Anti-crash circuit of automobile data recorder

Abstract

The utility model discloses an anti-crash circuit of an automobile data recorder, which comprises a socket unit used for being connected with an external farad capacitor, a charging and discharging unit used for being connected with an external network power supply and detecting the actual power storage condition of the external farad capacitor, and a control unit arranged between the charging and discharging unit and the socket unit, and the discharge switch is used for allowing the external farad capacitor to discharge to the external network power supply or forbidding the external farad capacitor to discharge to the external network power supply according to the power storage condition of the external farad capacitor. The circuit can change the discharge condition of the external farad capacitor according to the actual power storage condition of the external farad capacitor, and the discharge of the external farad capacitor is blocked when the external farad capacitor is not fully charged, so that the problem of system crash of the automobile data recorder due to the fact that the discharge voltage of the external farad capacitor does not meet the requirement is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of sensor circuits, and particularly relates to a driving recorder. Background Art

[0002] A farad capacitor is arranged in a driving recorder, and the charge and discharge characteristics of the farad capacitor are utilized to provide emergency power for the recorder.

[0003] As Figure 1 shown is the working principle diagram of the super capacitor arranged in the driving recorder provided in the prior art. As Figure 1 in the circuit, a farad capacitor socket CN13, a charging resistor R101 and a freewheeling diode D7 are arranged; the farad capacitor socket CN13 is used for connecting an external farad capacitor. Specifically, in implementation, the two pins of the external farad capacitor will be respectively connected to the 1st pin and the 2nd pin of the farad capacitor socket CN13; one end of the charging resistor R101 is connected to the network voltage +5V, and the other end is connected to the 1st pin in the farad capacitor socket CN13; the anode of the freewheeling diode D7 is connected to the 1st pin in the farad capacitor socket CN13, and its cathode is connected to the network voltage +5V; after the driving recorder is powered on, the network voltage +5V starts to be normally supplied, and charges the external farad capacitor connected to the farad capacitor socket CN13 through the charging resistor R101 until it is fully charged; if a sudden situation occurs and the driving recorder suddenly loses power, the network voltage +5V will also disappear simultaneously. At this time, the external farad capacitor will supply power to the network voltage +5V through the freewheeling diode D7, ensuring that within a period of time when the network voltage +5V suddenly disappears due to a sudden situation, the driving recorder still has power supply, and further ensuring that the driving recorder still has sufficient time to save the monitoring video after a sudden situation occurs.

[0004] However, when the above circuit is applied to a specific driving recorder, such as when the driving recorder is just powered on, the network voltage +5V just starts to charge the external farad capacitor and is not fully charged and then suddenly loses power. Since the external farad capacitor is not fully charged, the voltage supplied by the external farad capacitor to the network voltage +5V through the freewheeling diode D7 must be less than 5V. Although the driving recorder has power supply, the voltage of the supplied power is insufficient, and the driving recorder is prone to problems such as system crash and program runaway. Not only the last section of the video still cannot be saved after a sudden power failure, but the system is also very easy to be damaged. Content of the Utility Model

[0005] Based on this, it is necessary to provide an anti-crash circuit, which can change its discharge situation according to the actual power storage situation of the external farad capacitor and block its discharge when the external farad capacitor is not fully charged, so as to prevent the driving recorder from crashing due to the discharge voltage of the external farad capacitor not meeting the requirements.

[0006] The technical solution of the utility model is as follows:

[0007] A deadlock prevention circuit for a driving recorder, comprising:

[0008] A socket unit: used to connect an external farad capacitor;

[0009] A charge and discharge unit: used to connect an external network power supply and detect the actual power storage situation of the external farad capacitor;

[0010] And a discharge switch: arranged between the charge and discharge unit and the socket unit, used to allow or prohibit the external farad capacitor from discharging to the external network power supply according to the power storage situation of the external farad capacitor.

[0011] Optionally, the socket unit includes a capacitor socket, the capacitor socket has a first pin and a second pin, and the first pin and the second pin in the capacitor socket are respectively connected and conducted with both ends of the external farad capacitor.

[0012] Optionally, the charge and discharge unit includes a charging resistor and a charging diode; one end of the charging resistor is connected to the external network power supply, and the other end of the charging resistor is connected to the first pin in the capacitor socket; the cathode of the charging diode is connected to the external network power supply, and the anode of the charging diode is connected to the first pin in the capacitor socket.

[0013] Optionally, the discharge switch includes a main control chip, a first switching MOS transistor, a second switching MOS transistor, a first switching resistor, a second switching resistor, and a third switching resistor; the source of the first switching MOS transistor is connected to the second pin in the capacitor socket, the drain of the first switching MOS transistor is connected to the drain of the second switching MOS transistor, the source of the second switching MOS transistor is grounded, and the gate of the first switching MOS transistor is connected to the gate of the second switching MOS transistor; one end of the first switching resistor is connected to the second pin in the capacitor socket, and the other end of the first switching resistor is connected to the gate of the first switching MOS transistor; one end of the second switching resistor is connected to the drain of the second switching MOS transistor, and the other end of the second switching resistor is connected to the source of the second switching MOS transistor; one end of the third switching resistor is connected to the gate of the first switching MOS transistor, and the other end of the third switching resistor is connected to the main control chip.

[0014] Optionally, the common end of the charging resistor and the capacitor socket is led out as a detection end to detect whether the external farad capacitor is fully charged.

[0015] Optionally, the socket unit includes a capacitor socket, which has a first pin, a second pin, a third pin, and a fourth pin. The third pin and the fourth pin of the capacitor socket are grounded, and the first pin of the capacitor socket is respectively connected to and conducts with both ends of an external farad capacitor through the second pin.

[0016] Optionally, the charge and discharge unit includes a first charging resistor, a second charging resistor, and a charging diode. One end of the first charging resistor is connected to an external network power supply, and the other end of the first charging resistor is connected to the anode of the charging diode. The cathode of the charging diode is connected to one end of the second charging resistor, and the other end of the second charging resistor is connected to the second pin of the capacitor socket.

[0017] Optionally, the discharge switch includes a main control chip, a first switching MOS transistor, a second switching MOS transistor, a first switching triode, a first switching resistor, a second switching resistor, and a third switching resistor. The source of the first switching MOS transistor is connected to the common end of the second charging resistor and the capacitor socket. The drain of the first switching MOS transistor is connected to the drain of the second switching MOS transistor. The source of the second switching MOS transistor is connected to the anode of the charging diode. The gate of the first switching MOS transistor is connected to the gate of the second switching MOS transistor. One end of the first switching resistor is connected to the common end of the first switching MOS transistor and the capacitor socket, and the other end of the first switching resistor is connected to the gate of the first switching MOS transistor. The collector of the first switching triode is connected to the gate of the first switching MOS transistor. The emitter of the first switching triode is grounded. The base of the first switching triode is connected to one end of the second switching resistor, and the other end of the second switching resistor is connected to the main control chip. One end of the third switching resistor is connected to the common end of the first switching triode and the second switching resistor, and the other end of the third switching resistor is grounded.

[0018] Optionally, the specific model of the main control chip is NT96670.

[0019] Optionally, the common end of the second charging resistor and the capacitor socket is led out as a detection terminal to detect whether the external farad capacitor is fully charged.

[0020] The beneficial effects of the technical solution of the present utility model are as follows: A socket unit and a discharge switch are provided in the circuit. The socket unit is used to detect the power storage condition of the external farad capacitor. When the external farad capacitor is not fully charged, the discharge switch is disconnected to cut off the connection between the socket unit and the charge and discharge unit, so as to prevent the uncharged external farad capacitor from discharging to the external network power supply and avoid system crash caused by insufficient voltage discharge of the external farad capacitor. Description of the Drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.

[0022] Figure 1 It is the working principle diagram of the super capacitor provided in the driving recorder in the prior art.

[0023] Figure 2 It is the circuit principle diagram of the anti-freezing circuit of the driving recorder implemented in one of the specific embodiments.

[0024] Figure 3 It is the circuit principle diagram of the anti-freezing circuit of the driving recorder implemented in the second of the specific embodiments.

[0025] The realization of the object of the present invention, its functional characteristics and advantages will be further described in conjunction with the embodiments and with reference to the drawings. Specific Embodiments

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0027] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If this specific posture changes, the directional indications will also change accordingly.

[0028] In addition, the descriptions involving "first", "second", etc. in the present utility model are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, "and / or" throughout the text includes three scenarios. Taking A and / or B as an example, it includes the technical solution of A, the technical solution of B, and the technical solution where A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model. Specific Embodiment 1:

[0030] Reference Figure 1-2 。

[0031] In this specific embodiment, a circuit for preventing a driving recorder from crashing is provided, which includes a socket unit, a charge and discharge unit, and a discharge switch.

[0032] In this specific embodiment, the socket unit includes a capacitor socket EC. The capacitor socket EC has a first pin EC-1, a second pin EC-2, a third pin EC-3, and a fourth pin EC-4. The third pin EC-3 and the fourth pin EC-4 of the capacitor socket EC are grounded. The first pin EC-1 of the capacitor socket EC is respectively connected and conducted with both ends of an external farad capacitor (not shown in the figure) to the second pin EC-2. The charge and discharge unit includes a charging resistor R12 and a charging diode D3. One end of the charging resistor R12 is connected to an external network power supply SYS_PWR, and the other end of the charging resistor R12 is connected to the first pin EC-1 in the capacitor socket EC. The cathode of the charging diode D3 is connected to the external network power supply SYS_PWR, and the anode of the charging diode D3 is connected to the first pin EC-1 in the capacitor socket EC. The discharge switch includes a main control chip (not shown in the figure), a first switching MOS transistor Q29, a second switching MOS transistor Q19, a first switching resistor R635, a second switching resistor R676, and a third switching resistor R0402. The source of the first switching MOS transistor Q29 is connected to the second pin EC-2 in the capacitor socket EC. The drain of the first switching MOS transistor Q29 is connected to the drain of the second switching MOS transistor Q19. The source of the second switching MOS transistor Q19 is grounded. The gate of the first switching MOS transistor Q29 is connected to the gate of the second switching MOS transistor Q19. One end of the first switching resistor R635 is connected to the second pin EC-2 in the capacitor socket EC, and the other end of the first switching resistor R635 is connected to the gate of the first switching MOS transistor Q29. One end of the second switching resistor R676 is connected to the drain of the second switching MOS transistor Q19, and the other end of the second switching resistor R676 is connected to the source of the second switching MOS transistor Q19. One end of the third switching resistor R0402 is connected to the gate of the first switching MOS transistor Q29, and the other end of the third switching resistor R0402 is connected to the POW pin in the main control chip. In this specific embodiment, the common end of the charging resistor R12 and the capacitor socket EC is led out as a detection terminal TP1 to detect whether the external farad capacitor is fully charged.

[0033] The actual power storage situation of the external farad capacitor is directly reflected in the voltage amplitude at the detection terminal TP1 led out from the common end of the charging resistor R12 and the capacitor socket EC. By leading out the common end of the charging resistor R12 and the capacitor socket EC as the detection terminal TP1 and obtaining the voltage value at this detection terminal, the power storage situation of the external farad capacitor can be judged in real time.

[0034] At first, the external farad capacitor is in a state of having no charge at all. After the driving recorder is powered on, the external network power supply will provide a +5V voltage. The external network power supply is connected through the charge and discharge unit and continuously charges the external farad capacitor through the capacitor socket EC. The voltage amplitude at the common end of the charging resistor R12 and the capacitor socket EC changes continuously as the charge storage capacity of the external farad capacitor changes. If no accident occurs during this process of the driving recorder, the external network power supply will continuously charge the external farad capacitor until it is fully charged.

[0035] After the external farad capacitor is fully charged, it will maintain its fully charged state without change.

[0036] When the external farad capacitor is fully charged and an accident occurs to the driving recorder (such as the user suddenly shutting down, the system being damaged, the vehicle colliding and the circuit being interrupted, etc.), the external network power supply will lose power instantly when the accident occurs to the driving recorder. The discharge switch controlled by the main control chip is turned on, and the external farad capacitor can discharge to the external network power supply in a sufficient voltage state, maintaining the voltage amplitude of the external network power supply for a period of time, thereby ensuring that the driving recorder still has sufficient time to save the monitoring screen after an unexpected situation occurs.

[0037] If an accident occurs to the driving recorder and the external network power supply suddenly loses power when the external farad capacitor is not fully charged, then the voltage amplitude at the common end TP1 of the charging resistor R12 and the capacitor socket EC at the moment of power loss indicates that the external farad capacitor has not reached the fully charged state. The main control chip will also lose power, and the first switching MOS transistor Q29 and the second switching MOS transistor Q19 connected to the main control chip are controlled to be cut off. The external farad capacitor cannot discharge to the external network power supply through the discharge switch. Since a charging diode D3 is set in a direction completely opposite to the discharge direction of the external farad capacitor, the charge and discharge unit originally connected to the external farad capacitor also blocks the connection between the external farad capacitor and the external network power supply at this time. At this time, the external farad capacitor cannot discharge, and the system needs to seek other power sources or directly shut down, thus effectively avoiding problems such as system crash and program runaway due to the voltage not meeting the amplitude requirements. Specific Embodiment 2:

[0039] Please refer to Figure 1 、 3 。

[0040] In this specific embodiment, a circuit for preventing the driving recorder from crashing is provided, including a socket unit, a charge and discharge unit, and a discharge switch.

[0041] In this specific embodiment, the socket unit includes a capacitor socket CN4. The capacitor socket CN4 has a first pin CN4-1, a second pin CN4-2, a third pin CN4-3, and a fourth pin CN4-4. The third pin CN4-3 and the fourth pin CN4-4 of the capacitor socket CN4 are grounded. The first pin CN4-1 of the capacitor socket CN4 is respectively connected and conducted to both ends of an external farad capacitor (not shown in the figure) with the second pin CN4-2. The charge and discharge unit includes a first charging resistor R769, a second charging resistor R18, and a charging diode D13. One end of the first charging resistor R769 is connected to an external network power supply VUSB, and the other end of the first charging resistor R769 is connected to the anode of the charging diode D13. The cathode of the charging diode D13 is connected to one end of the second charging resistor R18, and the other end of the second charging resistor R18 is connected to the second pin of the capacitor socket CN4. The discharge switch includes a main control chip (not shown in the figure), a first switching MOS transistor Q39, a second switching MOS transistor Q40, a first switching triode Q41, a first switching resistor R21, a second switching resistor R22, and a third switching resistor R742. The source of the first switching MOS transistor Q39 is connected to the common terminal of the second charging resistor R18 and the capacitor socket CN4. The drain of the first switching MOS transistor Q39 is connected to the drain of the second switching MOS transistor Q40. The source of the second switching MOS transistor Q40 is connected to the anode of the charging diode D13. The gate of the first switching MOS transistor Q39 is connected to the gate of the second switching MOS transistor Q40. One end of the first switching resistor R21 is connected to the common terminal of the first switching MOS transistor Q39 and the capacitor socket CN4, and the other end of the first switching resistor R21 is connected to the gate of the first switching MOS transistor Q39. The collector of the first switching triode Q41 is connected to the gate of the first switching MOS transistor Q39. The emitter of the first switching triode Q41 is grounded. The base of the first switching triode Q41 is connected to one end of the second switching resistor R22, and the other end of the second switching resistor R22 is connected to the POW pin in the main control chip. One end of the third switching resistor R742 is connected to the common terminal of the first switching triode Q41 and the second switching resistor R22, and the other end of the third switching resistor R742 is grounded. The specific model of the main control chip is NT96670. The common terminal of the second charging resistor R18 and the capacitor socket CN4 is led out as a detection terminal CAP+ to detect whether the external farad capacitor is fully charged.

[0042] The main control chip determines whether the external farad capacitor is fully charged by monitoring the real-time voltage at the detection terminal CAP+ led out from the common terminal of the second charging resistor R18 and the capacitor socket CN4 or by timing. If the driving recorder suddenly loses power when the external farad capacitor is not fully charged, the main control chip will also lose power, the discharge switch controlled by the main control chip will be cut off, and the external farad capacitor cannot discharge to the external network power supply via the discharge switch. The system needs to seek other power sources or directly shut down, thus effectively avoiding the problems of system crash and program runaway caused by the voltage not meeting the amplitude requirements.

[0043] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A driving recorder anti-crash circuit, comprising: Connector unit: used to connect external farad capacitor; It is characterized by further comprising: Charging and discharging unit: used to connect to the external network power supply and detect the actual storage status of the external farad capacitor; and a discharge switch: arranged between the charging and discharging unit and the socket unit, for allowing the external farad capacitor to discharge to the external network power supply or prohibiting the external farad capacitor from discharging to the external network power supply according to the power storage condition of the external farad capacitor.

2. The anti-crash circuit of the driving recorder according to claim 1, characterized in that: The socket unit comprises a capacitor socket, wherein the capacitor socket is provided with a first pin and a second pin, and the first pin of the capacitor socket is respectively connected to the second pin and two ends of an external farad capacitor and is in conduction.

3. The anti-crash circuit of the driving recorder as claimed in claim 2, characterized in that: The charging and discharging unit includes a charging resistor and a charging diode; one end of the charging resistor is connected to an external network power supply, and the other end of the charging resistor is connected to the first pin in the capacitor socket; The cathode of the charging diode is connected to the external network power supply, and the anode of the charging diode is connected to the first pin in the capacitor socket.

4. The anti-crash circuit of the driving recorder as claimed in claim 3, characterized in that: The discharge switch includes a main control chip, a first switch MOS tube, a second switch MOS tube, a first switch resistor, a second switch resistor and a third switch resistor; the source of the first switch MOS tube is connected to the second pin in the capacitor socket, the drain of the first switch MOS tube is connected to the drain of the second switch MOS tube, the source of the second switch MOS tube is grounded, and the gate of the first switch MOS tube is connected to the gate of the second switch MOS tube; one end of the first switch resistor is connected to the second pin in the capacitor socket, and the other end of the first switch resistor is connected to the gate of the first switch MOS tube; One end of the second switch resistor is connected to the drain of the second switch MOS tube, and the other end of the second switch resistor is connected to the source of the second switch MOS tube; One end of the third switch resistor is connected to the gate of the first switch MOS tube, and the other end of the third switch resistor is connected to the main control chip.

5. The anti-crash circuit of the driving recorder as claimed in claim 4, characterized in that: The common end of the charging resistor and the capacitor socket is led out as a detection end to detect whether the external farad capacitor is fully charged.

6. The anti-crash circuit of the driving recorder as claimed in claim 1, characterized in that: The socket unit includes a capacitor socket, which has a first pin, a second pin, a third pin and a fourth pin. The third pin and the fourth pin of the capacitor socket are grounded, and the first pin of the capacitor socket is respectively connected and conducted with the second pin and two ends of an external farad capacitor.

7. The anti-crash circuit of the driving recorder as claimed in claim 6, characterized in that: The charge and discharge unit includes a first charging resistor, a second charging resistor and a charging diode; one end of the first charging resistor is connected to an external network power supply, and the other end of the first charging resistor is connected to the anode of the charging diode; the cathode of the charging diode is connected to one end of the second charging resistor, and the other end of the second charging resistor is connected to the second pin of the capacitor socket.

8. The anti-crash circuit of the driving recorder as claimed in claim 7, characterized in that: The discharge switch includes a main control chip, a first switch MOS tube, a second switch MOS tube, a first switch triode, a first switch resistor, a second switch resistor and a third switch resistor; the source of the first switch MOS tube is connected to the common end of the second charging resistor and the capacitor socket, the drain of the first switch MOS tube is connected to the drain of the second switch MOS tube, the source of the second switch MOS tube is connected to the anode of the charging diode, and the gate of the first switch MOS tube is connected to the gate of the second switch MOS tube; one end of the first switch resistor is connected to the common end of the first switch MOS tube and the capacitor socket, and the other end of the first switch resistor is connected to the gate of the first switch MOS tube; the collector of the first switch triode is connected to the gate of the first switch MOS tube, the emitter of the first switch triode is grounded, the base of the first switch triode is connected to one end of the second switch resistor, and the other end of the second switch resistor is connected to the main control chip; one end of the third switch resistor is connected to the common end of the first switch triode and the second switch resistor, and the other end of the third switch resistor is grounded.

9. The anti-crash circuit of the driving recorder as claimed in claim 8, characterized in that: The specific model of the main control chip is NT96670.

10. The anti-crash circuit of the driving recorder according to claim 9, characterized in that: The common end of the second charging resistor and the capacitor socket is led out as a detection end to detect whether the external farad capacitor is fully charged.

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