Audio signal conversion device of passenger information display system

Abstract

The invention relates to an audio signal conversion device of a passenger information display system, the audio signal conversion device comprises a memory (5), an RAM chip (2) and a CPU circuit (1) which are connected in sequence, the RAM chip (2) comprises a power supply protection circuit used for inhibiting and protecting surge ripples of an external power supply, one end of the power supply protection circuit is connected with a power supply pin of the RAM chip (2) and the power supply, and the other end of the power supply protection circuit is connected with an audio signal output end of the CPU circuit (1). The other end is grounded. Compared with the prior art, the system has the advantages that the stability of the RAM chip power supply circuit is improved, and the stability and usability of the passenger information display system are improved.

Description

Technical Field

[0001] The present invention relates to the field of audio signal conversion of a passenger information display system for rail transit vehicles, and particularly to an audio signal conversion device for a passenger information display system. Background Art

[0002] For a passenger information display system of a rail transit vehicle, its main functions are as follows: passengers can, through the broadcast dynamic audio information, learn about the running status of the train and the upcoming station information in a timely manner, which is convenient for transfer and reduces the possibility of getting off at the wrong station. In the event of a catastrophic accident or other emergency, emergency broadcasting can be carried out to guide passengers to evacuate, and at the same time, flight attendants are arranged to carry out rescue to reduce casualties in the accident.

[0003] The function of the TBA-2472N1 module is to connect to the train bus MVB through internal communication, and according to the key signal, realize the audio signal conversion of the passenger information display system (PIS). It can communicate with the central control unit in the passenger compartment to display the arrival station information and the information related to the next station, and control the communication between the emergency intercom device in each passenger compartment of the train and the driver's cab.

[0004] During actual maintenance, it is found that the faults of the vehicle passenger information display system mainly occur in the damage of the RAM chip BS62LV256SIP55 in the CPU circuit part of the audio signal conversion module TBA-2472N1, and the CPU circuit cannot work normally, resulting in the faults of the entire system.

[0005] How to achieve the stable operation of the passenger information display system has become a technical problem to be solved. Summary of the Invention

[0006] The purpose of the present invention is to provide an audio signal conversion device for a passenger information display system to overcome the defects existing in the above-mentioned prior art.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] According to one aspect of the invention, an audio signal conversion device for a passenger information display system is provided. The device includes a memory, a RAM chip, and a CPU circuit connected in sequence. The RAM chip includes a power protection circuit for suppressing and protecting the surge ripple of the external power supply. One end of the power protection circuit is connected to the power supply pin of the RAM chip and the power supply, and the other end is grounded.

[0009] Preferably, the power protection circuit includes a filter electrolytic capacitor, a non-polar capacitor, and a reverse protection zener diode connected in parallel. The positive electrode of the reverse protection zener diode is connected to the power supply pin of the RAM chip and the power supply, and the negative electrode is connected to the ground pin of the RAM chip.

[0010] More preferably, the filtering electrolytic capacitor is a 16V / 100uF capacitor.

[0011] More preferably, the non-polar capacitor is a 50V 100nF capacitor.

[0012] More preferably, the reverse protection zener diode is a diode with a regulated voltage of 5.1V / 1W.

[0013] Preferably, the RAM chip is a 28pcs chip.

[0014] More preferably, the RAM chip is a BS62LV256SIP55 chip.

[0015] Preferably, the device further includes a communication interface circuit, and the communication interface circuit is connected to the CPU circuit.

[0016] Preferably, the device further includes a functional circuit, and the functional circuit is connected to the CPU circuit.

[0017] Preferably, the memory is an E2PROM.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1) The present invention adds a power protection circuit in the RAM chip, which can effectively suppress and protect against the instantaneous surge of the external power supply, improve the stability of the RAM chip power supply circuit, thereby reducing the failure rate of the audio signal conversion module and the maintenance cost of the passenger information display system;

[0020] 2) After adding the power protection circuit in the RAM chip, the passenger information display system of the present invention is more stable, improving the usability of the passenger information display system. Description of the Drawings

[0021] Figure 1 is the circuit schematic diagram of the original RAM chip BS62LV256SIP55;

[0022] Figure 2 is the circuit schematic diagram of the RAM chip BS62LV256SIP55 in the present invention;

[0023] Figure 3 is the structural schematic diagram of the audio signal conversion module TBA-2472N1 in the present invention;

[0024] Appendix Figure 3 In the figure, 1: CPU circuit, 2: RAM chip, 3: communication interface circuit, 4: functional circuit, 5: memory. Detailed implementation mode

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the protection scope of the present invention.

[0026] As Figure 3 shown, the audio conversion module includes a RAM chip 2, a CPU circuit 1, a communication interface circuit 3, a function circuit 4, and a memory 5.

[0027] Among them, the memory 5 is an E2PROM, and the RAM chip 2 is used to store variables and corresponding variable operations.

[0028] When the audio signal conversion module TBA-2472N1 works, first the internal CPU circuit 1 starts the self-check mechanism, and then exchanges and processes the self-check signals with the CPU circuit 1 through the communication interface circuit 3.

[0029] During the repair of the audio conversion module TBA-2472N1, it is found that its main fault is that the power supply short circuit of the RAM chip BS62LV256SIP55 is damaged more.

[0030] As Figure 1 shown, it is the circuit schematic diagram of the original RAM chip BS62LV256SIP55. This chip is a 28-pcs chip, where the 14th pin is grounded and the 28th pin is connected to the power input supply.

[0031] As Figure 2 shown, it is the circuit schematic diagram of the improved RAM chip BS62LV256SIP55 of the present invention. A power protection circuit of the chip is added to the 28th pin (power supply pin) part.

[0032] The power protection circuit includes a filtering electrolytic capacitor C1 (16V / 100uF), a non-polar capacitor C2 (50V 100nF), and a reverse protection zener diode D1 1N4733A (regulated voltage 5.1V / 1W), which is used to reduce the impact of the surge ripple of the external power supply on the RAM chip 2.

[0033] The capacitors C1 / C2 are connected to the power supply pins of the RAM chip. By using their charge and discharge characteristics (energy storage function), the RAM chip obtains a stable DC voltage. When the external power supply input voltage is abnormal, the zener diode D1 can protect the RAM core by using the voltage regulation function of the zener diode.

[0034] When there is an instantaneous surge, the power protection circuit can play a role in suppressing and protecting the RAM chip 2, improve the stability of the power supply circuit of the RAM chip 2, and thus reduce the failure rate of the audio conversion module TBA-2472N1.

[0035] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An audio signal conversion device for a passenger information display system, the device comprising a memory (5), a RAM chip (2), and a CPU circuit (1) connected in sequence, characterized in that, The RAM chip (2) includes a power protection circuit for suppressing and protecting the surge ripple of the externally supplied power source. One end of the power protection circuit is connected to the power supply pin of the RAM chip (2) and the power supply, and the other end is grounded.

2. The audio signal conversion device of a passenger information display system according to claim 1, characterized in that The power protection circuit includes a parallel-connected filter electrolytic capacitor, a non-polar capacitor, and a reverse protection zener diode. The positive electrode of the reverse protection zener diode is connected to the power supply pin of the RAM chip (2) and the power supply, and the negative electrode is connected to the ground pin of the RAM chip (2).

3. The audio signal conversion device of a passenger information display system according to claim 2, characterized in that, The filter electrolytic capacitor is a 16V / 100uF capacitor.

4. The audio signal conversion device of a passenger information display system according to claim 2, characterized in that, The non-polar capacitor is a 50V 100nF capacitor.

5. The audio signal conversion device of a passenger information display system according to claim 2, characterized in that, The reverse protection zener diode is a diode with a regulated voltage of 5.1V / 1W.

6. The audio signal conversion device of a passenger information display system according to claim 1, characterized in that, The RAM chip (2) is 28 pcs of chips.

7. The audio signal conversion device of a passenger information display system according to claim 6, characterized in that The RAM chip (2) is a BS62LV256SIP55 chip.

8. The audio signal conversion device of a passenger information display system according to claim 1, characterized in that, The device further includes a communication interface circuit, and the communication interface circuit (3) is connected to the CPU circuit (1).

9. The audio signal conversion device of a passenger information display system according to claim 1, characterized in that The device further includes a functional circuit (4), and the functional circuit (4) is connected to the CPU circuit (1).

10. The audio signal conversion device of a passenger information display system according to claim 1, characterized in that The memory (5) is an E2PROM.

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