Method for using a signal conversion device for an onboard broadcasting system

Abstract

The application discloses a signal conversion device for a shipboard broadcasting system and a use method thereof, which comprises a case, a sound collecting plate, a mainboard, a main power supply unit and a wiring terminal; the case is a hollow box body installed outside a broadcasting main unit, a wiring terminal is installed on the left side of the middle of the case, and various types of signal cables are externally connected through the wiring terminal; the sound collecting plate and the mainboard are installed on the left and right sides of the upper middle position in the case, the sound collecting plate collects analog voice signals and compresses the voice signals, the mainboard processes various types of data and converts the data into digital signals, the mainboard contains a control logic unit to judge the priority of various signals and sequentially send the signals to the broadcasting main unit according to the priority, and the main power supply unit is installed on the right side of the middle of the case and supplies power through the main power supply unit. The application converts all input signals of different types into standard serial communication digital signals, realizes multi-channel signal input and single-channel signal output.

Description

Technical Field

[0001] The present invention relates to a signal conversion device, and in particular to a method for using the signal conversion device for an onboard broadcasting system. Background Art

[0002] The onboard broadcasting system consists of a main unit and a sound device (speaker). Some systems have their own sound devices, such as the general emergency alarm system / fire alarm system, which has independent alarm bells, buzzers, whistles, etc. When these systems sound an alarm, the sound of the broadcasting system should be shielded and their own sound devices should sound the alarm; but some onboard systems do not have their own sound devices and need to use the broadcasting system to make sounds; therefore, the broadcasting system needs to be connected to many external signals.

[0003] External signals typically connected to the PA system include the general emergency alarm system / fire alarm, microphone remote paging, telephone system paging, and entertainment system announcements. However, these external signals may be connected to the PA system simultaneously, requiring the PA system's main unit to integrate control logic to prioritize incoming signals and prioritize the higher-priority signals. The priority of each system, from highest to lowest, is as follows: general emergency alarm system / fire alarm, microphone remote paging, telephone system paging, and entertainment system announcements. A higher-priority system can interrupt a lower-priority system. For example, if the entertainment system is currently being broadcast over the ship's public address system and a telephone paging is required, a crew member can dial a number to interrupt the entertainment system and initiate a telephone paging call. If a fire occurs at this time, the fire detection system will send an interrupt signal to the PA system, interrupting the telephone paging call. This will cause the general emergency alarm system / fire alarm whistle, alarm bell, or buzzer to emit a continuous, long fire alarm tone.

[0004] The PA system handles a wide range of external signals, including digital and analog voice signals. This requires multiple interfaces on the main PA unit, which results in a larger unit. Furthermore, the main PA unit is manufactured in modular configurations, making it difficult to add additional interfaces if additional external signals are needed. This results in limited system scalability. Therefore, these issues urgently need to be addressed. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for using a signal conversion device for an onboard broadcasting system, which can convert all input signals of different types into serial communication digital signals that comply with IEC standards, thereby realizing the function of multiple signal inputs and one signal output, and simplifying the structure of the broadcasting main unit.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solutions: A method for using a signal conversion device for an in-vessel broadcasting system of the present invention is innovative in that the signal conversion device comprises a chassis, a sound collecting board, a mainboard, a main power supply unit, and a terminal; the chassis is a hollow rectangular parallelepiped box installed vertically outside the broadcasting main unit, and a terminal is installed on the left side of the center inside the chassis, through which various types of signal cables are externally connected; a sound collecting board and a mainboard are installed at intervals on the left and right sides of the upper center inside the chassis, the sound collecting board collects analog voice signals and compresses the voice signals; the mainboard processes various types of data and converts them into digital signals, and contains a control logic unit to determine the priority of each type of signal and send the signals to the broadcasting main unit in sequence according to the priority level; a main power supply unit is installed on the right side of the center inside the chassis, and power is supplied by the main power supply unit; a communication port is installed in the center of the chassis below the sound collecting board, and is electrically connected to the serial communication port on the broadcasting main unit through the communication port;

[0007] The method of use includes the following steps:

[0008] (1) Set up a serial communication port on the broadcast main unit and connect the communication port on the chassis to the serial communication port on the broadcast main unit;

[0009] (2) Connect broadcast interruption signals, general emergency alarm / fire alarm interruption signals, microphones, telephone systems and public entertainment systems through the connection terminals on the chassis;

[0010] (3) Convert the voice signals from microphones, telephone systems, and public entertainment systems to analog-to-digital via pulse code modulation on the motherboard;

[0011] In the above steps, the sampling circuit in the pulse code modulation extracts a sample value from the analog signal every Δt time, converting the continuously changing analog signal into a series of equally spaced pulse signals, whose amplitude is equal to the amplitude of the analog signal at each moment;

[0012] The signal is controlled by the sampling pulse. When the sampling pulse comes, the gate of the field effect transistor VT is added with a positive voltage, and it is turned on. The input signal reaches the output end through the drain-source of the field effect transistor VT. When there is no sampling pulse, VT is cut off and the signal cannot pass. Therefore, the sampling circuit samples when the sampling pulse is high, and the low level is the sampling interval time Δt.

[0013] In the above steps, the A / D conversion circuit in the pulse code modulation can be implemented by a single-chip microcomputer; wherein RA0 and RA1 are two I / O pins of the single-chip microcomputer, and they are set to output and input states respectively, and the VDD pin of the single-chip microcomputer is connected to a 5V power supply; the RA1 pin of the single-chip microcomputer is connected to pin 1 of the LM324 comparator, the pin 11 of the LM324 comparator is grounded, the pin 4 of the LM324 comparator is connected to a 5V power supply, the pin 3 of the LM324 comparator receives the analog input, the pin 2 of the LM324 comparator is connected to one end of the resistor R1 and the capacitor C1 respectively, the other end of the capacitor C1 is grounded, and the other end of the resistor R1 is connected to the RA0 pin of the single-chip microcomputer; in the process When performing A / D conversion, the PWM waveform is sent out from the RA0 pin of the microcontroller, and the RA1 pin of the microcontroller is used to detect the status of the comparator output terminal. Resistor R1 and capacitor C1 form a filter circuit to smooth the PWM waveform output from pin RA0. After the PWM waveform output from RA0 is filtered and delayed by resistor R1 and capacitor C1, a stable voltage value is generated at point U1. Its voltage value U1 = VDD*D1 / (D1+D2). The voltage at pin 2 of the LM324 comparator, U1, is compared with the analog input voltage at its pin 3. If the U1 voltage is greater than the analog input voltage, the output terminal of the LM324 comparator is low, otherwise it is high.

[0014] (4) The control logic unit uses binary digital coding technology to determine the priority of various signals and sends the signals to the broadcast main unit in sequence according to the priority level, realizing the function of multiple signal inputs and one signal output;

[0015] In the above steps, binary digital coding technology adopts ALF statements according to the IEC61162-1 standard protocol, and sets the priorities from high to low as broadcast interruption signal, general emergency alarm / fire alarm interruption signal, microphone, telephone system, and public entertainment system. The broadcast with a higher priority can interrupt the broadcast with a lower priority.

[0016] Preferably, a key position is provided on the front door panel of the chassis, and the interior of the chassis is protected from theft by being equipped with a key.

[0017] Preferably, a fan is installed on the right side of the interior of the chassis above the main power supply unit, and the fan is used to ventilate and dissipate heat inside the chassis.

[0018] Preferably, in the above step (2), the broadcast interruption signal and the general emergency alarm / fire alarm interruption signal are both dry contact signals, which are digital signals.

[0019] Preferably, in the above step (2), the microphone, telephone system and public entertainment system are all analog voice signals that need to be converted into digital signals, that is, the continuously changing analog signals are converted into binary digital 0 and 1.

[0020] Beneficial effects of the present invention:

[0021] (1) The present invention can convert all input signals of different types into serial communication digital signals that comply with IEC standards, thereby realizing the function of multiple signal inputs and one signal output, and simplifying the structure of the broadcast main unit;

[0022] (2) The present invention only requires one serial communication port to be provided on the broadcast main unit, thereby reducing the size of the broadcast main unit and solving the problem that the broadcast main unit is modularly produced by the manufacturer and cannot meet the needs of subsequent access to new signals on board.

[0023] (3) The present invention can be installed outside the broadcast main unit, which simplifies the structure of the broadcast main unit and improves the flexibility of the layout. In addition, it can increase the external signal input to the broadcast main unit, thereby improving the scalability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work. Figure 1 The figure is a structural schematic diagram of a signal conversion device for an onboard broadcasting system according to the present invention.

[0025] Figure 2 for Figure 1 side view.

[0026] Figure 3 This is a schematic diagram of the connection between the signal conversion device of the present invention and the external signal.

[0027] Figure 4 This is a schematic diagram of the pulse code modulation principle of the present invention.

[0028] Figure 5 Schematic diagram of the sampling circuit of pulse code modulation of the present invention.

[0029] Figure 6 This is a schematic diagram of the pulse code modulation A / D conversion circuit of the present invention.

[0030] Among them, 1-chassis; 2-sound board; 3-mainboard; 4-main power supply unit; 5-connection terminal; 6-fan; 7-key position; 8-communication port. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be clearly and completely described below through specific implementation methods.

[0032] The present invention relates to a signal conversion device for a shipboard broadcasting system, comprising a chassis 1, a sound collecting board 2, a main board 3, a main power supply unit 4 and a terminal 5; the specific structure is as follows Figures 1-3 As shown, the chassis 1 is a hollow rectangular box installed vertically outside the broadcast main unit, and a terminal 5 is installed on the left side of the middle inside, and various types of signal cables are connected to the outside through the terminal 5; a sound board 2 and a main board 3 are installed at intervals on the left and right sides of the upper middle position inside the chassis 1. The sound board 2 collects analog voice signals and compresses the voice signals; the main board 3 processes various types of data and converts them into digital signals. It also contains a control logic unit to determine the priority of various types of signals and sends the signals to the broadcast main unit in sequence according to the priority level; a main power supply unit 4 is also installed on the right side of the middle inside the chassis 1, and power is supplied by the main power supply unit 4; a communication port 8 is also installed in the middle of the chassis 1 below the sound board 2, and is electrically connected to the serial communication port on the broadcast main unit through the communication port 8.

[0033] like Figure 1 、 Figure 2 As shown, a key position 7 is provided on the front door panel of the chassis 1, and a key is provided to protect the interior of the chassis 1 from theft.

[0034] like Figure 1 、 Figure 2 As shown, a fan 6 is installed on the right side of the chassis 1 above the main power supply unit 4, and the fan 6 is used to ventilate and dissipate heat inside the chassis 1.

[0035] The present invention provides a method for using a signal conversion device for a shipboard broadcasting system, such as Figures 1 to 6 As shown, the following steps are included:

[0036] (1) Set up a serial communication port on the broadcast main unit and connect the communication port 8 on the chassis 1 to the serial communication port on the broadcast main unit.

[0037] (2) Connect external broadcast interruption signals, general emergency alarm / fire alarm interruption signals, microphones, telephone systems and public entertainment systems through terminal 5 on chassis 1;

[0038] In the above steps, the broadcast interruption signal and the general emergency alarm / fire alarm interruption signal are dry contact signals and are digital signals;

[0039] The microphone is a voice signal, which is an analog signal; the telephone system is a voice signal, which is an analog signal; the public entertainment system is a video signal, which is an analog signal; analog signals cannot be processed directly and need to be converted into digital signals first, that is, the continuously changing analog signals are converted into binary digital 0 and 1.

[0040] (3) The voice signals of the microphone, the telephone system and the public entertainment system are converted from analog to digital by the pulse code modulation on the main board 3.

[0041] In the above steps, as shown in Figure 5 the sampling circuit in the pulse code modulation extracts a sample value from the analog signal every Δt time, converting the continuously changing analog signal into individual pulse signals with equal intervals, and the amplitude of each pulse signal is equal to the amplitude of the analog signal at the moment.

[0042] In the above steps, as shown in

[0043] The conversion process of the A / D conversion circuit is as follows: the PWM waveform output by the RA0 pin of the single-chip microcomputer gradually changes from small to large in duty cycle, and the voltage of U1 gradually changes from small to large. When the voltage of U1 exceeds the analog input voltage, the output of the LM324 comparator changes from high to low, and it can be considered that the measured analog quantity at the moment is equal to the voltage of U1. Since the voltage value of U1 = VDD*D1 / (D1+D2), when VDD is fixed, the voltage value depends on the duty cycle of the PWM waveform, and the duty cycle of the PWM is determined by the register value used to control the PWM output in the software of the single-chip microcomputer. If an 8-bit register A is used in the software to store the duty cycle value of the PWM output by RA0, the value of the A register at the moment when RA1 detects the change from "1" to "0" is the A / D conversion value of the measured voltage, and the A / D conversion result is 8 bits. If a 16-bit register is used to output the duty cycle of the PWM, the A / D conversion value can reach 16 bits.

[0044] In the above steps, the A / D conversion circuit in the pulse code modulation can be implemented by a single-chip microcomputer; as shown in Figure 6As shown, RA0 and RA1 are two I / O pins of the microcontroller, and are set to output and input states respectively. The VDD pin of the microcontroller is connected to a 5V power supply; the RA1 pin of the microcontroller is connected to pin 1 of the LM324 comparator, the pin 11 of the LM324 comparator is grounded, the pin 4 of the LM324 comparator is connected to a 5V power supply, the pin 3 of the LM324 comparator receives the analog input, the pin 2 of the LM324 comparator is connected to one end of the resistor R1 and the capacitor C1 respectively, the other end of the capacitor C1 is grounded, and the other end of the resistor R1 is connected to the RA0 pin of the microcontroller; when performing A / D conversion, the R The A0 pin sends out a PWM waveform, and the RA1 pin of the microcontroller is used to detect the status of the comparator output terminal; the resistor R1 and the capacitor C1 form a filter circuit to smooth the PWM waveform output by the RA0 pin; the PWM waveform output by RA0 is filtered and delayed by the resistor R1 and the capacitor C1, and a stable voltage value is generated at the U1 point, and its voltage value U1=VDD*D1 / (D1+D2); the voltage at the pin 2 U1 of the LM324 comparator is compared with the analog input voltage at its pin 3. If the U1 voltage is greater than the analog input voltage, the output terminal of the LM324 comparator is a low level, otherwise it is a high level.

[0045] (4) The control logic unit uses binary digital coding technology to determine the priority of various signals and sends the signals to the broadcast main unit in sequence according to the priority level, realizing the function of multiple signal inputs and one signal output;

[0046] In the above steps, binary digital coding technology adopts ALF statements according to the IEC61162-1 standard protocol, and sets the priorities from high to low as broadcast interruption signal, general emergency alarm / fire alarm interruption signal, microphone, telephone system, and public entertainment system. The broadcast with a higher priority can interrupt the broadcast with a lower priority.

[0047] Beneficial effects of the present invention:

[0048] (1) The present invention can convert all input signals of different types into serial communication digital signals that comply with IEC standards, thereby realizing the function of multiple signal inputs and one signal output, and simplifying the structure of the broadcast main unit;

[0049] (2) The present invention only requires one serial communication port to be provided on the broadcast main unit, thereby reducing the size of the broadcast main unit and solving the problem that the broadcast main unit is modularly produced by the manufacturer and cannot meet the needs of subsequent access to new signals on board.

[0050] (3) The present invention can be installed outside the broadcast main unit, which simplifies the structure of the broadcast main unit and improves the flexibility of the layout. In addition, it can increase the external signal input to the broadcast main unit, thereby improving the scalability.

[0051] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements to the technical solutions of the present invention made by ordinary engineering technicians in this field should fall within the scope of protection of the present invention. The technical contents to be protected by the present invention have been fully recorded in the technical requirements.

Claims

1. A method for using a signal conversion device for an onboard broadcasting system, characterized in that: The signal conversion device includes a chassis, a sound collecting board, a main board, a main power supply unit and a terminal. The chassis is a hollow rectangular box installed vertically outside the broadcast main unit, and a terminal is installed on the left side of the middle of the chassis, through which various types of signal cables are externally connected. A sound collecting board and a main board are installed at intervals on the left and right sides of the upper middle position of the chassis. The sound collecting board collects analog voice signals and compresses the voice signals. The main board processes various types of data and converts them into digital signals. It contains a control logic unit to determine the priority of various signals and sends the signals to the broadcast main unit in sequence according to the priority level. A main power supply unit is also installed on the right side of the middle of the chassis and is powered by the main power supply unit. A communication port is also installed in the middle of the chassis below the sound collecting board, and is electrically connected to the serial communication port on the broadcast main unit through the communication port. The method of use includes the following steps: (1) Set up a serial communication port on the broadcast main unit and connect the communication port on the chassis to the serial communication port on the broadcast main unit; (2) Connect broadcast interruption signals, general emergency alarm / fire alarm interruption signals, microphones, telephone systems and public entertainment systems through the connection terminals on the chassis; (3) Convert the voice signals from microphones, telephone systems, and public entertainment systems to analog-to-digital via pulse code modulation on the motherboard; In the above steps, the sampling circuit in the pulse code modulation extracts a sample value from the analog signal every Δt time, converting the continuously changing analog signal into a series of equally spaced pulse signals, whose amplitude is equal to the amplitude of the analog signal at each moment; The signal is controlled by the sampling pulse. When the sampling pulse comes, the gate of the field effect transistor VT is added with a positive voltage, and it is turned on. The input signal reaches the output end through the drain-source of the field effect transistor VT. When there is no sampling pulse, VT is cut off and the signal cannot pass. Therefore, the sampling circuit samples when the sampling pulse is high, and the low level is the sampling interval time Δt. In the above steps, the A / D conversion circuit in the pulse code modulation can be implemented by a single-chip microcomputer; wherein RA0 and RA1 are two I / O pins of the single-chip microcomputer, and they are set to output and input states respectively, and the VDD pin of the single-chip microcomputer is connected to a 5V power supply; the RA1 pin of the single-chip microcomputer is connected to pin 1 of the LM324 comparator, the pin 11 of the LM324 comparator is grounded, the pin 4 of the LM324 comparator is connected to a 5V power supply, the pin 3 of the LM324 comparator receives the analog input, the pin 2 of the LM324 comparator is connected to one end of the resistor R1 and the capacitor C1 respectively, the other end of the capacitor C1 is grounded, and the other end of the resistor R1 is connected to the RA0 pin of the single-chip microcomputer; in the process When performing A / D conversion, the PWM waveform is sent out from the RA0 pin of the microcontroller, and the RA1 pin of the microcontroller is used to detect the status of the comparator output terminal. Resistor R1 and capacitor C1 form a filter circuit to smooth the PWM waveform output from pin RA0. After the PWM waveform output from RA0 is filtered and delayed by resistor R1 and capacitor C1, a stable voltage value is generated at point U1. Its voltage value U1 = VDD*D1 / (D1+D2). The voltage at pin 2 of the LM324 comparator, U1, is compared with the analog input voltage at its pin 3. If the U1 voltage is greater than the analog input voltage, the output terminal of the LM324 comparator is low, otherwise it is high. (4) The control logic unit uses binary digital coding technology to determine the priority of various signals and sends the signals to the broadcast main unit in sequence according to the priority level, realizing the function of multiple signal inputs and one signal output; In the above steps, binary digital coding technology adopts ALF statements according to the IEC61162-1 standard protocol, and sets the priorities from high to low as broadcast interruption signal, general emergency alarm / fire alarm interruption signal, microphone, telephone system, and public entertainment system. The broadcast with a higher priority can interrupt the broadcast with a lower priority.

2. The method for using the signal conversion device for an onboard broadcasting system according to claim 1, wherein: A key position is also provided on the front door panel of the chassis, and the interior of the chassis is protected from theft by being equipped with a key.

3. The method for using the signal conversion device for an in-vessel broadcasting system according to claim 1, wherein: A fan is also installed on the right side of the interior of the chassis above the main power supply unit, and the fan is used to ventilate and dissipate heat inside the chassis.

4. The method for using the signal conversion device for an onboard broadcasting system according to claim 1, wherein: In the above step (2), the broadcast interruption signal and the general emergency alarm / fire alarm interruption signal are both dry contact signals and are digital signals.

5. The method for using the signal conversion device for an in-vessel broadcasting system according to claim 1, characterized in that: In the above step (2), the microphone, telephone system and public entertainment system are all analog voice signals, which need to be converted into digital signals, that is, the continuously changing analog signals are converted into binary digital 0 and 1.

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