CN212413146U - Digital broadcast interphone - Google Patents

Abstract

The utility model discloses a digital broadcasting interphone, which identifies effectively pressed keys based on an input/output port module through a second singlechip unit, then outputs warning voice analog audio signals corresponding to the keys according to the effective keys by a voice chip, then converts the analog audio signals into digital signals through an analog-digital conversion chip after amplification processing of an operational amplification circuit, then carries out coding processing through a voice coding and decoding chip, then converts the coded data into serial port signals through a first singlechip unit, finally converts the serial port signals into RS485 signals through an RS485 isolation transceiver and transmits the RS485 signals to a bus, so that other digital broadcasting interphones positioned on the bus can receive the warning voice information to remind operators of safe operation, and an RS485 data bus structure is adopted to lead more interphones to be hung on the bus, theoretically, the number of the submachine can be as high as 128, and the expansion capability of the system is greatly improved.

Description

Digital broadcast interphone

Technical Field

The utility model relates to an intercom technical field especially relates to a digital broadcasting intercom.

Background

The interphone is a two-way mobile communication tool, can communicate without any network support, has no charge, is suitable for relatively fixed and frequent communication occasions, and has three types: analog interphone, digital interphone, IP interphone.

The existing interphone only has one-to-one or one-to-many conversation functions, the function is single, and the alarm voice cannot be broadcasted to remind workers in dangerous workplaces.

SUMMERY OF THE UTILITY MODEL

The utility model provides a digital broadcasting intercom to solve present intercom and do not possess the technical problem of warning voice broadcast function.

According to an aspect of the utility model, a digital broadcasting intercom is provided, including first singlechip unit, pronunciation codec chip, analog-digital/digital-analog conversion chip, RS485 keep apart transceiver, second singlechip unit, operational amplification circuit, pronunciation chip, a plurality of button and input/output port module, analog-digital/digital-analog conversion chip, RS485 keep apart transceiver, second singlechip unit, operational amplification circuit and a plurality of button respectively with input/output port module electric connection, pronunciation codec chip respectively with first singlechip unit, analog-digital/digital-analog conversion chip electric connection, pronunciation chip respectively with second singlechip unit, operational amplification circuit electric connection;

the second single chip microcomputer unit is used for controlling the voice chip to output a corresponding analog audio signal after effective key information of a key is identified through the input/output port module, the operational amplifier circuit is used for amplifying the analog audio signal and then transmitting the amplified analog audio signal to the analog-digital/digital-analog conversion chip through the input/output port module, the analog-digital/digital-analog conversion chip is used for converting the amplified analog audio signal into a digital signal and then transmitting the digital signal to the voice coding/decoding chip for coding, the first single chip microcomputer unit is used for converting multi-frame data formed after coding into a serial port signal and transmitting the serial port signal to the RS485 isolation transceiver, and the RS485 isolation transceiver is used for converting the serial port signal into an RS485 signal and then transmitting the RS485 signal to the bus through the input/output port module.

Further, the operational amplifier circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a capacitor C1, a capacitor C2, a capacitor C3, and an operational amplifier N1, a first end of the resistor R1 is connected to the voice chip, a second end of the resistor R1 is connected to a negative feedback end of the operational amplifier N1, a first end of the resistor R1, and a first end of the capacitor C1 are all connected to a positive feedback end of the operational amplifier N1, a second end of the resistor R1 and a second end of the capacitor C1 are all grounded, a second end of the resistor R1 and a second end of the capacitor C1 are all connected to the negative feedback end of the operational amplifier N1, a first end of the resistor R1 and a positive end of the capacitor C1 are all connected to a negative feedback end of the operational amplifier N1, a second end of the resistor R1 and a negative output end of the capacitor C1 are all connected to the output end of the operational amplifier N1, the first end of the capacitor C3 is connected with the output end of the operational amplifier N1, the second end of the capacitor C3 is connected with the input/output port module, the first end of the resistor R6 is connected with the power supply, and the second end of the resistor R6 is connected with the input/output port module.

Further, the model of the operational amplifier N1 is LM2904, and the resistance of the resistor R5 is 10k Ω.

The loudspeaker and the final-stage amplifying circuit are respectively and electrically connected with the input and output port module, and the pre-stage amplifying circuit is respectively and electrically connected with the analog-digital/digital-analog conversion chip and the final-stage amplifying circuit;

the input/output port module receives the voice coding signal transmitted from the bus and transmits the voice coding signal to the RS485 isolation transceiver, the RS485 isolation transceiver is also used for converting the voice coding signal into a serial port signal and transmitting the serial port signal to the first single chip unit, the first single chip unit is also used for decomposing the serial port signal into multi-frame data and transmitting the multi-frame data to the voice coding/decoding chip, the voice coding/decoding chip is also used for decoding the multi-frame data, the analog-to-digital conversion chip is also used for converting a digital signal formed after decoding into an analog audio signal and transmitting the analog audio signal to a pre-stage amplifying circuit, the pre-stage amplifying circuit is used for performing pre-stage amplification processing on the analog audio signal and transmitting the analog audio signal to a final-stage amplifying circuit, and the final-stage amplifying circuit is used for performing final-stage amplification processing on the analog audio signal and transmitting the analog audio signal to, and then playing the amplified analog audio signal through a loudspeaker.

Further, the pre-stage amplification circuit includes a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, and an operational amplifier N2, a first end of the capacitor C4 is connected to the analog-to-digital/digital-to-analog conversion chip, a second end of the capacitor C4 is connected to a first end of the resistor R7, a second end of the resistor R7 is connected to a negative feedback end of the operational amplifier N2, a first end of the resistor R9, and a first end of the capacitor C9 are connected to a positive feedback end of the operational amplifier N9, a second end of the resistor R9 and a second end of the capacitor C9 are both grounded, a second end of the resistor R9 and a second end of the capacitor C9 are both connected to a power supply, a first end of the resistor R9 is connected to an output end of the operational amplifier N9, a second end of the resistor R9 is grounded, a first end of the resistor R9, the second end of the resistor R8 and the negative end of the capacitor C5 are both connected with the output end of the operational amplifier N2, the first end of the capacitor C7 is connected with the output end of the operational amplifier N2, and the second end of the capacitor C7 is connected with the final-stage amplifying circuit.

Further, the final stage amplifying circuit includes a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12, an electrolytic capacitor C13, a capacitor C14, a transistor Q1, a power amplifier N3, a diode D1, a diode D2, and a sliding varistor P1, a first end of the resistor R12 is connected to a power supply, a second end of the resistor R12 is connected to a first end of the resistor R13, a second end of the resistor R13 is connected to a base of the transistor Q1, an emitter of the transistor Q1 is grounded, a first end of the sliding varistor P1 is connected to a second end of the capacitor C7, a second end of the sliding varistor P7 is grounded, a sliding end of the sliding varistor P7 is connected to a positive terminal of the capacitor C7, a positive terminal of the resistor N7 is connected to a positive terminal of the power amplifier N7, and a collector of the power amplifier N7 is connected to an input terminal of the power amplifier N7, a second end of the resistor R16 is connected to the positive terminal of the capacitor C9 and the first end of the resistor R15, a second end of the resistor R15 and the negative terminal of the capacitor C9 are grounded, a first end of the resistor R14 is connected to a power supply, a second end of the resistor R14 is connected to the first end of the resistor R15, a first end of the resistor R17 and a first end of the resistor R18 are both connected to the negative input terminal of the power amplifier N3, a second end of the resistor R17 is connected to the positive terminal of the capacitor C10, a negative terminal of the capacitor C10 is grounded, a second end of the resistor R18 is connected to the output terminal of the power amplifier N3, a pin v of the power amplifier N3 is connected to the positive terminal of the capacitor C11, the positive terminal of the capacitor C12 and the power supply, negative terminals of the capacitors C12 and C12 are grounded, a negative terminal of the diode D12, a positive terminal of the diode D12, a first terminal of the electrolytic capacitor C12 and a negative terminal of the diode N12 are connected to the output terminal of the power amplifier N12, the second end of the resistor R19 is connected with the first end of the capacitor C14, the second end of the capacitor C14 and the positive end of the diode D1 are grounded, and the negative end of the electrolytic capacitor C13 is connected with the input/output port module.

Further, the model of the power amplifier N3 is TDA2050, and the resistance of the resistor R17 is 3.9k Ω.

Furthermore, the first single chip microcomputer unit, the voice coding and decoding chip, the analog-digital/digital-analog conversion chip and the RS485 isolation transceiver are integrally arranged on a mainboard through SMT packaging, the second single chip microcomputer unit, the operational amplification circuit and the voice chip are integrally arranged on a voice control panel through SMT packaging, and the mainboard and the voice control panel are fixedly arranged in the case.

Further, still include the microphone with input/output port module electric connection, after the user pressed the transmission button on the microphone and sent pronunciation, the analog audio signal transmission to analog-digital/digital-analog conversion chip that input/output port module was gathered with the microphone, analog-digital/digital-analog conversion chip is used for sending after changing analog audio signal into digital signal for pronunciation codec chip carries out the code processing, first single chip microcomputer unit is used for converting the multiframe data that forms after the code processing into serial signals and transmits it to RS485 isolation transceiver, RS485 isolation transceiver is used for transmitting to the bus through input/output port module after converting serial signals into RS485 signals.

Furthermore, the case is made of a thin iron plate, a strong magnet ring is embedded in the back of the microphone, and the microphone is fixed on the surface of the case in a magnetic attraction mode.

The utility model discloses has following effect:

the utility model discloses a digital broadcasting interphone, through the second singlechip unit based on the identification of the input/output port module effectively pressed button, then according to the effective button control voice chip output and the button corresponding warning pronunciation analog audio signal, then after the amplification of operational amplification circuit, analog audio signal is converted into digital signal through the A/D conversion chip, then through the coding chip, then after the coding data is converted into serial port signal by the first singlechip unit, finally through the RS485 isolation transceiver, the serial port signal is converted into RS485 signal and then transmitted to the bus, thereby other digital broadcasting interphones on the bus can receive the warning pronunciation information, in order to remind the operating personnel to carry out safe operation, and, RS485 data bus structure has been adopted, make the interphone that can be hung on the bus more, theoretically, the number of the submachine can be as high as 128, and the expansion capability of the system is greatly improved.

In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be described in further detail with reference to the drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. In the drawings:

fig. 1 is a schematic block diagram of a digital broadcasting intercom according to a preferred embodiment of the present invention.

Fig. 2 is a schematic circuit diagram of an operational amplifier circuit according to a preferred embodiment of the present invention.

Fig. 3 is a schematic circuit diagram of a pre-stage amplifying circuit according to a preferred embodiment of the present invention.

Fig. 4 is a schematic circuit diagram of a final stage amplifier circuit according to a preferred embodiment of the present invention.

Description of the reference numerals

1. A first one-chip microcomputer unit; 2. a voice coding and decoding chip; 3. an analog-to-digital/digital-to-analog conversion chip; 4. RS485 isolation transceiver; 5. a second one-chip microcomputer unit; 6. an operational amplifier circuit; 7. a voice chip; 8. a speaker; 9. pressing a key; 10. an input-output port; 11. a microphone; 12. a pre-amplifier circuit; 13. and a final stage amplifying circuit.

Detailed Description

The embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways, which are defined and covered below.

As shown in fig. 1, the utility model discloses a first embodiment provides a digital broadcasting intercom, it includes that first single chip microcomputer unit 1, pronunciation codec chip 2, analog-to-digital/digital-to-analog conversion chip 3, RS485 keep apart transceiver 4, second single chip microcomputer unit 5, operational amplification circuit 6, pronunciation chip 7, a plurality of button 9 and input/output port module 10, transceiver 4, second single chip microcomputer unit 5, operational amplification circuit 6 and a plurality of button 9 are kept apart with input/output port module 10 electric connection respectively to analog-to-digital/digital-to-analog conversion chip 3, RS485, pronunciation codec chip 2 respectively with first single chip microcomputer unit 1, analog-to-digital/digital-to-analog conversion chip 3 electric connection, pronunciation chip 7 respectively with second single chip microcomputer unit 5, operational amplification circuit 6 electric connection. It can be understood that, first single chip microcomputer unit 1, pronunciation codec chip 2, analog-to-digital/digital-to-analog conversion chip 3, RS485 keep apart transceiver 4 and pass through SMT encapsulation integration and set up on a mainboard, second single chip microcomputer unit 5, operational amplifier circuit 6, pronunciation chip 7 pass through SMT encapsulation integration and set up on a voice control board, mainboard and voice control board fixed mounting are at quick-witted incasement, and a plurality of buttons 9 then set up on the surface of quick-witted case, and it is integrated to carry out electronic components's encapsulation through adopting the most advanced SMT to paste dress technique for produce the uniformity of performance good, also improved digital broadcast intercom reliability, stability, life, shock resistance also can satisfy abominable service environment's requirement.

The first single chip microcomputer unit 1 is configured to compress or decompress data, that is, compress or decompose a frame-by-frame data into a serial port signal, where a specific compression or decompression process belongs to the prior art, and therefore is not described herein again, and a model of the first single chip microcomputer unit 1 is preferably STC12C5616 AD. The voice coding and decoding chip 2 is configured to code a digital signal into data of one frame by one frame or decode the data of one frame by one frame into a digital signal, and a specific coding and decoding process belongs to the prior art, so that details are not repeated here, and the type of the voice coding and decoding chip 2 is preferably AMBE-1000. The analog-to-digital/digital-to-analog conversion chip 3 is used for performing mutual conversion between an analog signal and a digital signal, and a specific conversion process also belongs to the prior art, so that details are not repeated herein, and the model of the analog-to-digital/digital-to-analog conversion chip 3 is preferably CSP 1027. The RS485 isolation transceiver 4 is used for converting a serial port signal and an RS485 signal, and a specific conversion process also belongs to the prior art, so details are not repeated here, the model of the RS485 isolation transceiver 4 is preferably RSM485CHT, and by adopting an RS485 data bus structure, many interphones can be mounted on a bus, theoretically up to 128 submachine, and the expansion capability of the system is greatly improved. The second single chip microcomputer unit 5 is configured to identify valid key information of the key 9, that is, identify which key 9 is specifically and effectively pressed, and then control the voice chip 7 to output an analog audio signal according to the valid key information, where different analog audio signals are stored in the voice chip 7 in advance based on different keys 9, the model of the second single chip microcomputer unit 5 is preferably STC12C5a60S2, and the model of the voice chip 7 is preferably WTN 60640-8S. It is to be understood that the above-mentioned components are merely exemplary in type, and are not limited herein, and existing components that can respectively realize the above-mentioned functions may be selected and replaced.

The specific working process of the warning voice playing function of the digital broadcasting interphone of the embodiment is as follows: the second single chip microcomputer unit 5 controls the voice chip 7 to output a corresponding analog audio signal after identifying effective key information of a key 9 through the input/output port module 10, the operational amplifier circuit 6 amplifies the analog audio signal and transmits the amplified analog audio signal to the analog-digital/digital-analog conversion chip 3 through the input/output port module 10, the analog-digital/digital-analog conversion chip 3 converts the amplified analog audio signal into a digital signal and transmits the digital signal to the voice codec chip 2 for encoding to form data of one frame, the first single chip microcomputer unit 1 is used for compressing multi-frame data into a serial port signal and transmitting the serial port signal to the RS485 isolation transceiver 4, the RS485 isolation transceiver 4 is used for converting the serial port signal into an RS485 signal and transmitting the RS485 signal to a bus through the input/output port module 10, other digital broadcasting interphones on the bus can receive the analog audio signal, thereby realizing the playing of the warning voice. For example, the number of the keys 9 is six, and specifically includes a red 1 key, a red 2 key, a red 3 key, a red 4 key, a red 5 key and a green key, where the voice information corresponding to the red 1 key is "vehicle start, stable standing and firm holding", the voice information corresponding to the red 2 key is "approaching vehicle, attention to safety", the voice information corresponding to the red 3 key is "dangerous, no vehicle is to be loaded or unloaded", the voice information corresponding to the red 4 key is "vehicle running, vehicle door check", the voice information corresponding to the red 5 key is "operation end, platform confirmation", and the green key is correspondingly reset, and when a user presses any one of the six keys 9, the corresponding warning voice information can be broadcast on the bus. Of course, in other embodiments, other voice messages may be stored based on different keys 9.

It can be understood that, in the digital broadcasting interphone of this embodiment, the second single chip microcomputer unit 5 identifies the effectively pressed key 9 based on the input/output port module 10, then the voice chip 7 is controlled to output the warning voice analog audio signal corresponding to the key 9 according to the effective key 9, then the analog audio signal is converted into the digital signal by the analog-to-digital conversion chip 3 after the amplification processing of the operational amplifier circuit 6, then the digital signal is encoded by the voice encoding/decoding chip 2, then the encoded data is converted into the serial port signal by the first single chip microcomputer unit 1, finally the serial port signal is converted into the RS485 signal by the RS485 isolation transceiver 4 and then transmitted to the bus, so that other digital broadcasting interphones on the bus can receive the warning voice information to remind the operator of safe operation, and an RS485 data bus structure is adopted, the interphone has more interphone which can be mounted on the bus, theoretically, the interphone can reach 128 submachine, and the expansion capability of the system is greatly improved.

In addition, the digital broadcasting interphone also comprises a microphone 11 electrically connected with the input/output port module 10, after a user presses a transmitting key on the microphone 11 and makes a voice, the input/output port module 10 transmits the analog audio signal collected by the microphone 11 to the analog/digital/analog conversion chip 3, the analog-to-digital/digital-to-analog conversion chip 3 converts the analog audio signal into a digital signal and sends the digital signal to the voice coding and decoding chip 2 for coding, the first singlechip microcomputer unit 1 is used for converting the data after the coding processing into serial port signals and transmitting the serial port signals to the RS485 isolation transceiver 4, the RS485 isolation transceiver 4 is used for converting the serial port signal into an RS485 signal and then transmitting the RS485 signal to the bus through the input/output port module 10, and other digital broadcasting interphones on the bus can receive the voice information sent by the user, so that the transmitting function of the interphones is realized. Preferably, the case is made of a thin iron plate, so that the case has a good magnetic shielding effect, a strong magnet ring is embedded in the back of the microphone 11, and the microphone 11 is fixed on the surface of the case in a magnetic attraction manner, so that the microphone 11 can be conveniently taken and placed.

Specifically, as shown in fig. 2, the operational amplifier circuit 6 includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a capacitor C1, a capacitor C2, a capacitor C3, and an operational amplifier N1, a first end of the resistor R1 is connected to the voice chip 7, a second end of the resistor R1 is connected to a negative feedback end of the operational amplifier N1, a first end of the resistor R1, a first end of the capacitor C1 are connected to a positive feedback end of the operational amplifier N1, a second end of the resistor R1 and a second end of the capacitor C1 are all grounded, a second end of the resistor R1 and a second end of the capacitor C1 are all connected to a power supply, a first end of the resistor R1 is connected to an output end of the operational amplifier N1, a second end of the resistor R1 is grounded, a first end of the resistor R1 and a positive end of the capacitor C1 are all connected to a negative feedback end of the operational amplifier N1, and a negative end of the operational amplifier N1 are both, the first end of the capacitor C3 is connected to the output end of the operational amplifier N1, the second end of the capacitor C3 is connected to the io port module 10, the first end of the resistor R6 is connected to the power supply, and the second end of the resistor R6 is connected to the io port module 10. The operational amplifier circuit 6 has a simple circuit structure, adopts common electronic components in the market, and reduces the circuit cost. The model of the operational amplifier N1 is preferably LM2904, the resistances of the resistor R1, the resistor R5 and the resistor R6 are 10k Ω, the resistances of the resistor R2 and the resistor R3 are 100k Ω, the resistance of the resistor R4 is 6.2k Ω, the capacitance of the capacitor C1 is 6800pF, the capacitance of the capacitor C2 is 10uF, and the capacitance of the capacitor C3 is 0.15 uF. The resistance of the resistor R5 is not too large, and is the best 10k Ω, because the voice chip 7 outputs an analog audio signal, if the resistance of the resistor R5 is too large, the input signal of the operational amplifier N1 is affected, and the sound break phenomenon occurs at the receiving end.

In addition, the digital broadcasting interphone further comprises a loudspeaker 8, a pre-stage amplifying circuit 12 and a final-stage amplifying circuit 13, wherein the loudspeaker 8 and the final-stage amplifying circuit 13 are electrically connected with the input/output port module 10 respectively, and the pre-stage amplifying circuit 12 is electrically connected with the analog-to-digital/digital-to-analog conversion chip 3 and the final-stage amplifying circuit 13 respectively. The input/output port module 10 receives the voice coding signal transmitted from other interphones on the bus and transmits the signal to the RS485 isolation transceiver 4, the RS485 isolation transceiver 4 converts the voice coding signal into a serial port signal and transmits the serial port signal to the first single chip unit 1, the first single chip unit 1 decomposes the serial port signal into multi-frame data and transmits the multi-frame data to the voice codec chip 2, the voice codec chip 2 decodes the multi-frame data, the analog-to-digital conversion chip 3 converts the decoded data (i.e. digital signal) into an analog audio signal and transmits the analog audio signal to the pre-amplifier circuit 12, the pre-amplifier circuit 12 performs pre-amplification on the analog audio signal and transmits the analog audio signal to the final-stage amplifier circuit 13, and the final-stage amplifier circuit 13 performs final-stage amplification on the analog audio signal and transmits the analog audio signal to the input/output port module 10, and then the amplified analog audio signal is played through the loudspeaker 8, thereby realizing the voice receiving function. Loudspeaker 8 adopts the strong magnetism speaker of plastics basin neodymium iron boron, and not only dampproofing moisture-proof performance is good, and sound production efficiency is also higher. It can be understood that the digital broadcasting interphone effectively amplifies the analog signal by adopting a two-stage amplifying circuit, and has strong anti-interference capability, so that the voice distortion restored from the loudspeaker 8 is small, and the tone quality is clear.

Specifically, as shown in fig. 3, the preamplifier circuit 12 includes a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, and an operational amplifier N2, a first end of the capacitor C4 is connected to the analog-to-digital/digital-to-analog conversion chip 3, a second end of the capacitor C4 is connected to a first end of the resistor R7, a second end of the resistor R7 is connected to a negative feedback end of the operational amplifier N2, a first end of the resistor R9, and a first end of the capacitor C9 are connected to a positive feedback end of the operational amplifier N9, a second end of the resistor R9 and a second end of the capacitor C9 are both grounded, a second end of the resistor R9 is connected to a power supply, a first end of the resistor R9 is connected to an output end of the operational amplifier N9, a second end of the resistor R9 is grounded, a first end of the capacitor R9 and a negative feedback end of the capacitor C9, the second terminal of the resistor R8 and the negative terminal of the capacitor C5 are both connected to the output terminal of the operational amplifier N2, the first terminal of the capacitor C7 is connected to the output terminal of the operational amplifier N2, and the second terminal of the capacitor C7 is connected to the final-stage amplifier circuit 13. The circuit structure of the preceding stage amplifying circuit 12 is similar to that of the operational amplifying circuit 6, the circuit structure is simple, common electronic components in the market are adopted, and the circuit cost is reduced. The model of the operational amplifier N2 is preferably LM2904, the resistance of the resistor R7 is 10k Ω, the resistances of the resistor R8, the resistor R9, and the resistor R10 are 100k Ω, the resistance of the resistor R11 is 6.2k Ω, the capacitance of the capacitor C5 is 6800pF, the capacitance of the capacitor C6 is 10uF, and the capacitances of the capacitor C4 and the capacitor C7 are 0.15 uF.

As shown in fig. 4, the final amplifying circuit 13 includes a resistor R, a capacitor C, an electrolytic capacitor C, a transistor Q, a power amplifier N, a diode D, and a sliding rheostat P, a first end of the resistor R is connected to a power supply, a second end of the resistor R is connected to a first end of the resistor R, a second end of the resistor R is connected to a base of the transistor Q, an emitter of the transistor Q is grounded, a first end of the sliding rheostat P is connected to a second end of the capacitor C, a second end of the sliding rheostat P is grounded, a sliding end of the sliding rheostat P is connected to a negative end of the capacitor C, a positive end of the capacitor C is connected to a collector of the three-tube Q and a positive input end of, a first end of the resistor R16 is connected to an anode input end of the power amplifier N3, a second end of the resistor R16 is connected to an anode end of the capacitor C9 and a first end of the resistor R15, a second end of the resistor R15 and a cathode end of the capacitor C9 are grounded, a first end of the resistor R14 is connected to a power supply, a second end of the resistor R14 is connected to a first end of the resistor R15, a first end of the resistor R17 and a first end of the resistor R18 are both connected to a cathode input end of the power amplifier N3, a second end of the resistor R17 is connected to an anode end of the capacitor C10, a cathode end of the capacitor C10 is grounded, a second end of the resistor R10 is connected to an output end of the power amplifier N10, pins v 10 are respectively connected to an anode end of the capacitor C10, an anode end of the capacitor C10 and a cathode end of the capacitor C10 are both connected to a cathode end of the diode D10, a cathode end of the resistor R6372, a cathode end of the capacitor R6372 and an anode end of the capacitor N36, the cathode end of the diode D2 is connected with a power supply, the second end of the resistor R19 is connected with the first end of the capacitor C14, the second end of the capacitor C14 and the anode end of the diode D1 are grounded, and the cathode end of the electrolytic capacitor C13 is connected with the input/output port module 10. The total resistance value of the slide rheostat P1 is 50k omega, the resistance value of the resistor R13 is 4.7k omega, the resistance value of the resistor R12 is 10k omega, the resistance values of the resistor R14, the resistor R15, the resistor R16 and the resistor R18 are 100k omega, the resistance value of the resistor R17 is 3.9k omega, the resistance value of the resistor R19 is 2.2 omega, the capacitance value of the capacitor C8 is 2.2uF, the capacitance values of the capacitor C9 and the capacitor C10 are 10uF, the capacitance value of the capacitor C11 is 10uF/50V, the capacitance value of the capacitor C12 is 0.1uF, the capacitance value of the capacitor C13 is 220uF, the capacitance value of the capacitor C14 is 0.47uF, the model number of the triode Q1 is 9013, and the model numbers of the diode D1 and the diode D2 are 1N 4007. The final stage amplifying circuit 13 adopts a matching circuit based on a power amplifier N3, the circuit structure is simple, the price of electronic components is low, and the circuit cost is low. In addition, the model of the power amplifier N3 is preferably TDA2050, and the resistance of the resistor R17 is 3.9k Ω, so that not only the output power is increased, but also the output volume is increased compared with TDA 2030.

In addition, as preferable, in order to cope with strong electromagnetic interference and long-distance transmission of signals, a twisted pair transmission line magnetic ring is adopted at the interface input end of the RS485 isolation transceiver 4 for multiple turns and winding, so that common mode interference caused by coupling of external electromagnetic interference signals on the twisted pair transmission line is eliminated, normal signal transmission is not affected, and the anti-interference capability of system signal transmission can be further improved. Similarly, at the power supply access end of the digital broadcasting interphone, the magnetic ring of the bifilar power line is wound in multiple circles, common mode interference caused by coupling of external electromagnetic interference signals on the bifilar power line is eliminated, and the mode has no influence on normal direct current power supply.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A digital broadcasting interphone is characterized in that,

the voice encoding and decoding device comprises a first single chip microcomputer unit (1), a voice encoding and decoding chip (2), an analog-digital/digital-analog conversion chip (3), an RS485 isolation transceiver (4), a second single chip microcomputer unit (5), an operational amplification circuit (6), a voice chip (7), a plurality of keys (9) and an input/output port module (10), wherein the analog-digital/digital-analog conversion chip (3), the RS485 isolation transceiver (4), the second single chip microcomputer unit (5), the operational amplification circuit (6) and the plurality of keys (9) are respectively and electrically connected with the input/output port module (10), the voice encoding and decoding chip (2) is respectively and electrically connected with the first single chip microcomputer unit (1) and the analog-digital/digital-analog conversion chip (3), and the voice chip (7) is respectively and electrically connected with the second single chip microcomputer unit (5) and the operational amplification circuit (6;

the second singlechip microcomputer unit (5) is used for identifying effective key information of the keys (9) through the input-output port module (10) and then controlling the voice chip (7) to output corresponding analog audio signals, the operational amplifier circuit (6) is used for amplifying the analog audio signal and transmitting the amplified analog audio signal to the analog-digital/digital-analog conversion chip (3) through the input/output port module (10), the analog-to-digital/digital-to-analog conversion chip (3) is used for converting the amplified analog audio signal into a digital signal and then sending the digital signal to the voice coding and decoding chip (2) for coding, the first single chip microcomputer unit (1) is used for converting multi-frame data formed after coding processing into serial port signals and transmitting the serial port signals to the RS485 isolation transceiver (4), and the RS485 isolation transceiver (4) is used for converting the serial port signal into an RS485 signal and then transmitting the RS485 signal to the bus through the input/output port module (10).

2. The digital broadcasting interphone of claim 1, wherein,

the operational amplification circuit (6) comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a capacitor C1, a capacitor C2, a capacitor C3 and an operational amplifier N1, wherein a first end of the resistor R1 is connected with the voice chip (7), a second end of the resistor R1 is connected with a negative feedback end of the operational amplifier N1, a first end of the resistor R1 and a first end of the capacitor C1 are connected with a positive feedback end of the operational amplifier N1, a second end of the resistor R1 and a second end of the capacitor C1 are grounded, a second end of the resistor R1 is connected with a power supply, a first end of the resistor R1 is connected with an output end of the operational amplifier N1, a second end of the resistor R1 is grounded, a first end of the resistor R1 and a positive end of the capacitor C1 are connected with a negative feedback end of the operational amplifier N1, a negative end of the resistor R1 and a negative output end of the capacitor C1 are connected with an output end of the operational, the first end of the capacitor C3 is connected with the output end of the operational amplifier N1, the second end of the capacitor C3 is connected with the input/output port module (10), the first end of the resistor R6 is connected with the power supply, and the second end of the resistor R6 is connected with the input/output port module (10).

3. The digital broadcasting interphone of claim 2, wherein,

the model of the operational amplifier N1 is LM2904, and the resistance of the resistor R5 is 10k omega.

4. The digital broadcasting interphone of claim 1, wherein,

the loudspeaker (8) and the final stage amplifying circuit (13) are respectively electrically connected with the input and output port module (10), and the pre-stage amplifying circuit (12) is respectively electrically connected with the analog-to-digital/digital-to-analog conversion chip (3) and the final stage amplifying circuit (13);

the input and output port module (10) receives a voice coding signal transmitted from the bus and transmits the voice coding signal to the RS485 isolation transceiver (4), the RS485 isolation transceiver (4) is also used for converting the voice coding signal into a serial port signal and transmitting the serial port signal to the first single chip microcomputer unit (1), the first single chip microcomputer unit (1) is also used for decomposing the serial port signal into multi-frame data and transmitting the multi-frame data to the voice coding and decoding chip (2), the voice coding and decoding chip (2) is also used for decoding the multi-frame data, the analog-to-digital conversion chip (3) is also used for converting a digital signal formed after decoding into an analog audio signal and transmitting the analog audio signal to the pre-amplification circuit (12), and the pre-amplification circuit (12) is used for pre-amplifying the analog audio signal and transmitting the analog audio signal to the final-amplification circuit (13), the final-stage amplifying circuit (13) is used for performing final-stage amplifying processing on the analog audio signal, transmitting the analog audio signal to the input-output port module (10), and then playing the amplified analog audio signal through the loudspeaker (8).

5. The digital broadcasting interphone of claim 4, wherein,

the pre-amplification circuit (12) comprises a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11 and an operational amplifier N2, wherein a first end of the capacitor C4 is connected with the analog-digital/digital-analog conversion chip (3), a second end of the capacitor C4 is connected with a first end of the resistor R7, a second end of the resistor R7 is connected with a negative feedback end of the operational amplifier N2, a first end of the resistor R9 and a first end of the capacitor C9 are connected with a positive feedback end of the operational amplifier N9, a second end of the resistor R9 and a second end of the capacitor C9 are both grounded, a second end of the resistor R9 is connected with a power supply, a first end of the resistor R9 is connected with an output end of the operational amplifier N9, a second end of the resistor R9 is grounded, a first end of the resistor R9 and a negative feedback end of the capacitor C9 are both connected with a negative, the second end of the resistor R8 and the negative end of the capacitor C5 are both connected with the output end of the operational amplifier N2, the first end of the capacitor C7 is connected with the output end of the operational amplifier N2, and the second end of the capacitor C7 is connected with the final-stage amplifying circuit (13).

6. The digital broadcasting interphone of claim 5, wherein,

the final stage amplifying circuit (13) comprises a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12, an electrolytic capacitor C13, a capacitor C14, a triode Q1, a power amplifier N3, a diode D1, a diode D2 and a sliding rheostat P1, wherein a first end of the resistor R12 is connected with a power supply, a second end of the resistor R12 is connected with a first end of a resistor R13, a second end of the resistor R13 is connected with a base of a triode Q1, an emitter of the triode Q1 is grounded, a first end of the sliding rheostat P1 is connected with a second end of the capacitor C7, a second end of the sliding rheostat P7 is grounded, a negative end of the capacitor C7 is connected with a positive electrode of the capacitor C7, a collector of the sliding rheostat P7 is connected with an input end of the power amplifier N7, and a collector of the power amplifier N7 is connected with an input end of the third power, a second end of the resistor R16 is connected to the positive terminal of the capacitor C9 and the first end of the resistor R15, a second end of the resistor R15 and the negative terminal of the capacitor C9 are grounded, a first end of the resistor R14 is connected to a power supply, a second end of the resistor R14 is connected to the first end of the resistor R15, a first end of the resistor R17 and a first end of the resistor R18 are both connected to the negative input terminal of the power amplifier N3, a second end of the resistor R17 is connected to the positive terminal of the capacitor C10, a negative terminal of the capacitor C10 is grounded, a second end of the resistor R18 is connected to the output terminal of the power amplifier N3, a pin v of the power amplifier N3 is connected to the positive terminal of the capacitor C11, the positive terminal of the capacitor C12 and the power supply, negative terminals of the capacitors C12 and C12 are grounded, a negative terminal of the diode D12, a positive terminal of the diode D12, a first terminal of the electrolytic capacitor C12 and a negative terminal of the diode N12 are connected to the output terminal of the power amplifier N12, the second end of the resistor R19 is connected with the first end of the capacitor C14, the second end of the capacitor C14 and the positive end of the diode D1 are grounded, and the negative end of the electrolytic capacitor C13 is connected with the input/output port module (10).

7. The digital broadcasting interphone of claim 6, wherein,

the model of the power amplifier N3 is TDA2050, and the resistance value of the resistor R17 is 3.9k omega.

8. The digital broadcasting interphone of claim 1, wherein,

the voice isolation transceiver is characterized in that the first single chip microcomputer unit (1), the voice coding and decoding chip (2), the analog-digital/digital-analog conversion chip (3) and the RS485 isolation transceiver (4) are integrally arranged on a main board through SMT packaging, the second single chip microcomputer unit (5), the operational amplification circuit (6) and the voice chip (7) are integrally arranged on a voice control board through SMT packaging, and the main board and the voice control board are fixedly arranged in the case.

9. The digital broadcasting interphone of claim 8, wherein,

still include microphone (11) with input/output port module (10) electric connection, after the user pressed the transmission button on microphone (11) and sent pronunciation, input/output port module (10) transmitted analog audio signal to analog-digital-analog conversion chip (3) that microphone (11) were gathered, analog-digital-analog conversion chip (3) are used for sending after analog audio signal changes digital signal and carry out the code processing for pronunciation codec chip (2), first single chip microcomputer unit (1) are used for the multiframe data conversion who forms after the code processing serial signals and transmit it to RS485 isolation transceiver (4), RS485 isolation transceiver (4) are used for transmitting to the bus through input/output port module (10) after serial signals convert to RS485 signals.

10. The digital broadcasting interphone of claim 9, wherein,

the case is made of a thin iron plate, a strong magnet ring is embedded in the back of the microphone (11), and the microphone (11) is fixed on the surface of the case in a magnetic attraction mode.

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