CN216774370U - Circuit is prevented tearing open by on-vehicle unit - Google Patents

Abstract

The utility model provides a disassembly-preventing circuit of a vehicle-mounted unit, which comprises: the spare electricity unit, prevent tearing open unit, switch unit, the control unit, the input of preventing tearing open the unit is connected to the spare electricity unit, the output of preventing tearing open the unit connects switch unit's input and the first input of control unit respectively, and control unit's output connects switch unit's control end to through the on-off state of control end control switch unit, rear circuit is connected to switch unit's output. According to the utility model, the state of the anti-dismantling unit can be detected when the anti-dismantling unit acts through the control unit, and the power supply to the rear-stage circuit is cut off by switching off the switch unit, so that the continuous work of the rear-stage circuit is avoided, the demand on the electric energy capacity of the standby power unit is smaller, and the circuit can work in a short time, so that the state detection of the anti-dismantling unit of the system is accurately realized.

Description

Circuit is prevented tearing open by on-vehicle unit

Technical Field

The utility model relates to the field of vehicle-mounted equipment, in particular to a disassembly-preventing circuit of a vehicle-mounted unit.

Background

In the use process of ETC, because the charge rates of different vehicle types are different, the vehicle-mounted unit and the vehicle need to be bound, so that the vehicle-mounted unit can only correspond to the vehicle, and the accuracy of charging is ensured.

The anti-dismantling switch of the present ETC vehicle-mounted unit needs an electronic circuit to maintain a state, namely, the state can not be powered off, and in order to avoid the influence of vehicle power maintenance and the power-off condition of a vehicle-mounted power system on the anti-dismantling switch, the vehicle-mounted unit is internally integrated with a standby capacitor for storing energy to work for a long time in order to maintain the system, so that the dismantling action detection is realized. The standby capacitor is required to have larger capacity and higher cost for realizing long-time work; in addition, the power supply of the standby capacitor is greatly influenced by temperature, the change of long-time working capacity is large, the voltage fluctuation is large, and the capacitor maintaining system is easy to break down after continuously working for a long time.

SUMMERY OF THE UTILITY MODEL

In order to achieve the above object, the present invention provides a detachment prevention circuit for an in-vehicle unit, including: the power supply comprises a standby power unit, an anti-dismantling unit, a switch unit and a control unit, wherein the standby power unit is connected with the input end of the anti-dismantling unit, the output end of the anti-dismantling unit is respectively connected with the input end of the switch unit and the first input end of the control unit, the output end of the control unit is connected with the control end of the switch unit so as to pass through the control end to control the switch state of the switch unit, and the output end of the switch unit is connected with a rear-stage circuit.

Optionally, the control unit includes a timing circuit, the timing circuit is configured to start timing when the tamper unit is closed, and when the timing circuit times out, the control unit controls the switch unit to disconnect the power supply of the subsequent circuit.

Optionally, the control unit includes a control resistor, and the control resistor is used to set the interval time of the timing circuit.

Optionally, the switch further comprises a level detection unit, a first output end of the switch unit is connected to a signal input end of the level detection unit, a second output end of the switch unit is connected to a power supply end of the level detection unit, a signal output end of the level detection unit is connected to a second input end of the control unit, and the control unit is configured to control a switching state of the switch unit according to an output signal of the level detection unit and a timing time of the timing circuit.

Optionally, still include normal electricity unit and power supply protection unit, the output of normal electricity unit is connected the first input of power supply protection unit, the second output of switch unit is connected the second input of power supply protection unit, the output of power supply protection unit is connected the feed end of level detecting element.

Optionally, the power supply protection unit includes an anti-reverse connection circuit, and the anti-reverse connection circuit is configured to prevent reverse charging of the switch unit when the normal power unit supplies power to the level detection unit or reverse charging of the normal power unit when the standby power unit supplies power to the level detection unit.

Optionally, the reverse connection preventing circuit includes a first diode and a second diode, an anode of the first diode is connected to the output end of the normally-powered unit, and a cathode of the first diode is connected to the power supply end of the level detecting unit; and the anode of the second diode is connected with the second output end of the switch unit, and the cathode of the second diode is connected with the power supply end of the level detection unit.

Optionally, the power supply unit includes: any one of a lithium ion composite capacitor, a lithium ion battery and a nickel-metal hydride battery.

Optionally, the tamper unit includes: a microswitch or a travel switch.

Optionally, the switch unit includes: any one of MOS tube, triode, load switch and relay.

The beneficial effects of the utility model are as follows: this anti-disassembly circuit installs in ETC on-board unit (OBU), detect the dismantlement condition of ETC on-board OBU mounted position department, it is concrete, can realize when preventing tearing open the unit action through the control unit, to preventing tearing open the detection of unit state, through turning off to the switch unit, in order to realize the disconnection to the power supply of back level circuit, avoid back level circuit continuous work, because this prevents that the circuit need not continuous work, therefore its energy storage capacitor can set up the capacity less, circuit operating time is short, simultaneously can accurately realize that the system prevents tearing open the switch detection action.

Drawings

Fig. 1 is a circuit block diagram of a detachment prevention circuit of a vehicle-mounted unit according to an embodiment of the present invention.

FIG. 2 is a circuit block diagram of another on-board unit tamper circuit according to an embodiment of the present invention.

Fig. 3 is a circuit block diagram of another on-board unit detachment prevention circuit according to an embodiment of the present invention.

Fig. 4 is a circuit block diagram of a further on-board unit tamper circuit according to an embodiment of the present invention.

Fig. 5 is a circuit block diagram of a further on-board unit tamper circuit according to an embodiment of the present invention.

Fig. 6 is a circuit diagram of a detachment prevention circuit of an on-board unit according to an embodiment of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to fig. 1 and the specific embodiments.

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the utility model. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

It should be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It should also be understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

As used in this specification and the appended claims, the term "if" may be interpreted contextually as "when", "upon" or "in response to" determining "or" in response to detecting ".

In accordance with a specific implementation provided by an embodiment of the present disclosure, with reference to figure 1,

the anti-dismantling circuit of the vehicle-mounted unit comprises a standby power unit, an anti-dismantling unit, a switch unit and a control unit, wherein the standby power unit is connected with an input end of the anti-dismantling unit, the standby power unit can adopt a standby energy storage device and is used for providing energy for the anti-dismantling unit to work, the standby power unit can adopt energy storage devices such as a lithium ion composite capacitor, a lithium ion battery and a nickel-hydrogen battery, and in specific implementation, the standby power unit can support the anti-dismantling circuit to realize at least one anti-dismantling detection.

The anti-dismounting unit can adopt a mechanical switch, such as a microswitch, a travel switch and other mechanical structures which can realize related functions, and is used for controlling the standby power unit to supply power to a rear-stage circuit and physically detecting mechanical dismounting actions;

the output end of the anti-dismantling unit is respectively connected with the input end of the switch unit and the first input end of the control unit, the first input end is a power supply and enabling end of the control unit, the output end of the control unit is connected with the control end of the switch unit so as to control the on-off state of the switch unit through the control end, and the output end of the switch unit is connected with the rear-stage circuit. The switch unit can be an electronic switch, and specifically can be devices such as an MOS (metal oxide semiconductor) transistor, a triode, a load switch and a relay, and is used for controlling the standby power unit to supply power to the rear-stage circuit. The control unit can realize that the state of the switch unit is controlled by detecting the output end signal of the anti-dismounting unit, for example, when the anti-dismounting unit is detected to act, the switch unit is switched off so as to switch off the power supply of the rear-stage circuit.

Through the technical scheme, the utility model has the beneficial effects that: can realize through the control unit when preventing tearing open the unit action, to preventing tearing open the detection of unit state, through turn-offeing the switch unit to realize the disconnection to the power supply of back stage circuit, avoid back stage circuit continuous operation, consequently less to the electric energy capacity demand of stand-by electricity unit, the circuit can be through short time work, and accurate realization system prevents tearing open the unit state and detects.

According to a specific implementation manner provided by the embodiment of the disclosure, as shown in fig. 2, the control unit includes a timing circuit configured to start timing when the detachment prevention unit is closed, and when the timing circuit times out, the control unit controls the switch unit to disconnect the power supply of the subsequent stage circuit. Specifically, when the anti-dismantling unit is closed, namely when the anti-dismantling switch acts, the standby power supply supplies power, the timing circuit is powered on to initialize the timing time, the switch unit is opened until the timing time of the timing unit is overtime, the control unit controls the switch unit to be closed, the standby power unit stops supplying power to the rear-stage circuit, only the timing circuit needs to be supplied with power, the timing circuit can adopt a timer with low power consumption, and at the moment, the power consumption of the anti-dismantling circuit is extremely low.

According to the specific implementation manner provided by the embodiment of the present disclosure, as shown in fig. 3, the control unit may include a control resistor R1, one end of the control resistor R1 is grounded, the other end is connected to the timing circuit, and the control resistor R1 is used to set the interval time of the timing circuit. The timing time can be adjusted by adjusting the control resistor R1, the anti-dismantling circuit works within the timing time, the timing time is exceeded, the anti-dismantling circuit does not work when power failure occurs, and the electric energy of the standby power unit is saved.

According to the specific implementation manner provided by the embodiment of the disclosure, as shown in fig. 4, the tamper circuit further includes a level detection unit, a first output terminal of the switch unit is connected to a signal input terminal (I/01) of the level detection unit, a second output terminal of the switch unit is connected to a POWER supply terminal (POWER) of the level detection unit, a signal output terminal (I/O2) of the level detection unit is connected to a second input terminal of the control unit, the second input terminal is a logic input terminal, and the control unit is configured to control a switching state of the switch unit according to an output signal of the level detection unit and a timing time of the timing circuit. Specifically, the level detecting unit is used for detecting the level, judge the action of preventing tearing open the unit, the switching element opens the back, output high level signal to level detecting element's signal input part (I/01), when level detecting element gathered the high level, it prevents tearing open the state unusually to set for on-vehicle unit, control signal output part (I/O2) output pulse signal timing circuit, timing circuit closes the switching element, level detecting element outage stop work, the stand-by power unit only supplies power for the control unit this moment, when the control unit only includes the timing element, only supply power for the timing circuit promptly, timing circuit can adopt the timing device of low-power consumption, it is extremely low to prevent tearing open the circuit consumption this moment. In the above case, the timing time of the timing circuit is longer than the entire time of detecting and outputting the pulse signal by the level detecting unit, that is, when the level detecting unit outputs the pulse to the timing circuit, the timing time of the timing circuit is not overtime, otherwise, the switching unit can be directly turned off by directly overtime of the timing circuit, and the subsequent circuit stops supplying power.

According to the specific implementation manner provided by the embodiment of the present disclosure, as shown in fig. 5, the tamper-proof circuit further includes a normal POWER unit and a POWER supply protection unit, an output end of the normal POWER unit is connected to a first input end of the POWER supply protection unit, a second output end of the switch unit is connected to a second input end of the POWER supply protection unit, and an output end of the POWER supply protection unit is connected to a POWER supply end (POWER) of the level detection unit. The normal electricity unit can be a direct current source and is used for supplying power to the anti-dismantling circuit, specifically, the negative pole of the normal electricity unit is connected with GND, and the positive pole is connected with the power supply protection unit. The power supply protection unit is used for protecting the anti-dismantling circuit when the normal power unit or the standby power unit supplies power. Specifically, the power supply protection unit includes an anti-reverse connection circuit for preventing reverse charging of the switch unit when the normal power unit supplies power to the level detection unit or reverse charging of the normal power unit when the standby power unit supplies power to the level detection unit. In one embodiment, the reverse connection preventing circuit comprises a first diode and a second diode, wherein the anode of the first diode is connected with the output end of the constant POWER unit, and the cathode of the first diode is connected with the POWER supply end (POWER) of the level detection unit; the anode of the second diode is connected with the second output end of the switch unit, and the cathode of the second diode is connected with the POWER supply end (POWER) of the level detection unit.

The following describes in detail a specific operation principle of the tamper circuit applied to the on-board unit according to the present invention with reference to fig. 6.

When the outage of normal electric power supply DC1, prevent tearing open the unit and adopt mechanical switch K1, when K1 opened, prevent tearing open the circuit outage inoperative, prevent tearing open the circuit and have no power consumption, prevent tearing open the circuit and have no electrical signal output. When the mechanical switch K1 is turned off, the energy storage device BT1 (standby power unit) supplies power to the subsequent circuit. A timer (timing circuit) U1 in the control unit is powered on to work, a control resistor R1 is set to be in a timer working mode, a timer U1 works according to a preset working mode, a timer U1 is started to conduct timing, a timer U1 turns on an electronic switch (switch unit) S1, the electronic switch S1 is conducted, and a diode D1 is conducted in the forward direction. The processor U2 (level detection unit) is powered on to work, the processor U2 is powered on to detect the state of the I/O1, at this time, the processor U2 detects that the level of the I/O1 is high, the processor U2 sets that the OBU anti-dismounting state is abnormal, the processor U2 controls the I/O2 to output a pulse signal to the timer U1, the timer U1 closes the electronic switch S1, the processor U2 is powered off to stop working, the energy storage device BT1 only supplies power to the timer U1 at this time, the timer U1 is a low-power-consumption device, and at this time, the power consumption of the anti-dismounting circuit is extremely low.

When the normal electricity unit supplies power, the diode D1 is cut off reversely, the processor U2 works normally, when the mechanical switch K1 is turned on, the anti-dismantling circuit is powered off and does not work, the anti-dismantling circuit does not have electric energy consumption, and the anti-dismantling circuit does not have electric signal output. When the mechanical switch K1 is closed, the energy storage device BT1 supplies power to the rear-stage anti-disassembly circuit. The timer U1 is powered on to work, the resistor R1 sets a timer working mode, the timer U1 works according to a preset working mode, the timer U1 is started to time, the timer U1 opens the electronic switch S1, the electronic switch S1 is conducted, the level of the I/O1 is changed to be high, the interrupt triggers the processor U2 to detect the anti-disassembly action or the processor U2 to inquire the state of the I/O1 at fixed time, at the moment, the processor U2 detects that the level of the I/O1 is high, and the processor U2 sets the anti-disassembly state of the vehicle-mounted unit to be abnormal. The processor U2 controls the I/O2 to output pulse signals to the timer U1, the timer U1 closes the electronic switch S1, and the energy storage device BT1 is prevented from supplying power to the rear-stage anti-disassembly circuit.

In addition, another application scenario exists, the processor U2 does not control the I/O2 to output a pulse signal, the resistor R1 sets a timer operation mode, at this time, the timer U1 will continue to operate in the preset operation mode until the timer U1 times out regularly, the timer U1 closes the electronic switch S1, the energy storage device BT1 stops supplying power to the processor U2, at this time, the energy storage device BT1 only supplies power to the timer U1, the timer U1 is a low-power-consumption device, and at this time, the power consumption of the anti-detachment circuit is very low.

In conclusion, the anti-dismantling circuit does not need to work continuously, the energy storage device has low power capacity requirement, and the circuit can accurately realize the detection action of the system anti-dismantling switch through short-time work.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

Units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; while the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art will appreciate that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein.

Claims (10)

1. An on-board unit tamper circuit, comprising: the power supply comprises a standby power unit, an anti-dismantling unit, a switch unit and a control unit, wherein the standby power unit is connected with the input end of the anti-dismantling unit, the output end of the anti-dismantling unit is respectively connected with the input end of the switch unit and the first input end of the control unit, the output end of the control unit is connected with the control end of the switch unit so as to pass through the control end to control the switch state of the switch unit, and the output end of the switch unit is connected with a rear-stage circuit.

2. The tamper circuit of claim 1, wherein the control unit comprises a timing circuit configured to start timing when the tamper unit is closed, and the control unit controls the switching unit to turn off the power supply of the rear stage circuit when the timing circuit times out.

3. The tamper circuit of claim 2, wherein the control unit comprises a control resistor for setting the interval of the timing circuit.

4. The tamper circuit of claim 2, further comprising a level detection unit, wherein a first output terminal of the switch unit is connected to a signal input terminal of the level detection unit, a second output terminal of the switch unit is connected to a power supply terminal of the level detection unit, a signal output terminal of the level detection unit is connected to a second input terminal of the control unit, and the control unit is configured to control a switching state of the switch unit according to an output signal of the level detection unit and a timing time of the timing circuit.

5. The tamper circuit according to claim 4, further comprising a normal power unit and a power supply protection unit, wherein an output terminal of the normal power unit is connected to a first input terminal of the power supply protection unit, a second output terminal of the switch unit is connected to a second input terminal of the power supply protection unit, and an output terminal of the power supply protection unit is connected to a power supply terminal of the level detection unit.

6. The tamper circuit of claim 5, wherein the power supply protection unit comprises a reverse connection prevention circuit for preventing reverse charging of the switching unit when the normal power unit supplies power to the level detection unit or reverse charging of the normal power unit when the backup power unit supplies power to the level detection unit.

7. The tamper circuit of claim 6, wherein the anti-reverse connection circuit comprises a first diode and a second diode, wherein an anode of the first diode is connected to the output terminal of the normally-powered unit, and a cathode of the first diode is connected to the power supply terminal of the level detection unit; and the anode of the second diode is connected with the second output end of the switch unit, and the cathode of the second diode is connected with the power supply end of the level detection unit.

8. The tamper circuit of claim 1, wherein the power backup unit comprises: any one of a lithium ion composite capacitor, a lithium ion battery and a nickel-metal hydride battery.

9. The tamper circuit of claim 1, wherein the tamper unit comprises: a microswitch or a travel switch.

10. The tamper circuit of claim 1, wherein the switching unit comprises: any one of MOS tube, triode, load switch and relay.

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