Digital board self-checking circuit for very high frequency ground platform

Abstract

The utility model discloses a digital board self-checking circuit for a very high frequency ground platform, and the circuit is characterized in that a first detection module is connected with the input end of a sampling circuit, and is used for detecting a sampling signal inputted into the sampling circuit; the second detection module is connected to the output end of the sampling circuit and used for detecting the intermediate frequency signal output by the sampling circuit; the third detection module is connected to the output end of the audio conversion circuit and is used for detecting an analog audio signal output by the audio conversion circuit; after fault positioning is carried out through the multiplexer, a result is output to the feedback unit for feedback, and maintenance personnel can position the fault through the feedback result, so that the defect that the maintenance personnel cannot carry out fault positioning even if the maintenance personnel know that the digital board has the fault due to lack of a positioning self-checking circuit for the very high frequency ground platform digital board at present is overcome. However, positioning processing cannot be carried out, and the efficiency is low.

Description

Technical Field

[0001] The utility model relates to the technical field of digital board self-test, in particular to a digital board self-test circuit for a very high frequency ground station. Background Art

[0002] A VHF ground station is a ground-based navigation beacon equipped with a digital signal processing board. This board receives the intermediate frequency (IF) signal from the RF front end and outputs the audio signal in voice mode, completing the IF-to-audio signal conversion. The self-test function of a VHF ground station is crucial, allowing maintenance personnel to locate and repair board defects.

[0003] The digital board of the VHF ground station mainly integrates a sampling module for collecting intermediate frequency signals and an audio conversion module for converting intermediate frequency signals into audio signals. The detection of the digital board mainly involves the detection of the input and output signals of the sampling module and the audio conversion module. Currently, there is a lack of positioning self-test circuits for the digital board of the VHF ground station. As a result, even if maintenance personnel know that there is a fault in the digital board, they cannot locate it and process it, which is inefficient. Utility Model Content

[0004] In response to the problems raised by the above-mentioned background technology, the purpose of the present utility model is to provide a digital board self-test circuit for a very high frequency ground station, so as to solve the problem of lack of a positioning self-test circuit for the digital board of the very high frequency ground station, which results in maintenance personnel being unable to locate and process the digital board even if they know that there is a fault, resulting in low efficiency.

[0005] The utility model is achieved through the following technical solutions:

[0006] A digital board self-test circuit for a very high frequency ground station, comprising:

[0007] a first detection module, connected to an input end of the sampling circuit, and configured to detect a sampling signal input into the sampling circuit;

[0008] a second detection module, connected to the output end of the sampling circuit, and configured to detect the intermediate frequency signal output by the sampling circuit;

[0009] a third detection module, connected to the output end of the audio conversion circuit, and configured to detect the analog audio signal output by the audio conversion circuit;

[0010] The positioning module includes a multiplexer and a feedback unit, the first detection module, the second detection module and the third detection module are respectively connected to the three input ends of the multiplexer, and the output end of the multiplexer is connected to the feedback unit.

[0011] In the above technical solution, the first detection module is connected to the input of the sampling circuit and is used to detect the sampling signal input to the sampling circuit. When the sampling signal input to the sampling circuit is normal, the first detection module outputs a low level to the positioning module. If the sampling signal input to the sampling circuit is abnormal, the first detection module outputs a high level to the positioning module. At this time, the signal of the channel connected to the first detection module in the multiplexer is set to 1, indicating that the signal input to the digital board is abnormal.

[0012] Specifically, in an embodiment of the present invention, the first detection module is used to detect whether a sampling signal exists, and specifically includes a comparator and a T trigger connected in sequence. The comparator has a reference voltage. When the voltage of the sampling signal is greater than the reference voltage, the sampling signal is considered to exist. At this time, the comparator sends a high-level signal to the T trigger, and the T trigger outputs a low-level signal to the positioning module through the inversion of the T trigger. Conversely, when the voltage of the sampling signal is less than or equal to the reference voltage, the sampling signal is considered to be absent. At this time, the comparator sends a low-level signal to the T trigger, and the T trigger outputs a high-level signal to the positioning module through the inversion of the T trigger.

[0013] The second detection module is connected to the output of the sampling circuit and is used to detect the intermediate frequency signal output by the sampling circuit. When the intermediate frequency signal output by the sampling circuit is normal, the second detection module outputs a low level to the positioning module. If the intermediate frequency signal output by the sampling circuit is abnormal, the second detection module outputs a high level to the positioning module. At this time, the signal connected to the second detection module in the multiplexer is set to 1, indicating an abnormal intermediate frequency signal. When the signal connected to the first detection module in the multiplexer is 0 and the signal connected to the second detection module is 1, it indicates an abnormality in the sampling circuit.

[0014] The third detection module is connected to the output end of the audio conversion circuit and is used to detect the analog audio signal output by the audio conversion circuit. When the analog audio signal output by the audio conversion circuit is normal, the third detection module outputs a low level to the positioning module; if there is an abnormality in the analog audio signal output by the audio conversion circuit, the third detection module outputs a high level to the positioning module. At this time, the signal connected to the third detection module in the multiplexer is set to 1, indicating that there is an abnormality in the analog audio signal. When the signals connected to the first detection module and the second detection module in the multiplexer are both 0, and the signal connected to the third detection module is 1, it indicates that there is an abnormality in the audio conversion circuit.

[0015] After the fault is located by the multiplexer, the result is output to the feedback unit for feedback, and maintenance personnel can locate the fault based on the feedback result.

[0016] In an optional embodiment, the second detection module includes a first rectifier unit, a first amplitude detection unit, and a first comparison unit connected in sequence; the third detection module includes a second rectifier unit, a second detection unit, and a second comparison unit connected in sequence;

[0017] The output terminal of the first amplitude detection unit is connected to the input terminal of the second comparison unit.

[0018] In an optional embodiment, the second rectifying unit includes:

[0019] The switch tube Q2 has a delay component and a drive component disposed between the drain and the source of the switch tube Q2 , and the delay component is connected to the drive component.

[0020] In an optional embodiment, the delay component includes: a MOS transistor Q1, a resistor R2, a MOS transistor Q3, a resistor R3 and a capacitor C2;

[0021] The source of the MOS transistor Q3 is connected to the source of the switch transistor Q2, the resistor R2 and the resistor R3 are connected in series and then connected to the drain of the MOS transistor Q3, the capacitor C2 is connected to the gate of the MOS transistor Q3, the drain of the MOS transistor Q1 is connected to the drain of the MOS transistor Q3, and the gate of the MOS transistor Q1 is connected to the drain of the switch transistor Q2.

[0022] In an optional embodiment, the driving component includes: a capacitor C3, a capacitor C4, a resistor R4 and a chip U1;

[0023] Among them, the two ends of the capacitor C3 are respectively connected between pin 1 and pin 3 of the chip U1; the source of the MOS tube Q1 is respectively connected to pin 7 and pin 8 of the chip U1; the two ends of the resistor R4 are respectively connected between pin 3 and pin 5 of the chip U1; the two ends of the capacitor C4 are respectively connected between pin 7 and pin 6 of the chip U1.

[0024] In an optional embodiment, the model of the chip U1 is AUIRS1170S.

[0025] In an optional embodiment, the second amplitude detection unit includes: a capacitor C5, a resistor R5, a diode D1, a capacitor C6, a resistor R6, a resistor R7, a resistor R8, a capacitor C7, a diode D2 and a mutual inductor T1;

[0026] The capacitor C5 is connected in series with the resistor R5, and a diode D1, a resistor R7, and a diode D2 are connected in series once between the capacitor C5 and the resistor R5; the capacitor C6 and the resistor R6 are connected in parallel between the diode D1 and the resistor R7; the resistor R8 and the capacitor C7 are connected in parallel between the resistor R7 and the diode D2; one side of the mutual inductor T1 is connected to the output end of the diode D2, and the other side is connected to the capacitor C5.

[0027] In an optional embodiment, a sampling resistor R9 is provided in the mutual inductor T1.

[0028] In an optional embodiment, the second comparison unit includes: a resistor R10, a resistor R11, a resistor R12, a resistor R13, an operational amplifier U2 and an operational amplifier U3;

[0029] Among them, the resistor R11, the resistor R12 and the resistor R13 are connected in series, the resistor R11 is connected to the control end of the operational amplifier U2, one end of the resistor R13 is connected to the control end of the operational amplifier U3, and the other end is connected to the positive input end of the operational amplifier U3; the positive input end of the operational amplifier U2 and the negative input end of the operational amplifier U3 are connected to the resistor R10; the negative input end of the operational amplifier U2 is connected to the first amplitude detection unit.

[0030] In an optional embodiment, the multiplexer is a four-to-one selector.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] After the fault is located through the multiplexer, the result is output to the feedback unit for feedback. Maintenance personnel can locate the fault based on the feedback result, overcoming the current lack of a positioning self-test circuit for the VHF ground station digital board, which results in maintenance personnel being unable to locate and process the digital board even if they know there is a fault, resulting in low efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings:

[0034] Figure 1 This is a structural diagram of a digital board self-test circuit for a VHF ground station provided by Example 1 of the present utility model;

[0035] Figure 2A schematic diagram of the structure of the second detection module and the third detection module provided in Example 1 of the present utility model;

[0036] Figure 3 This is a circuit schematic diagram of the rectifier unit and amplitude detection unit provided in Example 1 of the present utility model;

[0037] Figure 4 This is a circuit schematic diagram of the comparison unit provided in Example 1 of the present utility model. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is described in detail in an optional embodiment in combination with the embodiments and drawings below. The schematic implementation manner of the present invention and its description are only used to explain the present invention and are not intended to limit the present invention.

[0039] Example 1

[0040] This embodiment 1 provides a digital board self-test circuit for a very high frequency ground station, such as Figure 1 As shown, a digital board self-test circuit for a very high frequency ground station includes:

[0041] a first detection module, connected to an input end of the sampling circuit, and configured to detect a sampling signal input into the sampling circuit;

[0042] a second detection module, connected to the output end of the sampling circuit, and configured to detect the intermediate frequency signal output by the sampling circuit;

[0043] a third detection module, connected to the output end of the audio conversion circuit, and configured to detect the analog audio signal output by the audio conversion circuit;

[0044] The positioning module includes a multiplexer and a feedback unit, the first detection module, the second detection module and the third detection module are respectively connected to the three input ends of the multiplexer, and the output end of the multiplexer is connected to the feedback unit.

[0045] It should be noted that the digital board of the VHF ground station mainly integrates a sampling module for collecting intermediate frequency signals and an audio conversion module for converting intermediate frequency signals into audio signals. The detection of the digital board mainly involves the detection of the input and output signals of the sampling module and the audio conversion module. There is currently a lack of positioning self-test circuits for the digital board of the VHF ground station, resulting in maintenance personnel being unable to locate and process the fault even if they know that the digital board has a fault, resulting in low efficiency.

[0046] In view of the above problems, the present invention proposes a self-test circuit for performing self-test on a digital board. The self-test circuit includes four modules, including three detection modules and one positioning module.

[0047] Specifically, the first detection module is connected to the input of the sampling circuit and is used to detect the sampling signal input to the sampling circuit. When the sampling signal input to the sampling circuit is normal, the first detection module outputs a low level to the positioning module. If the sampling signal input to the sampling circuit is abnormal, the first detection module outputs a high level to the positioning module. At this time, the signal in the multiplexer connected to the first detection module is set to 1, indicating that the signal input to the digital board is abnormal.

[0048] The second detection module is connected to the output of the sampling circuit and is used to detect the intermediate frequency signal output by the sampling circuit. When the intermediate frequency signal output by the sampling circuit is normal, the second detection module outputs a low level to the positioning module. If the intermediate frequency signal output by the sampling circuit is abnormal, the second detection module outputs a high level to the positioning module. At this time, the signal connected to the second detection module in the multiplexer is set to 1, indicating an abnormal intermediate frequency signal. When the signal connected to the first detection module in the multiplexer is 0 and the signal connected to the second detection module is 1, it indicates an abnormality in the sampling circuit.

[0049] The third detection module is connected to the output end of the audio conversion circuit and is used to detect the analog audio signal output by the audio conversion circuit. When the analog audio signal output by the audio conversion circuit is normal, the third detection module outputs a low level to the positioning module; if there is an abnormality in the analog audio signal output by the audio conversion circuit, the third detection module outputs a high level to the positioning module. At this time, the signal connected to the third detection module in the multiplexer is set to 1, indicating that there is an abnormality in the analog audio signal. When the signals connected to the first detection module and the second detection module in the multiplexer are both 0, and the signal connected to the third detection module is 1, it indicates that there is an abnormality in the audio conversion circuit.

[0050] After the fault is located by the multiplexer, the result is output to the feedback unit for feedback, and maintenance personnel can locate the fault based on the feedback result.

[0051] In an optional embodiment, the second detection module includes a first rectifier unit, a first amplitude detection unit, and a first comparison unit connected in sequence; the third detection module includes a second rectifier unit, a second detection unit, and a second comparison unit connected in sequence;

[0052] The output terminal of the first amplitude detection unit is connected to the input terminal of the second comparison unit.

[0053] It should be noted that if Figure 2As shown, for the detection of the intermediate frequency signal and the analog audio signal, it is necessary to first rectify them through the rectification unit. After rectification by the rectification unit, the intermediate frequency signal and the analog audio signal are converted into a DC voltage, and then the amplitude of the converted DC voltage is detected by the amplitude detection unit, and then compared by the comparison unit. If the amplitude of the DC voltage is less than the upper threshold and greater than the lower threshold, it is determined that there is no abnormality in the intermediate frequency signal or the corresponding analog audio signal corresponding to the DC voltage, and the comparison unit outputs a low level; otherwise, the comparison unit outputs a high level.

[0054] Since the amplitude of the audio signal is smaller than the amplitude of the intermediate frequency signal when the intermediate frequency signal is converted into an analog audio signal in a digital board, in the present invention, the first amplitude detection unit is connected to the second comparison unit, and the output amplitude of the first amplitude detection unit is used as the upper limit threshold in the second comparison unit for comparison. If the amplitude of the analog audio signal is greater than or equal to the amplitude of the intermediate frequency signal, it indicates that there is an abnormality in the audio conversion unit.

[0055] In an optional embodiment, the second rectifying unit includes:

[0056] The switch tube Q2 has a delay component and a drive component disposed between the drain and the source of the switch tube Q2 , and the delay component is connected to the drive component.

[0057] It should be noted that in the present invention, the first rectifier unit and the second rectifier unit have the same structure, and the present invention takes the structure in the second rectifier unit as an example. Among them, the second rectifier unit includes three components: a switch tube, a delay component and a drive component. Specifically, the delay component outputs a delayed voltage to the drive component, and the drive component sends a drive signal to the switch tube Q2 after receiving the delayed voltage. At this time, under the action of the delay component, the switch tube Q2 is close to a diode. Compared with the prior art, the bridge rectifier circuit uses a larger voltage drop due to the use of a diode, and the conduction loss is larger under large current. The present invention simulates the function of the diode through the switch tube Q2, the delay component and the drive component, thereby overcoming the problem of large loss in the prior art.

[0058] In an optional embodiment, the delay component includes: a MOS transistor Q1, a resistor R2, a MOS transistor Q3, a resistor R3 and a capacitor C2;

[0059] The source of the MOS transistor Q3 is connected to the source of the switch transistor Q2, the resistor R2 and the resistor R3 are connected in series and then connected to the drain of the MOS transistor Q3, the capacitor C2 is connected to the gate of the MOS transistor Q3, the drain of the MOS transistor Q1 is connected to the drain of the MOS transistor Q3, and the gate of the MOS transistor Q1 is connected to the drain of the switch transistor Q2.

[0060] In an optional embodiment, the driving component includes: a capacitor C3, a capacitor C4, a resistor R4 and a chip U1;

[0061] Among them, the two ends of the capacitor C3 are respectively connected between pin 1 and pin 3 of the chip U1; the source of the MOS tube Q1 is respectively connected to pin 7 and pin 8 of the chip U1; the two ends of the resistor R4 are respectively connected between pin 3 and pin 5 of the chip U1; the two ends of the capacitor C4 are respectively connected between pin 7 and pin 6 of the chip U1.

[0062] In an optional embodiment, the model of the chip U1 is AUIRS1170S.

[0063] It should be noted that pin 1 of the chip U1 is the Vd port, pin 2 is the Vgate port, pin 3 is the Vs port, pin 5 is the MDT port, pin 6 is the SYNC port, pin 7 is the EN port, and pin 8 is the VCC port.

[0064] When the Vd port of the chip U1 reaches a certain threshold, the driving signal sent by the chip U1 is high level. At this time, the driving signal can turn on the switch tube Q2 and at the same time, turn off the MOS tube Q3.

[0065] In the driving assembly, the capacitor C3 and the capacitor C4 in the present invention function as filtering.

[0066] In an optional embodiment, the second amplitude detection unit includes: a capacitor C5, a resistor R5, a diode D1, a capacitor C6, a resistor R6, a resistor R7, a resistor R8, a capacitor C7, a diode D2 and a mutual inductor T1;

[0067] The capacitor C5 is connected in series with the resistor R5, and a diode D1, a resistor R7, and a diode D2 are connected in series once between the capacitor C5 and the resistor R5; the capacitor C6 and the resistor R6 are connected in parallel between the diode D1 and the resistor R7; the resistor R8 and the capacitor C7 are connected in parallel between the resistor R7 and the diode D2; one side of the mutual inductor T1 is connected to the output end of the diode D2, and the other side is connected to the capacitor C5.

[0068] In an optional embodiment, a sampling resistor R9 is provided in the mutual inductor T1.

[0069] It should be noted that capacitor C6 and resistor R6, capacitor C7, and resistor R8 form two peak detectors. The DC voltage signal is converted by capacitor voltage division, and the intelligent current signal is converted into a voltage signal through sampling resistor R9 of transformer T1. The voltage signal is loaded between the anode and cathode of diodes D1 and D2, respectively, to detect the DC signal. The detected voltage can represent the amplitude signal.

[0070] In an optional embodiment, the second comparison unit includes: a resistor R10, a resistor R11, a resistor R12, a resistor R13, an operational amplifier U2 and an operational amplifier U3;

[0071] Among them, the resistor R11, the resistor R12 and the resistor R13 are connected in series, the resistor R11 is connected to the control end of the operational amplifier U2, one end of the resistor R13 is connected to the control end of the operational amplifier U3, and the other end is connected to the positive input end of the operational amplifier U3; the positive input end of the operational amplifier U2 and the negative input end of the operational amplifier U3 are connected to the resistor R10; the negative input end of the operational amplifier U2 is connected to the first amplitude detection unit.

[0072] It should be noted that operational amplifier U2 is used to compare the upper amplitude limit, while operational amplifier U3 is used to compare the lower amplitude limit. The second comparison unit has a similar structure to the first comparison unit, but the difference between the two lies in the connection of the negative input terminal of operational amplifier U2. In the second comparison unit, the negative input terminal of operational amplifier U2 is connected to the first amplitude detection unit, and the detected amplitude in the first amplitude detection unit is used in the second comparison unit as the upper amplitude limit.

[0073] Among them, the first amplitude detection unit is Figure 3 The a2 port in the output detection amplitude is Figure 4 The a3 port in the inputs the detected amplitude into the operational amplifier U2 as the upper limit of the comparison amplitude.

[0074] In an optional embodiment, the multiplexer is a four-to-one selector.

[0075] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above description is only a specific implementation method of the utility model and is not intended to limit the scope of protection of the utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the utility model should be included in the scope of protection of the utility model.

Claims

1. A digital board self-test circuit for a very high frequency ground station, characterized in that: include: a first detection module, connected to an input end of the sampling circuit, and configured to detect a sampling signal input into the sampling circuit; a second detection module, connected to the output end of the sampling circuit, and configured to detect the intermediate frequency signal output by the sampling circuit; a third detection module, connected to the output end of the audio conversion circuit, and configured to detect the analog audio signal output by the audio conversion circuit; The positioning module includes a multiplexer and a feedback unit, the first detection module, the second detection module and the third detection module are respectively connected to the three input ends of the multiplexer, and the output end of the multiplexer is connected to the feedback unit.

2. A digital board self-test circuit for a VHF terrestrial station according to claim 1, characterized in that: The second detection module includes a first rectifier unit, a first amplitude detection unit, and a first comparison unit connected in sequence; the third detection module includes a second rectifier unit, a second amplitude detection unit, and a second comparison unit connected in sequence; The output terminal of the first amplitude detection unit is connected to the input terminal of the second comparison unit.

3. A digital board self-test circuit for a VHF terrestrial station according to claim 2, characterized in that: The second rectifying unit includes: The switch tube Q2 has a delay component and a drive component disposed between the drain and the source of the switch tube Q2 , and the delay component is connected to the drive component.

4. A digital board self-test circuit for a VHF terrestrial station according to claim 3, characterized in that: The delay component includes: MOS tube Q1, resistor R2, MOS tube Q3, resistor R3 and capacitor C2; The source of the MOS transistor Q3 is connected to the source of the switch transistor Q2, the resistor R2 and the resistor R3 are connected in series and then connected to the drain of the MOS transistor Q3, the capacitor C2 is connected to the gate of the MOS transistor Q3, the drain of the MOS transistor Q1 is connected to the drain of the MOS transistor Q3, and the gate of the MOS transistor Q1 is connected to the drain of the switch transistor Q2.

5. A digital board self-test circuit for a VHF terrestrial station according to claim 4, characterized in that: The driving component includes: capacitor C3, capacitor C4, resistor R4 and chip U1; Among them, the two ends of the capacitor C3 are respectively connected between pin 1 and pin 3 of the chip U1; the source of the MOS tube Q1 is respectively connected to pin 7 and pin 8 of the chip U1; the two ends of the resistor R4 are respectively connected between pin 3 and pin 5 of the chip U1; the two ends of the capacitor C4 are respectively connected between pin 7 and pin 6 of the chip U1.

6. A digital board self-test circuit for a VHF terrestrial station according to claim 5, characterized in that: The model of the chip U1 is AUIRS1170S.

7. A digital board self-test circuit for a VHF terrestrial station according to claim 2, characterized in that: The second amplitude detection unit includes: a capacitor C5, a resistor R5, a diode D1, a capacitor C6, a resistor R6, a resistor R7, a resistor R8, a capacitor C7, a diode D2 and a mutual inductor T1; The capacitor C5 is connected in series with the resistor R5, and a diode D1, a resistor R7, and a diode D2 are connected in series once between the capacitor C5 and the resistor R5; the capacitor C6 and the resistor R6 are connected in parallel between the diode D1 and the resistor R7; the resistor R8 and the capacitor C7 are connected in parallel between the resistor R7 and the diode D2; one side of the mutual inductor T1 is connected to the output end of the diode D2, and the other side is connected to the capacitor C5.

8. A digital board self-test circuit for a VHF terrestrial station according to claim 7, characterized in that: The mutual inductor T1 is provided with a sampling resistor R9.

9. The digital board self-test circuit for a VHF terrestrial station according to claim 2, characterized in that: The second comparison unit includes: a resistor R10, a resistor R11, a resistor R12, a resistor R13, an operational amplifier U2 and an operational amplifier U3; Among them, the resistor R11, the resistor R12 and the resistor R13 are connected in series, the resistor R11 is connected to the control end of the operational amplifier U2, one end of the resistor R13 is connected to the control end of the operational amplifier U3, and the other end is connected to the positive input end of the operational amplifier U3; the positive input end of the operational amplifier U2 and the negative input end of the operational amplifier U3 are connected to the resistor R10; the negative input end of the operational amplifier U2 is connected to the first amplitude detection unit.

10. The digital board self-test circuit for a VHF terrestrial station according to claim 1, characterized in that: The multiplexer is a four-to-one selector.

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