Power supply circuit and vehicle accessories for vehicle digital keys

Abstract

This utility model discloses a power supply circuit and vehicle accessories for a vehicle-mounted digital key. The power supply circuit for the vehicle-mounted digital key includes: a power supply terminal for connecting to a power source; a power supply terminal for electrically connecting to the vehicle-mounted digital key to supply power to it; a battery unit with an output terminal; and a first switch unit with a first connection terminal, a second connection terminal, and an on / off control terminal. The first connection terminal is electrically connected to the output terminal of the battery unit, the power supply terminal is electrically connected to the second connection terminal and the power supply terminal via a unidirectional conduction unit, and the on / off control terminal is electrically connected to the power supply terminal. The first switch unit is open when there is power voltage at the power supply terminal, and the power supply terminal is powered by the power source. The first switch unit is closed when there is no power voltage at the power supply terminal, and the power supply terminal is powered by the battery unit. This utility model's technical solution allows the vehicle-mounted digital key to still function normally when the power to the vehicle accessories is turned off or disconnected, and the user can still control the car doors using the vehicle-mounted digital key, making it more convenient.

Description

Technical Field

[0001] This utility model relates to the field of vehicle-mounted product technology, and in particular to a power supply circuit and vehicle-mounted accessories for a vehicle-mounted digital key. Background Technology

[0002] As aftermarket digital keys for vehicles become increasingly popular, car owners can use smartphones or wearable devices to replace traditional physical keys, providing functions such as keyless entry and remote control. To improve the aesthetics of the vehicle interior, related technologies propose integrating aftermarket digital keys into in-vehicle accessories (such as parking signs, dashcams, and car chargers). This would solve problems such as inconvenient installation and unsightly aftermarket digital keys.

[0003] Currently, in-vehicle accessories are typically powered by the car's power supply. However, in some scenarios (such as car interior cleaning or electrical system maintenance), it is necessary to turn off or disconnect the power to in-vehicle accessories. In these situations, the digital key in the in-vehicle accessory loses power and stops working, making it impossible to control the car doors. A physical key must then be used, which is very inconvenient. Utility Model Content

[0004] This utility model provides a power supply circuit and vehicle accessories for a vehicle digital key, aiming to ensure that the operation of the vehicle digital key is not affected when the power supply of the vehicle accessories is turned off, so that users can still control the car doors through the vehicle digital key.

[0005] To achieve the above objectives, the power supply circuit for the vehicle-mounted digital key proposed in this utility model includes:

[0006] The power supply terminal is used to connect to the power source.

[0007] The power supply terminal is used to electrically connect to the vehicle digital key to supply power to the vehicle digital key;

[0008] The battery unit has an output terminal;

[0009] The first switching unit has a first connection terminal, a second connection terminal, and an on / off control terminal. The first connection terminal is electrically connected to the output terminal of the battery unit. The power supply terminal is electrically connected to the second connection terminal and the power supply terminal via a unidirectional conduction unit. The on / off control terminal is electrically connected to the power supply terminal.

[0010] The first switching unit is disconnected when there is power voltage at the power supply terminal, and the power supply terminal is powered by the power supply terminal; the first switching unit is turned on when there is no power voltage at the power supply terminal, and the power supply terminal is powered by the battery unit.

[0011] In some embodiments, the first switching unit includes a first switching transistor and a first resistor. The trigger terminal of the first switching transistor is grounded through the first resistor. The first end of the first switching transistor is the first connection terminal, and the second end of the first switching transistor is the first connection terminal. The trigger terminal of the first switching transistor is electrically connected to the on / off control terminal.

[0012] In some embodiments, the first switching unit further includes a second resistor connected in series between the on / off control terminal and the trigger terminal of the first switching transistor. The resistance values ​​of the first resistor and the second resistor are related such that when there is a power supply voltage at the power supply terminal, the voltage drop across the first resistor can keep the first switching transistor in the off state.

[0013] In some embodiments, the first switching transistor is a PMOS transistor, and the first terminal, the second terminal, and the trigger terminal of the first switching transistor are the source, drain, and gate of the PMOS transistor, respectively.

[0014] In some embodiments, the power supply circuit of the vehicle digital key further includes a second switching unit, which is connected in series between the second connection terminal and the power supply terminal to control the power supply on / off of the power supply terminal.

[0015] In some embodiments, the output terminal of the battery unit is electrically connected to the second switching unit so that the second switching unit remains in a conducting state;

[0016] The second switching unit also has a reset terminal for electrically connecting to a reset unit, and the second switching unit disconnects when the reset terminal receives a reset signal.

[0017] In some embodiments, the second switching unit includes a second switching transistor and a driving subunit. A first end of the second switching transistor is electrically connected to the second connection terminal, a second end of the second switching transistor is electrically connected to the power supply terminal, a trigger end of the second switching transistor is electrically connected to the driving subunit, and the output terminal of the battery unit is electrically connected to the control terminal of the driving subunit to keep the second switching transistor in a conducting state. The reset end is electrically connected to the control terminal of the driving subunit.

[0018] In some embodiments, the driving subunit includes a third switch and a fourth resistor. The first terminal of the third switch is electrically connected to the trigger terminal of the second switch via the third resistor. The second terminal of the third switch is grounded. The trigger terminal of the third switch is electrically connected to the output terminal of the battery unit via the fourth resistor. The trigger terminal of the third switch is the control terminal of the driving subunit.

[0019] In some embodiments, the second switch is a PMOS transistor, and the first terminal, the second terminal, and the trigger terminal of the second switch are the source, drain, and gate of the PMOS transistor, respectively.

[0020] In some embodiments, the power supply circuit of the vehicle digital key further includes the reset unit, the reset unit includes a reset button, one end of the reset button is electrically connected to the reset terminal, and the other end of the reset button is grounded.

[0021] In some embodiments, the power supply circuit of the vehicle digital key further includes a power acquisition unit, which is electrically connected to the output terminal of the battery unit and is used to acquire the power status information of the battery unit to feed back to the control unit.

[0022] In some embodiments, the power supply circuit of the vehicle digital key further includes a Zener diode, one end of which is electrically connected to the output terminal of the battery unit, and the other end is grounded.

[0023] In some embodiments, the power supply circuit of the vehicle digital key further includes a filter capacitor, one end of which is electrically connected to the output terminal of the battery unit, and the other end is grounded.

[0024] In some embodiments, the power acquisition unit includes a fifth resistor, a sixth resistor, and a first capacitor. The first end of the fifth resistor is electrically connected to the output terminal of the battery cell, and the second end of the fifth resistor is grounded through the sixth resistor. The first capacitor is connected in parallel with the sixth resistor, and the second end of the fifth resistor is used to feed back the power status information to the control unit.

[0025] This utility model also proposes a vehicle accessory, including a vehicle digital key and the power supply circuit of the vehicle digital key, wherein the power supply terminal is electrically connected to the vehicle digital key to supply power to the vehicle digital key.

[0026] The technical solution of the power supply circuit for the vehicle-mounted digital key of this utility model includes a power supply terminal, a battery unit, and a first switch unit. The first connection terminal of the first switch unit is electrically connected to the output terminal of the battery unit. The power supply terminal is electrically connected to the second connection terminal and the power supply terminal of the first switch unit via a unidirectional conduction unit. The on / off control terminal of the first switch unit is electrically connected to the power supply terminal. When the power supply connected to the power supply terminal is turned on, the power supply terminal has a power supply voltage acting on the on / off control terminal of the first switch unit, keeping the first switch unit in an off state, and the power supply terminal is powered by the power supply voltage output from the power supply terminal. When the power supply connected to the power supply terminal is turned off or disconnected, the power supply terminal has no power supply voltage acting on the on / off control terminal of the first switch unit, and the first switch unit switches from an off state to a conducting state, connecting the output terminal of the battery unit to the power supply terminal. Thus, the output terminal of the battery unit outputs voltage to power the vehicle-mounted digital key, that is, the battery unit serves as a backup power supply when the power is turned off or disconnected. In this way, the vehicle-mounted digital key can continue to work normally when the power supply to the vehicle-mounted digital key is turned off or disconnected. Thus, when the power supply circuit of the vehicle-mounted digital key of this utility model is used, the vehicle-mounted digital key can still work normally when the power supply of the vehicle-mounted digital key is turned off or disconnected from the vehicle-mounted digital key. Users can still control the car doors with the vehicle-mounted digital key without using a physical key, which is more convenient. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a module of an embodiment of the power supply circuit for the vehicle-mounted digital key of this utility model;

[0028] Figure 2 A schematic diagram of the circuit structure of a power supply circuit for a vehicle-mounted digital key according to this utility model;

[0029] Figure 3 This is a schematic diagram of a module of an embodiment of the power supply circuit for the vehicle-mounted digital key of this utility model;

[0030] Figure 4 This is a schematic diagram of a module of an embodiment of the power supply circuit for the vehicle-mounted digital key of this utility model;

[0031] Figure 5 This is a schematic diagram of a module of an embodiment of the power supply circuit for the vehicle-mounted digital key of this utility model;

[0032] Figure 6 A schematic diagram of the circuit structure of a power supply circuit for a vehicle-mounted digital key according to this utility model;

[0033] Figure 7 This is a schematic diagram of a module of an embodiment of the power supply circuit for the vehicle-mounted digital key of this utility model;

[0034] Figure 8A schematic diagram of the circuit structure of a power supply circuit for a vehicle-mounted digital key according to this utility model;

[0035] Figure 9 This is a circuit diagram of one embodiment of the power supply circuit for the vehicle-mounted digital key of this utility model. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0037] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0038] It should also be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0039] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0040] With the increasing popularity of aftermarket digital keys for vehicles, car owners can use smartphones or wearable devices to replace traditional physical keys, providing functions such as keyless entry and remote control. To improve the aesthetics of the vehicle interior, related technologies propose integrating aftermarket digital keys into in-vehicle accessories (such as parking signs, dashcams, and car chargers). This solves problems such as inconvenient installation and unsightly aftermarket digital keys. Currently, in-vehicle accessories are typically powered by the car's electrical system. However, in certain scenarios (such as interior washing or electrical system maintenance), the power to these accessories needs to be turned off or disconnected. During these times, the digital key within the accessory stops working and cannot control the doors, requiring the use of a physical key, which is very inconvenient.

[0041] To address the aforementioned issues, the applicant of this utility model proposes a power supply circuit solution for a vehicle digital key, which effectively solves the problem of the vehicle digital key stopping working when the power supply to the vehicle accessories is turned off or disconnected, ensuring that the operation of the vehicle digital key is not affected, and users can still control the car doors through the vehicle digital key.

[0042] This utility model proposes a power supply circuit for a vehicle digital key, which is used to achieve continuous power supply for the vehicle digital key.

[0043] Reference Figure 1 In this embodiment, the power supply circuit 100 of the vehicle digital key includes a power supply terminal Vin, a power supply terminal Vout, a battery unit 20, and a first switch unit 30.

[0044] The power supply terminal Vin is used to connect to the power source 200, i.e., the vehicle's power source 200, to receive the power voltage provided by the power source 200; the power supply terminal Vout is used to electrically connect to the vehicle digital key 300 to supply power to the vehicle digital key 300, enabling the vehicle digital key 300 to operate. The battery unit 20 has an output terminal 21 for outputting voltage.

[0045] The first switching unit 30 has a first connection terminal A1, a second connection terminal A2, and an on / off control terminal B. The first connection terminal A1 is electrically connected to the output terminal 21 of the battery unit 20. The power supply terminal Vin is electrically connected to the second connection terminal A2 and the power supply terminal Vout via a unidirectional conduction unit 10 (such as a diode). That is, the power supply terminal Vin conducts unidirectionally to the second connection terminal A2 or the power supply terminal Vout. The on / off control terminal B of the first switching unit 30 is electrically connected to the power supply terminal Vin. The first switching unit 30 is disconnected when there is a power supply voltage at the power supply terminal Vin (i.e., when the power supply 200 connected to the voltage terminal is turned on), and the power supply terminal Vout is powered by the power supply terminal Vin. When there is no power supply voltage at the power supply terminal Vin (i.e., when the power supply 200 connected to the voltage terminal is turned off or disconnected), the power supply terminal Vout is powered by the battery unit 20.

[0046] The working principle of the power supply circuit 100 of the vehicle digital key in this embodiment is as follows: when the power supply 200 is not turned off or disconnected, there is a power supply voltage at the power supply terminal Vin. The power supply voltage at the power supply terminal Vin acts on the on / off control terminal B of the first switch unit 30, so that the first switch unit 30 remains in the off state. At this time, the power supply voltage at the power supply terminal Vin is provided to the power supply terminal Vout through the unidirectional conduction unit 10 to supply power to the vehicle digital key 300, so that the vehicle digital key 300 remains in the working state. When the power supply 200 is turned off or disconnected, there is no power supply voltage at the power supply terminal Vin. At this time, there is no power supply voltage output from the power supply terminal Vin to the power supply terminal Vout. However, there is also no power supply voltage acting on the on / off control terminal B of the first switching unit 30. The first switching unit 30 then switches from the off state to the on state, making the output terminal 21 of the battery unit 20 connected to the power supply terminal Vout. The battery unit 20 outputs voltage to the power supply terminal Vout through the output terminal 21 to supply power to the vehicle digital key 300. In this way, the power supply circuit ensures that the power supply to the vehicle digital key 300 is uninterrupted, and the operation of the vehicle digital key 300 is not affected, and it continues to maintain normal operation. Furthermore, due to the presence of the unidirectional conduction unit 10, the power supply terminal Vout will not provide reverse voltage to the power supply terminal Vin.

[0047] The technical solution of the power supply circuit 100 of the vehicle digital key in this embodiment includes a power supply terminal Vin, a power supply terminal Vout, a battery unit 20 and a first switch unit 30. The first connection terminal A1 of the first switch unit 30 is electrically connected to the output terminal 21 of the battery unit 20. The power supply terminal Vin is electrically connected to the second connection terminal A2 of the first switch unit 30 and the power supply terminal Vout via a unidirectional conduction unit 10. The on / off control terminal B of the first switch unit 30 is electrically connected to the power supply terminal Vin. When the power supply 200 connected to the power supply terminal Vin is turned on, the power supply terminal Vin has a power supply voltage applied to the on / off control terminal B of the first switching unit 30, keeping the first switching unit 30 in the off state. The power supply terminal Vout is powered by the power supply voltage output from the power supply terminal Vin. When the power supply 200 connected to the power supply terminal Vin is turned off or disconnected, the power supply terminal Vin has no power supply voltage applied to the on / off control terminal B of the first switching unit 30. The first switching unit 30 then switches from the off state to the on state, connecting the output terminal 21 of the battery unit 20 to the power supply terminal Vout. Thus, the output terminal 21 of the battery unit 20 outputs voltage to power the vehicle digital key 300. That is, the battery unit 20 serves as a backup power supply when the power supply 200 is turned off or disconnected. In this way, the vehicle digital key 300 can continue to work normally when the power supply 200 of the vehicle digital key 300 is turned off or disconnected. In this way, when the power supply circuit 100 of the vehicle-mounted digital key in this embodiment is turned off or disconnected from the power supply 200 of the vehicle-mounted digital key, the vehicle-mounted digital key 300 can still work normally, and the user can still control the car door through the vehicle-mounted digital key 300 without using a physical key, which is more convenient.

[0048] In some embodiments, the battery unit 20 may employ a micro battery (e.g., a button cell), which can be a micro disposable battery or a micro rechargeable battery. This reduces the space occupied by the battery unit 20, thereby reducing the size of the vehicle accessories using the power supply circuit 100 of the vehicle digital key of this embodiment. Of course, in other embodiments, the battery unit 20 may also employ other types of batteries or power supply units.

[0049] Reference Figure 2 and Figure 9In some embodiments, the first switching unit 30 includes a first switching transistor Q1 and a first resistor R1. The trigger terminal of the first switching transistor Q1 is grounded through the first resistor R1. The first terminal of the first switching transistor Q1 is the first connection terminal A1, and the second terminal of the first switching transistor Q1 is the first connection terminal A1. The trigger terminal of the first switching transistor Q1 is electrically connected to the on / off control terminal B. In this embodiment, the working principle of the first switching unit 30 is as follows: when the power supply 200 connected to the power supply terminal Vin is turned on, the power supply terminal Vin outputs a power supply voltage to the on / off control terminal B, so that the trigger terminal of the first switching transistor Q1 is in a high-level state, keeping the first switching transistor Q1 in an off state; when the power supply 200 connected to the power supply terminal Vin is turned off or disconnected, the power supply terminal Vin has no power supply voltage output to the on / off control terminal B. At this time, the trigger terminal of the first switching transistor Q1 is grounded, that is, in a low-level state, and the first switching transistor Q1 meets the conduction condition, so the first switching transistor Q1 is turned on.

[0050] In some embodiments, the first switching unit 30 further includes a second resistor R2, which is connected in series between the on / off control terminal B and the trigger terminal of the first switching transistor Q1. The resistance values ​​of the first resistor R1 and the second resistor R2 satisfy the following: when there is a power supply voltage at the power supply terminal Vin, the voltage division on the first resistor R1 (i.e., the voltage at the trigger terminal of the first switching transistor Q1) can keep the first switching transistor Q1 in the off state, that is, the voltage division on the first resistor R1 is a high-level signal.

[0051] In this embodiment, when the power supply 200 connected to the power supply terminal Vin is turned on, the power supply terminal Vin outputs a power supply voltage to the on / off control terminal B. At this time, the voltage at the trigger terminal of the first switching transistor Q1 is the voltage division across the second resistor R2, which is a high-level state, keeping the first switching transistor Q1 off. When the power supply 200 connected to the power supply terminal Vin is turned off or disconnected, the power supply terminal Vin has no power supply voltage output to the on / off control terminal B. At this time, the voltage at the trigger terminal of the first switching transistor Q1 is 0V, which is a low-level state, turning the first switching transistor Q1 on. This embodiment limits the current by adding a second resistor R2 between the on / off control terminal B and the trigger terminal of the first switching transistor Q1 to prevent excessive current from burning out the first switching transistor Q1 and to ensure the safe and stable operation of the circuit.

[0052] In some embodiments, the first switch Q1 is a PMOS transistor, and its first terminal, second terminal, and trigger terminal are the source, drain, and gate of the PMOS transistor, respectively. When the trigger terminal of the first switch Q1 is at a high level, that is, the gate of the PMOS transistor is at a high level, the first switch Q1 is in the off state. When the trigger terminal of the first switch Q1 is at a low level, that is, the gate of the PMOS transistor is at a low level, the voltage of the first connection terminal A1 (i.e., the source) of the first switch Q1 is the same as the voltage of the output terminal 21 of the battery cell 20, that is, the voltage difference between the gate and the source of the PMOS transistor is negative and reaches the threshold voltage of the PMOS transistor, that is, the conduction condition of the PMOS transistor is met, and the first switch Q1 is in the on state.

[0053] Of course, in some other embodiments, the first switch Q1 can also be other switches that have the same function as the PMOS transistor.

[0054] In other instances, the first switching unit 30 may also be other circuits, devices, or chips that can perform the same function.

[0055] Reference Figure 3 In some embodiments, the power supply circuit 100 of the vehicle digital key further includes a second switch unit 40, which is connected in series between the second connection terminal A2 and the power supply terminal Vout, and is used to control the power supply to the power supply terminal Vout. In this embodiment, by controlling the power supply to the power supply terminal Vout through the second switch unit 40, the operation of the vehicle digital key 300 can be controlled. Furthermore, by controlling the power supply to the power supply terminal Vout to be disconnected and then restored through the second switch unit 40, the vehicle digital key 300 can be restarted after power failure. When the vehicle digital key 300 experiences a common fault such as jamming, the second switch unit 40 can control the vehicle digital key 300 to be restarted after power failure to perform a reset, thereby eliminating the common fault such as jamming.

[0056] In some embodiments, the second switching unit 40 may be a mechanical switch, an electronic switch, or other types of switches.

[0057] Reference Figure 4 In some embodiments, the output terminal 21 of the battery unit 20 is electrically connected to the second switching unit 40 to keep the second switching unit 40 in a conducting state. That is to say, the second switching unit 40 is an electronically controlled switch, and the voltage of the output terminal 21 of the battery unit 20 controls the second switching unit 40 to remain in a conducting state, thereby ensuring a stable power supply to the vehicle digital key 300 and enabling the vehicle digital key 300 to maintain continuous and stable operation.

[0058] In some embodiments, the second switching unit 40 further includes a reset terminal RSET for electrically connecting to a reset unit. The second switching unit 40 disconnects when the reset terminal RSET receives a reset signal. In this embodiment, by setting the reset terminal RSET of the second switching unit 40, when the vehicle digital key 300 experiences a common fault such as jamming, a reset signal can be sent to the reset terminal RSET to cause the second switching unit 40 to disconnect briefly and then resume conduction. This achieves the control of restarting and resetting the vehicle digital key 300 to eliminate common faults such as jamming.

[0059] Reference Figure 5 In some embodiments, the second switching unit 40 includes a second switching transistor Q2 and a driving subunit 41. The first end of the second switching transistor Q2 is electrically connected to the second connection terminal A2, the second end of the second switching transistor Q2 is electrically connected to the power supply terminal Vout, the trigger terminal of the second switching transistor Q2 is electrically connected to the driving subunit 41, and the output terminal 21 of the battery unit 20 is electrically connected to the control terminal of the driving subunit 41 to keep the second switching transistor Q2 in a conducting state. That is, the voltage at the output terminal 21 of the battery unit 20 causes the driving subunit 41 to control the second switching transistor Q2 to remain in a conducting state. The reset terminal RSET is electrically connected to the control terminal of the driving subunit 41. When the reset terminal RSET receives a reset signal, the reset signal will cause the second switching transistor Q2 to switch to an off state. After the reset signal at the reset terminal RSET disappears, the driving subunit 41 will, under the action of the voltage at the output terminal 21 of the battery unit 20, switch the second switching transistor Q2 back to a conducting state.

[0060] Reference Figure 6 and Figure 9 In some embodiments, the driving subunit 41 includes a third switch Q3 and a third resistor R3. The first end of the third switch Q3 is electrically connected to the trigger end of the second switch Q2 via the third resistor R3. The second end of the third switch Q3 is grounded. The trigger end of the third switch Q3 is electrically connected to the output end 21 of the battery unit 20 via the fourth resistor R4. The trigger end of the third switch Q3 is the control end of the driving subunit 41.

[0061] In this embodiment, the voltage at the output terminal 21 of the battery unit 20 keeps the trigger terminal of the third switch Q3 at a high level, thus keeping the third switch Q3 on and keeping the trigger terminal of the second switch Q2 grounded, thus keeping the second switch Q2 on. When the reset terminal RSET receives a low-level signal, it pulls the trigger terminal of the third switch Q3 low, causing the third switch Q3 to change from on to off, and the trigger terminal of the second switch Q2 to change from grounded to floating, thus turning the second switch Q2 off. When the low-level signal at the reset terminal RSET disappears, the trigger terminal of the third switch Q3 returns to a high level under the action of the voltage at the output terminal 21 of the battery unit 20, thus restoring the third switch Q3 to on, and thus restoring the trigger terminal of the second switch Q2 to ground, thus restoring the second switch Q2 to on. In this way, the power-off restart reset of the vehicle digital key 300 is completed through the reset signal of the reset terminal RSET.

[0062] In some embodiments, the second switch Q2 is a PMOS transistor, and its first terminal, second terminal, and trigger terminal are, in sequence, the source, drain, and gate of the PMOS transistor. Of course, in other examples, the second switch Q2 can also be any other switch that performs the same function as a PMOS transistor.

[0063] In some embodiments, the third switch Q3 can be an NPN transistor, with its first terminal, second terminal, and trigger terminal being the collector, emitter, and base of the NPN transistor, respectively. Of course, in other examples, the third switch Q3 can also be any other switch that performs the same function as an NPN transistor.

[0064] In some embodiments, the power supply circuit 100 of the vehicle digital key further includes a reset unit (not shown in the figure). The reset unit includes a reset button, one end of which is electrically connected to the reset terminal RSET, and the other end of which is grounded. When the user needs to reset the vehicle digital key 300, they only need to press the reset button once. When the reset button is pressed, the reset button grounds the reset terminal RSET, and the reset terminal RSET generates a low-level signal, causing the second switch unit 40 to open and the vehicle digital key 300 to disconnect. Then, the reset button is released or pressed again, causing the reset button to disconnect the reset terminal RSET from ground. The low-level signal of the reset terminal RSET disappears, causing the second switch unit 40 to resume conduction, and the vehicle digital key 300 is powered on and restarted, completing the reset.

[0065] Of course, in some other embodiments, the reset unit may also be other circuits, devices, or chips.

[0066] Reference Figure 7In some embodiments, the power supply circuit 100 of the vehicle digital key further includes a power acquisition unit 50, which is electrically connected to the output terminal 21 of the battery unit 20. The power acquisition unit 50 is used to acquire the power status information of the battery unit 20 and feed it back to the control unit 400. The control unit 400 can be a controller for vehicle accessories (such as an MCU) or the controller of the power supply circuit 100 itself. In this embodiment, by adding the power acquisition unit 50 to acquire the power status of the battery unit 20 and feed it back to the control unit 400, the control unit 400 can clearly see the real-time power status of the battery unit 20. This allows the control unit 400 to issue a reminder when the battery unit 20's power is insufficient or low, prompting the user to replace the battery unit 20 in a timely manner, thereby ensuring the stable and continuous operation of the vehicle digital key 300.

[0067] Reference Figure 8 and Figure 9 In some embodiments, the power acquisition unit 50 includes a fifth resistor R5, a sixth resistor R6, and a first capacitor C1. The first end of the fifth resistor R5 is electrically connected to the output terminal 21 of the battery unit 20, and the second end of the fifth resistor R5 is grounded through the sixth resistor R6. The first capacitor C1 is connected in parallel with the sixth resistor R6. The second end of the fifth resistor R5 is used to feed back power status information to the control unit 400. In this embodiment, the power acquisition unit 50 uses the fifth resistor R5 and the sixth resistor R6 to form a voltage divider circuit. The power status information (i.e., the voltage division value of the sixth resistor R6 across the output terminal 21 of the battery unit 20) is fed back to the control unit 400 through the second end of the fifth resistor R5. The first capacitor C1 is used for filtering and anti-interference to ensure the accuracy of the fed-back power status information. The overall circuit structure is simple and low in cost.

[0068] Of course, in some other embodiments, the circuit acquisition unit may also be a circuit composed of other devices.

[0069] Reference Figure 9 In some embodiments, the power supply circuit 100 of the vehicle digital key also includes a Zener diode D, one end of which is electrically connected to the output terminal 21 of the battery unit 20, and the other end is grounded. This ensures the stability of the voltage at the output terminal 21 of the battery unit 20, provides overvoltage protection for the battery unit 20, and guarantees the operational stability of the entire circuit.

[0070] In some embodiments, the power supply circuit 100 of the vehicle digital key further includes a filter capacitor Cs, one end of which is electrically connected to the output terminal 21 of the battery unit 20, and the other end is grounded. The filter capacitor Cs performs filtering and anti-interference to ensure that the voltage output by the battery unit 20 is not affected by interference.

[0071] In some embodiments, the battery unit 20 may be a rechargeable battery unit 20, and the power supply circuit 100 of the vehicle digital key may also include a charging unit. The charging unit is electrically connected to the power supply terminal Vin and the battery unit 20. In this way, when the power supply 200 of the power supply terminal Vin is turned on, the power supply voltage of the power supply terminal Vin can charge the battery unit 20 through the charging unit, thus ensuring that the battery unit 20 has sufficient power and that the user does not need to replace the battery unit 20 regularly, making it more convenient to use.

[0072] It should be noted that, in the absence of any contradiction or conflict between the above embodiments of this utility model, the above embodiments can be arbitrarily combined or combined to form new embodiments.

[0073] This utility model further proposes a vehicle accessory, which can be a parking sign, a dashcam, a car charger, a car air freshener, a car central control unit, etc. The vehicle accessory includes a car digital key and a power supply circuit for the aforementioned car digital key. The power supply terminal of the power supply circuit for the car digital key is electrically connected to the car digital key, supplying power to the car digital key. The specific structure of this vehicle accessory is as described in the above embodiments. Since this vehicle accessory adopts all the technical solutions of all embodiments of the power supply circuit for the aforementioned car digital key, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here.

[0074] The above description is only a part or preferred embodiment of this utility model. Neither the text nor the drawings should limit the scope of protection of this utility model. All equivalent structural transformations made using the content of this utility model specification and drawings under the overall concept of this utility model, or direct / indirect applications in other related technical fields, are included within the scope of protection of this utility model.

Claims

1. A power supply circuit for a digital key on board a vehicle, characterized in that, include: The power supply terminal is used to connect to the power source. The power supply terminal is used to electrically connect to the vehicle digital key to supply power to the vehicle digital key; The battery unit has an output terminal; The first switching unit has a first connection terminal, a second connection terminal, and an on / off control terminal. The first connection terminal is electrically connected to the output terminal of the battery unit. The power supply terminal is electrically connected to the second connection terminal and the power supply terminal via a unidirectional conduction unit. The on / off control terminal is electrically connected to the power supply terminal. The first switching unit is disconnected when there is a power supply voltage at the power supply terminal, and the power supply terminal is powered by the power supply terminal. The first switching unit is turned on when there is no power supply voltage at the power supply terminal, and the power supply terminal is powered by the battery unit.

2. The power supply circuit for a digital key for vehicle according to claim 1, characterized by, The first switching unit includes a first switching transistor and a first resistor. The trigger terminal of the first switching transistor is grounded through the first resistor. The first end of the first switching transistor is the first connection terminal, and the second end of the first switching transistor is the first connection terminal. The trigger terminal of the first switching transistor is electrically connected to the on / off control terminal.

3. The power supply circuit for a digital key for vehicle according to claim 2, characterized by, The first switching unit further includes a second resistor, which is connected in series between the on / off control terminal and the trigger terminal of the first switching transistor. The resistance values ​​of the first resistor and the second resistor are related in such a way that when there is a power supply voltage at the power supply terminal, the voltage drop across the first resistor is sufficient to keep the first switching transistor in the off state; and / or, The first switching transistor is a PMOS transistor, and the first terminal, the second terminal, and the trigger terminal of the first switching transistor are the source, drain, and gate of the PMOS transistor, respectively.

4. The power supply circuit for a digital key for vehicle according to any one of claims 1 to 3, characterized in that, It also includes a second switching unit, which is connected in series between the second connection terminal and the power supply terminal, and is used to control the power supply to the power supply terminal.

5. The power supply circuit for the vehicle-mounted digital key according to claim 4, characterized in that, The output terminal of the battery unit is electrically connected to the second switch unit so that the second switch unit remains in the on state; The second switching unit also has a reset terminal for electrically connecting to a reset unit, and the second switching unit disconnects when the reset terminal receives a reset signal.

6. The power supply circuit for the vehicle-mounted digital key according to claim 5, characterized in that, The second switching unit includes a second switching transistor and a driving subunit. The first end of the second switching transistor is electrically connected to the second connection terminal, the second end of the second switching transistor is electrically connected to the power supply terminal, the trigger terminal of the second switching transistor is electrically connected to the driving subunit, and the output terminal of the battery unit is electrically connected to the control terminal of the driving subunit to keep the second switching transistor in a conducting state. The reset terminal is electrically connected to the control terminal of the driving subunit.

7. The power supply circuit for the vehicle-mounted digital key according to claim 6, characterized in that, The driving subunit includes a third switch and a third resistor. The first terminal of the third switch is electrically connected to the trigger terminal of the second switch via the third resistor. The second terminal of the third switch is grounded. The trigger terminal of the third switch is electrically connected to the output terminal of the battery unit via a fourth resistor. The trigger terminal of the third switch serves as the control terminal of the driving subunit; and / or, The second switching transistor is a PMOS transistor, and its first terminal, second terminal, and trigger terminal are, in sequence, the source, drain, and gate of the PMOS transistor; and / or, The power supply circuit of the vehicle digital key also includes the reset unit, which includes a reset button. One end of the reset button is electrically connected to the reset terminal, and the other end of the reset button is grounded.

8. The power supply circuit for the vehicle-mounted digital key according to any one of claims 1 to 3, characterized in that, It also includes a power acquisition unit, which is electrically connected to the output terminal of the battery cell and is used to acquire the power status information of the battery cell to feed back to the control unit; and / or, The power supply circuit of the vehicle digital key also includes a voltage regulator diode, one end of which is electrically connected to the output terminal of the battery unit, and the other end is grounded; and / or, The power supply circuit of the vehicle digital key also includes a filter capacitor, one end of which is electrically connected to the output terminal of the battery unit, and the other end is grounded.

9. The power supply circuit for the vehicle-mounted digital key according to claim 8, characterized in that, The power acquisition unit includes a fifth resistor, a sixth resistor, and a first capacitor. The first end of the fifth resistor is electrically connected to the output terminal of the battery unit, and the second end of the fifth resistor is grounded through the sixth resistor. The first capacitor is connected in parallel with the sixth resistor, and the second end of the fifth resistor is used to feed back the power status information to the control unit.

10. A vehicle accessory, characterized in that, The system includes a vehicle digital key and a power supply circuit for the vehicle digital key as described in any one of claims 1 to 9, wherein the power supply terminal is electrically connected to the vehicle digital key to supply power to the vehicle digital key.

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