Dual-power-amplifier audio input device for rail transit

Abstract

The utility model discloses a rail transit dual-power-amplifier audio input device. Two power amplifier playing units are configured in a rail transit tool; the device comprises a main controller, a manual broadcast input circuit, an either-or input circuit and an audio processing circuit. The output end of the main controller is electrically connected with the input ends of the two power amplifier playing units, the input end of the either-or input circuit and the input end of the audio processing circuit, and the input end of the manual broadcast input circuit is electrically connected with an external audio transmitting end. The output end of the manual broadcast input circuit is electrically connected with the input end of the audio processing circuit through the alternative input circuit, and the output end of the audio processing circuit is electrically connected with the input ends of the two power amplifier playing units. According to the utility model, high-quality input and playing of dual-channel broadcast in a dual-power-amplifier playing mode of rail transit are realized, playing of various types of broadcast of the rail transit can be adapted, and the real situation of the broadcast of the rail transit is better met.

Description

Technical Field

[0001] The utility model relates to the technical field of rail transit broadcasting, in particular to a rail transit dual-power amplifier audio input device. Background Art

[0002] In rail transit vehicles, in order to facilitate passengers in the carriage to better listen to broadcasts (such as train arrival information, etc.), a dual-amplifier playback mode is usually adopted, that is, speakers are set on both sides of the carriage, and the speakers on both sides are controlled by different amplifier chips.

[0003] Rail transit announcements typically include automatic and manual announcements. Automatic announcements include train arrival and arrival announcements, scheduled announcements (e.g., train out of service, ticket sales), and idle announcements (e.g., safety announcements, background music). Manual announcements are made by station attendants or customer service personnel through microphones. To ensure that different types of announcements can be transmitted to passengers via dual-amplification, allowing passengers to receive them from all locations in the train car, a special audio input device is required to implement both input and playback for rail transit dual-channel announcements. Utility Model Content

[0004] In view of this, the present invention provides a rail transit dual-amplifier audio input device to solve the problem that the existing rail transit broadcasting system cannot realize the input and playback of dual-channel broadcasting in the dual-amplifier playback mode.

[0005] The utility model provides a dual-power amplifier audio input device for rail transportation, wherein two power amplifier playback units are configured in a rail transportation vehicle;

[0006] The device includes a main controller, a manual broadcast input circuit, a two-choose-one input circuit and an audio processing circuit;

[0007] The output end of the main controller is electrically connected to the input ends of the two power amplifier playback units, the input end of the two-selection input circuit and the input end of the audio processing circuit. The input end of the manual broadcast input circuit is electrically connected to the external audio sending end. The output end of the manual broadcast input circuit is electrically connected to the input end of the audio processing circuit through the two-selection input circuit. The output end of the audio processing circuit is electrically connected to the input ends of the two power amplifier playback units.

[0008] Optionally, the manual broadcast input circuit includes a first resistor R194, a second resistor R195, a third resistor R358, a fourth resistor R359, a fifth resistor R360, a sixth resistor R361, a first capacitor C116, a second capacitor C117, a third capacitor C118, a fourth capacitor C119, a fifth capacitor C286, a sixth capacitor C287, a seventh capacitor C288, and a first dual operational amplifier consisting of a first operational amplifier U28A and a second operational amplifier U28B;

[0009] The positive power supply pin VCC of the first operational amplifier U28A is electrically connected to the 5V power supply end, the first end of the first capacitor C116 and the first end of the second capacitor C117 are both connected to the common connection end between the positive power supply pin VCC of the first operational amplifier U28A and the 5V power supply end, and the second end of the first capacitor C116 and the second end of the second capacitor C117 are both grounded; the negative power supply pin VEE of the first operational amplifier U28A is grounded; the positive input pin IN+ of the first operational amplifier U28A is electrically connected to the 5V power supply end through the first resistor R194, and the first end of the second resistor R195 and the first end of the fifth capacitor C286 are both connected between the positive input pin IN+ of the first operational amplifier U28A and the first resistor R194. At the common connection end, the second end of the second resistor R195 and the second end of the fifth capacitor C286 are both grounded; the inverting input pin IN- of the first operational amplifier U28A is electrically connected to the external audio transmitting end via the third resistor R358 and the third capacitor C118 in sequence, the inverting input pin IN- of the first operational amplifier U28A is also electrically connected to the output pin of the first operational amplifier U28A via the fourth resistor R359, the first end of the fourth capacitor C119 is connected to the common connection end between the inverting input pin IN- of the first operational amplifier U28A and the third resistor R358, and the second end of the fourth capacitor C119 is connected to the common connection end between the fourth resistor R359 and the output pin of the first operational amplifier U28A;

[0010] The output pin of the first op amp U28A is also electrically connected to the positive input pin IN+ of the second op amp U28B through the sixth resistor R361 and the fifth resistor R360 in sequence. The first end of the sixth capacitor C287 is connected to the common connection end between the fifth resistor R360 and the positive input pin IN+ of the second op amp U28B. The second end of the sixth capacitor C287 is grounded. The first end of the seventh capacitor C288 is connected to the common connection end between the sixth resistor R361 and the fifth resistor R360. The second end of the seventh capacitor C288 is electrically connected to the output pin of the second op amp U28B. The inverting input pin IN- of the second op amp U28B is directly electrically connected to the output pin of the second op amp U28B. The output pin of the second op amp U28B is also electrically connected to the input end of the two-selection input circuit.

[0011] Optionally, the first dual operational amplifier is specifically an OPA1662AID operational amplifier.

[0012] Optionally, the two-choose-one input circuit includes an analog switch U64, a seventh resistor R98, an eighth resistor R384, a ninth resistor R385 and an eighth capacitor C43;

[0013] The input pin IN of the analog switch U64 is electrically connected to the output end of the main controller through the seventh resistor R98; the normally open pin NO of the analog switch U64 is electrically connected to the output end of the manual broadcast input circuit; the idle pin NC of the analog switch U64 is electrically connected to the output end of the main controller, the first end of the eighth resistor R384 and the first end of the ninth resistor R385 are both electrically connected to the idle pin NC of the analog switch U64, the second end of the eighth resistor R384 is electrically connected to the 5V power supply end, and the second end of the ninth resistor R385 is grounded; the output pin COM of the analog switch U64 is electrically connected to the input end of the audio processing circuit; the power pin V+ of the analog switch U64 is electrically connected to the 5V power supply end, the ground pin GND of the analog switch U64 is grounded, the first end of the eighth capacitor C43 is connected to the common connection end between the power pin V+ of the analog switch U64 and the 5V power supply end, and the second end of the eighth capacitor C43 is grounded.

[0014] Optionally, the analog switch U64 is specifically a TS5A4624DCKT analog switch chip.

[0015] Optionally, the audio processing circuit includes an audio attenuator U12, a tenth resistor R77, an eleventh resistor R79, a twelfth resistor R84, a thirteenth resistor R86, a fourteenth resistor R993, a fifteenth resistor R994, a ninth capacitor C40, a tenth capacitor C41, an eleventh capacitor C44, a twelfth capacitor C46, ​​a thirteenth capacitor C1026, a fourteenth capacitor C1027, and a second dual operational amplifier consisting of a third operational amplifier U13A and a fourth operational amplifier U13B;

[0016] The power pin VCC of the audio attenuator U12 is electrically connected to the 5V power supply terminal, the first end of the eleventh capacitor C44 and the first end of the twelfth capacitor C46 are both connected to the common connection terminal between the power pin VCC of the audio attenuator U12 and the 5V power supply terminal, and the second end of the eleventh capacitor C44 and the second end of the twelfth capacitor C46 are both grounded; the reference voltage pin VREF_IN of the audio attenuator U12 is electrically connected to the 2.5V reference voltage power supply terminal, and the signal input pin IN of the audio attenuator U12 is electrically connected to the output terminal of the two-select-one input circuit through the thirteenth capacitor C1026; the download pin LOAD of the audio attenuator U12 is electrically connected to the output terminal of the main controller through the eleventh resistor R79, the data pin DATA of the audio attenuator U12 is electrically connected to the output terminal of the main controller through the tenth resistor R77, and the clock pin CLOCK of the audio attenuator U12 is electrically connected to the output terminal of the main controller through the twelfth resistor R84; the ground pin GND of the audio attenuator U12 is grounded;

[0017] The output pin of the audio attenuator U12 is electrically connected to the positive input pin IN+ of the third op amp U13A, the inverting input pin IN- of the third op amp U13A is directly electrically connected to the output pin of the third op amp U13A, and the output pin of the third op amp U13A is electrically connected to the input terminals of the two power amplifier playback units; the positive power pin VCC of the third op amp U13A is electrically connected to the 5V power supply terminal, the first end of the ninth capacitor C40 and the first end of the tenth capacitor C41 are both connected to the common connection terminal between the positive power pin VCC of the third op amp U13A and the 5V power supply terminal, the second end of the ninth capacitor C40 and the second end of the tenth capacitor C41 are both grounded; the negative power pin VEE of the first op amp U28A is grounded;

[0018] The non-inverting input pin IN+ of the fourth op amp U13B is electrically connected to the 5V power supply terminal through the fourteenth resistor R993, the first end of the fifteenth resistor R994 and the first end of the fourteenth capacitor C1027 are both connected to the common connection terminal between the fourteenth resistor R993 and the 5V power supply terminal, the second end of the fifteenth resistor R994 and the second end of the fourteenth capacitor C1027 are both grounded; the inverting input pin IN- of the fourth op amp U13B is directly electrically connected to the output pin of the fourth op amp U13B, and the output pin of the fourth op amp U13B is also electrically connected to the 2.5V reference voltage power supply terminal.

[0019] Optionally, the second dual operational amplifier is specifically an OPA1662AID operational amplifier.

[0020] Optionally, the audio attenuator U12 is specifically an LM1971M audio attenuation chip.

[0021] Optionally, the main controller is specifically a single chip microcomputer of the STM32 series.

[0022] Optionally, the device further comprises a power supply circuit;

[0023] The power supply circuit is electrically connected to the two power amplifier playback units, the main controller, the manual broadcast input circuit, the two-choice input circuit and the audio processing circuit.

[0024] Beneficial effects of the utility model:

[0025] For the rail transit dual-amplification playback system, the output end of the main controller is electrically connected to the two power amplifier playback units. Therefore, based on the control of the main controller, the two power amplifier playback units can control the sound players (such as speakers) configured on the system to perform broadcast playback, thereby realizing dual-amplification broadcast playback; wherein, at the front end of the two power amplifier playback units, the output end of the manual broadcast input circuit is electrically connected to the input end of the two-choice input circuit, and the manual broadcast can be input to the two-choice input circuit; since the output end of the main controller is also electrically connected to the input end of the two-choice input circuit, on the one hand, the automatic broadcast pre-stored in the main controller can be input to the two-choice input circuit, and on the other hand, the two-choice input of the broadcast received by the two-choice input circuit can be controlled; the output end of the two-choice input circuit is electrically connected to the input end of the audio processing circuit, and the broadcast transmitted by the two-choice input circuit can be audio-processed by the audio processing circuit to improve the audio quality, and finally transmitted to the input ends of the two power amplifier playback units through the audio processing circuit, so as to realize high-quality input and playback of dual-channel broadcast in the rail transit dual-amplification playback mode, which can adapt to the playback of various types of broadcasts in rail transit and is more in line with the actual situation of rail transit broadcasting. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0027] Figure 1 The following is a structural diagram of a dual-amplifier audio input device for rail transit according to an embodiment of the present utility model;

[0028] Figure 2 Shows a circuit design diagram of the manual broadcast input circuit in an embodiment of the present utility model;

[0029] Figure 3 The circuit design diagram of the two-choose-one input circuit in the embodiment of the utility model is shown.

[0030] Figure 4 and Figure 5 The circuit design diagram of the audio processing circuit in the embodiment of the present utility model is shown.

[0031] Figure 6 The structure diagram of another rail transit dual-power amplifier playback and monitoring device in an embodiment of the present utility model is shown. DETAILED DESCRIPTION

[0032] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0033] Example

[0034] like Figure 1 As shown, a rail transit dual-amplifier audio input device is configured with two amplifier playback units in a rail transit vehicle;

[0035] The device includes a main controller, a manual broadcast input circuit, a two-choose-one input circuit and an audio processing circuit;

[0036] The output end of the main controller is electrically connected to the input ends of the two power amplifier playback units, the input end of the two-selection input circuit and the input end of the audio processing circuit. The input end of the manual broadcast input circuit is electrically connected to the external audio sending end. The output end of the manual broadcast input circuit is electrically connected to the input end of the audio processing circuit through the two-selection input circuit. The output end of the audio processing circuit is electrically connected to the input ends of the two power amplifier playback units.

[0037] In this embodiment, for the rail transit dual-amplification playback system, the output end of the main controller is electrically connected to the two power amplifier playback units. Therefore, based on the control of the main controller, the two power amplifier playback units can control the sound players (such as speakers) configured on the system to perform broadcast playback, thereby realizing dual-amplification broadcast playback; wherein, at the front end of the two power amplifier playback units, the output end of the manual broadcast input circuit is electrically connected to the input end of the two-choice input circuit, and the manual broadcast can be input to the two-choice input circuit; since the output end of the main controller is also electrically connected to the input end of the two-choice input circuit, on the one hand, the automatic broadcast pre-stored in the main controller can be input to the two-choice input circuit, and on the other hand, the two-choice input of the broadcast received by the two-choice input circuit can be controlled; the output end of the two-choice input circuit is electrically connected to the input end of the audio processing circuit, and the broadcast transmitted by the two-choice input circuit can be audio-processed by the audio processing circuit to improve the audio quality, and finally transmitted to the input ends of the two power amplifier playback units through the audio processing circuit, so as to realize high-quality input and playback of dual-channel broadcasts in the rail transit dual-amplification playback mode, which can adapt to the playback of various types of rail transit broadcasts and better conform to the actual situation of rail transit broadcasts.

[0038] It should be understood that the present invention only improves the hardware circuitry of the dual-amplifier audio input device for rail transit, achieving dual-channel broadcast input and playback in dual-amplifier playback mode through hardware circuit design, and does not involve improvements to computer programs. The computer programs for controlling the operation of the power amplifier playback unit, as well as the operation of the two-choice input circuit and audio processing circuit, all utilize conventional control programs. For example, the main controller can control the power amplifier playback unit by sending control instructions to the power amplifier playback unit. These control programs can be pre-stored in the memory or storage area of ​​the main controller.

[0039] In this embodiment, rail transportation vehicles include buses, subways, motor vehicles, high-speed trains and other transportation vehicles.

[0040] In this embodiment, the power amplifier playback unit utilizes a conventional power amplifier configuration, such as a power amplifier processing circuit, a filter circuit, and a switch control circuit. The power amplifier circuit sequentially receives audio signals and sequentially transmits the audio signals to the speaker through the power amplifier circuit, the filter circuit, and the switch circuit to achieve broadcasting. The power amplifier circuit, the filter circuit, and the switch circuit all utilize conventional circuit designs and are not limited herein.

[0041] In this embodiment, the main controller is specifically a single chip microcomputer of the STM32 series.

[0042] The STM32 series of microcontrollers has the advantages of high performance, low power consumption, rich peripherals, and easy development. It can better realize the control of two power amplifier playback units and two audio monitoring circuits, and thus better adapt to the rail transit dual-amplifier playback system and realize real-time monitoring in the rail transit dual-amplifier playback mode.

[0043] Preferably, if Figure 2 As shown, the manual broadcast input circuit includes a first resistor R194, a second resistor R195, a third resistor R358, a fourth resistor R359, a fifth resistor R360, a sixth resistor R361, a first capacitor C116, a second capacitor C117, a third capacitor C118, a fourth capacitor C119, a fifth capacitor C286, a sixth capacitor C287, a seventh capacitor C288 and a first dual operational amplifier consisting of a first operational amplifier U28A and a second operational amplifier U28B;

[0044] The positive power supply pin VCC of the first operational amplifier U28A is electrically connected to the 5V power supply end, the first end of the first capacitor C116 and the first end of the second capacitor C117 are both connected to the common connection end between the positive power supply pin VCC of the first operational amplifier U28A and the 5V power supply end, and the second end of the first capacitor C116 and the second end of the second capacitor C117 are both grounded; the negative power supply pin VEE of the first operational amplifier U28A is grounded; the positive input pin IN+ of the first operational amplifier U28A is electrically connected to the 5V power supply end through the first resistor R194, and the first end of the second resistor R195 and the first end of the fifth capacitor C286 are both connected between the positive input pin IN+ of the first operational amplifier U28A and the first resistor R194. At the common connection end, the second end of the second resistor R195 and the second end of the fifth capacitor C286 are both grounded; the inverting input pin IN- of the first operational amplifier U28A is electrically connected to the external audio transmitting end via the third resistor R358 and the third capacitor C118 in sequence, the inverting input pin IN- of the first operational amplifier U28A is also electrically connected to the output pin of the first operational amplifier U28A via the fourth resistor R359, the first end of the fourth capacitor C119 is connected to the common connection end between the inverting input pin IN- of the first operational amplifier U28A and the third resistor R358, and the second end of the fourth capacitor C119 is connected to the common connection end between the fourth resistor R359 and the output pin of the first operational amplifier U28A;

[0045] The output pin of the first op amp U28A is also electrically connected to the positive input pin IN+ of the second op amp U28B through the sixth resistor R361 and the fifth resistor R360 in sequence. The first end of the sixth capacitor C287 is connected to the common connection end between the fifth resistor R360 and the positive input pin IN+ of the second op amp U28B. The second end of the sixth capacitor C287 is grounded. The first end of the seventh capacitor C288 is connected to the common connection end between the sixth resistor R361 and the fifth resistor R360. The second end of the seventh capacitor C288 is electrically connected to the output pin of the second op amp U28B. The inverting input pin IN- of the second op amp U28B is directly electrically connected to the output pin of the second op amp U28B. The output pin of the second op amp U28B is also electrically connected to the input end of the two-selection input circuit.

[0046] The above circuit is the input circuit for manual broadcasting, which can be transmitted from the external audio transmitting end to the input end of the manual broadcasting input circuit through connectors such as the audio bus and the backplane connector, and then through the first dual operational amplifier composed of the first operational amplifier U28A and the second operational amplifier U28B, the operational amplifier of the manual broadcasting is realized, which can effectively prevent the sound from being too small due to the long line or other reasons, and realize the audio amplification of the manual broadcasting from the hardware aspect, thereby obtaining high-quality manual broadcasting and transmitting it to the subsequent two-choice input circuit.

[0047] In this embodiment, the first dual operational amplifier is specifically an operational amplifier of the OPA1662AID model. The other electronic components in the manual broadcast input circuit can be selected according to the actual situation. Suitable specifications or product models, see Figure 2 As shown, the specific ones are not listed here.

[0048] In this embodiment, the audio signal output by the manual broadcast input circuit is Figure 2 The signal output by the PA_OUT_LP port.

[0049] Preferably, if Figure 3 As shown, the two-choose-one input circuit includes an analog switch U64, a seventh resistor R98, an eighth resistor R384, a ninth resistor R385 and an eighth capacitor C43;

[0050] The input pin IN of the analog switch U64 is electrically connected to the output end of the main controller through the seventh resistor R98; the normally open pin NO of the analog switch U64 is electrically connected to the output end of the manual broadcast input circuit; the idle pin NC of the analog switch U64 is electrically connected to the output end of the main controller, the first end of the eighth resistor R384 and the first end of the ninth resistor R385 are both electrically connected to the idle pin NC of the analog switch U64, the second end of the eighth resistor R384 is electrically connected to the 5V power supply end, and the second end of the ninth resistor R385 is grounded; the output pin COM of the analog switch U64 is electrically connected to the input end of the audio processing circuit; the power pin V+ of the analog switch U64 is electrically connected to the 5V power supply end, the ground pin GND of the analog switch U64 is grounded, the first end of the eighth capacitor C43 is connected to the common connection end between the power pin V+ of the analog switch U64 and the 5V power supply end, and the second end of the eighth capacitor C43 is grounded.

[0051] for Figure 3 In the two-choose-one input circuit shown, the audio signal output by the artificial broadcast circuit (i.e. Figure 3 The signal input from the PA_OUT_LP port in the main controller) and the audio signal output from the main controller (i.e. Figure 3 The signal input from the vs1603_out port in the analog switch U64 is input from the 6th and 4th pins respectively, and the 1st pin of the analog switch U64 is connected to the control signal of the main controller (i.e. Figure 3 The signal output by the AUDIO_TEST_CTL port in the middle) can record and select the broadcast input from the two channels, and then output it through the 5-pin of the analog switch U64 (i.e. Figure 3 The signal output from the Amp_To_1971 port in the DAC is sent to the audio input circuit for audio processing. The two-choose-one input circuit structure described above can simply and efficiently implement the input and selection of dual-channel broadcasts in bi-amp playback mode.

[0052] In this embodiment, the analog switch U64 is specifically a TS5A4624DCKT analog switch chip. Other electronic components can be selected according to the actual situation. Suitable specifications or product models, see Figure 3 As shown, the specific ones are not listed here.

[0053] Preferably, if Figure 4 and Figure 5As shown, the audio processing circuit includes an audio attenuator U12, a tenth resistor R77, an eleventh resistor R79, a twelfth resistor R84, a thirteenth resistor R86, a fourteenth resistor R993, a fifteenth resistor R994, a ninth capacitor C40, a tenth capacitor C41, an eleventh capacitor C44, a twelfth capacitor C46, ​​a thirteenth capacitor C1026, a fourteenth capacitor C1027, and a second dual operational amplifier consisting of a third operational amplifier U13A and a fourth operational amplifier U13B;

[0054] The power pin VCC of the audio attenuator U12 is electrically connected to the 5V power supply terminal, the first end of the eleventh capacitor C44 and the first end of the twelfth capacitor C46 are both connected to the common connection terminal between the power pin VCC of the audio attenuator U12 and the 5V power supply terminal, and the second end of the eleventh capacitor C44 and the second end of the twelfth capacitor C46 are both grounded; the reference voltage pin VREF_IN of the audio attenuator U12 is electrically connected to the 2.5V reference voltage power supply terminal, and the signal input pin IN of the audio attenuator U12 is electrically connected to the output terminal of the two-select-one input circuit through the thirteenth capacitor C1026; the download pin LOAD of the audio attenuator U12 is electrically connected to the output terminal of the main controller through the eleventh resistor R79, the data pin DATA of the audio attenuator U12 is electrically connected to the output terminal of the main controller through the tenth resistor R77, and the clock pin CLOCK of the audio attenuator U12 is electrically connected to the output terminal of the main controller through the twelfth resistor R84; the ground pin GND of the audio attenuator U12 is grounded;

[0055] The output pin of the audio attenuator U12 is electrically connected to the positive input pin IN+ of the third op amp U13A, the inverting input pin IN- of the third op amp U13A is directly electrically connected to the output pin of the third op amp U13A, and the output pin of the third op amp U13A is electrically connected to the input terminals of the two power amplifier playback units; the positive power pin VCC of the third op amp U13A is electrically connected to the 5V power supply terminal, the first end of the ninth capacitor C40 and the first end of the tenth capacitor C41 are both connected to the common connection terminal between the positive power pin VCC of the third op amp U13A and the 5V power supply terminal, the second end of the ninth capacitor C40 and the second end of the tenth capacitor C41 are both grounded; the negative power pin VEE of the first op amp U28A is grounded;

[0056] The non-inverting input pin IN+ of the fourth op amp U13B is electrically connected to the 5V power supply terminal through the fourteenth resistor R993, the first end of the fifteenth resistor R994 and the first end of the fourteenth capacitor C1027 are both connected to the common connection terminal between the fourteenth resistor R993 and the 5V power supply terminal, the second end of the fifteenth resistor R994 and the second end of the fourteenth capacitor C1027 are both grounded; the inverting input pin IN- of the fourth op amp U13B is directly electrically connected to the output pin of the fourth op amp U13B, and the output pin of the fourth op amp U13B is also electrically connected to the 2.5V reference voltage power supply terminal.

[0057] In the audio processing circuit of the above structure, the audio attenuator is used to reduce the amplitude or power of the signal, process the excessively strong signal to an appropriate level, balance the power difference between the input signals of different channels, and ensure the accuracy and stability of the signal; and then the second dual operational amplifier composed of the third op amp U13A and the fourth op amp U13B is used to amplify, filter, reverberate, etc., so as to achieve the purpose of optimizing the sound quality and enhancing the effect of the dual-channel signal, reducing distortion, and finally enabling the two power amplifier playback units to perform high-quality dual-channel broadcast playback.

[0058] In this embodiment, the second dual operational amplifier is specifically an operational amplifier of the OPA1662AID model, and the audio attenuator U12 is specifically an audio attenuator chip of the LM1971M model. Other electronic components can be selected according to the actual situation. Suitable specifications or product models, see Figure 4 and Figure 5 As shown, the specific ones are not listed here.

[0059] Preferably, if Figure 6 As shown, the device further includes a power supply circuit;

[0060] The power supply circuit is electrically connected to the two power amplifier playback units, the main controller, the manual broadcast input circuit, the two-choice input circuit and the audio processing circuit.

[0061] The power supply circuit can provide the required operating voltage for each component in the entire rail transit dual-power amplifier audio input device, ensuring that each component can work normally.

[0062] The power supply circuit may include a 24V power supply circuit, a 5V power supply circuit, and a 3.3V power supply circuit, respectively providing 24V, 5V, and 3.3V power supply voltages to each component. The 24V, 5V, and 3.3V power supply circuits may all employ conventional circuit designs and are not specifically limited herein.

[0063] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. A rail transit dual-amplifier audio input device, characterized in that: Two amplifier playback units are configured in rail transportation vehicles; The device includes a main controller, a manual broadcast input circuit, a two-choose-one input circuit and an audio processing circuit; The output end of the main controller is electrically connected to the input ends of the two power amplifier playback units, the input end of the two-selection input circuit and the input end of the audio processing circuit. The input end of the manual broadcast input circuit is electrically connected to the external audio sending end. The output end of the manual broadcast input circuit is electrically connected to the input end of the audio processing circuit through the two-selection input circuit. The output end of the audio processing circuit is electrically connected to the input ends of the two power amplifier playback units.

2. The rail transit dual-amplifier audio input device according to claim 1, characterized in that: The manual broadcast input circuit includes a first resistor R194, a second resistor R195, a third resistor R358, a fourth resistor R359, a fifth resistor R360, a sixth resistor R361, a first capacitor C116, a second capacitor C117, a third capacitor C118, a fourth capacitor C119, a fifth capacitor C286, a sixth capacitor C287, a seventh capacitor C288, and a first dual operational amplifier consisting of a first operational amplifier U28A and a second operational amplifier U28B; The positive power supply pin VCC of the first operational amplifier U28A is electrically connected to the 5V power supply end, the first end of the first capacitor C116 and the first end of the second capacitor C117 are both connected to the common connection end between the positive power supply pin VCC of the first operational amplifier U28A and the 5V power supply end, and the second end of the first capacitor C116 and the second end of the second capacitor C117 are both grounded; the negative power supply pin VEE of the first operational amplifier U28A is grounded; the positive input pin IN+ of the first operational amplifier U28A is electrically connected to the 5V power supply end through the first resistor R194, and the first end of the second resistor R195 and the first end of the fifth capacitor C286 are both connected between the positive input pin IN+ of the first operational amplifier U28A and the first resistor R194. At the common connection end, the second end of the second resistor R195 and the second end of the fifth capacitor C286 are both grounded; the inverting input pin IN- of the first operational amplifier U28A is electrically connected to the external audio transmitting end via the third resistor R358 and the third capacitor C118 in sequence, the inverting input pin IN- of the first operational amplifier U28A is also electrically connected to the output pin of the first operational amplifier U28A via the fourth resistor R359, the first end of the fourth capacitor C119 is connected to the common connection end between the inverting input pin IN- of the first operational amplifier U28A and the third resistor R358, and the second end of the fourth capacitor C119 is connected to the common connection end between the fourth resistor R359 and the output pin of the first operational amplifier U28A; The output pin of the first op amp U28A is also electrically connected to the positive input pin IN+ of the second op amp U28B through the sixth resistor R361 and the fifth resistor R360 in sequence. The first end of the sixth capacitor C287 is connected to the common connection end between the fifth resistor R360 and the positive input pin IN+ of the second op amp U28B. The second end of the sixth capacitor C287 is grounded. The first end of the seventh capacitor C288 is connected to the common connection end between the sixth resistor R361 and the fifth resistor R360. The second end of the seventh capacitor C288 is electrically connected to the output pin of the second op amp U28B. The inverting input pin IN- of the second op amp U28B is directly electrically connected to the output pin of the second op amp U28B. The output pin of the second op amp U28B is also electrically connected to the input end of the two-selection input circuit.

3. The rail transit dual-amplifier audio input device according to claim 2, characterized in that: The first dual operational amplifier is specifically an OPA1662AID operational amplifier.

4. The rail transit dual-amplifier audio input device according to claim 1, characterized in that: The two-choose-one input circuit includes an analog switch U64, a seventh resistor R98, an eighth resistor R384, a ninth resistor R385 and an eighth capacitor C43; The input pin IN of the analog switch U64 is electrically connected to the output end of the main controller through the seventh resistor R98; the normally open pin NO of the analog switch U64 is electrically connected to the output end of the manual broadcast input circuit; the idle pin NC of the analog switch U64 is electrically connected to the output end of the main controller, the first end of the eighth resistor R384 and the first end of the ninth resistor R385 are both electrically connected to the idle pin NC of the analog switch U64, the second end of the eighth resistor R384 is electrically connected to the 5V power supply end, and the second end of the ninth resistor R385 is grounded; the output pin COM of the analog switch U64 is electrically connected to the input end of the audio processing circuit; the power pin V+ of the analog switch U64 is electrically connected to the 5V power supply end, the ground pin GND of the analog switch U64 is grounded, the first end of the eighth capacitor C43 is connected to the common connection end between the power pin V+ of the analog switch U64 and the 5V power supply end, and the second end of the eighth capacitor C43 is grounded.

5. The rail transit dual-amplifier audio input device according to claim 4, characterized in that: The analog switch U64 is specifically a TS5A4624DCKT analog switch chip.

6. The rail transit dual-amplifier audio input device according to claim 2, characterized in that: The audio processing circuit includes an audio attenuator U12, a tenth resistor R77, an eleventh resistor R79, a twelfth resistor R84, a thirteenth resistor R86, a fourteenth resistor R993, a fifteenth resistor R994, a ninth capacitor C40, a tenth capacitor C41, an eleventh capacitor C44, a twelfth capacitor C46, ​​a thirteenth capacitor C1026, a fourteenth capacitor C1027, and a second dual operational amplifier consisting of a third operational amplifier U13A and a fourth operational amplifier U13B; The power pin VCC of the audio attenuator U12 is electrically connected to the 5V power supply terminal, the first end of the eleventh capacitor C44 and the first end of the twelfth capacitor C46 are both connected to the common connection terminal between the power pin VCC of the audio attenuator U12 and the 5V power supply terminal, and the second end of the eleventh capacitor C44 and the second end of the twelfth capacitor C46 are both grounded; the reference voltage pin VREF_IN of the audio attenuator U12 is electrically connected to the 2.5V reference voltage power supply terminal, and the signal input pin IN of the audio attenuator U12 is electrically connected to the output terminal of the two-select-one input circuit through the thirteenth capacitor C1026; the download pin LOAD of the audio attenuator U12 is electrically connected to the output terminal of the main controller through the eleventh resistor R79, the data pin DATA of the audio attenuator U12 is electrically connected to the output terminal of the main controller through the tenth resistor R77, and the clock pin CLOCK of the audio attenuator U12 is electrically connected to the output terminal of the main controller through the twelfth resistor R84; the ground pin GND of the audio attenuator U12 is grounded; The output pin of the audio attenuator U12 is electrically connected to the positive input pin IN+ of the third op amp U13A, the inverting input pin IN- of the third op amp U13A is directly electrically connected to the output pin of the third op amp U13A, and the output pin of the third op amp U13A is electrically connected to the input terminals of the two power amplifier playback units; the positive power pin VCC of the third op amp U13A is electrically connected to the 5V power supply terminal, the first end of the ninth capacitor C40 and the first end of the tenth capacitor C41 are both connected to the common connection terminal between the positive power pin VCC of the third op amp U13A and the 5V power supply terminal, the second end of the ninth capacitor C40 and the second end of the tenth capacitor C41 are both grounded; the negative power pin VEE of the first op amp U28A is grounded; The non-inverting input pin IN+ of the fourth op amp U13B is electrically connected to the 5V power supply terminal through the fourteenth resistor R993, the first end of the fifteenth resistor R994 and the first end of the fourteenth capacitor C1027 are both connected to the common connection terminal between the fourteenth resistor R993 and the 5V power supply terminal, the second end of the fifteenth resistor R994 and the second end of the fourteenth capacitor C1027 are both grounded; the inverting input pin IN- of the fourth op amp U13B is directly electrically connected to the output pin of the fourth op amp U13B, and the output pin of the fourth op amp U13B is also electrically connected to the 2.5V reference voltage power supply terminal.

7. The rail transit dual-amplifier audio input device according to claim 6, characterized in that: The second dual operational amplifier is specifically an operational amplifier of model OPA1662AID.

8. The rail transit dual-amplifier audio input device according to claim 6, characterized in that: The audio attenuator U12 is specifically an audio attenuation chip of the LM1971M model.

9. The rail transit dual-amplifier audio input device according to any one of claims 1 to 8, characterized in that: The main controller is specifically a single chip microcomputer of the STM32 series.

10. The rail transit dual-amplifier audio input device according to any one of claims 1 to 8, characterized in that: The device also includes a power supply circuit; The power supply circuit is electrically connected to the two power amplifier playback units, the main controller, the manual broadcast input circuit, the two-choice input circuit and the audio processing circuit.

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