Signal source switching system and frequency modulation transmitting station

Abstract

The utility model discloses a signal source switching system and a frequency modulation transmitting station. The signal source switching system comprises a state acquisition module, a signal comparison module and a switching module, wherein the state acquisition module is electrically connected with the signal comparison module and is used for receiving audio signals respectively corresponding to a first circuit of the first signal source and a second circuit of the second signal source and outputting circuit state signals respectively corresponding to the first circuit and the second circuit; the signal comparison module is electrically connected with the state acquisition module and the switching module and is used for sending a switching control signal to the switching module according to the circuit state signal output by the state acquisition module; and the switching module is electrically connected with the signal comparison module and is used for switching the signal source according to the switching control signal sent by the signal comparison module. According to the invention, the rapid and automatic switching of the signal source is realized, the duration of a broadcast stop accident caused by the fault of the signal source or the audio processor is shortened, and the safe broadcasting of the frequency modulation broadcast is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of frequency modulation broadcasting, in particular to a signal source switching system and a frequency modulation transmitting station. Background Art

[0002] FM broadcasting is a broadcasting method that uses frequency modulation technology to convert audio signals into high-frequency signals for transmission. It is widely used in social life. For FM transmitters, the stability of the signal source is crucial. The most important link in the FM signal source processing system is the audio processor. Once a failure occurs, it will cause the external broadcast to be silent. At present, the judgment of whether the audio processor signal is normal is based on the silent alarm. The time judgment threshold of this method is about more than 15 seconds, and after the alarm, it is necessary to manually switch the backup audio processor operation, which makes it difficult to estimate the suspension time. Utility Model Content

[0003] The utility model provides a signal source switching system and an FM transmitter, so as to realize fast and automatic switching of signal sources, shorten the duration of broadcast suspension accidents caused by failure of signal sources or audio processors, and ensure the safe broadcast of FM radio.

[0004] According to one aspect of the utility model, a signal source switching system is provided, the signal source switching system comprising: a state acquisition module, a signal comparison module and a switching module; wherein,

[0005] A state acquisition module, electrically connected to the signal comparison module, for receiving audio signals corresponding to the first circuit of the first signal source and the second circuit of the second signal source, respectively, and outputting circuit state signals corresponding to the first circuit and the second circuit, respectively;

[0006] The signal comparison module is electrically connected to the state acquisition module and the switching module respectively, and is used to send a switching control signal to the switching module according to the circuit state signal output by the state acquisition module;

[0007] The switching module is electrically connected to the signal comparison module and is used to switch the signal source according to the switching control signal sent by the signal comparison module.

[0008] Optionally, the status acquisition module includes: a first audio detection relay switch and a second audio detection relay switch; wherein, the first audio detection relay switch and the second audio detection relay switch respectively include a switch input end and a switch output end, the switch input end is electrically connected to the output end of the audio processor of the first signal source or the second signal source, and the switch output end is electrically connected to the signal comparison module, if the switch input end detects that the audio signal disconnection time of the corresponding first circuit or the second circuit exceeds a preset time threshold, the corresponding switch output end outputs a circuit status signal of a low level, otherwise, the corresponding switch output end outputs a circuit status signal of a high level.

[0009] Optionally, the signal comparison module includes: a NOT gate and an OR gate; wherein the input end of the NOT gate is electrically connected to the switch output end of the second audio detection relay switch of the state acquisition module; the output end of the NOT gate and the switch output end of the first audio detection relay switch of the state acquisition module are electrically connected to the input end of the OR gate respectively; the output end of the OR gate outputs a corresponding switching control signal according to the detected circuit state signal.

[0010] Optionally, the signal source switching system further includes:

[0011] When the circuit state signals output by the first audio detection relay switch and the second audio detection relay switch are both at a high level, the switching control signal output by the OR gate is at a high level;

[0012] When the circuit state signals output by the first audio detection relay switch and the second audio detection relay switch are both at a low level, the switching control signal output by the OR gate is at a high level;

[0013] When the switching control signal output by the first audio detection relay switch is at a high level and the switching control signal output by the second audio detection relay switch is at a low level, the switching control signal output by the OR gate is at a high level;

[0014] When the switching control signal output by the first audio detection relay switch is at a low level and the switching control signal output by the second audio detection relay switch is at a high level, the switching control signal output by the OR gate is at a low level.

[0015] Optionally, the switching module includes: a switching relay, wherein the input end of the switching relay is electrically connected to the signal comparison module, and when the switching control signal sent by the signal comparison module is at a high level, the contacts of the switching relay are connected to the first circuit to maintain the output of the first signal source; and when the switching control signal is at a low level, the contacts of the switching relay are connected to the second circuit to switch to the output of the second signal source.

[0016] Optionally, the first audio detection relay switch and the second audio detection relay switch at least include a time relay.

[0017] Optionally, the time relay includes a knob for setting a preset time threshold.

[0018] Optionally, the preset time threshold includes at least 2 seconds.

[0019] Optionally, the first signal source and the second signal source include at least a frequency modulation signal source.

[0020] According to another aspect of the present invention, a frequency modulation transmitter is provided, the frequency modulation transmitter comprising: a first signal source, a second signal source, a signal source switching system and an audio modulator; wherein:

[0021] A first signal source and a second signal source are used to transmit audio signals to the signal source switching system;

[0022] The signal source switching system integrates the signal source switching system of any embodiment of the utility model;

[0023] The audio modulator is used to process the audio signal output by the signal source switching system.

[0024] A signal source switching system provided by an embodiment of the utility model includes: a state acquisition module, a signal comparison module and a switching module; wherein the state acquisition module is electrically connected to the signal comparison module, and is used to receive audio signals corresponding to the first circuit of the first signal source and the second circuit of the second signal source, respectively, and output circuit state signals corresponding to the first circuit and the second circuit, respectively; the signal comparison module is electrically connected to the state acquisition module and the switching module, respectively, and is used to send a switching control signal to the switching module according to the circuit state signal output by the state acquisition module; the switching module is electrically connected to the signal comparison module, and is used to switch the signal source according to the switching control signal sent by the signal comparison module. The signal source switching system provided by an embodiment of the utility model determines the corresponding switching control signal according to the collected circuit state signals corresponding to the first circuit and the second circuit, and then completes the switching of the signal source according to the switching control signal, thereby realizing rapid and automatic switching of the signal source, shortening the duration of the broadcast suspension accident caused by the failure of the signal source or the audio processor, and ensuring the safe broadcasting of FM radio.

[0025] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present utility model, nor are they intended to limit the scope of the present utility model. Other features of the present utility model will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 It is a structural schematic diagram of a signal source switching system provided according to the first embodiment of the utility model;

[0028] Figure 2 It is a structural schematic diagram of a signal source switching system provided according to the second embodiment of the utility model;

[0029] Figure 3 It is a structural schematic diagram of a signal source switching system provided according to Embodiment 3 of the present utility model;

[0030] Figure 4 is a structural schematic diagram of another signal source switching system provided according to Embodiment 3 of the present utility model;

[0031] Figure 5 It is a logic circuit diagram of a signal comparison module provided according to the third embodiment of the present utility model;

[0032] Figure 6 It is a structural schematic diagram of a frequency modulation transmitting station provided according to the fourth embodiment of the utility model. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0034] It should be noted that the terms "first", "second", etc. in the specification and claims of the utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the utility model described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0035] Embodiment 1

[0036] Figure 1 This is a schematic diagram of the structure of a signal source switching system provided in the first embodiment of the utility model. This embodiment is applicable to the situation of fast and automatic switching of signal sources. Figure 1 As shown, the signal source switching system includes: a state acquisition module 10, a signal comparison module 20 and a switching module 30. The structure of the signal source switching system of this embodiment is described in detail below.

[0037] The state acquisition module 10 is electrically connected to the signal comparison module 20, and is used to receive audio signals corresponding to the first circuit of the first signal source and the second circuit of the second signal source, and output circuit state signals corresponding to the first circuit and the second circuit, respectively.

[0038] The first circuit may refer to a main circuit corresponding to a first signal source (main signal source), and the second circuit may refer to a backup circuit corresponding to a second signal source (backup signal source). The first signal source and the second signal source may include at least a frequency modulation signal source.

[0039] Exemplarily, taking the first signal source and the second signal source as frequency modulation signal sources, the first circuit and the second circuit also include an audio processor for processing the audio signal corresponding to the first signal source or the second signal source. It can be understood that in the same circuit, whether it is the signal source or the audio processor, as long as at least one of the two fails, the state acquisition module 10 cannot collect the corresponding audio signal.

[0040] Specifically, the state acquisition module 10 can be electrically connected to the first circuit of the first signal source and the second circuit of the second signal source, respectively, to respectively acquire the audio signals of the corresponding circuits, and output the circuit state signals of the corresponding circuits by detecting the presence or absence of the audio signals. Exemplarily, if the state acquisition module 10 detects that the audio signal of a certain signal source circuit is disconnected, and the disconnection time exceeds a preset time threshold, the circuit state signal output by the corresponding circuit is low level; otherwise, the circuit state signal output by the corresponding circuit is high level.

[0041] The signal comparison module 20 is electrically connected to the state acquisition module 10 and the switching module 30 respectively, and is used to send a switching control signal to the switching module 30 according to the circuit state signal output by the state acquisition module 10 .

[0042] The switching control signal may refer to a control signal used to implement switching between the first signal source and the second signal source.

[0043] Specifically, the signal comparison module 20 is used to feed back the corresponding switching control signal to the switching module 30 according to the circuit state signals corresponding to the first circuit and the second circuit respectively. Exemplarily, the signal comparison module 20 may have the following control logic: when it is detected that the circuit state signal corresponding to the first circuit is at a high level (the corresponding circuit has no fault), or the circuit state signals corresponding to the first circuit and the second circuit are both at a low level, the corresponding output switching control signal is at a high level; when it is detected that only the circuit state signal corresponding to the second circuit is at a high level, the corresponding output switching control signal is at a low level.

[0044] The switching module 30 is electrically connected to the signal comparison module 20 , and is used to switch the signal source according to the switching control signal sent by the signal comparison module 20 .

[0045] Specifically, the switching module 30 can choose to maintain the output of the first signal source or switch the first signal source to the second signal source in response to the switching control signal sent by the signal comparison module 20, so as to always maintain the normal output of one channel of audio signal. Exemplarily, the switching module 30 can be a switching relay, and when the switching control signal is at a high level, the contact of the switching relay is connected to the first circuit to maintain the output of the first signal source; and when the switching control signal is at a low level, the contact of the switching relay is connected to the second circuit to switch to the second signal source for output.

[0046] The embodiment of the utility model provides a signal source switching system, including: a state acquisition module, a signal comparison module and a switching module; wherein the state acquisition module is electrically connected to the signal comparison module, and is used to receive audio signals corresponding to the first circuit of the first signal source and the second circuit of the second signal source, respectively, and output circuit state signals corresponding to the first circuit and the second circuit, respectively; the signal comparison module is electrically connected to the state acquisition module and the switching module, respectively, and is used to send a switching control signal to the switching module according to the circuit state signal output by the state acquisition module; the switching module is electrically connected to the signal comparison module, and is used to switch the signal source according to the switching control signal sent by the signal comparison module. The signal source switching system provided by the embodiment of the utility model determines the corresponding switching control signal according to the collected circuit state signals corresponding to the first circuit and the second circuit, and then completes the switching of the signal source according to the switching control signal, thereby realizing the rapid automatic switching of the signal source, shortening the duration of the broadcast suspension accident caused by the failure of the signal source or the audio processor, and ensuring the safe broadcast of FM radio.

[0047] Embodiment 2

[0048] Figure 2 This is a schematic diagram of the structure of a signal source switching system provided by Embodiment 2 of the present utility model. Figure 2 As shown, a signal source switching system provided in the second embodiment is a further refinement of the state acquisition module 10, the signal comparison module 20 and the switching module 30 on the basis of the above embodiment, wherein the state acquisition module 10 includes: a first audio detection relay switch 11 and a second audio detection relay switch 12; the signal comparison module 20 includes: a NOT gate 21 and an OR gate 22; the switching module 30 includes: a switching relay 31. The structural composition of the signal source switching system of the present embodiment is specifically described below.

[0049] The first audio detection relay switch 11 and the second audio detection relay switch 12 in the status acquisition module 10 respectively include a switch input end and a switch output end. The switch input end is electrically connected to the output end of the audio processor of the first signal source or the second signal source, and the switch output end is electrically connected to the signal comparison module 20. If the switch input end detects that the audio signal disconnection time of the corresponding first circuit or the second circuit exceeds the preset time threshold, the corresponding switch output end outputs a circuit state signal of a low level. Otherwise, the corresponding switch output end outputs a circuit state signal of a high level.

[0050] Specifically, the first audio detection relay switch 11 and the second audio detection relay switch 12 may respectively include a switch input terminal and a switch output terminal, wherein the switch input terminal is electrically connected to the output terminal of the audio processor of the corresponding signal source, and the switch output terminal is electrically connected to the signal comparison module 20, and the first audio detection relay switch 11 and the second audio detection relay switch 12 are respectively used to: detect the interruption of the audio signal of the corresponding circuit, that is: if the switch input terminal detects that the signal disconnection time of the audio signal of the corresponding circuit exceeds the preset time threshold, the circuit state signal output by the switch output terminal is a low level; otherwise, the circuit state signal output by the switch output terminal is a high level. Among them, the preset time threshold can include at least 2 seconds, which can be set accordingly according to the actual application requirements, and this embodiment does not make specific limitations on this.

[0051] Further, based on the above-mentioned embodiment of the utility model, the first audio detection relay switch 11 and the second audio detection relay switch 12 may at least include a time relay, and the time relay may include a knob for setting a preset time threshold.

[0052] Specifically, the first audio detection relay switch 11 and the second audio detection relay switch 12 may be of the type of a time relay, which is used to determine the output circuit state signal according to the detection of the audio signal of the corresponding circuit within a preset time threshold. The time relay may include a knob for setting the preset time threshold, and the time parameter may be conveniently adjusted using the knob. It is understandable that in practical applications, in addition to the above-mentioned knob-type time relay, other types of time relays may also be used, such as a digital display time relay, etc., and this embodiment does not specifically limit this.

[0053] Further, based on the above-mentioned embodiment of the utility model, the first signal source and the second signal source may at least include a frequency modulation signal source.

[0054] Specifically, the signal source may be an FM signal source for outputting FM broadcast audio signals. An audio processor for processing audio signals is also included after the signal source of the corresponding circuit. Once the signal source and / or the audio processor in the circuit fails, the audio detection relay switch of the corresponding circuit will not be able to detect the audio signal, resulting in a silent broadcast. At this time, the signal source needs to be switched to ensure the normal broadcast of the FM broadcast.

[0055] The signal comparison module 20 includes: a NOT gate 21 and an OR gate 22, wherein the input end of the NOT gate 21 is electrically connected to the switch output end of the second audio detection relay switch 12 of the state acquisition module 10; the output end of the NOT gate 21 and the switch output end of the first audio detection relay switch 11 of the state acquisition module 10 are electrically connected to the input end of the OR gate 22 respectively; the output end of the OR gate 22 outputs a corresponding switching control signal according to the detected circuit state signal.

[0056] Specifically, the signal comparison module 20 may include a NOT gate 21 and an OR gate 22, wherein the input end of the NOT gate 21 is electrically connected to the switch output end of the second audio detection relay switch 12 of the state acquisition module 10, and the output end of the NOT gate 21 is electrically connected to the input end of the OR gate 22, for inverting the circuit state signal output by the second audio detection relay switch 12; the input end of the OR gate 22 is also electrically connected to the switch output end of the first audio detection relay switch 11 of the state acquisition module 10, and the output end of the OR gate 22 is electrically connected to the switching module 30, for performing a logic OR operation on the circuit state signal output by the first audio detection relay switch 11 and the circuit state signal output by the second audio detection relay switch 12 after inversion, and using the signal output after the logic OR operation as the corresponding switching control signal.

[0057] Further, based on the above utility model embodiment, the signal comparison module 20 specifically includes the following control logic:

[0058] When the circuit state signals output by the first audio detection relay switch 11 and the second audio detection relay switch 12 are both at a high level, the switching control signal output by the OR gate 22 is at a high level;

[0059] When the circuit state signals output by the first audio detection relay switch 11 and the second audio detection relay switch 12 are both at a low level, the switching control signal output by the OR gate 22 is at a high level;

[0060] When the switching control signal output by the first audio detection relay switch 11 is at a high level and the switching control signal output by the second audio detection relay switch 12 is at a low level, the switching control signal output by the OR gate 22 is at a high level;

[0061] When the switching control signal output by the first audio detection relay switch 11 is at a low level and the switching control signal output by the second audio detection relay switch 12 is at a high level, the switching control signal output by the OR gate 22 is at a low level.

[0062] The switching module 30 includes: a switching relay 31, wherein the input end of the switching relay 31 is electrically connected to the signal comparison module 20, and when the switching control signal sent by the signal comparison module 20 is at a high level, the contacts of the switching relay 31 are connected to the first circuit to maintain the output of the first signal source; and when the switching control signal is at a low level, the contacts of the switching relay 31 are connected to the second circuit to switch to the output of the second signal source.

[0063] Specifically, the switching relay 31 in the switching module 30 has an input end electrically connected to the output end of the signal comparison module 20, and is used to detect that the switching control signal is at a high level, that is, the circuit state at this time is that the first circuit signal is normal (the second circuit signal is normal or faulty) or both the first circuit and the second circuit signals are faulty, and the switching relay 31 is valid at a low level and does not operate, and the contacts are connected to the first circuit to maintain the output of the first signal source; and when the switching control signal is detected to be at a low level, that is, the circuit state at this time is that the first circuit signal is faulty but the second circuit signal is normal, the switching relay 31 is valid at a low level, the contacts are connected to the second circuit, and it switches to the second signal source output.

[0064] The embodiment of the utility model provides a signal source switching system, which is used to output the corresponding circuit state signal according to the disconnection time of the detected audio signal through the first audio detection relay switch 11 and the second audio detection relay switch 12 in the state acquisition module 10; the NOT gate 21 and the OR gate 22 in the signal comparison module 20 are used to determine the corresponding switching control signal according to the circuit state signals respectively output by the first circuit and the second circuit; the switching relay 31 included in the switching module 30 is used to connect the contact to the corresponding signal source circuit according to the detected switching control signal. The fast automatic switching of the signal source is realized, the duration of the suspension accident caused by the failure of the signal source or the audio processor is shortened, and the safe broadcasting of FM radio is ensured.

[0065] Embodiment 3

[0066] Figure 3 This is a schematic diagram of the structure of a signal source switching system provided by Embodiment 3 of the present utility model. Figure 3 As shown, a signal source switching system provided in Embodiment 3 of the utility model takes the first signal source as the main signal source and the second signal source as the backup signal source as an example, integrates the switching functions of the main and backup audio source and the output signal of the audio processor, and realizes fast and automatic switching of the FM signal source by introducing a signal comparison module of the main and backup audio processor output signal comparison strategy.

[0067] The signal source switching system provided in this embodiment is such that when the main signal source is silent, the main circuit status signal collected by the status acquisition module is silent; when the main audio processor fails, the main circuit status signal collected by the status acquisition module is still silent. The backup judgment process is the same. Therefore, whether the signal source is silent or the audio processor fails, it will eventually be reflected in the circuit status signal output by the status acquisition module, and then combined with the signal switching after the audio comparison strategy of the signal comparison module is implemented, the integration of automatic switching of the signal source and automatic switching of the audio processor output signal is finally realized.

[0068] The signal source switching system provided in this embodiment has a switching function as shown in the following table (○ in the table indicates a normal signal, and × indicates a signal failure):

[0069] Main circuit status signal Backup circuit status signal Switching Modules ○ ○ Main output ○ × Main output × × Main output × ○ Backup output

[0070] It can be seen from the above table that after comparing the circuit status signals of the main path and the backup path, the switching module action is controlled according to the comparison result, thereby always maintaining the normal output of one audio signal.

[0071] Figure 4 This is a schematic diagram of the structure of another signal source switching system provided in Embodiment 3 of the present utility model. Figure 4 As shown, the state acquisition module in the signal source switching system can be composed of two audio detection relay switches, that is, the main circuit corresponds to the main circuit audio detection relay switch, and the backup circuit corresponds to the backup circuit audio detection relay switch. The two audio detection relay switches are respectively used to detect the audio signal processed by the audio processor of the corresponding circuit, and output the corresponding circuit state signal according to the disconnection of the audio signal of each circuit within the preset time threshold. Specifically, when the audio detection relay switch detects that the signal disconnection time of the audio signal of the corresponding circuit exceeds the preset time threshold (for example, 2 seconds), a low level is output; otherwise, if the signal is normal, a high level is output.

[0072] According to the signal source switching function requirements expressed in the above table, the corresponding logic truth table is as follows (1 in the table represents a high level and 0 represents a low level):

[0073] Main circuit status signal (X) Backup circuit status signal (Y) Switching control signal (F) 1 1 1 1 0 1 0 0 1 0 1 0

[0074] According to the above logic truth table, it can be converted into a logical expression: After simplification, we get in, Indicates that the inversion operation is performed on the standby circuit state signal Y. Therefore, according to the above signal comparison logic, the signal comparison module can be composed of a NOT gate and an OR gate. The logic circuit diagram is shown in Figure 5 shown.

[0075] The switching module can be composed of a switching relay, which is used to perform corresponding actions according to the input switching control signal F, and realize automatic switching of the signal source by connecting the contacts to the audio signal processed by the audio processor of the main or backup channel, thereby ensuring the normal broadcast of the FM radio signal.

[0076] In summary, based on the above logic truth table, the processing logic of the signal comparison module and the switching module is as follows:

[0077] ① When the main circuit status signal X and the backup circuit status signal Y are both high, it means that the main and backup circuit signals are normal. At this time, the output switching control signal F is high, the switching relay control terminal is low level effective, no action, the normally closed contact receives the main signal, and the main output is maintained;

[0078] ② When the main circuit status signal X is high and the standby circuit status signal Y is low, it means that the main signal is normal and the standby signal is faulty. At this time, the output switching control signal F is high, the switching relay control terminal is low level valid, no action, the normally closed contact receives the main signal, and the main output is still maintained;

[0079] ③ When the main circuit status signal X and the backup circuit status signal Y are both at low level, it means that both the main and backup circuit signals are faulty. At this time, the output switching control signal F is at high level, the switching relay control terminal is at low level and effective, and does not act. The normally closed contact receives the main signal and maintains the main output;

[0080] ④ When the main circuit status signal X is at a low level and the standby circuit status signal Y is at a high level, it means that the main signal is faulty and the standby signal is normal. At this time, the output switching control signal F is at a low level, and the switching relay control terminal is valid at a low level, switching to the standby output.

[0081] Through the above-mentioned signal source switching system, fast and automatic switching of FM signal sources is achieved, which greatly shortens the duration of broadcast suspension accidents caused by signal source or audio processor failures and ensures the safe broadcasting of FM radio.

[0082] The embodiment of the utility model provides a signal source switching system, which detects the disconnection of the audio signal of the corresponding circuit through the audio detection relay switch of the main circuit and the backup circuit, and outputs the corresponding circuit state signals X and Y; the signal comparison module is used to perform logic processing on the detected circuit state signals X and Y, and output the corresponding switching control signal F; the switching module is used to perform corresponding actions according to the input switching control signal F, and realizes automatic switching of the signal source by connecting the contact to the audio signal processed by the audio processor of the main circuit or the backup circuit, thereby shortening the suspension accident duration caused by the failure of the signal source or the audio processor, and ensuring the safe broadcasting of FM radio.

[0083] Embodiment 4

[0084] Figure 6 This is a schematic diagram of the structure of a frequency modulation transmitter provided by the fourth embodiment of the utility model. This embodiment is applicable to the situation where the signal source is switched quickly and automatically. Figure 6 As shown, the FM transmitter includes: a first signal source 41, a second signal source 42, a signal source switching system 43 and an audio modulator 44; wherein,

[0085] The first signal source 41 and the second signal source 42 are used to transmit audio signals to the signal source switching system 43 .

[0086] The signal source switching system 43 integrates the signal source switching system described in any embodiment of the present utility model.

[0087] The audio modulator 44 is used to process the audio signal output by the signal source switching system 43 .

[0088] In this embodiment, the first signal source 41 and the second signal source 42 can be frequency modulation signal sources, which are used to transmit frequency modulation broadcast signals to the signal source switching system 43. The signal source switching system 43 collects the audio signals of the first circuit of the first signal source and the second circuit of the second signal source, and then outputs the corresponding circuit state signals according to the collected audio signals, and then determines the corresponding switching control signal according to the above circuit state signals, and executes the corresponding signal source switching action, so as to determine the audio signal of the signal source that should be switched and played and output. The signal source switching system 43 integrates the signal source switching system described in any embodiment of the utility model, and the specific structure thereof is not repeated in this embodiment. Finally, the audio modulator 44 performs further audio signal processing on the audio signal output by the signal source switching system 43, for example, the audio signal can be superimposed on the high-frequency oscillation signal to facilitate the transmission of the audio signal.

[0089] The embodiment of the utility model provides an FM transmitter, which realizes fast and automatic switching of FM signal sources by introducing a signal source switching system, greatly shortens the duration of broadcast suspension accidents caused by signal source or audio processor failures, and ensures the safe broadcasting of FM radio.

[0090] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A signal source switching system, characterized in that: The system includes: a state acquisition module, a signal comparison module and a switching module; wherein, The state acquisition module is electrically connected to the signal comparison module, and is used to receive audio signals corresponding to the first circuit of the first signal source and the second circuit of the second signal source, respectively, and output circuit state signals corresponding to the first circuit and the second circuit, respectively; The signal comparison module is electrically connected to the state acquisition module and the switching module respectively, and is used to send a switching control signal to the switching module according to the circuit state signal output by the state acquisition module; The switching module is electrically connected to the signal comparison module, and is used to switch the signal source according to the switching control signal sent by the signal comparison module.

2. The system according to claim 1, characterized in that The state acquisition module includes: a first audio detection relay switch and a second audio detection relay switch; wherein, The first audio detection relay switch and the second audio detection relay switch respectively include a switch input end and a switch output end, the switch input end is electrically connected to the output end of the audio processor of the first signal source or the second signal source, and the switch output end is electrically connected to the signal comparison module. If the switch input end detects that the audio signal disconnection time of the corresponding first circuit or the second circuit exceeds a preset time threshold, the corresponding switch output end outputs the circuit status signal as a low level, otherwise, the corresponding switch output end outputs the circuit status signal as a high level.

3. The system according to claim 1, characterized in that The signal comparison module includes: a NOT gate and an OR gate; wherein, The input end of the NOT gate is electrically connected to the switch output end of the second audio detection relay switch of the state acquisition module; the output end of the NOT gate and the switch output end of the first audio detection relay switch of the state acquisition module are electrically connected to the input end of the OR gate respectively; the output end of the OR gate outputs the corresponding switching control signal according to the detected circuit state signal.

4. The system according to claim 3, characterized in that Also includes: When the circuit state signals output by the first audio detection relay switch and the second audio detection relay switch are both at a high level, the switching control signal output by the OR gate is at a high level; When the circuit state signals output by the first audio detection relay switch and the second audio detection relay switch are both at a low level, the switching control signal output by the OR gate is at a high level; When the switching control signal output by the first audio detection relay switch is at a high level and the switching control signal output by the second audio detection relay switch is at a low level, the switching control signal output by the OR gate is at a high level; When the switching control signal output by the first audio detection relay switch is at a low level and the switching control signal output by the second audio detection relay switch is at a high level, the switching control signal output by the OR gate is at a low level.

5. The system according to claim 1, characterized in that The switching module includes: a switching relay, wherein: The input end of the switching relay is electrically connected to the signal comparison module. When the switching control signal sent by the signal comparison module is at a high level, the contacts of the switching relay are connected to the first circuit to maintain the output of the first signal source; and, when the switching control signal is at a low level, the contacts of the switching relay are connected to the second circuit to switch to the output of the second signal source.

6. The system according to claim 2, characterized in that The first audio detection relay switch and the second audio detection relay switch at least include a time relay.

7. The system according to claim 6, characterized in that The time relay comprises a knob for setting a preset time threshold.

8. The system according to claim 2, characterized in that The preset time threshold includes at least 2 seconds.

9. The system according to claim 1, characterized in that The first signal source and the second signal source at least include a frequency modulation signal source.

10. A frequency modulation transmitter, characterized in that: include: A first signal source, a second signal source, a signal source switching system and an audio modulator; wherein, The first signal source and the second signal source are used to transmit audio signals to the signal source switching system; The signal source switching system integrates the signal source switching system as described in any one of claims 1 to 9; The audio modulator is used to process the audio signal output by the signal source switching system.

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