Centralized monitoring alarm device for instrument landing system

Abstract

The utility model discloses a centralized monitoring alarm device for an instrument landing system, which relates to the field of monitoring alarm, and is characterized in that a signal access circuit is used for accessing and processing alarm signals sent by navigation equipment in the instrument landing system; the power supply control circuit is used for controlling the working state of the alarm trigger circuit according to the output signal of the signal access circuit; the alarm trigger circuit is used for generating a control signal and controlling the alarm to give an alarm through the control signal; according to the utility model, centralized monitoring of each navigation device in the instrument landing system is realized, and when any device fails, an operator can be prompted rapidly through a remarkable sound-light alarm.

Description

Technical Field

[0001] The utility model relates to the field of monitoring and alarm, in particular to a centralized monitoring and alarm device for an instrument landing system. Background Technique

[0002] As an important aviation navigation system, the Instrument Landing System (ILS) plays a crucial role in ensuring flight safety. This system guides the aircraft to land safely by transmitting two sets of radio signals (localizer and glide slope), ensuring that the aircraft can accurately align with the runway under adverse weather conditions or low visibility. Its core components include the localizer equipment (LLZ), glide slope equipment (GP), marker beacon (MB), and distance measuring equipment (DME), which jointly construct the virtual path for the aircraft to land.

[0003] With the rapid development of the civil aviation industry, the popularity rate of the instrument landing system has been continuously increasing, and it has almost become the standard configuration for each runway. Nevertheless, most of such systems used in domestic airports rely on imports, especially products made in Europe and America, highlighting the need for domestic substitution. Given the extreme importance of flight safety, strict requirements are put forward for the immediate monitoring and fault response capabilities of ILS equipment. Once any abnormality occurs in the navigation equipment, the pilot must be notified promptly to avoid potential safety risks.

[0004] Despite the technological advancements of ILS equipment, which have brought functions such as remote control, remote status monitoring, and computer software monitoring, the current device status monitoring solutions on the market still have defects, mainly reflected in two aspects: one is the lack of a comprehensive centralized monitoring system that cannot simultaneously monitor the operating status of all navigation equipment; the other is that the existing alarm mechanisms of the equipment are not effective enough in an environment with high noise. The alarm volume is small and it is difficult to attract the attention of operators, especially in an environment such as an airport where there is already a relatively high background noise, and the effectiveness of the alarm is greatly reduced.

[0005] Therefore, in response to the monitoring requirements of the instrument landing system, it is particularly urgent to develop a new type of alarm device that can centrally monitor the alarm status of each navigation equipment and can effectively increase the alarm volume to adapt to different working environments. The design of this alarm device should have the ability to centrally monitor all key navigation equipment, ensuring that when any equipment fails, operators can be quickly reminded through significant acoustic and optical alarms, thereby improving the response speed and ensuring flight safety. Content of the Utility Model

[0006] In order to centrally monitor the alarm status of each navigation equipment, the utility model proposes to centrally monitor the alarm status of each navigation equipment, including:

[0007] A signal access circuit, a power control circuit electrically connected to the signal access circuit, an alarm trigger circuit, and an alarm; wherein: the signal access circuit is used to access and process the warning signals sent by each navigation device in the instrument landing system; the power control circuit is used to control the working state of the alarm trigger circuit according to the output signal of the signal access circuit; the alarm trigger circuit is used to generate a control signal and control the alarm of the alarm through the control signal.

[0008] Further, the signal access circuit includes:

[0009] A signal input interface;

[0010] An indicator light circuit, which is used to access the warning signals sent by each navigation device in the instrument landing system through the signal input interface, merge the accessed warning signals, and transmit the merged warning signals to the power control circuit.

[0011] Further, the centralized monitoring and alarm device further includes:

[0012] A power supply module, which is used to output DC power to the signal input interface and the power control circuit;

[0013] The power supply module includes a power input interface, a power switch circuit, and a power supply; the input end of the power switch circuit is electrically connected to the power input interface, and the output end is electrically connected to the power supply; wherein:

[0014] The power input interface is used to access an AC voltage;

[0015] The power switch circuit is used to control the access state of the AC voltage;

[0016] The power supply is used to convert the accessed AC voltage into DC power.

[0017] Further, the power control circuit includes:

[0018] The first chip U1 is connected to the power supply input terminal +12VP. The first pin of the first chip U1 is grounded. The second pin is connected to one end of the eighth resistor R8 and one end of the first capacitor C1, and then connected to the negative terminal of the seventh diode D7. The other end of the eighth resistor R8 is grounded. The other end of the first capacitor C1 is connected to the DC power supply. The positive terminal of the seventh diode D7 is connected to one end of the seventh resistor R7. The other end of the seventh resistor R7 is connected to one end of the sixth resistor R6 and then connected to the output terminal of the signal access circuit. One end of the sixth resistor R6 is grounded. The fourth pin of the first chip U1 is connected to the DC power supply. The fifth pin is connected to one end of the second capacitor C2. The other end of the second capacitor C2 is grounded. The sixth pin of the first chip U1 is connected to the second pin of the first chip U1. The seventh pin of the first chip U1 is connected to one end of the first relay K1 and the positive terminal of the eighth diode D8. The negative terminal of the eighth diode D8 is connected to the other end of the first relay K1 and then connected to the DC power supply. The power supply input terminal +12VP is electrically connected to the alarm trigger circuit. When the normally open contact of the first relay K1 is in the normally open state, the power supply input terminal +12VP is in the disconnected state from the DC power supply. When the normally open contact of the first relay K1 is in the closed state, the power supply input terminal +12VP is in the connected state with the DC power supply. The eighth pin of the first chip U1 is connected to the DC power supply.

[0019] Further, the alarm trigger circuit includes:

[0020] A level control circuit and an audio trigger circuit; the level control circuit is used to generate a periodic control signal and send it to the audio trigger circuit;

[0021] The audio trigger circuit is used to control the alarm to generate alternating high and low alarm audio according to the periodic control signal.

[0022] Further, the level control circuit includes:

[0023] The second chip U2 and the tenth resistor R10; the first pin of the second chip U2 is grounded and connected to one end of the fourth capacitor C4, the third pin is connected to the audio trigger circuit, the fourth pin is connected to the power supply input +12VP in the power control circuit, the fifth pin is connected to one end of the third capacitor C3, and the other end of the third capacitor C3 is grounded; one end of the tenth resistor R10 is connected to the sixth pin of the second chip U2 and at the same time connected to the other end of the fourth capacitor C4, and after being connected to the other end of the fourth capacitor C4, it is connected to the second pin of the second chip U2; the other end of the tenth resistor R10 is connected to one end of the ninth resistor R9; the seventh pin of the second chip U2 is connected to the connection end of the tenth resistor R10 and the ninth resistor R9; the eighth pin of the second chip U2 is connected to the DC power supply and then connected to the other end of the ninth resistor R9.

[0024] Further, the audio trigger circuit includes:

[0025] The third chip U3 and the thirteenth resistor R13; the first pin of the third chip U3 is grounded and connected to one end of the fifth capacitor C5, the third pin is connected to one end of the sixth capacitor C6 and one end of the fourteenth resistor R14, and the other end of the sixth capacitor C6 and the other end of the fourteenth resistor R14 are connected to the alarm; the fourth pin of the third chip U3 is connected to the power supply input +12VP in the power control circuit, the fifth pin is connected to one end of the eleventh resistor R11, and the other end of the eleventh resistor R11 is connected to the third pin of the second chip U2; one end of the thirteenth resistor R13 is connected to the sixth pin of the third chip U3 and at the same time connected to the other end of the fifth capacitor C5, and after being connected to the other end of the fifth capacitor C5, it is connected to the second pin of the third chip U3; the other end of the thirteenth resistor R13 is connected to one end of the twelfth resistor R12; the seventh pin of the third chip U3 is connected to the connection end of the thirteenth resistor R13 and the twelfth resistor R12; the eighth pin of the third chip U3 is connected to the DC power supply and then connected to the other end of the twelfth resistor R12.

[0026] Further, the alarm includes: a speaker module and an indicator light module; where:

[0027] The speaker module includes a speaker LS1; one end of the speaker LS1 is grounded, and the other end is connected to one end of the speaker switch S7; the other end of the speaker switch S7 is connected to the other end of the sixth capacitor C6 in the audio trigger circuit;

[0028] The indicator light module includes a sound alarm indicator light ALED; the positive terminal of the sound alarm indicator light ALED is connected to the other end of the fourteenth resistor R14 in the audio trigger circuit, and the negative terminal is grounded.

[0029] Furthermore, the centralized monitoring and alarming device further includes: a first panel; the alarm, the power switch circuit, and the indicator light circuit are all arranged on the first panel.

[0030] Furthermore, the centralized monitoring and alarming device further includes: a second panel; the power input interface and the signal input interface are both arranged on the second panel.

[0031] Compared with the prior art, the present utility model has at least the following beneficial effects:

[0032] (1) In the present utility model, the signal access circuit is used to access and process the warning signals sent by each navigation device in the instrument landing system; the power control circuit is used to control the working state of the alarm trigger circuit according to the output signal of the signal access circuit; the alarm trigger circuit is used to generate a control signal and control the alarm of the alarm through the control signal; the present utility model realizes the centralized monitoring of each navigation device in the instrument landing system, ensuring that when any device fails, the operator can be quickly reminded through obvious sound and light alarms.

[0033] (2) In the present utility model, the alarm trigger circuit includes: a level control circuit and an audio trigger circuit; the level control circuit is used to generate a periodic control signal and send it to the audio trigger circuit; the audio trigger circuit is used to control the alarm to generate alternating high and low alarm audio according to the periodic control signal; by generating alternating high and low alarm audio, the present utility model is more likely to attract the attention of the operator. Especially in a noisy environment, this changing audio mode can effectively penetrate the background noise, improving the recognizability and urgency of the alarm. Description of the Drawings

[0034] Figure 1 It is the overall circuit diagram of a centralized monitoring and alarming device for an instrument landing system;

[0035] Figure 2 It is the power control circuit diagram;

[0036] Figure 3 It is the level control circuit diagram;

[0037] Figure 4 It is the audio trigger circuit diagram;

[0038] Figure 5 It is the power input interface circuit diagram;

[0039] Figure 6 It is the power switch circuit diagram;

[0040] Figure 7 It is the circuit diagram of the power supply;

[0041] Figure 8 It is a circuit diagram of the signal input interface;

[0042] Figure 9 It is a circuit diagram of the indicator light;

[0043] Figure 10 It is a circuit diagram of the alarm. Specific implementation manner

[0044] The following are specific embodiments of the present invention and, in conjunction with the accompanying drawings, further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0045] In order to centrally monitor the alarm status of each navigation device, such as Figure 1 As shown, the present invention proposes a centralized monitoring and alarm device for an instrument landing system, including:

[0046] A signal access circuit, a power control circuit electrically connected to the signal access circuit, an alarm trigger circuit, and an alarm; wherein: the signal access circuit is used to access and process the alarm signals sent by each navigation device in the instrument landing system; the power control circuit is used to control the working state of the alarm trigger circuit according to the output signal of the signal access circuit; the alarm trigger circuit is used to generate a control signal and control the alarm to alarm through the control signal.

[0047] The signal access circuit includes:

[0048] Such as Figure 8 The signal input interface shown (specifically a Male type DB9 socket);

[0049] Such as Figure 9 The indicator light circuit shown, which is used to access the alarm signals sent by each navigation device in the instrument landing system through the signal input interface, merge the accessed alarm signals, and transmit the merged alarm signals to the power control circuit.

[0050] Such as Figure 9 As shown, when any navigation device has an alarm, the corresponding alarm signal (P1 - P5) will cause the normally closed end of the corresponding switch (S1 - S5) to close. Since these normally closed ends are connected in parallel to form the AIN signal (i.e., the merged alarm signal), when any alarm signal arrives, the AIN signal will be sent to the power control circuit to trigger the alarm logic.

[0051] The centralized monitoring and alarm device further includes:

[0052] A power module, which is used to output DC power to the signal input interface and the power control circuit;

[0053] The power module includes as Figure 5The power input interface shown, such as Figure 6 the power switch circuit shown and such as Figure 7 the power supply; the input end of the power switch circuit is electrically connected to the power input interface, and the output end is electrically connected to the power supply; wherein:

[0054] The power input interface is used to access the AC voltage of 220VAC;

[0055] The power switch circuit is used to control the access state of the AC voltage;

[0056] The power supply is used to convert the accessed AC voltage into a DC power supply.

[0057] The power supply in this embodiment is an MW switching power supply: the model is S-25-12, the output voltage is 12V, and the input current is 2.1A. The power supply is used to convert the AC voltage of 220VAC into the DC power supply of 12VDC.

[0058] Such as Figure 2 shown, the power control circuit includes:

[0059] The first chip U1 and the power supply input terminal +12VP. The first pin of the first chip U1 is grounded, the second pin is connected to one end of the eighth resistor R8 and one end of the first capacitor C1 and then connected to the negative terminal of the seventh diode D7; the other end of the eighth resistor R8 is grounded, and the other end of the first capacitor C1 is connected to the DC power supply; the positive terminal of the seventh diode D7 is connected to one end of the seventh resistor R7, and the other end of the seventh resistor R7 is connected to one end of the sixth resistor R6 and then connected to the output end of the signal access circuit; one end of the sixth resistor R6 is grounded; the fourth pin of the first chip U1 is connected to the DC power supply, the fifth pin is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is grounded; the sixth pin of the first chip U1 is connected to the second pin of the first chip U1; the seventh pin of the first chip U1 is connected to one end of the first relay K1 and the positive terminal of the eighth diode D8; the negative terminal of the eighth diode D8 is connected to the other end of the first relay K1 and then connected to the DC power supply; the power supply input terminal +12VP is electrically connected to the alarm trigger circuit; when the normally open contact of the first relay K1 is in the normally open state, the power supply input terminal +12VP is disconnected from the DC power supply; when the normally open contact of the first relay K1 is in the closed state, the power supply input terminal +12VP is connected to the DC power supply; the eighth pin of the first chip U1 is connected to the DC power supply.

[0060] In this embodiment, K1 is a 12VDC relay, and its main function in the circuit is to control the power supply of the alarm trigger circuit. When there is no alarm signal, the contacts of K1 are in the normal state, that is, the normally open contacts are disconnected and do not supply power to the alarm trigger circuit. Once the navigation equipment in the instrument landing system issues an alarm signal, it will trigger the operation of the NE555 chip (i.e., the first chip U1), and then drive the first relay K1; when K1 is triggered, its normally open contacts close, and these closed contacts conduct the power supply input terminal +12VP to the DC power supply, so the DC power supply is input to the alarm trigger circuit, and thus, the alarm trigger circuit starts to work.

[0061] It should be noted that the power control circuit in this embodiment is provided with a delay mechanism, that is, C1 is discharged through R8 (a 100K ohm resistor), which makes the discharge of the capacitor take a certain time (about 10 seconds) even if the AIN signal no longer exists. During this period, the output state of NE555 will not change immediately, so the first relay K1 still remains closed, and the alarm trigger circuit continues to be powered. The purpose of this design is to ensure that even if the alarm signal is an instantaneous and possibly overlooked minor fault, it has sufficient duration to attract the attention of the operator. Specifically:

[0062] In this embodiment, when the alarm of the instrument landing system navigation equipment enters the power control circuit through the AIN signal, it first charges the capacitor C1 through the 1K ohm resistor R7 and the guiding diode D7. When the voltage at the second pin of C1 and U1 reaches more than 8V, the internal power supply of pin 7 of U1 is connected, and at this time, the relay K1 operates, and the normally open contacts of K1 close, and the DC power supply 12VDC is provided to the alarm trigger circuit through the closed contacts. When the alarm signal of the instrument landing system navigation equipment disappears, the capacitor C1 discharges through the 100K ohm resistor R8. At this time, it is in the alarm delay stage. After about 10 seconds, the voltage at the second pin of C1 and U1 reaches less than 4V, the internal power supply of pin 7 of U1 is disconnected, and at this time, the relay K1 is restored, the normally open contacts of K1 are reset, and the contacts are interrupted and no longer supply power to the alarm trigger circuit.

[0063] The alarm trigger circuit includes:

[0064] A level control circuit and an audio trigger circuit; the level control circuit is used to generate a periodic control signal and send it to the audio trigger circuit;

[0065] As Figure 3 shown, the level control circuit includes:

[0066] The second chip U2 and the tenth resistor R10; the first pin of the second chip U2 is grounded and connected to one end of the fourth capacitor C4 at the same time, the third pin is connected to the audio trigger circuit, the fourth pin is connected to the power supply input +12VP in the power control circuit, the fifth pin is connected to one end of the third capacitor C3, and the other end of the third capacitor C3 is grounded; one end of the tenth resistor R10 is connected to the sixth pin of the second chip U2 and connected to the other end of the fourth capacitor C4 at the same time, and after being connected to the other end of the fourth capacitor C4, it is connected to the second pin of the second chip U2; the other end of the tenth resistor R10 is connected to one end of the ninth resistor R9; the seventh pin of the second chip U2 is connected to the connection end of the tenth resistor R10 and the ninth resistor R9; the eighth pin of the second chip U2 is connected to the DC power supply and then connected to the other end of the ninth resistor R9.

[0067] The audio trigger circuit is used to control the alarm to generate alternating high and low alarm audio according to a periodic control signal.

[0068] As Figure 4 shown, the audio trigger circuit includes:

[0069] The third chip U3 and the thirteenth resistor R13; the first pin of the third chip U3 is grounded and connected to one end of the fifth capacitor C5 at the same time, the third pin is connected to one end of the sixth capacitor C6 and one end of the fourteenth resistor R14, and the other end of the sixth capacitor C6 and the other end of the fourteenth resistor R14 are connected to the alarm; the fourth pin of the third chip U3 is connected to the power supply input +12VP in the power control circuit, the fifth pin is connected to one end of the eleventh resistor R11, and the other end of the eleventh resistor R11 is connected to the third pin of the second chip U2; one end of the thirteenth resistor R13 is connected to the sixth pin of the third chip U3 and connected to the other end of the fifth capacitor C5 at the same time, and after being connected to the other end of the fifth capacitor C5, it is connected to the second pin of the third chip U3; the other end of the thirteenth resistor R13 is connected to one end of the twelfth resistor R12; the seventh pin of the third chip U3 is connected to the connection end of the thirteenth resistor R13 and the twelfth resistor R12; the eighth pin of the third chip U3 is connected to the DC power supply and then connected to the other end of the twelfth resistor R12.

[0070] It should be noted that the working principle of the audio trigger circuit involves the charging and discharging processes of two NE555 timer chips U2 and U3 and the capacitors C4 and C5 they control to generate alternating high and low alarm audio.

[0071] First, when the circuit is powered on, the 10uF capacitor C4 starts to charge through the 10K ohm resistor R9 and the 22K ohm resistor R10. When the voltage on C4 rises above 8V, the pin 3 of the NE555 chip U2 outputs a high level, and at the same time, the internal power supply of pin 7 of U2 is connected. At this time, C4 discharges through R10. When the voltage of C4 drops below 4V, the pin 3 of U2 returns to the low level state, the internal power supply of pin 7 of U2 is disconnected, and C4 starts to charge again. This process forms a periodic pulse waveform.

[0072] Next, the charging and discharging of the 0.1uF capacitor C5 is affected by the state of pin 3 of U2. When pin 3 of U2 is at a high level, C5 will trigger the pin 3 of U3 to output a high level when the voltage exceeds 8.5V. On the contrary, when pin 3 of U2 is at a low level, C5 will also trigger the pin 3 of U3 to output a high level when the voltage is higher than 6.95V. C5 discharges through the 5K ohm resistor R13 until the voltage drops to 4.26V (when U2 is at a high level) or 3.47V (when U2 is at a low level), and the pin 3 of U3 returns to the low level, and C5 starts to charge again. The pin 5 of U3 is connected to the pin 3 of U2 through R11 to ensure that the charging and discharging of C5 is controlled by the state of U2, thus generating alternating high and low alarm audio.

[0073] The signal output from pin 3 of U3 is transmitted to the speaker LS1 through the 10uF DC-blocking capacitor C6 to generate an audio alarm. At the same time, the same signal is transmitted to the sound alarm indicator ALED through the 2.2K ohm current-limiting resistor R14, so that there is a visual prompt while generating an audio alarm. This design ensures that even in a noisy environment, the operator can detect the alarm situation through both visual and auditory prompts. In addition, by adjusting the resistance and capacitance values in the circuit, the frequency and duration of the audio can be changed, thereby adjusting the tone and rhythm of the alarm.

[0074] As Figure 10 shown, the alarm includes: a speaker module and an indicator module; where:

[0075] The speaker module includes the speaker LS1; one end of the speaker LS1 is grounded, and the other end is connected to one end of the speaker switch S7; the other end of the speaker switch S7 is connected to the other end of the sixth capacitor C6 in the audio trigger circuit;

[0076] The indicator module includes the sound alarm indicator ALED; the positive terminal of the sound alarm indicator ALED is connected to the other end of the fourteenth resistor R14 in the audio trigger circuit, and the negative terminal is grounded.

[0077] The centralized monitoring and alarming device further includes: a first panel and a second panel; the alarm, the power switch circuit and the indicator light circuit are all arranged on the first panel; the power input interface and the signal input interface are both arranged on the second panel.

[0078] In the present utility model, the signal access circuit is used for accessing and processing the warning signals sent by each navigation device in the instrument landing system; the power control circuit is used for controlling the working state of the alarm trigger circuit according to the output signal of the signal access circuit; the alarm trigger circuit is used for generating a control signal and controlling the alarm of the alarm through the control signal. The present utility model realizes the centralized monitoring of each navigation device in the instrument landing system, ensuring that when any device fails, the operator can be quickly reminded through obvious sound and light alarms.

[0079] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present utility model are only used to explain the relative positional relationship and movement conditions between components in a certain specific posture (as shown in the attached drawings). If this specific posture changes, then the directional indication also changes accordingly.

[0080] In addition, in the present utility model, descriptions such as "first", "second", "one", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0081] In the present utility model, unless otherwise clearly specified and defined, terms such as "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0082] In addition, the technical solutions between various embodiments of the present utility model can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.

Claims

1. A centralized monitoring and alarm device for an instrument landing system, characterized in that: include: A signal access circuit, a power control circuit electrically connected to the signal access circuit, an alarm trigger circuit and an alarm; wherein: the signal access circuit is used to access and process the alarm signals sent by various navigation devices in the instrument landing system; the power control circuit is used to control the working state of the alarm trigger circuit according to the output signal of the signal access circuit; the alarm trigger circuit is used to generate a control signal and control the alarm to sound an alarm through the control signal.

2. A centralized monitoring and alarm device for an instrument landing system according to claim 1, characterized in that: The signal access circuit comprises: Signal input interface; The indicator light circuit is used to access the alarm signals sent by various navigation devices in the instrument landing system through the signal input interface, merge the accessed alarm signals, and transmit the merged alarm signals to the power control circuit.

3. A centralized monitoring and alarm device for an instrument landing system according to claim 2, characterized in that: The centralized monitoring alarm device also includes: A power module, used to output DC power to the signal input interface and the power control circuit; The power module includes a power input interface, a power switch circuit and a power supply; the input end of the power switch circuit is electrically connected to the power input interface, and the output end is electrically connected to the power supply; wherein: The power input interface is used to access AC voltage; The power switch circuit is used to control the access state of the AC voltage; The power supply is used to convert the input AC voltage into a DC power supply.

4. A centralized monitoring and alarm device for an instrument landing system according to claim 3, characterized in that: The power control circuit comprises: The first chip U1 is connected to the power supply input terminal +12VP, the first pin of the first chip U1 is grounded, the second pin is connected to one end of the eighth resistor R8 and one end of the first capacitor C1 and then connected to the negative end of the seventh diode D7; the other end of the eighth resistor R8 is grounded, and the other end of the first capacitor C1 is connected to the DC power supply; the positive end of the seventh diode D7 is connected to one end of the seventh resistor R7, the other end of the seventh resistor R7 is connected to one end of the sixth resistor R6 and then connected to the output end of the signal access circuit; one end of the sixth resistor R6 is grounded; the fourth pin of the first chip U1 is connected to the DC power supply, the fifth pin is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is connected to ground; the sixth pin of the first chip U1 is connected to the second pin of the first chip U1; the seventh pin of the first chip U1 is connected to one end of the first relay K1 and the positive end of the eighth diode D8; the negative end of the eighth diode D8 is connected to the other end of the first relay K1 and then connected to a DC power supply; the power supply input terminal +12VP is electrically connected to the alarm trigger circuit; when the normally open contact of the first relay K1 is in the normally open state, the power supply input terminal +12VP is in a disconnected state from the DC power supply; when the normally open contact of the first relay K1 is in a closed state, the power supply input terminal +12VP is in a connected state from the DC power supply; the eighth pin of the first chip U1 is connected to a DC power supply.

5. A centralized monitoring and alarm device for an instrument landing system according to claim 4, characterized in that: The alarm triggering circuit comprises: A level control circuit and an audio trigger circuit; the level control circuit is used to generate a periodic control signal and send it to the audio trigger circuit; The audio trigger circuit is used to control the alarm to generate alternating high and low alarm audio frequencies according to a periodic control signal.

6. A centralized monitoring and alarm device for an instrument landing system according to claim 5, characterized in that: The level control circuit comprises: The second chip U2 and the tenth resistor R10; the first pin of the second chip U2 is grounded and connected to one end of the fourth capacitor C4, the third pin is connected to the audio trigger circuit, the fourth pin is connected to the power supply input terminal +12VP in the power control circuit, the fifth pin is connected to one end of the third capacitor C3, and the other end of the third capacitor C3 is grounded; one end of the tenth resistor R10 is connected to the sixth pin in the second chip U2 and the other end of the fourth capacitor C4, and is connected to the second pin of the second chip U2 after being connected to the other end of the fourth capacitor C4; the other end of the tenth resistor R10 is connected to one end of the ninth resistor R9; the seventh pin of the second chip U2 is connected to the connection end of the tenth resistor R10 and the ninth resistor R9; the eighth pin of the second chip U2 is connected to the other end of the ninth resistor R9 after being connected to the DC power supply.

7. A centralized monitoring and alarm device for an instrument landing system according to claim 6, characterized in that: The audio trigger circuit comprises: The third chip U3 and the thirteenth resistor R13; the first pin of the third chip U3 is grounded and connected to one end of the fifth capacitor C5, the third pin is connected to one end of the sixth capacitor C6 and one end of the fourteenth resistor R14, and the other end of the sixth capacitor C6 and the other end of the fourteenth resistor R14 are connected to the alarm; the fourth pin of the third chip U3 is connected to the power supply input terminal +12VP in the power control circuit, the fifth pin is connected to one end of the eleventh resistor R11, and the other end of the eleventh resistor R11 is connected to the third pin of the second chip U2; one end of the thirteenth resistor R13 is connected to the sixth pin in the third chip U3 and the other end of the fifth capacitor C5, and is connected to the second pin of the third chip U3 after being connected to the other end of the fifth capacitor C5; the other end of the thirteenth resistor R13 is connected to one end of the twelfth resistor R12; the seventh pin of the third chip U3 is connected to the connection end of the thirteenth resistor R13 and the twelfth resistor R12; the eighth pin of the third chip U3 is connected to the other end of the twelfth resistor R12 after being connected to the DC power supply.

8. A centralized monitoring and alarm device for an instrument landing system according to claim 7, characterized in that: The alarm device comprises: a speaker module and an indicator light module; wherein: The speaker module includes a speaker LS1; one end of the speaker LS1 is grounded, and the other end is connected to one end of a speaker switch S7; the other end of the speaker switch S7 is connected to the other end of the sixth capacitor C6 in the audio trigger circuit; The indicator light module comprises an audible alarm indicator light ALED; the positive terminal of the audible alarm indicator light ALED is connected to the other end of the fourteenth resistor R14 in the audio trigger circuit, and the negative terminal is grounded.

9. A centralized monitoring and alarm device for an instrument landing system according to claim 8, characterized in that: The centralized monitoring alarm device also includes: a first panel; the alarm, power switch circuit and indicator light circuit are all arranged on the first panel.

10. A centralized monitoring and alarm device for an instrument landing system according to claim 9, characterized in that: The centralized monitoring alarm device also includes: a second panel; the power input interface and the signal input interface are both arranged on the second panel.

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