a current-limiting resistor, limiting the current of the DC_IN voltage input to the car battery power supply module before supplying power to the electronic products through the switch control unit.

[0040] Furthermore, the host power control module also includes a filtering unit and a diode D3. The filtering unit includes a resistor R40, a capacitor C174, and a capacitor CE1. The vehicle power supply module, resistor R40, capacitor C174, and capacitor CE1 form a common terminal connected to one end of diode D3, and the other end of diode D3 is connected to MOSFET QE1. The combination of resistor R40, capacitor C174, and capacitor CE1 forms the filtering unit, which filters the 5V_TYPEC-DECT signal provided to the vehicle power supply module, and then supplies power to electronic products after passing through the anti-reverse current diode D3.

[0041] Furthermore, the host power control module also includes resistors R45, R42, and R17. Resistors R45, R42, and R17 are connected in parallel to a common terminal formed by resistors R143 and R16. Resistor R45 is the connection resistor for the switch control signal, and R17 and R42 are reserved connection resistors for pre-set signals.

[0042] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A circuit capable of preventing power fluctuations in automotive electronics, characterized by, The application relates to a power supply circuit for an electronic product, which comprises the following parts: a car audio power supply module for providing a car audio voltage signal; a car battery power supply module for providing a car battery voltage signal; a host power supply control module for controlling and managing power supply of the electronic product; the car audio power supply module and the car battery power supply module are connected to the host power supply control module.

2. The circuit capable of preventing power fluctuation of an automotive electronic product according to claim 1, characterized in that, The circuit further comprises a voltage reduction module, which is arranged between the car battery power supply module and the host power supply control module.

3. The circuit capable of preventing power fluctuation of an automotive electronic product according to claim 1, characterized in that, The host power supply control module comprises a power supply signal switching unit and a switch control unit, the car audio power supply module and the car battery power supply module are connected to the switch control unit, and the car audio power supply module, the car battery power supply module and the switch control unit are connected to the power supply signal switching unit.

4. The circuit capable of preventing power fluctuation of an automotive electronic product according to claim 3, characterized in that, The power supply signal switching unit comprises a MOS tube QE1, and three pins of the MOS tube QE1 are connected to the car audio power supply module, the car battery power supply module and the switch control unit respectively.

5. The circuit capable of preventing power fluctuation of an automotive electronic product according to claim 4, characterized in that, The host power supply control module comprises a resistor R141, the switch control unit comprises a triode Q13, a resistor R143, a resistor R16 and a capacitor C89, one end of the resistor R141 is connected to the car battery power supply module, the other end of the resistor R141 is connected to the MOS tube QE1 to form a common end connected to the triode Q13, the resistor R16 and the resistor R143 are connected in series and then connected in parallel to the capacitor C89 and the triode Q13, and the capacitor C89 and the triode Q13 are connected to form a common end connected to the ground; one end of the resistor R16, which is away from the resistor R143, is connected to the ground.

6. The circuit capable of preventing power fluctuation of an automotive electronic product according to claim 5, wherein The host power supply control module further comprises a filter unit and a diode D3, the filter unit comprises a resistor R40, a capacitor C174 and a capacitor CE1, the car audio power supply module, the resistor R40, the capacitor C174 and the capacitor CE1 form a common end connected to one end of the diode D3, and the other end of the diode D3 is connected to the MOS tube QE1.

7. The circuit capable of preventing power fluctuation of an automotive electronic product according to claim 5, wherein The host power supply control module further comprises a resistor R45, a resistor R42 and a resistor R17, and the resistor R45, the resistor R42 and the resistor R17 are connected in parallel and then connected to the common end formed by the resistor R143 and the resistor R16.

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