A signal detection circuit and a vehicle

Abstract

This utility model discloses a signal detection circuit and a vehicle. When two functional signals are the same, the second functional signal, after being level-flipped by an inverting amplifier, cancels out the first functional signal, thereby turning off the first isolation circuit. The second input terminal of the first comparator is at a low level, and a normal detection result signal is output. When the two functional signals are different, the second functional signal, after being level-flipped by an inverting amplifier, cannot cancel out the first functional signal, thereby automatically turning on the first isolation circuit. The second input terminal of the first comparator is connected to a first reference voltage. If the voltage at the second input terminal of the first comparator is greater than the voltage at the first input terminal, an abnormal detection result signal is output. The isolation circuit can automatically turn on when the functional signals are different, thereby switching the output of the first comparator. By outputting different signals, it reflects whether the functional signals are consistent, thereby achieving automatic and efficient detection of whether the functional signals are abnormal.

Description

Technical Field

[0001] This utility model relates to the field of power electronics technology, and in particular to a signal detection circuit and a vehicle. Background Technology

[0002] In the control process of a maglev train, the control device outputs corresponding functional signals to each controlled device, enabling each device to perform its corresponding function according to the signals. These functional signals include those used to control the maglev train's start, braking, speed adjustment, or state switching. It is evident that if any functional signal malfunctions, the maglev train cannot be safely and accurately controlled. Therefore, it is crucial to ensure that the controlled devices accurately receive these signals. Existing technologies typically employ redundant control devices to output redundant functional signals identical to the primary functional signal to the controlled devices. The controlled devices can then perform their corresponding functions upon receiving either the primary or redundant functional signal. However, any anomaly in either the primary or redundant functional signal poses a risk of the controlled devices malfunctioning. Therefore, how to detect both the primary and redundant functional signals is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0003] The purpose of this invention is to provide a signal detection circuit and a vehicle. The isolation circuit can automatically turn on when the functional signals are different, thereby switching the output of the first comparator. By outputting different signals, it reflects whether the functional signals are consistent, so as to realize automatic and efficient detection of whether the functional signals are abnormal.

[0004] To solve the above-mentioned technical problems, this utility model provides a signal detection circuit, including a first isolation circuit, a first comparator, and an inverting amplifier;

[0005] The first terminal of the first isolation circuit is connected to a first reference voltage, and the second terminal of the first isolation circuit is connected to the second input terminal of the first comparator; the first input terminal of the first comparator is connected to a preset detection signal, and the second input terminal of the first comparator is connected to the output terminal of the inverting amplifier and connected to the first function signal; the first input terminal of the inverting amplifier is connected to the second function signal, and the second input terminal of the inverting amplifier is grounded;

[0006] The inverting amplifier is used to perform level flipping processing on the second functional signal; the first isolation circuit is used to conduct when the first functional signal and the second functional signal are not the same, so that the second input terminal of the first comparator is connected to the first reference voltage; the highest voltage of the preset detection signal is less than the first reference voltage; the first comparator is used to output a first detection result normal signal when the first isolation circuit is not conducted, and to output a detection result abnormal signal when the first isolation circuit is conducted.

[0007] Preferably, the first isolation circuit includes a first isolation capacitor, the first end of the first isolation capacitor is the first end of the first isolation circuit, and the second end of the first isolation capacitor is the second end of the first isolation circuit.

[0008] Preferably, it further includes a second isolation circuit and a first pull-down resistor;

[0009] The first input terminal of the first comparator is also connected to the first reference voltage and the second reference voltage; the absolute values ​​of the first reference voltage and the second reference voltage are the same, and their polarities are opposite.

[0010] The first end of the first pull-down resistor is connected to the second reference voltage, and the second end of the first pull-down resistor is connected to the first end of the second isolation circuit.

[0011] The second terminal of the second isolation circuit is connected to the second input terminal of the first comparator, and is used to turn on when the first reference voltage and / or the second reference voltage changes, and to turn on the first isolation circuit.

[0012] Preferably, the second isolation circuit includes a second isolation capacitor, wherein the first end of the second isolation capacitor is the first end of the second isolation circuit, and the second end of the second isolation capacitor is the second end of the second isolation circuit.

[0013] Preferably, it further includes a first current-limiting resistor, a second current-limiting resistor, a third current-limiting resistor, a fourth current-limiting resistor, and a fifth current-limiting resistor;

[0014] The first end of the first current-limiting resistor is connected to the preset detection signal, and the second end of the first current-limiting resistor is connected to the first input end of the first comparator.

[0015] The first end of the second current-limiting resistor is connected to the first reference voltage, and the second end of the second current-limiting resistor is connected to the first input terminal of the first comparator.

[0016] The first end of the third current-limiting resistor is connected to the second reference voltage, and the second end of the third current-limiting resistor is connected to the first input end of the first comparator;

[0017] The first end of the fourth current-limiting resistor is connected to the first functional signal, and the second end of the fourth current-limiting resistor is connected to the second input end of the first comparator.

[0018] The first end of the fifth current-limiting resistor is connected to the output terminal of the inverting amplifier, and the second end of the fifth current-limiting resistor is connected to the second input terminal of the first comparator.

[0019] Preferably, the system further includes a filter capacitor, wherein a first end of the filter capacitor is connected to a first input terminal of the first comparator, and a second end of the filter capacitor is connected to a second input terminal of the first comparator.

[0020] Preferably, the system further includes an alarm circuit, the input of which is connected to the output of the first comparator, for triggering an alarm when an abnormal detection result signal is received.

[0021] Preferably, the preset detection signal is a square wave signal; the first normal detection result signal is a square wave signal with the same phase as the preset detection signal; the signal detection circuit further includes an output switch and a second pull-down resistor;

[0022] The control terminal of the output switch is connected to the output terminal of the first comparator. The first terminal of the output switch is connected to a preset detection voltage. The second terminal of the output switch is connected to the first terminal of the second pull-down resistor. The second terminal of the second pull-down resistor is grounded.

[0023] The output switch is used to turn on or off based on the first normal detection result signal when the first detection result signal is received, so as to output a second normal detection result signal through its second terminal, and to turn off when the detection result abnormal signal is received, so as to output a first preset low level through its second terminal.

[0024] The second detection result normal signal is a square wave signal whose phase is consistent with the phase of the preset detection signal, and whose high level is the preset detection voltage.

[0025] Preferably, it also includes a transformer, a first anti-reverse diode, a voltage regulator capacitor, and a third pull-down resistor;

[0026] The first end of the primary winding of the transformer is connected to the second end of the output switching transistor, and the second end of the primary winding of the transformer is grounded. The first end of the secondary winding of the transformer is connected to the input end of the first anti-reverse diode, the output end of the first anti-reverse diode is connected to the first end of the voltage stabilizing capacitor, the second end of the voltage stabilizing capacitor is connected to the second end of the secondary winding of the transformer and grounded, the first end of the third pull-down resistor is connected to the output end of the first anti-reverse diode, the second end of the third pull-down resistor is grounded, and the first end of the third pull-down resistor is the output end of the signal detection circuit.

[0027] The transformer is used to charge the voltage regulator capacitor when the output switch outputs the second detection result normal signal at a high level; the voltage regulator capacitor is used to discharge when the second detection result normal signal is at a low level, so that the signal detection circuit outputs a preset high level when the output switch outputs the second detection result normal signal.

[0028] The third pull-down resistor is used to pull down the voltage at the output terminal of the signal detection circuit when the output switch outputs the first preset low level, so that the signal detection circuit outputs the second preset low level.

[0029] To solve the above-mentioned technical problems, this utility model provides a vehicle including the signal detection circuit as described above.

[0030] This application provides a signal detection circuit and a vehicle. When two functional signals are identical, the second functional signal, after level inversion processing by an inverting amplifier, cancels out the first functional signal, thereby turning off the first isolation circuit. The second input terminal of the first comparator remains at a low level and outputs a normal detection result signal according to a preset detection signal. When the two functional signals are different, the second functional signal, after level inversion processing by an inverting amplifier, cannot cancel out the first functional signal, causing the first isolation circuit to automatically turn on. This connects the second input terminal of the first comparator to a first reference voltage. Since the highest voltage of the preset detection signal is lower than the first reference voltage, the voltage at the second input terminal of the first comparator is greater than the voltage at the first input terminal, resulting in an abnormal detection result signal being output. Therefore, the isolation circuit in this application can automatically turn on when the functional signals are different, thereby switching the output of the first comparator. By outputting different signals, it reflects whether the functional signals are consistent, thus achieving automatic and efficient detection of whether the functional signals are abnormal. Attached Figure Description

[0031] To more clearly illustrate the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This application provides a schematic diagram of the structure of a signal detection circuit;

[0033] Figure 2 This is a schematic diagram of the specific structure of a signal detection circuit provided in this application. Detailed Implementation

[0034] The core of this utility model is to provide a signal detection circuit and a vehicle. The isolation circuit can automatically turn on when the functional signals are different, thereby switching the output of the first comparator. By outputting different signals, it reflects whether the functional signals are consistent, so as to realize automatic and efficient detection of whether the functional signals are abnormal.

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0036] Please refer to Figure 1 , Figure 1 A schematic diagram of a signal detection circuit provided in this application includes a first isolation circuit 1, a first comparator U1, and an inverting amplifier U2;

[0037] The first terminal of the first isolation circuit 1 is connected to the first reference voltage, and the second terminal of the first isolation circuit 1 is connected to the second input terminal of the first comparator U1. The first input terminal of the first comparator U1 is connected to the preset detection signal, and the second input terminal of the first comparator U1 is connected to the output terminal of the inverting amplifier U2 and connected to the first function signal. The first input terminal of the inverting amplifier U2 is connected to the second function signal, and the second input terminal of the inverting amplifier U2 is grounded.

[0038] The inverting amplifier U2 is used to perform level flipping processing on the second function signal; the first isolation circuit 1 is used to turn on when the first function signal and the second function signal are different, so that the second input terminal of the first comparator U1 is connected to the first reference voltage; the maximum voltage of the preset detection signal is less than the first reference voltage; the first comparator U1 is used to output a first detection result normal signal when the first isolation circuit 1 is not turned on, and to output a detection result abnormal signal when the first isolation circuit 1 is turned on.

[0039] Functional signals are used for control or modulation, and their accuracy is directly related to the normal operation of the entire system. Therefore, to prevent system malfunction due to abnormal functional signals, redundant functional signals are usually set up. These redundant signals are identical to the primary functional signals, and control can be switched to the redundant signals when the primary functional signal is abnormal. However, while the redundant signals can ensure normal system operation when the primary functional signal is abnormal, an abnormal primary functional signal may indicate a malfunction in the control device that outputs the primary functional signal. If the functional signal is only switched when the primary functional signal is abnormal, operators can only confirm that the system is operating normally, but cannot determine whether the primary functional signal is abnormal. Alternatively, if the primary functional signal is normal but the redundant functional signal is abnormal, although no switching is necessary, switching to the redundant signals after the primary functional signal becomes abnormal still cannot guarantee normal system operation.

[0040] Based on this, an inverting amplifier circuit is provided in this application. When the first functional signal and the second functional signal are the same, the first isolation circuit 1 is in the off state. The inverting amplifier circuit outputs a signal with the opposite potential to the first functional signal after level inversion of the second functional signal. For example, when both the first functional signal and the second functional signal are 000111, the inverting amplifier U2 outputs 111000 after level inversion of the second functional signal. The voltage after the two are superimposed is 000000. At this time, the levels of the first functional signal and the signal output by the inverting amplifier U2 cancel each other out. The voltage at the second terminal of the first isolation circuit 1 is low, and the first isolation circuit 1 remains in the off state. The second input terminal of the first comparator U1 is pulled low. The first input terminal of the first comparator U1 is also connected to a preset detection signal. Then the first comparator U1 can output a high level when the level of the preset detection signal is greater than the low level of the second input terminal, and output a low level when the level of the preset detection signal is not greater than the low level of the second input terminal. That is, it outputs a normal detection result signal to reflect that the two functional signals are the same. Conversely, if either the first functional signal or the second functional signal changes, for example, if the first functional signal remains 000111 while the second functional signal becomes 000011, the inverting amplifier U2 will convert the second functional signal to 111100. At this time, the two signals are superimposed and become 000100. The voltage at the second terminal of the first isolation circuit 1 is not 0, that is, it is not low. The first isolation circuit 1 confirms that the first functional signal and the second functional signal are not the same and is turned on. The voltage at the second input terminal of the first comparator U1 is pulled up to the first reference voltage by the first isolation circuit 1. Then, the voltage at the second input terminal of the first comparator U1 remains greater than the voltage of the preset detection signal at the first input terminal. The first comparator U1 outputs an abnormal detection result signal to reflect that the two functional signals are different.

[0041] As can be seen, by setting the inverting amplifier U2, when the two functional signals are the same, the level of the second terminal of the first isolation circuit 1 or the second input terminal of the first comparator U1 can be set to a low level. When the two functional signals are different, the levels of the second functional signal after level inversion and the first functional signal cannot cancel each other out, thereby automatically turning on the first isolation circuit 1, which in turn switches the level of the first input terminal and the second input terminal of the first comparator U1, so that the output of the first comparator U1 changes with the sameness and difference of the two functional signals, thereby realizing the detection of whether the two functional signals are consistent.

[0042] It should be noted that the first input terminal of the first comparator U1 is the positive input terminal, and the second input terminal is the negative input terminal. The first function signal is the main function signal, and the second function signal is the redundant function signal, or the first function signal is the redundant function signal, and the second function signal is the main redundant function signal; this application does not limit this.

[0043] In summary, the isolation circuit can automatically turn on when the functional signals are different, thereby switching the output of the first comparator U1. By outputting different signals, it reflects whether the functional signals are consistent, so as to realize automatic and efficient detection of whether the functional signals are abnormal.

[0044] Based on the above embodiments:

[0045] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the specific structure of a signal detection circuit provided in this application.

[0046] In a preferred embodiment, the first isolation circuit 1 includes a first isolation capacitor C1, the first end of the first isolation capacitor C1 being the first end of the first isolation circuit 1, and the second end of the first isolation capacitor C1 being the second end of the first isolation circuit 1.

[0047] In the first isolation circuit 1, the first isolation capacitor C1 is connected between the first reference voltage and the second input terminal of the first comparator U1. Therefore, the second terminal of the first isolation capacitor C1 is also connected to the first functional signal and the output terminal of the inverting amplifier U2. When the first functional signal and the second functional signal are the same, the voltages at the output terminals of the first functional signal and the inverting amplifier U2 cancel each other out, and the voltage at the second terminal of the first isolation capacitor C1 remains stable. The first isolation capacitor C1 is in a voltage isolation state, and the second input terminal of the first comparator U1 is not connected to the first reference voltage through the first isolation capacitor C1, but rather to the first functional signal and the output terminal of the inverting amplifier U2. When the voltages cancel each other out and the voltage level is low, the voltage at the first input terminal of the first comparator U1 is greater than the voltage at the second input terminal, and the first comparator U1 outputs a normal detection result signal. When the first function signal and / or the second function signal changes, causing a difference between the first function signal and the second function signal, the first isolation capacitor C1 conducts due to the change in the voltage at its second terminal, that is, the first isolation capacitor C1 is charged or discharged, allowing AC current to pass through, connecting the second input terminal of the first comparator U1 to the first reference voltage. When the voltage at the first input terminal of the first comparator U1 is less than the voltage at the second input terminal, the first comparator U1 outputs an abnormal detection result signal.

[0048] In a preferred embodiment, it further includes a second isolation circuit and a first pull-down resistor R1;

[0049] The first input terminal of the first comparator U1 is also connected to a first reference voltage and a second reference voltage; the absolute values ​​of the first reference voltage and the second reference voltage are the same, and their polarities are opposite.

[0050] The first end of the first pull-down resistor R1 is connected to the second reference voltage, and the second end of the first pull-down resistor R1 is connected to the first end of the second isolation circuit.

[0051] The second terminal of the second isolation circuit is connected to the second input terminal of the first comparator U1, and is used to turn on when the first reference voltage and / or the second reference voltage changes, and to turn on the first isolation circuit 1.

[0052] In this embodiment, the detection of the first reference voltage and the second reference voltage is added. The accuracy of the first reference voltage and the second reference voltage is a prerequisite for the stable operation of the control system. If the first reference voltage and / or the second reference voltage is abnormal, the control system will not be able to work properly.

[0053] Based on this, the first input terminal of the first comparator U1 is also connected to the first reference voltage and the second reference voltage. Since the absolute values ​​of the first reference voltage and the second reference voltage are the same and their polarities are opposite when the first reference voltage and the second reference voltage are connected to the first input terminal of the first comparator U1 at the same time, the first reference voltage and the second reference voltage cancel each other out, so that the input signal of the first input terminal of the first comparator U1 is still the preset detection signal. The second input terminal of the first comparator U1 is connected to the second reference voltage through the first pull-down resistor R1 and the second isolation circuit. When the first reference voltage and the second reference voltage are normal, the first isolation circuit 1 and the second isolation circuit are both in the off state. If the first function signal and the second function signal are consistent, the level of the second input terminal of the first comparator U1 is still the low level after the first function signal and the output signal of the inverting amplifier U2 cancel each other out. The first comparator U1 outputs a normal detection result signal. If the first function signal and the second function signal are inconsistent, the level of the second input terminal of the first comparator U1 is connected to the first reference voltage by the first isolation circuit 1. The first comparator U1 outputs an abnormal detection result signal.

[0054] If the first reference voltage and / or the second reference voltage are abnormal, that is, when the first reference voltage and / or the second reference voltage change, the second isolation circuit is turned on, which in turn turns on the first isolation circuit 1. Due to the limitation of the first pull-down resistor R1, the level of the second input terminal of the first comparator U1 will not be pulled down to the second reference voltage by the second isolation circuit, but will be pulled up to the first reference voltage by the first isolation circuit 1. The first comparator U1 outputs an abnormal detection result signal.

[0055] It should be noted that the first reference voltage is a high voltage and the second reference voltage is a low voltage, such as the first reference voltage being +10V and the second reference voltage being -10V. Of course, this application does not limit this.

[0056] In a preferred embodiment, the second isolation circuit includes a second isolation capacitor C2, the first terminal of the second isolation capacitor C2 being the first terminal of the second isolation circuit, and the second terminal of the second isolation capacitor C2 being the second terminal of the second isolation circuit.

[0057] In the second isolation circuit, the second isolation capacitor C2 is connected between the second reference voltage and the first pull-down resistor R1. Therefore, when the first functional signal and the second functional signal are the same, and the first reference voltage and / or the second reference voltage remain unchanged, the voltage at the first terminals of the first isolation capacitor C1 and the second isolation capacitor C2 remains stable. Both the first isolation capacitor C1 and the second isolation capacitor C2 remain in the off state, i.e., in the isolated state. The second input terminal of the first comparator U1 is not connected to the first reference voltage through the first isolation capacitor C1, but is instead connected to a low level after the first functional signal and the voltage at the output terminal of the inverting amplifier U2 cancel each other out. The voltage at the first input terminal of the first comparator U1 is greater than the voltage at the second input terminal. 1. Output a normal detection result signal; When the first reference voltage and / or the second reference voltage change, the voltage at the first terminal of the first isolation capacitor C1 changes and turns on, and / or the voltage at the first terminal of the second isolation capacitor C2 changes and turns on. When the voltage at the first terminal of the second isolation capacitor C2 changes and turns on, the voltage at the second terminal of the first isolation capacitor C1 also changes and turns on. Therefore, no matter which of the first reference voltage and / or the second reference voltage changes, the first isolation capacitor C1 will turn on, thereby connecting the second input terminal of the first comparator U1 to the first reference voltage. When the voltage at the first input terminal of the first comparator U1 is less than the voltage at the second input terminal, the first comparator U1 outputs an abnormal detection result signal.

[0058] Based on this, the abnormal signal output by the first comparator U1 can not only indicate that the functional signal is abnormal, but also that the reference voltage is abnormal.

[0059] In a preferred embodiment, it further includes a first current-limiting resistor R11, a second current-limiting resistor R12, a third current-limiting resistor R13, a fourth current-limiting resistor R14, and a fifth current-limiting resistor R15;

[0060] The first end of the first current-limiting resistor R11 is connected to a preset detection signal, and the second end of the first current-limiting resistor R11 is connected to the first input end of the first comparator U1.

[0061] The first end of the second current-limiting resistor R12 is connected to the first reference voltage, and the second end of the second current-limiting resistor R12 is connected to the first input terminal of the first comparator U1.

[0062] The first end of the third current-limiting resistor R13 is connected to the second reference voltage, and the second end of the third current-limiting resistor R13 is connected to the first input end of the first comparator U1.

[0063] The first terminal of the fourth current-limiting resistor R14 is connected to the first functional signal, and the second terminal of the fourth current-limiting resistor R14 is connected to the second input terminal of the first comparator U1.

[0064] The first end of the fifth current-limiting resistor R15 is connected to the output of the inverting amplifier U2, and the second end of the fifth current-limiting resistor R15 is connected to the second input of the first comparator U1.

[0065] If the input voltage of the first comparator U1 is too high, it may cause the first comparator U1 to burn out due to surge current in the internal circuit, thereby affecting the normal operation of the entire circuit. Based on this, in this embodiment, a first current-limiting resistor R11, a second current-limiting resistor R12, a third current-limiting resistor R13, a fourth current-limiting resistor R14, and a fifth current-limiting resistor R15 are set to limit the current input to the first input terminal and the second input terminal of the first comparator U1, so as to protect the first comparator U1 and avoid damage to the first comparator U1 due to large input current.

[0066] In a preferred embodiment, a filter capacitor C3 is also included. The first end of the filter capacitor C3 is connected to the first input terminal of the first comparator U1, and the second end of the filter capacitor C3 is connected to the second input terminal of the first comparator U1.

[0067] In this embodiment, a filter capacitor C3 is set between the first input terminal and the second input terminal of the first comparator U1 to prevent the first comparator U1 from outputting an incorrect signal when voltage fluctuations occur at the first input terminal and / or the second input terminal, thereby improving the accuracy of the detection results.

[0068] For example, if the input voltage at the first input terminal of the first comparator U1 fluctuates and becomes less than the input voltage at the second input terminal of the first comparator U1, the filter capacitor C3 is provided to suppress the fluctuation of the input voltage at the first input terminal of the first comparator U1, thereby preventing the first comparator U1 from erroneously outputting an abnormal signal of the detection result, which would lead to the failure of the detection result.

[0069] In a preferred embodiment, an alarm circuit is also included, the input of which is connected to the output of the first comparator U1, for triggering an alarm when an abnormal detection result signal is received.

[0070] This embodiment also includes an alarm circuit. When the alarm circuit receives an abnormal signal from the detection result, it will issue an abnormal alarm to alert the staff that the function signal is abnormal and / or the reference voltage is abnormal.

[0071] In addition, a controller can be set up, which is connected between the output of the first comparator U1 and the input of the alarm circuit. When the controller receives an abnormal detection result signal, it controls the alarm circuit to sound an alarm. Of course, this application does not limit this.

[0072] In a preferred embodiment, the preset detection signal is a square wave signal; the first detection result normal signal is a square wave signal with the same phase as the preset detection signal; the signal detection circuit also includes an output switch G1 and a second pull-down resistor R2;

[0073] The control terminal of the output switch G1 is connected to the output terminal of the first comparator U1. The first terminal of the output switch G1 is connected to a preset detection voltage, and the second terminal of the output switch G1 is connected to the first terminal of the second pull-down resistor R2. The second terminal of the second pull-down resistor R2 is grounded. The output switch G1 is used to turn on or off based on the first normal detection result signal when it receives the first normal detection result signal, so as to output a second normal detection result signal through its second terminal. When it receives an abnormal detection result signal, it turns off, so as to output a first preset low level through its second terminal. The second normal detection result signal has the same phase as the preset detection signal, and the high level is a square wave signal of the preset detection voltage.

[0074] In this embodiment, an additional output switch G1 and a second pull-down resistor R2 are provided to convert the first normal detection result signal output by the first comparator U1 into a second normal detection result signal. This is to prevent the high-level voltage of the first normal detection result signal from being too low when the operating voltage of the first comparator U1 is low, which would prevent the back-end alarm circuit or control circuit from accurately identifying the first normal detection result signal and thus causing a misjudgment. The high level of the second normal detection result signal is a preset detection voltage to ensure that the back-end alarm circuit or control circuit can accurately identify and promptly distinguish the second normal detection result signal, thereby improving the accuracy of the detection result.

[0075] Specifically, the preset detection signal is a square wave signal, which is an alternating high and low level signal. When the first functional signal and the second functional signal are the same, the first isolation circuit is in the off state, the input of the first input terminal of the first comparator U1 is the preset detection signal, and the input of the second input terminal of the first comparator U1 is low. When the preset detection signal is high, the voltage at the first input terminal of the first comparator U1 is greater than the voltage at the second input terminal, and the first comparator U1 outputs a high level. When the preset detection signal is low, the voltage at the first input terminal of the first comparator U1 is the same as the voltage at the second input terminal, and the first comparator U1 outputs a low level. Based on this, the phase of the first detection result normal signal output by the first comparator U1 is consistent with the phase of the preset detection signal. When the preset detection signal is high, the first normal detection result signal is high; when the preset detection signal is low, the first normal detection result signal is low. When the first function signal and / or the second function signal change, or when the first function signal and the second function signal are inconsistent, the first isolation circuit is turned on. The input of the first input terminal of the first comparator U1 is the preset detection signal, and the input of the second input terminal of the first comparator U1 is the first reference voltage. Since the highest voltage of the preset detection signal is less than the first reference voltage, regardless of whether the preset detection signal is high or low, the voltage of the first input terminal of the first comparator U1 is less than the voltage of the second input terminal. The first comparator U1 maintains a low-level output, and the detection result abnormal signal output by the first comparator U1 is low.

[0076] When the first comparator U1 outputs a normal detection result signal, if the signal is high, the output switch G1 is turned on, and the output voltage at the second terminal of G1 is the preset detection voltage. If the signal is low, G1 is turned off, and the output voltage at the second terminal is low. In this case, the phase of the normal second detection result signal is the same as the phase of the normal first detection result signal, but the maximum voltage of the normal second detection result signal is different from that of the normal first detection result signal. Therefore, when the operating voltage of the first comparator U1 is low, by making the preset detection voltage higher than the operating voltage of the first comparator U1, the maximum voltage of the normal second detection result signal can be greater than that of the normal first detection result signal. This makes it easier for subsequent circuits to identify the normal second detection result signal and determine if the first and second functional signals are consistent. When the first comparator U1 outputs an abnormal detection result signal, G1 is turned off, and the output voltage at the second terminal of G1 is pulled low by the second pull-down resistor R2 to the first preset low level.

[0077] It should be noted that the preset detection voltage can be 5V, and this application does not limit it.

[0078] As a preferred embodiment, it also includes a transformer T1, a first anti-reverse diode D1, a voltage regulator capacitor C3, and a third pull-down resistor R3;

[0079] The first end of the primary winding of transformer T1 is connected to the second end of the output switch transistor. The second end of the primary winding of transformer T1 is grounded. The first end of the secondary winding of transformer T1 is connected to the input end of the first anti-reverse diode D1. The output end of the first anti-reverse diode D1 is connected to the first end of the voltage stabilizing capacitor C3. The second end of the voltage stabilizing capacitor C3 is connected to the second end of the secondary winding of transformer T1 and grounded. The first end of the third pull-down resistor R3 is connected to the output end of the first anti-reverse diode D1. The second end of the third pull-down resistor R3 is grounded. The first end of the third pull-down resistor R3 is the output end of the signal detection circuit.

[0080] Transformer T1 is used to charge the voltage regulator capacitor C3 when the output switch tube outputs a high-level second detection result normal signal; voltage regulator capacitor C3 is used to discharge when the second detection result normal signal is low-level, so that the signal detection circuit outputs a preset high level when the output switch tube outputs a second detection result normal signal.

[0081] The third pull-down resistor R3 is used to pull down the voltage at the output terminal of the signal detection circuit when the output switch outputs the first preset low level, so that the signal detection circuit outputs the second preset low level.

[0082] In this embodiment, considering that the second detection result normal signal output by the output switch is a square wave signal, the back-end circuit needs to identify the output signal of the output switch. For example, when the back-end circuit receives a low voltage output from the output switch, it cannot directly determine that the first function signal and the second function signal are inconsistent or that the first reference voltage and / or the second reference voltage have changed. Instead, it needs to wait for a period of time to determine whether the voltage output by the output switch has changed from low voltage to high voltage, thereby determining whether the output signal of the output switch is the second detection result normal signal. This results in a delay in the identification of the output signal of the output switch and may also lead to misjudgment.

[0083] Based on this, in this embodiment, transformer T1 is connected to the second terminal of the output switch. When the second terminal of the output switch outputs a second normal detection result signal, the primary coil of transformer T1 transmits the second normal detection result signal to the secondary coil. When the second normal detection result signal is high, the secondary coil transmits the high level of the second normal detection result signal to the output terminal of the signal detection circuit through the first diode, while also charging the voltage regulator capacitor C3. When the second normal detection result signal is low, the voltage regulator capacitor C3 discharges to ensure that the output terminal of the signal detection circuit remains high. That is, as long as the output switch outputs the second normal detection result signal, the signal detection circuit maintains a preset high-level output. Conversely, if the second terminal of the output switch outputs a first preset low level, no current is transmitted in either the primary or secondary coil, and the voltage regulator capacitor C3 cannot charge or discharge. In this case, the voltage at the output terminal of the signal detection circuit is pulled to ground by the third pull-down resistor R3, thereby making the voltage at the output terminal of the signal detection circuit the second preset low level.

[0084] As can be seen, when the first functional signal and the second functional signal are consistent, and both the first reference voltage and the second reference voltage remain normal, the signal detection circuit continuously outputs a preset high level. When the first functional signal and the second functional signal are inconsistent, or when the first reference voltage and / or the second reference voltage change, the signal detection circuit continuously outputs a second preset low level. Based on this, the back-end circuit can directly determine the state of the first functional signal, the second functional signal, the first reference voltage, and the second reference voltage by whether the output of the signal detection circuit is a preset high level or a second preset low level, thus simplifying the signal identification process of the back-end circuit.

[0085] The signal detection circuit is now described with reference to a specific embodiment:

[0086] The first end of the first current-limiting resistor R11 is connected to a preset detection signal, and the second end of the first current-limiting resistor R11 is connected to the first input end of the first comparator U1.

[0087] The first end of the second current-limiting resistor R12 is connected to the first reference voltage, and the second end of the second current-limiting resistor R12 is connected to the first input terminal of the first comparator U1.

[0088] The first end of the third current-limiting resistor R13 is connected to the second reference voltage, and the second end of the third current-limiting resistor R13 is connected to the first input end of the first comparator U1.

[0089] The first terminal of the fourth current-limiting resistor R14 is connected to the first functional signal, and the second terminal of the fourth current-limiting resistor R14 is connected to the second input terminal of the first comparator U1.

[0090] The first input terminal of the inverting amplifier U2 is connected to the second function signal, and the second input terminal of the inverting amplifier U2 is grounded.

[0091] The first end of the fifth current-limiting resistor R15 is connected to the output terminal of the inverting amplifier U2, and the second end of the fifth current-limiting resistor R15 is connected to the second input terminal of the first comparator U1.

[0092] The first terminal of the first isolation capacitor C1 is connected to the first reference voltage, and the second terminal of the first isolation capacitor C1 is connected to the second input terminal of the first comparator U1.

[0093] The first end of the first pull-down resistor R1 is connected to the second reference voltage, and the second end of the first pull-down resistor R1 is connected to the first end of the second isolation capacitor C2.

[0094] The second terminal of the second isolation capacitor C2 is connected to the second input terminal of the first comparator U1;

[0095] The first terminal of the filter capacitor C3 is connected to the first input terminal of the first comparator U1, and the second terminal of the filter capacitor C3 is connected to the second input terminal of the first comparator U1.

[0096] The control terminal of the output switch G1 is connected to the output terminal of the first comparator U1, the first terminal of the output switch G1 is connected to a preset detection voltage, and the second terminal of the output switch G1 is connected to the first terminal of the second pull-down resistor R2.

[0097] The second terminal of the second pull-down resistor R2 is grounded;

[0098] The first end of the primary winding of transformer T1 is connected to the second end of the output switch transistor. The second end of the primary winding of transformer T1 is grounded. The first end of the secondary winding of transformer T1 is connected to the input end of the first anti-reverse diode D1. The output end of the first anti-reverse diode D1 is connected to the first end of the voltage stabilizing capacitor C3. The second end of the voltage stabilizing capacitor C3 is connected to the second end of the secondary winding of transformer T1 and grounded. The input end of the second anti-reverse diode D2 is connected to the first end of the voltage stabilizing capacitor C3. The output end of the second anti-reverse diode D2 is connected to the first end of the third pull-down resistor R3. The second end of the third pull-down resistor R3 is grounded. The input end of the alarm circuit or controller is connected to the first end of the third pull-down resistor R3.

[0099] If the first reference voltage is +10V, the second reference voltage is -10V, and the preset detection signal is a square wave signal with a high level of 5V, and the preset detection voltage is 5V, when the first function signal and the second function signal are consistent, and both the first reference voltage and the second reference voltage are normal, at the first input terminal of the first comparator U1, the first reference voltage +10V and the second reference voltage -10V cancel each other out, and only the preset detection signal is input to the first input terminal of the first comparator U1; at the second input terminal of the first comparator U1, both the first isolation capacitor C1 and the second isolation capacitor C2 are in the off state. Due to the inverting processing of the inverting amplifier, the output of the inverting amplifier and the first function signal cancel each other out, and only a low level is input to the second input terminal of the first comparator U1. The first comparator U1 outputs a first detection result normal signal, and the second terminal of the output switch G1 outputs a second detection result normal signal. Transformer T1 is in When the second detection result normal signal is high, the voltage regulator capacitor C3 is charged, and the second detection result normal signal is output in the form of a preset high level through the first anti-reverse diode D1 and the second anti-reverse diode D2. When the second detection result normal signal is low, the transformer T1 does not charge the voltage regulator capacitor C3, and the voltage regulator capacitor C3 is in a discharging state. The voltage regulator capacitor C3 outputs the stored electrical energy in the form of a preset high level through the first anti-reverse diode D1 and the second anti-reverse diode D2. When the first function signal and the second function signal are consistent, and the first reference voltage and the second reference voltage are both normal, the alarm circuit receives the preset high level, thus not performing an abnormal alarm, or providing a prompt that the signal and reference voltage are both normal; or the controller continuously receives the preset high level, thus confirming that the first function signal and the second function signal are consistent, and that the first reference voltage and the second reference voltage are both normal.

[0100] When the first function signal and the second function signal are inconsistent, but both the first reference voltage and the second reference voltage are normal, the first reference voltage +10V and the second reference voltage -10V cancel each other out at the first input terminal of the first comparator U1. Only the preset detection signal is input at the first input terminal of the first comparator U1. The output of the inverting amplifier and the first function signal cannot cancel each other out. The first isolation capacitor C1 is turned on. The input voltage at the second input terminal of the first comparator U1 is the first reference voltage. The first comparator U1 outputs an abnormal detection result signal. The second terminal of the output switch G1 outputs the first preset low level. The transformer T1 is not turned on, and the voltage regulator C3 does not charge or discharge. The voltage at the output terminal of the second anti-reverse diode D2 is pulled down to the second preset low level by the third pull-down resistor R3. The alarm circuit and the control circuit continuously receive the second preset level and continuously perform abnormal alarms or determine the abnormality of the inconsistency between the current first function signal and the second function signal.

[0101] When the first function signal and the second function signal are the same, but the first reference voltage and / or the second reference voltage change, such as the first reference voltage changing from +10V to +5V while the second reference voltage remains -10V, at the first input of the first comparator U1, the first reference voltage +5V and the second reference voltage -10V cannot cancel each other out. The remaining -5V voltage after cancellation is superimposed on the preset detection signal. The preset detection signal, originally a square wave signal with a high level of 5V and a low level of 0V, is distorted into a square wave signal with a high level of 0V and a low level of -5V. The preset detection signal input to the first input of the first comparator U1 is distorted; the second input of the first comparator U1... At the terminal, both the first isolation capacitor C1 and the second isolation capacitor C2 are turned on. The second input terminal of the first comparator U1 is only input with the first reference voltage +5V. The voltage at the second input terminal of the first comparator U1 is greater than the highest voltage of the preset detection signal at the first input terminal. The first comparator U1 outputs an abnormal detection result signal, and the second terminal of the output switch G1 outputs the first preset low level. The transformer T1 is not turned on, and the voltage regulator capacitor C3 does not charge or discharge. The voltage at the output terminal of the second anti-reverse diode D2 is pulled down to the second preset low level by the third pull-down resistor R3. The alarm circuit and the control circuit continuously receive the second preset level and continuously perform abnormal alarms or determine the abnormality that the current first reference voltage and / or the second reference voltage are inconsistent.

[0102] It should be noted that the first anti-reverse diode D1 is used to prevent the voltage regulator capacitor C3 from discharging in reverse to the secondary coil of the transformer and short-circuiting the first end of the third pull-down resistor R3 when the voltage regulator capacitor C3 is discharging. The second anti-reverse diode D2 is used to prevent the output terminal of the signal detection circuit, that is, the first end of the third pull-down resistor R3, from charging the voltage regulator capacitor in reverse when the output switch G1 outputs the first preset low level, or to prevent the alarm circuit or controller connected to the first end of the third pull-down resistor R3 from charging the voltage regulator capacitor in reverse. In addition, the first anti-reverse diode D1 prevents the first end of the third pull-down resistor R3 from supplying power to the secondary coil of the transformer T1 in reverse.

[0103] The vehicle described in this application includes the signal detection circuit described above.

[0104] For an introduction to the vehicle provided by this utility model, please refer to the above-described embodiment of the signal detection circuit; this utility model will not be described in detail here.

[0105] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes said element.

[0106] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A signal detection circuit, characterized in that, It includes a first isolation circuit, a first comparator, and an inverting amplifier; The first terminal of the first isolation circuit is connected to a first reference voltage, and the second terminal of the first isolation circuit is connected to the second input terminal of the first comparator; the first input terminal of the first comparator is connected to a preset detection signal, and the second input terminal of the first comparator is connected to the output terminal of the inverting amplifier and connected to a first function signal; the first input terminal of the inverting amplifier is connected to a second function signal, and the second input terminal of the inverting amplifier is grounded; The inverting amplifier is used to perform level flipping processing on the second functional signal; The first isolation circuit is used to turn on when the first functional signal and the second functional signal are different, so that the second input terminal of the first comparator is connected to the first reference voltage; The highest voltage of the preset detection signal is less than the first reference voltage; The first comparator is used to output a normal detection result signal when the first isolation circuit is not turned on, and to output an abnormal detection result signal when the first isolation circuit is turned on.

2. The signal detection circuit as described in claim 1, characterized in that, The first isolation circuit includes a first isolation capacitor, the first end of the first isolation capacitor is the first end of the first isolation circuit, and the second end of the first isolation capacitor is the second end of the first isolation circuit.

3. The signal detection circuit as described in claim 1, characterized in that, It also includes a second isolation circuit and a first pull-down resistor; The first input terminal of the first comparator is also connected to the first reference voltage and the second reference voltage; the absolute values ​​of the first reference voltage and the second reference voltage are the same, and their polarities are opposite. The first end of the first pull-down resistor is connected to the second reference voltage, and the second end of the first pull-down resistor is connected to the first end of the second isolation circuit. The second terminal of the second isolation circuit is connected to the second input terminal of the first comparator, and is used to turn on when the first reference voltage and / or the second reference voltage changes, and to turn on the first isolation circuit.

4. The signal detection circuit as described in claim 3, characterized in that, The second isolation circuit includes a second isolation capacitor, the first end of which is the first end of the second isolation circuit, and the second end of which is the second end of the second isolation circuit.

5. The signal detection circuit as described in claim 3, characterized in that, It also includes a first current-limiting resistor, a second current-limiting resistor, a third current-limiting resistor, a fourth current-limiting resistor, and a fifth current-limiting resistor; The first end of the first current-limiting resistor is connected to the preset detection signal, and the second end of the first current-limiting resistor is connected to the first input end of the first comparator. The first end of the second current-limiting resistor is connected to the first reference voltage, and the second end of the second current-limiting resistor is connected to the first input terminal of the first comparator. The first end of the third current-limiting resistor is connected to the second reference voltage, and the second end of the third current-limiting resistor is connected to the first input end of the first comparator; The first end of the fourth current-limiting resistor is connected to the first functional signal, and the second end of the fourth current-limiting resistor is connected to the second input end of the first comparator. The first end of the fifth current-limiting resistor is connected to the output terminal of the inverting amplifier, and the second end of the fifth current-limiting resistor is connected to the second input terminal of the first comparator.

6. The signal detection circuit as described in claim 1, characterized in that, It also includes a filter capacitor, the first end of which is connected to the first input terminal of the first comparator, and the second end of which is connected to the second input terminal of the first comparator.

7. The signal detection circuit as described in claim 1, characterized in that, It also includes an alarm circuit, the input of which is connected to the output of the first comparator, for triggering an alarm when an abnormal detection result signal is received.

8. The signal detection circuit as described in any one of claims 1-7, characterized in that, The preset detection signal is a square wave signal; the first normal detection result signal is a square wave signal with the same phase as the preset detection signal; the signal detection circuit also includes an output switch and a second pull-down resistor; The control terminal of the output switch is connected to the output terminal of the first comparator. The first terminal of the output switch is connected to a preset detection voltage. The second terminal of the output switch is connected to the first terminal of the second pull-down resistor. The second terminal of the second pull-down resistor is grounded. The output switch is used to turn on or off based on the first normal detection result signal when the first detection result signal is received, so as to output a second normal detection result signal through its second terminal, and to turn off when the detection result abnormal signal is received, so as to output a first preset low level through its second terminal. The second detection result normal signal is a square wave signal whose phase is consistent with the phase of the preset detection signal, and whose high level is the preset detection voltage.

9. The signal detection circuit as described in claim 8, characterized in that, It also includes a transformer, a first anti-reverse diode, a voltage regulator capacitor, and a third pull-down resistor; The first end of the primary winding of the transformer is connected to the second end of the output switching transistor, and the second end of the primary winding of the transformer is grounded. The first end of the secondary winding of the transformer is connected to the input end of the first anti-reverse diode, the output end of the first anti-reverse diode is connected to the first end of the voltage stabilizing capacitor, the second end of the voltage stabilizing capacitor is connected to the second end of the secondary winding of the transformer and grounded, the first end of the third pull-down resistor is connected to the output end of the first anti-reverse diode, the second end of the third pull-down resistor is grounded, and the first end of the third pull-down resistor is the output end of the signal detection circuit. The transformer is used to charge the voltage regulator capacitor when the output switch outputs the second detection result normal signal at a high level; the voltage regulator capacitor is used to discharge when the second detection result normal signal is at a low level, so that the signal detection circuit outputs a preset high level when the output switch outputs the second detection result normal signal. The third pull-down resistor is used to pull down the voltage at the output terminal of the signal detection circuit when the output switch outputs the first preset low level, so that the signal detection circuit outputs the second preset low level.

10. A vehicle, characterized in that, Includes the signal detection circuit as described in any one of claims 1-9.

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