Detection circuit for detecting state on audio transmission line and fire-fighting product

Abstract

The utility model relates to a detection circuit for detecting the state on an audio transmission line, namely a fire-fighting product, which comprises an input voltage, and a transmission line and a voice signal processing module which are connected with the input voltage, the transmission line is connected with a plurality of groups of detection modules, and the plurality of groups of detection modules are sequentially connected in parallel on the transmission line. The detection module comprises voltage stabilization modules and a voltage switching module connected with the voltage stabilization modules, the voltage stabilization values of the voltage stabilization modules are smaller than the input voltage, the voltage stabilization values of the multiple voltage stabilization modules are sequentially reduced, the output end of the voltage switching module is a detection point, and the load and fault state on the transmission line is detected through the level change of the output end. Load and fault state detection of the two-wire system audio transmission line is realized by using fewer discrete components, the circuit is simplified, and the circuit cost is reduced. The IO logic level of each group of detection modules is detected through the MCU, the state of the transmission line can be judged, the consumption of MCU resources is reduced, and the detection granularity can be enhanced by properly increasing the number of detection circuits and IO ports.

Description

TECHNICAL FIELD

[0001] The utility model relates to, especially a kind of detection circuit and fire-fighting product for detecting audio transmission line on-line state. BACKGROUND

[0002] In fire emergency lighting, evacuation indication and alarm system, two-wire system wiring technology has become the mainstream configuration scheme of the industry due to its significant advantages such as wiring simplification, cost optimization and strong compatibility. This system realizes the dual functions of device power supply and signal transmission through a single loop, significantly reducing the complexity of cable laying. However, in actual application scenarios, transmission lines are often subjected to strong electromagnetic interference, temperature and humidity fluctuations, and mechanical stress, which can cause insulation aging, contact impedance abnormalities, short circuit / disconnection and other progressive or sudden failures, directly affecting the emergency response reliability of the fire safety system.

[0003] The current detection method mainly uses a combination of periodic manual inspection and basic electrical parameter threshold determination, which has significant technical defects: existing detection circuits generally rely on multiple signal conditioning, high-precision ADC analog-digital conversion and complex impedance matching networks, requiring the configuration of operational amplifiers, special measurement chips and other discrete components, resulting in increased hardware costs per node and high circuit board area occupancy, making it difficult to meet the miniaturization design requirements of fire safety equipment. At the same time, it cannot achieve more detailed granularity detection, with large detection errors. SUMMARY

[0004] The technical problem to be solved by the utility model is that existing detection circuits generally rely on multiple signal conditioning, high-precision ADC analog-digital conversion and complex impedance matching networks, requiring the configuration of operational amplifiers, special measurement chips and other discrete components, resulting in increased hardware costs per node and high circuit board area occupancy, making it difficult to meet the miniaturization design requirements of fire safety equipment. At the same time, it cannot achieve more detailed granularity detection, with large detection errors. In view of the above defects of the prior art, a detection circuit for detecting the state of an audio transmission line and a fire-fighting product are provided.

[0005] To solve the above technical problems, the utility model adopts the technical scheme of:

[0006] The application discloses a detection circuit for detecting the state of an audio transmission line, which comprises an input voltage, a transmission line and a voice signal processing module connected with the input voltage, wherein the input voltage provides a bias voltage for the voice signal processing module and a pull-up voltage for the transmission line; a plurality of detection modules are connected in parallel on the transmission line; each detection module comprises a voltage stabilizing module and a voltage switching module connected with the voltage stabilizing module; the voltage stabilizing value of the voltage stabilizing module is smaller than the input voltage, and the voltage stabilizing values of the plurality of voltage stabilizing modules decrease successively; the output end of the voltage switching module is a detection point; and the voltage switching module is turned on after the voltage stabilizing module is turned on, so as to detect the load state and the fault state of the transmission line through the level change of the output end of the voltage switching module.

[0007] Preferably, the detection module comprises a voltage stabilizing module connected with the transmission line, and a voltage switching module connected with the voltage stabilizing module; a filter module is connected between the voltage switching module and the voltage stabilizing module; the voltage switching module is connected with a bias voltage; and the output end of the voltage switching module is a detection end.

[0008] Preferably, the voltage stabilizing module is a voltage stabilizing tube, the voltage switching module is a triode, the filter module comprises a capacitor and a resistor, the bias voltage is connected with the triode through the resistor, and the collector end of the triode is the detection end.

[0009] Preferably, the first detection module further comprises a short-circuit detection module connected with the voltage switching module, which turns on the voltage switching module when the transmission line is short-circuited.

[0010] Preferably, the short-circuit detection module comprises a first triode and a first diode connected with the first triode, the first diode is connected with the transmission line, and the emitter of the first triode is connected with the bias voltage.

[0011] Preferably, the first triode and the second triode are connected through a current-limiting resistor, and the first triode is provided with the bias voltage through a first resistor.

[0012] Preferably, the voice signal processing module is connected with the transmission line through a coupling module, and the coupling module comprises a capacitor and a resistor connected in series.

[0013] The application further discloses a fire-fighting product comprising the detection circuit.

[0014] The detection circuit of the utility model has the advantages that the detection circuit can detect the load state and the fault state of the two-wire system audio frequency transmission line through less discrete components, simplifies the circuit and reduces the circuit cost. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely below, obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by the ordinary skilled in the art without creative labor belong to the protection scope of the utility model.

[0016] Figure 1 The principle block diagram of the detection circuit of the preferred embodiment of the utility model;

[0017] Figure 2 The principle block diagram of the first detection module of the preferred embodiment of the utility model;

[0018] Figure 3 The principle block diagram of the second detection module of the preferred embodiment of the utility model;

[0019] Figure 4 The specific circuit diagram of the detection circuit of the preferred embodiment of the utility model. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely below, obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by the ordinary skilled in the art without creative labor belong to the protection scope of the utility model.

[0021] The detection circuit of the utility model has the advantages that the detection circuit can detect the load state and the fault state of the two-wire system audio frequency transmission line through less discrete components, simplifies the circuit and reduces the circuit cost. Figure 1As shown, it comprises JP1 terminal connected with transmission line, through which the transmission line is connected to the circuit, and it also comprises pull-up voltage and voice signal processing module 10 connected with transmission line, which is connected with transmission line through coupling module, and the transmission line is sequentially connected with first detection module 20, second detection module 30, third detection module 40 and Nth detection module 50, through which the level signal size of detection end can be known to get the state of transmission line. The number of N can be set according to the need, in this application, N is taken as 3 for example. The transmission line is connected to the detection circuit through JP1 terminal, and the voice signal is transmitted to the voice signal processing module 10 through coupling module 70 to process the voice signal, and 18V voltage is connected to the transmission line through the third resistor R3, which can provide bias voltage for the voice signal processing module and also provide pull-up voltage for the transmission line.

[0022] Specifically, in this application, three groups of detection modules are taken as an example, such as Figure 1 As shown, the first detection module 20 comprises voltage stabilizing module 200 connected with transmission line, and filter module 60 connected with voltage stabilizing module, and voltage switching module 203 connected with filter module, the output end of which is detection end 204, and the voltage switching module is connected with bias voltage 202 and short circuit detection module 205. The second detection module 30 and the third detection module 40 are different from the first detection module only in that the short circuit detection module 205 is not set, so the specific structure of the second detection module and the third detection module is not repeated.

[0023] Further, as shown in Figure 2 and Figure 4As shown, in the first detection module 20, the voltage stabilizing module 200 is a first voltage stabilizing tube VZ1, the negative terminal of the first voltage stabilizing tube VZ1 is connected to the transmission line, the positive terminal is connected to the filter module 60, the voltage switching module 203 is a second triode Q2, the emitter of the second triode Q2 is grounded, and a second capacitor C2 is connected between the emitter and the base, and the base is connected to the first voltage stabilizing tube VZ1 through a sixth resistor R6, and the sixth resistor R6 and the second capacitor C2 constitute a filter module to filter out interference signals. The collector of the second triode Q2 is connected to the first detection end, and is also connected to the bias voltage 202 through a second resistor R2. The short circuit detection module 205 includes a first diode D1 connected to the transmission line, the negative terminal of the first diode D1 is connected to the transmission line, the positive terminal is connected to a fourth resistor R4, and the other end of the fourth resistor R4 is connected to the base of a first triode Q1, the base of the first triode Q1 is grounded through a first capacitor C1, the collector is connected to the base of the second triode Q2 through a fifth resistor R5, the emitter of the first triode Q1 is connected to a 5V bias voltage, and is connected to the base through a first resistor R1, and the first resistor R1 provides a bias voltage for the base of the first triode Q1, so that the first triode Q1 is not conductive under normal circumstances, and the fifth resistor R5 also provides a certain current limiting for the first triode Q1, so as to avoid damage to the first triode Q1 due to excessive current when the first triode Q1 is turned on.

[0024] Further, as Figure 3 and Figure 4As shown in the second detection module 30, the voltage stabilizing module 200 is a second voltage stabilizing tube VZ2, the negative terminal of the second voltage stabilizing tube is connected to the transmission line, the positive terminal is connected to the filter module 60, the voltage switching module 203 is a third triode Q3, the emitter of the third triode Q3 is grounded, and the emitter and the base are connected by a third capacitor C3, and the base and the second voltage stabilizing tube VZ2 are connected by a ninth resistor R9, and the ninth resistor R9 and the third capacitor C3 form a filter module to filter out interference signals. The collector of the third triode Q3 is connected to the second detection terminal, and is connected to the bias voltage 202 through an eighth resistor R8. In the third detection module 40, the voltage stabilizing module 200 is a third voltage stabilizing tube VZ3, the negative terminal of the third voltage stabilizing tube is connected to the transmission line, the positive terminal is connected to the filter module 60, the voltage switching module 203 is a fourth triode Q4, the emitter of the fourth triode Q4 is grounded, and the emitter and the base are connected by a fourth capacitor C4, and the base and the third voltage stabilizing tube VZ3 are connected by a twelfth resistor R12, and the twelfth resistor R12 and the fourth capacitor C4 form a filter module to filter out interference signals. The collector of the fourth triode Q4 is connected to the second detection terminal, and is connected to the bias voltage 202 through an eleventh resistor R11. In order to meet the working of the detection circuit, the voltage stabilizing value of the first voltage stabilizing tube VZ1 should be greater than that of the second voltage stabilizing tube VZ2, and the voltage stabilizing value of the second voltage stabilizing tube VZ2 should be greater than that of the third voltage stabilizing tube VZ3. When multiple detection modules are set, the voltage stabilizing tubes should also meet the requirement, that is, the closer the detection module to the transmission line, the greater the voltage stabilizing value of the voltage stabilizing tube, and the farther the detection module to the transmission line, the smaller the voltage stabilizing value of the voltage stabilizing tube, that is, the voltage stabilizing value of the voltage stabilizing tube should meet VZ1>VZ2>VZ3>…>VZN, and at the same time, all are less than the pull-up voltage, so as to realize that when the first voltage stabilizing tube VZ1 is turned on, the second triode Q2 is still turned on with sufficient voltage, that is, the pull-up voltage not only needs to make the voltage stabilizing tube conduct, but also needs to make the triode corresponding to the voltage stabilizing tube conduct. It is assumed that in this application, the value is set to 1V, and other values can also be set according to the actual situation.

[0025] For convenience of description, as shown in the drawings, Figure 4 The following will be described as JP1 terminal and the transmission line connection point A, the positive terminal of the first voltage stabilizing tube VZ1 B point, the positive terminal of the second voltage stabilizing tube VZ2 C point, and the positive terminal of the third voltage stabilizing tube VZ3 D point.

[0026] The detection circuit of the present application in detection, as shown in the drawings, Figure 4 The pull-up voltage is 18V, and when the transmission line is in an open circuit state, the load current is zero, at this time, the voltage value V A of point A is approximately 18V, so the first voltage stabilizing tube VZ1, the second voltage stabilizing tube VZ2 and the third voltage stabilizing tube VZ3 are all in the conductive state, and the voltage value V B of point B is 18V-V VZ1, C point voltage value V C = 18V - V VZ2 , D point voltage value V D = 18V - V VZ3 , since V VZ1 , V VZ2 and V VZ3 are all less than (18-1)V, V B , V C , V D >1V, the second, third and fourth triodes Q2, Q3 and Q4 will be turned on, thus the first, second and third detection points IO1, IO2 and IO3 are all low, and vice versa, when the first, second and third detection points IO1, IO2 and IO3 are all low, it indicates that the transmission line is in open circuit state.

[0027] As shown in Figure 4 , when the transmission line is normally connected, and the DC load current is I2, at this time, the A point voltage value V A = 18V - R3*I2, the voltage satisfies V VZ2 , V VZ3 <V A <V VZ1 , thus the first zener VZ1 will not be reversed on, while the second and third zeners VZ2 and VZ3 can be reversed on, thus resulting in that the second triode Q2 is not turned on, while the third and fourth triodes Q3 and Q4 are turned on, at this time, the first detection end IO1 is high, while the second and third detection points IO2 and IO3 are low, and vice versa, when the first detection end IO1 is high, while the second and third detection points IO2 and IO3 are low, it indicates that the transmission line is normally connected, and the DC load current is I2.

[0028] As shown in Figure 4 , when the transmission line is normally connected, and the DC load is increased to I3, at this time, the A point voltage value V A = 18V - R3*I3, the voltage satisfies V VZ3 <V A <V VZ1 , V VZ2 , thus the first and second zeners VZ1 and VZ2 will not be reversed on, while the third zener VZ3 can be reversed on, thus resulting in that the second and third triodes Q2 and Q3 are not turned on, while the fourth triode Q4 is turned on, at this time, the first detection end IO1 and the second detection point IO2 are high, while the third detection point IO3 is low, and vice versa, when the first detection end IO1 and the second detection point IO2 are high, while the third detection point IO3 is low, it indicates that the transmission line is normally connected, and the DC load current is I3.

[0029] As shown in Figure 4As shown, when the transmission line is properly connected and the DC load increases to I4, the voltage value at point A is V. A =18V - R3 * I4, the voltage satisfies V A <V VZ1 V VZ2 V VZ3 Therefore, the first Zener diode VZ1, the second Zener diode VZ2, and the third Zener diode VZ3 will all be unable to conduct in reverse, which will cause the second transistor Q2, the third transistor Q3, and the fourth transistor Q4 to not conduct. At this time, the first detection terminal IO1, the second detection point IO2, and the third detection point IO3 are at a high level. Conversely, when the first detection terminal IO1, the second detection point IO2, and the third detection point IO3 are at a high level, it indicates that the transmission line is normally connected and the DC load current is I4.

[0030] like Figure 4 As shown, when the transmission line is short-circuited, point A will be pulled to ground. Referring to the above process, the second detection point IO2 and the third detection point IO3 are at a high level, while the base of the first transistor Q1 is pulled low, and the first transistor Q1 is turned on. The +5V voltage is connected to the base of the second transistor Q2 through the first transistor Q1 and the fifth resistor R5, causing the second transistor to turn on. At this time, the first detection point IO1 is at a low level. Conversely, when the first detection point IO1 is at a low level, the second detection point IO2 and the third detection point IO3 are at a high level, indicating that the transmission line is short-circuited.

[0031] The MCU can determine the load and fault status on the transmission line by detecting the level changes of the first detection point IO1, the second detection point IO2, and the third detection point IO3. More groups can also be set as needed, the difference being that the DC load current will gradually increase.

[0032] A preferred embodiment of this utility model provides a fire protection product that includes a detection circuit as described above for detecting the status of an audio transmission line, in order to detect the load condition of the transmission line. The specific detection circuit structure is the same as described above and will not be repeated here.

[0033] It should be understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.

Claims

1. A detection circuit for detecting the state of an audio transmission line, comprising an input voltage, a transmission line connected to the input voltage, and a voice signal processing module, wherein the input voltage provides a bias voltage for the voice signal processing module and a pull-up voltage for the transmission line, characterized in that: Multiple detection modules are connected to the transmission line in parallel. Each detection module includes a voltage regulator module and a voltage switching module connected to the voltage regulator module. The voltage regulation value of the voltage regulator module is less than the input voltage, and the voltage regulation values ​​of the multiple voltage regulator modules decrease sequentially. The output terminal of the voltage switching module is the detection point. When the voltage regulator module is turned on, the voltage switching module is also turned on. The load status and fault status on the transmission line are detected by the level change at the output terminal of the voltage switching module.

2. The detection circuit according to claim 1, characterized in that: The detection module includes a voltage regulator module connected to the transmission line and a voltage switching module connected to the voltage regulator module. A filter module is connected between the voltage switching module and the voltage regulator module. The voltage switching module is connected to a bias voltage. The output terminal of the voltage switching module is the detection terminal.

3. The detection circuit according to claim 2, characterized in that: The voltage regulation module is a Zener diode, the voltage switching module is a transistor, the filtering module includes a capacitor and a resistor, the bias voltage is connected to the transistor through the resistor, and the collector terminal of the transistor is the detection terminal.

4. The detection circuit according to claim 2, characterized in that: The first detection module also includes a short-circuit detection module, which is connected to the voltage switching module. When the transmission line is short-circuited, the short-circuit detection module turns on the voltage switching module.

5. The detection circuit according to claim 4, characterized in that: The short-circuit detection module includes a first transistor and a first diode connected to the first transistor. The first diode is connected to a transmission line, and the emitter of the first transistor is connected to a bias voltage.

6. The detection circuit according to claim 5, characterized in that: The first transistor and the second transistor are connected by a current-limiting resistor, and the first transistor is provided with a bias voltage through a first resistor.

7. The detection circuit according to claim 1, characterized in that: The voice signal processing module is connected to the transmission line via a coupling module, which includes a capacitor and a resistor connected in series.

8. A fire protection product, characterized in that: It includes a detection circuit for detecting the state of an audio transmission line as described in any one of claims 1-7.

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