AC and DC current trigger circuit, switch machine monitoring unit and railway signal lightning protection distribution cabinet

Abstract

The disclosure relates to an AC / DC current trigger circuit, a switch machine monitoring unit and a railway signal lightning protection distribution cabinet. The AC / DC current trigger circuit comprises a voltage conversion module configured to output a voltage signal according to a measured current; a window comparison module configured to compare an upper threshold voltage and a lower threshold voltage of the voltage signal, and output a high level signal or a low level signal according to a comparison result; a detection discharge module configured to output a high level signal in the case that the window comparison module outputs a high level signal, and output a high level signal in the case that a duration of a low level signal output after the window comparison module outputs a high level signal is less than or equal to a time threshold, and output a low level signal in the case that the duration is greater than the time threshold; and a shaping module configured to shape a level signal output by the detection discharge module into a square wave trigger signal, and output the square wave trigger signal. The AC / DC current trigger circuit can trigger AC signals and DC signals.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of electronics, in particular to an AC / DC current trigger circuit, a switch machine monitoring unit and a railway signal lightning protection distribution cabinet. BACKGROUND

[0002] The current threshold trigger module or window comparator will generate a square wave signal with the same frequency as the AC signal when facing an AC signal, instead of a continuous trigger signal. Therefore, the current threshold trigger module or window comparator only triggers for DC signals, and cannot trigger for AC signals. SUMMARY

[0003] The purpose of the present disclosure is to provide an AC / DC current trigger circuit, a switch machine monitoring unit and a railway signal lightning protection distribution cabinet to solve the above problems.

[0004] To achieve the above purpose, the present disclosure provides an AC / DC current trigger circuit, comprising: a voltage conversion module, a window comparison module, a detection and discharge module and a shaping module connected in sequence;

[0005] The voltage conversion module is used to output a voltage signal according to the measured current;

[0006] The window comparison module is used to compare the voltage signal with the upper threshold voltage and the lower threshold voltage of the window comparison module, and output a high level signal or a low level signal according to the comparison result;

[0007] The detection and discharge module is used to output a high level signal when the window comparison module outputs a high level signal, and output a high level signal when the duration of the low level signal output after the window comparison module outputs a high level signal is less than or equal to a time threshold, and output a low level signal when the duration is greater than the time threshold;

[0008] The shaping module is used to shape the level signal output by the detection and discharge module into a square wave trigger signal, and output the square wave trigger signal.

[0009] Optionally, the detection and discharge module comprises a first capacitor, a first resistor, a first power switch, a first diode, a second power switch and a second capacitor, the first power switch is an NPN triode, and the second power switch is a PNP triode;

[0010] The first end of the first capacitor is connected with the output end of the window comparison module, the second end of the first capacitor is grounded, the first end of the first resistor is connected with the first end of the first capacitor, the second end of the first resistor is grounded, the collector of the first power switch is connected with the first end of the first resistor, the emitter is grounded, the base is connected with the collector of the second power switch, the anode of the first diode is connected with the collector of the first power switch, the cathode is connected with the emitter of the second power switch, the base of the second power switch is connected with the collector of the first power switch, the first end of the second capacitor is connected between the emitter of the second power switch and the output end of the detection discharge module, and the second end of the second capacitor is connected with the ground.

[0011] Optionally, the detection discharge module further comprises a second diode and a second resistor.

[0012] The anode of the second diode is connected with the output end of the window comparison module, and the cathode is connected with the first end of the first capacitor; the first end of the second resistor is connected between the output end of the window comparison module and the anode of the second diode, and the second end of the second resistor is grounded.

[0013] Optionally, the voltage conversion module comprises a voltage acquisition module and a differential amplification module, the output end of the voltage acquisition module is connected with the input end of the differential amplification module, and the output end of the differential amplification module is connected with the input end of the window comparison module.

[0014] The voltage acquisition module is configured to output a measurement voltage signal according to the measured current.

[0015] The differential amplification module is configured to amplify the measurement voltage signal and output the voltage signal.

[0016] Optionally, the voltage acquisition module is a Hall sensor, the voltage acquisition module comprises a collection voltage output end and a reference voltage output end, and the differential amplification module comprises a third resistor, a fourth resistor, a fifth resistor, a sixth resistor and a first operational amplifier.

[0017] The third resistor is connected between the reference voltage output end and the inverting input end of the first operational amplifier, one end of the fourth resistor is connected with the inverting input end of the first operational amplifier, and the other end is connected with the output end of the first operational amplifier, the fifth resistor is connected between the collection voltage output end and the non-inverting input end of the first operational amplifier, one end of the sixth resistor is connected with the non-inverting input end of the first operational amplifier, and the other end is configured to be connected with a first power supply.

[0018] Optionally, the window comparison module comprises a second operational amplifier, a third diode, a third operational amplifier and a fourth diode.

[0019] The non-inverting input terminal of the second operational amplifier is connected with the inverting input terminal of the third operational amplifier, and the output terminal of the second operational amplifier is connected with the output terminal of the first operational amplifier, the inverting input terminal of the second operational amplifier is connected with a second power supply, and the output terminal of the second operational amplifier is connected with the anode of the third diode, the cathode of the third diode is connected with the output terminal of the window comparison module, the non-inverting input terminal of the second operational amplifier is connected with a third power supply, and the output terminal of the second operational amplifier is connected with the anode of the fourth diode, the cathode of the fourth diode is connected with the output terminal of the window comparison module.

[0020] Optionally, the shaping module comprises a fourth operational amplifier, the non-inverting input terminal of the fourth operational amplifier is connected with the output terminal of the detection and discharge module, the inverting input terminal of the fourth operational amplifier is connected with a fourth power supply, and the output terminal of the fourth operational amplifier is the output terminal of the AC / DC current trigger circuit.

[0021] Optionally, the capacity of the first capacitor is 100nF, the resistance value of the first resistor is 2.4Meg, the resistance value of the third resistor is 1kΩ, the resistance value of the fourth resistor is 50kΩ, the resistance value of the fifth resistor is 1kΩ, the resistance value of the sixth resistor is 50kΩ, the voltage of the power supply of the first operational amplifier, the second operational amplifier and the third operational amplifier is 5V, the voltage of the power supply of the fourth operational amplifier is 3.3V, and the voltage of the first power supply is 2.5V.

[0022] The disclosure also provides a switch machine monitoring unit comprising the above-mentioned AC / DC current trigger circuit.

[0023] The disclosure also provides a railway signal lightning protection distribution cabinet comprising the above-mentioned switch machine monitoring unit.

[0024] Through the above technical solution, AC signals and DC signals can be triggered.

[0025] Other features and advantages of the disclosure will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings are included to provide a further understanding of the disclosure and constitute a part of the specification, and together with the following specific embodiments, serve to explain the disclosure but do not constitute a limitation on the disclosure. In the drawings:

[0027] Figure 1 is a block diagram of an AC / DC current trigger circuit according to an embodiment of the disclosure.

[0028] Figure 2 When the measured current is alternating current, according to Figure 1 The provided AC / DC current triggering circuit is illustrated in the signal output diagram of each module when processing the measured current.

[0029] Figure 3 When the measured current is DC, according to Figure 1 The provided AC / DC current triggering circuit is illustrated in the signal output diagram of each module when processing the measured current.

[0030] Figure 4 This is a structural diagram of a detector discharge module provided according to one embodiment of the present disclosure.

[0031] Figure 5 It shows a partial waveform diagram of the input current under test and the level signal output by the detector and discharge module.

[0032] Figure 6 Is Figure 5 The schematic diagram of the high-level output of the detector discharge module during the time period from t1' to t2'.

[0033] Figure 7 Is Figure 5 The schematic diagram of the high-level output of the detector discharge module during the time period from t2' to t3'.

[0034] Figure 8 Is Figure 5 The schematic diagram of the high-level output of the detector discharge module during the time period from t3' to t4'.

[0035] Figure 9 Is Figure 5 The schematic diagram shows the principle of the detector discharge module outputting a low level for discharge after time t6'.

[0036] Figure 10 This is a structural diagram of a detector discharge module provided according to another embodiment of the present disclosure.

[0037] Figure 11 This is a structural diagram of an AC / DC current trigger circuit provided according to one embodiment of the present disclosure.

[0038] Figure 12 This is a schematic diagram of a window comparison module that outputs a high-level signal in a first state according to an embodiment of the present disclosure.

[0039] Figure 13 This is a schematic diagram of a window comparison module that outputs a high-level signal in the second state according to one embodiment of the present disclosure. Detailed Implementation

[0040] The specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are intended to explain and illustrate the present disclosure, but not to limit the present disclosure.

[0041] It should be noted that all actions of obtaining signals, information or data in the present disclosure are carried out in accordance with the corresponding data protection regulations and policies of the country where the device is located, and with the authorization given by the owner of the corresponding device.

[0042] The present disclosure provides an AC-DC current trigger circuit. Figure 1 A block diagram of an AC-DC current trigger circuit according to an embodiment of the present disclosure is shown in FIG. 1. As shown in FIG. 1, the AC-DC current trigger circuit includes a voltage conversion module 10, a window comparison module 20, a detection and discharge module 30 and a shaping module 40 connected in sequence. Figure 1

[0043] The voltage conversion module 10 is configured to output a voltage signal according to a measured current;

[0044] The window comparison module 20 is configured to compare the voltage signal with an upper threshold voltage and a lower threshold voltage of the window comparison module 20, and output a high-level signal or a low-level signal according to the comparison result;

[0045] The detection and discharge module 30 is configured to output a high-level signal when the window comparison module 20 outputs a high-level signal, and output a high-level signal when the duration of the low-level signal output after the window comparison module 20 outputs a high-level signal is less than or equal to a time threshold, and output a low-level signal when the duration is greater than the time threshold;

[0046] The shaping module 40 is configured to shape the level signal output by the detection and discharge module 30 into a square wave trigger signal, and output the square wave trigger signal.

[0047] In order to explain the principle of the AC-DC current trigger circuit provided by the present disclosure for triggering an AC signal, the signals output by each module of the AC-DC current trigger circuit when processing a measured current will be described below, as shown in FIG. 2. Figure 2

[0048] ​​The measured current is the action current of the analog switch machine. The t1-t3 time period shows the situation that the continuous trigger signal should not be generated, for example, the current value of the action current of the switch machine is 0 or a very small value (less than the preset current value) due to noise in the t1-t2 time period, and the frequency of the action current of the switch machine is very low (less than the preset frequency value) in the t2-t3 time period. The t3-t4 time period shows the situation that the continuous trigger signal should be generated, for example, the current value of the action current of the switch machine is greater than or equal to the preset current value, such as 200 mA; the frequency is greater than or equal to the preset frequency value, for example, the preset frequency value is 42 Hz, and when the frequency of the action current of the switch machine is 50 Hz, the frequency is greater than or equal to the preset frequency value.

[0049] The voltage signal output by the voltage conversion module 10 is the voltage signal output by the measured current after passing through the voltage conversion module 10. According to the function of the voltage conversion module 10, the voltage signal output by the voltage conversion module 10 is a voltage signal with the same frequency and form as the measured current.

[0050] The level signal output by the window comparison module 20 is the level signal output by the voltage signal output by the voltage conversion module 10 after being processed by the window comparison module 20. According to the function of the window comparison module 20, by setting the upper threshold voltage and the lower threshold voltage of the window comparison module 20, the signal with a current value less than the preset current value in the measured current can be converted into a low-level signal; the signal with a current value greater than or equal to the preset current value in the measured current can be converted into a high-level signal. Therefore, the window comparison module 20 outputs a low-level signal in the t1-t2 time period; the window comparison module 20 outputs a square wave level signal with a frequency of 2 times the measured current in the t2-t4 time period. Since the frequency of the measured current in the t2-t3 time period is less than the frequency of the measured current in the t3-t4 time period, the frequency of the square wave level signal in the t2-t3 time period is less than the frequency of the square wave level signal in the t3-t4 time period.

[0051] The level signal output by the detection and discharge module 30 is the level signal output by the detection and discharge module 30 after the level signal output by the window comparison module 20 is processed. According to the function of the detection and discharge module 30, it can be known that the low level signal can be output when the frequency of the measured current is lower than the preset frequency threshold, and the high level signal can be output when the frequency of the measured current is higher than the preset frequency threshold by setting the time threshold. For example, in the time period from t2 to t3, the frequency output by the window comparison module 20 is small, the duration of the low level signal output by the window comparison module 20 after the high level signal is output is greater than the time threshold, and therefore the detection and discharge module 30 outputs the high level signal and the low level signal staggered around t2 and t3. In the time period from t3 to t4, the frequency output by the window comparison module 20 is large, the duration of the low level signal output by the window comparison module 20 after the high level signal is output is less than or equal to the time threshold, and therefore the detection and discharge module 30 outputs the continuous high level signal around t3 and t4 (t5).

[0052] The square wave trigger signal output by the shaping module 40 is the square wave trigger signal output by the shaping module 40 after the level signal output by the detection and discharge module 30 is processed. According to the function of the shaping module 40, it can be known that the high level signal with different amplitudes around t3 and t4 (t5) can be arranged to have the same amplitude, thereby forming the continuous square wave trigger signal. The high level signal with different amplitudes around t2 and t3 can also be arranged to have the same amplitude, thereby forming the discontinuous square wave pulse signal. By setting, in actual application, the AC / DC current trigger circuit provided by the embodiment of the present disclosure can recognize the AC signal of 50 Hz and above as the continuous current signal, and recognize the DC current signal below 50 Hz.

[0053] Therefore, according to Figure 2 As shown in FIG. 6, the AC / DC current trigger circuit provided by the present disclosure realizes the monitoring of the AC signal, and can generate the continuous square wave trigger signal (the square wave trigger signal output by the shaping module 40 around t3 and t5) when the AC signal is triggered (in the time period from t3 to t4).

[0054] In addition, the AC / DC current trigger circuit provided by the present disclosure can also realize the monitoring of the DC signal, as shown in FIG. 7. Figure 3 Figure 3 For the measured current being the DC current, the signal diagram output by each module of the AC / DC current trigger circuit. The principle of triggering the DC signal by the AC / DC current trigger circuit is similar to the principle of triggering the AC signal, which will not be repeated here. From Figure 3 ​It can be seen that when the measured current is a direct current, the AC / DC current trigger circuit can trigger the positive direct current signal (current in the t1-t2 period) and the negative direct current signal (measured current in the t3-t4 period). It should be noted that in a fixed use scenario, the measured current can only include a positive direct current signal (i.e. over time, the measured current is always greater than or equal to 0 in the fixed use scenario), or the measured current can only include a negative direct current signal (i.e. over time, the measured current is always less than or equal to 0 in the fixed use scenario), or the measured current can include a positive direct current signal and a negative direct current signal (i.e. over time, the measured current can be greater than 0, equal to 0, or less than 0 in the fixed use scenario; for example, the measured current is the motor current, when the motor does not rotate, the measured current is 0, when the motor rotates forward, the measured current is greater than 0, and when the motor reverses, the measured current is less than 0).

[0055] Therefore, the AC / DC current trigger circuit provided by the present disclosure can trigger AC signals and DC signals.

[0056] Optionally, as shown in Figure 4 The detection and discharge module 30 includes a first capacitor C1, a first resistor R1, a first power switch Q1, a first diode D1, a second power switch Q2, and a second capacitor C2. The first power switch Q1 is an NPN triode, and the second power switch Q2 is a PNP triode.

[0057] The first end of the first capacitor C1 is connected to the output end of the window comparison module 20, and the second end of the first capacitor C1 is grounded. The first end of the first resistor R1 is connected to the first end of the first capacitor C1, and the second end of the first resistor R1 is grounded. The collector of the first power switch Q1 is connected to the first end of the first resistor R1, the emitter is grounded, and the base is connected to the collector of the second power switch Q2. The anode of the first diode D1 is connected to the collector of the first power switch Q1, and the cathode is connected to the emitter of the second power switch Q2. The base of the second power switch Q2 is connected to the collector of the first power switch Q1. The first end of the second capacitor C2 is connected between the emitter of the second power switch Q2 and the output end of the detection and discharge module 30, and the second end of the second capacitor C2 is connected to the ground.

[0058] The following will be described in combination with Figures 5 to 9 , and Figure 2 The last segment of the measured current in the t3-t4 period (at this time, the measured current is an alternating current, and the waveform is a sine wave) will be taken as an example (as shown in the measured current in Figure 5 , the measured current in the t3-t4 period is taken as an example (as shown in the measured current in Figure 4The working principle of the detection and discharge module 30 generating the trigger signal is described.

[0059] As shown in FIG. 4, in the t1' to t2' time period, when the amplitude of the voltage signal converted by the voltage conversion module 10 from the measured current exceeds the upper threshold voltage of the window comparison module 20, the window comparison module 20 outputs a high level signal, which charges the first capacitor C1 and the second capacitor C2, the voltage drop between the second capacitor C2 and the first capacitor C1 is less than the on-voltage of the second power switch Q2, the second power switch Q2 is off, the first power switch Q1 is off, and the detection and discharge module 30 outputs a high level at this time. Figure 6 Figure 5 As shown in FIG. 5, in the t2' to t3' time period, when the amplitude of the voltage signal converted by the voltage conversion module 10 from the measured current is less than the upper threshold voltage of the window comparison module 20 and greater than the lower threshold voltage of the window comparison module 20, the window comparison module 20 outputs a low level signal, the first capacitor C1 is discharged through the first resistor R1, the voltage of the first capacitor C1 is less than the voltage of the second capacitor C2, and by designing at least one of the resistance value of the first resistor R1, the capacity of the first capacitor C1, the maximum voltage of the first capacitor C1, and the on-voltage of the second power switch Q2, the voltage drop between the second capacitor C2 and the first capacitor C1 in the t2' to t3' time period can be less than the on-voltage of the second power switch Q2, the second power switch Q2 is off, the first power switch Q1 is off, and the detection and discharge module 30 outputs a high level.

[0060] As shown in FIG. 6, in the t3' to t4' time period, when the amplitude of the voltage signal converted by the voltage conversion module 10 from the measured current is less than the lower threshold voltage of the window comparison module 20, the window comparison module 20 outputs a high level signal, which charges the first capacitor C1 and the second capacitor C2, the voltage drop between the second capacitor C2 and the first capacitor C1 is less than the on-voltage of the second power switch Q2, the second power switch Q2 is off, the first power switch Q1 is off, and the detection and discharge module 30 outputs a high level at this time. Figure 7 Figure 5 As shown in FIG. 7, after the t5' moment, the trigger of the measured current ends, the first capacitor C1 is discharged through the first resistor R1 first, the voltage of the first capacitor C1 decreases, the voltage drop between the second capacitor C2 and the first capacitor C1 in the t5' to t6' time period is less than the on-voltage of the second power switch Q2, the second power switch Q2 and the first power switch Q1 are off, the detection and discharge module 30 outputs a high level, and the working principle is similar to that shown in FIG. 4.

[0061] As shown in FIG. 8, after the t5' moment, the trigger of the measured current ends, the first capacitor C1 is discharged through the first resistor R1 first, the voltage of the first capacitor C1 decreases, the voltage drop between the second capacitor C2 and the first capacitor C1 in the t5' to t6' time period is less than the on-voltage of the second power switch Q2, the second power switch Q2 and the first power switch Q1 are off, the detection and discharge module 30 outputs a high level, and the working principle is similar to that shown in FIG. 4. Figure 8 Figure 5 As shown in FIG. 9, after the t5' moment, the trigger of the measured current ends, the first capacitor C1 is discharged through the first resistor R1 first, the voltage of the first capacitor C1 decreases, the voltage drop between the second capacitor C2 and the first capacitor C1 in the t5' to t6' time period is less than the on-voltage of the second power switch Q2, the second power switch Q2 and the first power switch Q1 are off, the detection and discharge module 30 outputs a high level, and the working principle is similar to that shown in FIG. 4.

[0062] As shown in FIG. 10, after the t5' moment, the trigger of the measured current ends, the first capacitor C1 is discharged through the first resistor R1 first, the voltage of the first capacitor C1 decreases, the voltage drop between the second capacitor C2 and the first capacitor C1 in the t5' to t6' time period is less than the on-voltage of the second power switch Q2, the second power switch Q2 and the first power switch Q1 are off, the detection and discharge module 30 outputs a high level, and the working principle is similar to that shown in FIG. 4. Figure 5 Figure 7 As shown in FIG. 11, after the t5' moment, the trigger of the measured current ends, the first capacitor C1 is discharged through the first resistor R1 first, the voltage of the first capacitor C1 decreases, the voltage drop between the second capacitor C2 and the first capacitor C1 in the t5' to t6' time period is less than the on-voltage of the second power switch Q2, the second power switch Q2 and the first power switch Q1 are off, the detection and discharge module 30 outputs a high level, and the working principle is similar to that shown in FIG. 4. Figure 9 ​​​​As shown in Figure 5 After the t6' moment, the voltage drop between the second capacitor C2 and the first capacitor C1 is greater than the on-voltage of the second power switch Q2, the second power switch Q2 is turned on, the first power switch Q1 is turned on, and the first capacitor C1 and the second capacitor C2 are discharged through the first power switch Q1, so that the end time of the square wave trigger signal output by the AC-DC current trigger circuit is as close as possible to the actual end time of the measured current.

[0063] Similarly, when the AC-DC current trigger circuit monitors the DC signal, the working principle of the detection and discharge module 30 for generating a trigger signal is similar, which will not be repeated here.

[0064] Through the above technical solution, the detection and discharge module 30 is cleverly set, so that the AC-DC current trigger circuit can trigger AC signals and DC signals; and at the end of triggering, the end time of the square wave trigger signal output by the AC-DC current trigger circuit is as close as possible to the actual end time of the measured current, solving the problem of slow level drop speed of the traditional detection circuit, making the collection of trigger time more accurate.

[0065] Optionally, as shown in Figure 10 The detection and discharge module 30 further comprises a second diode D2 and a second resistor R2.

[0066] The positive electrode of the second diode D2 is connected to the output end of the window comparison module 20, and the negative electrode is connected to the first end of the first capacitor C1. The first end of the second resistor R2 is connected between the output end of the window comparison module 20 and the positive electrode of the second diode D2, and the second end of the second resistor R2 is grounded.

[0067] Through the above technical solution, the second resistor R2 and the second diode D2 are set to ensure that the AC-DC current trigger circuit does not have a residual voltage.

[0068] Optionally, as shown in Figure 11 The voltage conversion module 10 comprises a voltage acquisition module 11 and a differential amplification module 12. The output end of the voltage acquisition module 11 is connected to the input end of the differential amplification module 12, and the output end of the differential amplification module 12 is connected to the input end of the window comparison module 20.

[0069] The voltage acquisition module 11 is configured to output a measurement voltage signal according to the measured current.

[0070] The differential amplification module 12 is configured to amplify the measurement voltage signal and output the voltage signal.

[0071] By the technical scheme, the differential amplification module 12 is arranged to amplify the voltage signal collected by the voltage collection module 11, so that the AC / DC current trigger circuit provided by the present application can be triggered when the current value of the measured current is small.

[0072] Optionally, the voltage collection module 11 is a Hall sensor, and the voltage collection module 11 comprises a collection voltage output end and a reference voltage output end, and the differential amplification module 12 comprises a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a first operational amplifier U1.

[0073] The third resistor R3 is connected between the reference voltage output end and the inverting input end of the first operational amplifier U1, one end of the fourth resistor R4 is connected to the inverting input end of the first operational amplifier U1, and the other end of the fourth resistor R4 is connected to the output end of the first operational amplifier U1, the fifth resistor R5 is connected between the collection voltage output end and the non-inverting input end of the first operational amplifier U1, and one end of the sixth resistor R6 is connected to the non-inverting input end of the first operational amplifier U1, and the other end of the sixth resistor R6 is connected to the first power supply VCC1.

[0074] The first power supply VCC1 can be a voltage source, and is configured to provide a lifted voltage, i.e., a zero voltage of the output voltage signal.

[0075] By designing the specific structures of the voltage collection module 11 and the differential amplification module 12, the voltage collection module 11 and the differential amplification module 12 with simple structures are provided, and the circuit structure of the AC / DC current trigger circuit is simpler.

[0076] Optionally, the window comparison module 20 comprises a second operational amplifier U2, a third diode D3, a third operational amplifier U3, and a fourth diode D4.

[0077] The non-inverting input end of the second operational amplifier U2 is connected to the inverting input end of the third operational amplifier U3, and the output end of the second operational amplifier U2 is connected to the output end of the first operational amplifier U1, the inverting input end of the second operational amplifier U2 is connected to the second power supply VCC2, the output end of the second operational amplifier U2 is connected to the anode of the third diode D3, the cathode of the third diode D3 is connected to the output end of the window comparison module 20, the non-inverting input end of the second operational amplifier U2 is connected to the third power supply VCC3, and the output end of the second operational amplifier U2 is connected to the anode of the fourth diode D4, and the cathode of the fourth diode D4 is connected to the output end of the window comparison module 20.

[0078] The second power supply VCC2 can be a voltage source, and is configured to provide an upper threshold voltage. The third power supply VCC3 can be a voltage source, and is configured to provide a lower threshold voltage.

[0079] As shown in Figure 12 the output end of the first operational amplifier U1 (i.e. the output end of the voltage conversion module 10, also the output end of the differential amplification module 12) outputs a voltage signal greater than or equal to the upper threshold voltage, the output end of the second operational amplifier U2 outputs a high level signal, which is output to the detection discharge module 30 through the third diode D3.

[0080] As shown in Figure 13 the output end of the first operational amplifier U1 (i.e. the output end of the voltage conversion module 10, also the output end of the differential amplification module 12) outputs a voltage signal less than or equal to the lower threshold voltage, the output end of the third operational amplifier U3 outputs a high level signal, which is output to the detection discharge module 30 through the fourth diode D4.

[0081] When the output end of the first operational amplifier U1 (i.e. the output end of the voltage conversion module 10, also the output end of the differential amplification module 12) outputs a voltage signal less than the upper threshold voltage and greater than the lower threshold voltage, the second operational amplifier U2 and the third operational amplifier U3 output low level signals to the detection discharge module 30.

[0082] Through the above technical solution, the specific structure of the window comparison module 20 is designed, and the window comparison module 20 with simple structure is provided, so that the circuit structure of the AC / DC current trigger circuit is simpler.

[0083] Please continue to read Figure 11 Optionally, the shaping module 40 comprises a fourth operational amplifier U4, the non-inverting input end of the fourth operational amplifier U4 is connected with the output end of the detection discharge module 30, the inverting input end is used to be connected with the fourth power supply VCC4, and the output end is used as the output end of the AC / DC current trigger circuit.

[0084] The fourth power supply VCC4 can be a voltage source, which is used to provide the threshold voltage of the fourth operational amplifier U4. When the level signal output by the detection discharge module 30 is greater than or equal to the threshold voltage, the fourth operational amplifier U4 will output a voltage with a fixed amplitude, so as to realize the shaping of the high level signals with different amplitudes output by the detection discharge module 30, and thus output a square wave trigger signal.

[0085] Through the above technical solution, the specific structure of the shaping module 40 is designed, and the shaping module 40 with simple structure is provided, so that the circuit structure of the AC / DC current trigger circuit is simpler.

[0086] The inventors discovered that currently, the monitoring of turnout machine operating current acquisition time and the generation of trigger signals for acquisition of operating current are mainly achieved through the centralized railway signal monitoring system. With the rapid development of railway construction, railway signal lightning protection distribution cabinets, in addition to their original lightning protection and distribution functions, need to add the function of monitoring the acquisition time of turnout machine operating current and generating trigger signals for acquisition of operating current. However, the acquisition location of the railway signal lightning protection distribution cabinet differs from that of the centralized railway signal monitoring system, resulting in the railway signal lightning protection distribution cabinet being unable to acquire the relevant switching signals.

[0087] To solve the aforementioned technical problems, the inventors proposed using this AC / DC current triggering circuit to monitor the acquisition time of the switch machine's operating current and to generate a square wave trigger signal for acquiring the operating current. To adapt to the triggering characteristics of the switch machine's operating current (e.g., current amplitude reaching 200mA and above, frequency 50Hz), [further details are needed]. Figure 11 The values ​​of each circuit component were designed. Optionally, the capacitance of the first capacitor C1 is 100nF, the resistance of the first resistor R1 is 2.4Meg, the resistance of the second resistor R2 is 10kΩ, the resistance of the third resistor R3 is 1kΩ, the resistance of the fourth resistor R4 is 50kΩ, the resistance of the fifth resistor R5 is 1kΩ, the resistance of the sixth resistor R6 is 50kΩ, the power supply voltage of the first operational amplifier U1, the second operational amplifier U2, and the third operational amplifier U3 is 5V, the power supply voltage of the fourth operational amplifier U4 is 3.3V, and the voltage of the first power supply VCC1 is 2.5V.

[0088] Through the above design, the differential amplifier module 12 achieves a gain of 50, and the use of 2.5V as the boost voltage (zero-point voltage) reduces the delay introduced by the detector discharge module 30 (e.g., Figure 5 The time interval from t5' to t6' is approximately 100nF * 2.4Meg * 10% = 24ms. Therefore, it is possible to monitor the measured current with a frequency above 1 / 24 ≈ 42Hz, generating a continuous square wave trigger signal to meet our requirements for monitoring and triggering the switch machine's operating current. Furthermore, by setting the power supply voltage of the fourth operational amplifier U4 to 3.3V, the AC / DC current trigger circuit can output a voltage signal with an amplitude of 3.3V, thus meeting the requirement that the operating voltage of most subsequent circuits does not exceed 3.3V.

[0089] Accordingly, after using 2.5V as the boost voltage, the upper threshold voltage provided by the second power supply VCC2 can be 3V, and the lower threshold voltage provided by the third power supply VCC3 can be 2V; the upper threshold voltage provided by the second power supply VCC2 can also be 3.5V, and the lower threshold voltage provided by the third power supply VCC3 can also be 1.5V, etc., without any restrictions.

[0090] Based on the technical concept, the disclosure further provides a switch machine monitoring unit. The switch machine monitoring unit comprises the AC / DC current trigger circuit.

[0091] Since the switch machine monitoring unit comprises the AC / DC current trigger circuit, it has similar beneficial effects as the AC / DC current trigger circuit, which will not be repeated here.

[0092] Based on the technical concept, the disclosure further provides a railway signal lightning protection distribution cabinet. The railway signal lightning protection distribution cabinet comprises the switch machine monitoring unit.

[0093] Since the switch machine monitoring unit comprises the AC / DC current trigger circuit, and then the railway signal lightning protection distribution cabinet comprises the AC / DC current trigger circuit, it has similar beneficial effects as the AC / DC current trigger circuit, which will not be repeated here.

[0094] The preferred embodiments of the disclosure are described in detail above in combination with the drawings, but the disclosure is not limited to the specific details in the above embodiments. Within the technical concept range of the disclosure, various simple modifications can be made to the technical solutions of the disclosure, and these simple modifications all belong to the protection range of the disclosure.

[0095] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the disclosure will not further describe various possible combinations.

[0096] In addition, various different embodiments of the disclosure can also be combined in any manner, as long as it does not deviate from the idea of the disclosure, it should also be considered as disclosed by the disclosure.

Claims

1. An AC / DC current triggering circuit, characterized in that, include: The voltage conversion module (10), window comparison module (20), detector discharge module (30) and shaping module (40) are connected in sequence. The voltage conversion module (10) is used to output a voltage signal according to the measured current; The window comparison module (20) is used to compare the voltage signal with the upper threshold voltage and the lower threshold voltage of the window comparison module (20), and output a high-level signal or a low-level signal according to the comparison result; The detector discharge module (30) is used to output a high-level signal when the window comparison module (20) outputs a high-level signal, and outputs a high-level signal when the duration of the low-level signal after the window comparison module (20) outputs a high-level signal is less than or equal to a time threshold, and outputs a low-level signal when the duration is greater than the time threshold. The shaping module (40) is used to shape the level signal output by the detector discharge module (30) into a square wave trigger signal and output the square wave trigger signal. The detector discharge module (30) includes: a first capacitor (C1), a first resistor (R1), a first power switch (Q1), a first diode (D1), a second power switch (Q2), and a second capacitor (C2). The first power switch (Q1) is an NPN transistor, and the second power switch (Q2) is a PNP transistor. The first terminal of the first capacitor (C1) is connected to the output terminal of the window comparison module (20), and the second terminal of the first capacitor (C1) is grounded. The first terminal of the first resistor (R1) is connected to the first terminal of the first capacitor (C1), and the second terminal of the first resistor (R1) is grounded. The collector of the first power switch (Q1) is connected to the first terminal of the first resistor (R1), the emitter is grounded, and the base is connected to the collector of the second power switch (Q2). The anode of the first diode (D1) is connected to the collector of the first power switch (Q1), and the cathode is connected to the emitter of the second power switch (Q2). The base of the second power switch (Q2) is connected to the collector of the first power switch (Q1). The first terminal of the second capacitor (C2) is connected between the emitter of the second power switch (Q2) and the output terminal of the detector discharge module (30), and the second terminal of the second capacitor (C2) is connected to ground.

2. The AC / DC current triggering circuit according to claim 1, characterized in that, The detector discharge module (30) further includes: a second diode (D2) and a second resistor (R2); The positive terminal of the second diode (D2) is connected to the output terminal of the window comparison module (20), and the negative terminal is connected to the first terminal of the first capacitor (C1). The first terminal of the second resistor (R2) is connected between the output terminal of the window comparison module (20) and the positive terminal of the second diode (D2), and the second terminal of the second resistor (R2) is grounded.

3. The AC / DC current triggering circuit according to claim 1 or 2, characterized in that, The voltage conversion module (10) includes a voltage acquisition module (11) and a differential amplifier module (12). The output terminal of the voltage acquisition module (11) is connected to the input terminal of the differential amplifier module (12), and the output terminal of the differential amplifier module (12) is connected to the input terminal of the window comparison module (20). The voltage acquisition module (11) is used to output a measured voltage signal based on the measured current; The differential amplifier module (12) is used to amplify the measured voltage signal and output the voltage signal.

4. The AC / DC current triggering circuit according to claim 3, characterized in that, The voltage acquisition module (11) is a Hall sensor. The voltage acquisition module (11) includes a voltage acquisition output terminal and a reference voltage output terminal. The differential amplifier module (12) includes: a third resistor (R3), a fourth resistor (R4), a fifth resistor (R5), a sixth resistor (R6), and a first operational amplifier (U1). The third resistor (R3) is connected between the reference voltage output terminal and the inverting input terminal of the first operational amplifier (U1). One end of the fourth resistor (R4) is connected to the inverting input terminal of the first operational amplifier (U1), and the other end is connected to the output terminal of the first operational amplifier (U1). The fifth resistor (R5) is connected between the sampling voltage output terminal and the non-inverting input terminal of the first operational amplifier (U1). One end of the sixth resistor (R6) is connected to the non-inverting input terminal of the first operational amplifier (U1), and the other end is used to connect to the first power supply (VCC1).

5. The AC / DC current triggering circuit according to claim 4, characterized in that, The window comparison module (20) includes: a second operational amplifier (U2), a third diode (D3), a third operational amplifier (U3), and a fourth diode (D4); The non-inverting input of the second operational amplifier (U2) is connected to the inverting input of the third operational amplifier (U3) and then connected to the output of the first operational amplifier (U1). The inverting input of the second operational amplifier (U2) is connected to the second power supply (VCC2), and its output is connected to the positive terminal of the third diode (D3). The negative terminal of the third diode (D3) is connected to the output of the window comparator module (20). The non-inverting input of the second operational amplifier (U2) is connected to the third power supply (VCC3), and its output is connected to the positive terminal of the fourth diode (D4). The negative terminal of the fourth diode (D4) is connected to the output of the window comparator module (20).

6. The AC / DC current triggering circuit according to claim 5, characterized in that, The shaping module (40) includes a fourth operational amplifier (U4), the non-inverting input of which is connected to the output of the detector discharge module (30), the inverting input which is connected to the fourth power supply (VCC4), and the output which serves as the output of the AC / DC current trigger circuit.

7. The AC / DC current triggering circuit according to claim 6, characterized in that, The first capacitor (C1) has a capacitance of 100nF, the first resistor (R1) has a resistance of 2.4Meg, the third resistor (R3) has a resistance of 1kΩ, the fourth resistor (R4) has a resistance of 50kΩ, the fifth resistor (R5) has a resistance of 1kΩ, the sixth resistor (R6) has a resistance of 50kΩ, the power supply voltage for the first operational amplifier (U1), the second operational amplifier (U2), and the third operational amplifier (U3) is 5V, the power supply voltage for the fourth operational amplifier (U4) is 3.3V, and the voltage of the first power supply (VCC1) is 2.5V.

8. A switch machine monitoring unit, characterized in that, Includes the AC / DC current triggering circuit according to any one of claims 1-7.

9. A railway signal lightning protection distribution cabinet, characterized in that, Includes the switch machine monitoring unit as described in claim 8.

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