CN114302300A - Audio input interface circuit and fire extinguishing system control center - Google Patents
Audio input interface circuit and fire extinguishing system control center Download PDFInfo
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- CN114302300A CN114302300A CN202111677920.3A CN202111677920A CN114302300A CN 114302300 A CN114302300 A CN 114302300A CN 202111677920 A CN202111677920 A CN 202111677920A CN 114302300 A CN114302300 A CN 114302300A
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Abstract
The invention provides an audio input interface circuit which comprises a first socket, a second socket, a playing module and a detection module, wherein the first socket and the second socket are connected in parallel and then are connected with the playing module, the detection module is connected with the input end of the playing module in parallel, an audio signal output by the second socket contains a direct current offset signal, the audio signal output by the first socket does not contain the direct current offset signal, and the detection module detects the direct current offset signal. The invention can play the audio signal with or without DC bias and detect the source of the played audio signal.
Description
Technical Field
The invention relates to the technical field of electronics, in particular to an audio input interface circuit and a fire-fighting system control center.
Background
The fire-fighting system control center is provided with a plurality of audio signal input ports such as an MP3, an SD card or an external audio circuit, and when an audio signal is transmitted to the fire-fighting system control center, the fire-fighting system control center cannot judge which input port transmits the audio signal, so that the fire-fighting system control center cannot send out a correct control instruction.
Disclosure of Invention
In view of the above problems, the present invention provides an audio input interface circuit capable of playing an audio signal with or without dc offset and detecting the source of the audio signal.
In order to achieve the purpose, the invention mainly adopts the following technical scheme:
an audio input interface circuit comprises a first socket, a second socket, a playing module and a detection module, wherein the first socket and the second socket are connected in parallel and then are connected with the playing module, the detection module is connected with the input end of the playing module in parallel, an audio signal output by the second socket contains a direct current offset signal, the audio signal output by the first socket does not contain the direct current offset signal, and the detection module detects the direct current offset signal.
Furthermore, two terminals of a third output end of the first socket and a second output end of the second socket which are connected in parallel are respectively connected with the playing module through a second capacitor and a third capacitor.
Furthermore, the detection module comprises a first resistor, a second resistor, a third resistor and a first capacitor, wherein the second resistor is connected with the first capacitor in parallel, the first resistor is connected with the first capacitor in series and then connected with a first terminal of a third output end, and the third resistor is connected with the first capacitor in series and then connected with a second terminal of the third output end.
Further, the detection module further comprises the first switch, and a control end of the first switch is connected with the first capacitor.
Further, the first switch is an NPN type triode, a base and an emitter of the first switch are connected in parallel with the first capacitor, and a collector of the first switch outputs a detection signal.
Furthermore, the detection module further comprises a comparator, a first input end of the comparator is connected with the positive electrode of the first capacitor, a second input end of the comparator is connected with a reference level, and an output end of the comparator outputs a detection signal.
Furthermore, the first output end of the first socket comprises a first audio signal output terminal and a second audio signal output terminal, the first audio signal output terminal is connected with the first elastic pin, the second audio signal output terminal is connected with the second elastic pin, when the plug is inserted into the first socket, the first elastic pin is disconnected from the first audio signal output terminal, and the second elastic pin is disconnected from the second audio signal output terminal.
Further, a third audio signal output terminal and a fourth audio signal output terminal of a second output terminal of the second socket are connected to the first elastic pin and the second elastic pin, respectively.
Further, the second socket comprises an audio signal demodulation module, an output signal of the audio signal demodulation module contains a direct current offset, and an output end of the audio signal demodulation module is connected with the second output end in parallel.
Further, two terminals of the second output terminal of the second socket are respectively connected with a first voltage and a second voltage in parallel.
The invention also provides a fire fighting system control console which comprises the audio input interface circuit provided by the invention.
The audio input interface circuit and the anti-system control center provided by the invention can be used for playing audio signals which are transmitted from an MP3 or an SD card and contain direct current bias, can also play audio signals which are transmitted from an external audio line and do not contain direct current bias, and can detect whether the played audio signals are from the MP3 or the SD card or from the external audio line.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings according to the drawings.
Fig. 1 is a schematic diagram of a first embodiment of an audio input interface circuit according to the present invention.
Fig. 2 is a schematic diagram of a second embodiment of the audio input interface circuit according to the present invention.
Fig. 3 is a schematic diagram of a third embodiment of an audio input interface circuit according to the present invention.
Fig. 4 is a schematic diagram of a fourth embodiment of the audio input interface circuit according to the present invention.
Fig. 5 is a schematic diagram of a fifth embodiment of an audio input interface circuit according to the present invention.
Fig. 6 is a waveform diagram of an audio signal with dc offset.
Description of reference numerals:
1-a first socket, 11-a socket port, 12-a ground pin, 13-a first audio signal input, 14-a first spring pin, 15-a second audio signal input, 16-a second spring pin;
2-a second socket, 21-an audio signal demodulation module, 3-a playing module, 4-a control module, 5-a detection module, 6-a plug and 7-a USB plug.
Detailed Description
The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without any inventive step, are within the scope of protection of the invention.
As shown in fig. 1, the present invention provides an audio input interface circuit, which includes a first socket 1, a second socket 2, a playing module 3, a control module 4 and a detection module 5. The first socket 1 comprises a socket port 11, a ground pin 12, a first audio signal input end 13, a first elastic pin 14, a second audio signal input end 15 and a second elastic pin 16, the socket port 11 is connected with the ground pin 12, the first socket 1 further comprises an audio signal output end a and an audio signal output end b, the audio signal output end a is connected with the first elastic pin 14, and the audio signal output end b is connected with the second elastic pin 16, when the plug 6 is inserted into the first socket 1, the first elastic pin 14 is disconnected with the audio signal output end a, the second elastic pin 16 is disconnected with the audio signal output end b, an audio signal transmitted by an external audio circuit passes through the first socket 1 and then is output from the audio signal output end a and the audio signal output end b, and the audio signal output from the first socket 1 does not contain a direct current bias signal.
The second socket 2 is generally used for connecting with an MP3 or SD card, the MP3 or SD card is connected with the second socket 2 by, for example, a USB plug 7, the second socket 2 has audio signal output terminals c and d, and if an audio signal of the MP3 or SD card is inserted into the second socket 2, the audio signal is output from the audio signal output terminal c and the audio signal output terminal d. The second socket 2 includes an audio signal demodulation module 21, and the audio signal demodulation module 21 has an audio decoding chip for demodulating the audio signal received from the MP3 OR SD card, outputting the demodulated audio signal from the output terminal OR and the output terminal OL, and outputting the demodulated audio signal from the audio signal output terminal c and the audio signal output terminal d of the second socket 2 through the resistors R4 and R5, respectively. Generally, the audio signal output by the audio signal demodulation module 21 contains a dc offset, as shown in fig. 3, S1 is the demodulated audio signal with a positive offset voltage, and V1 is the positive offset voltage. If the audio signal decoded by the audio signal demodulation module 21 does not contain dc offset, an offset voltage may be respectively applied to the output terminals OR and OL of the audio signal demodulation module 21, as shown in fig. 2, a dc voltage V1 is applied to the output terminal OL, and a dc voltage V2 is applied to the output terminal OR. Therefore, the audio signals output from the two audio signal output terminals of the second jack 2 contain a dc offset.
As shown in fig. 1, the audio signal output terminal C of the second socket 2 is connected to the first elastic pin 14, and the audio signal output terminal d is connected to the second elastic pin 16, such that the two audio signal output terminals a and b of the first socket 1 are connected in parallel to the two audio signal output terminals C and d of the second socket 2, and form a third output terminal after being connected in parallel, the third output terminal has a first end e and a second end f, the first end e is connected to the playing module 3 through a capacitor C2, the second end f is connected to the playing module through a capacitor C3, the capacitor C2 and the capacitor C3 have a dc blocking function, and the playing module 3 includes a device capable of playing audio, such as a speaker.
As shown in fig. 1, the detection module 5 includes resistors R1, R2, R3, a capacitor C1, and a switch Q1, a first end e of the third output end is sequentially connected in series with the resistor R1 and the capacitor C1 and then grounded, a second end f of the third output end is sequentially connected in series with the resistor R3 and the capacitor C1 and then grounded, a resistor R2 is connected in parallel with the capacitor C1, and a series midpoint of the resistor R3 and the capacitor C1 outputs a detection signal P1.
As shown in fig. 1, when the plug 6 is not inserted into the first socket 1, but the plug 7 is inserted into the socket 2, an audio signal with a dc bias is output through the audio signal output terminal C and the audio signal output terminal d, and is transmitted to the first end e and the second end f of the third output terminal through the first elastic pin 14 and the second elastic pin 16 in the first socket 1, and then is transmitted to the playing module 3 through the dc blocking capacitors C2 and C3, so as to play the audio in the MP3 or SD card. The first terminal e of the third output terminal charges the capacitor C1 through the resistor R1, the second terminal f of the third output terminal charges the capacitor C1 through the resistor R3, a dc voltage is generated on the capacitor C1, and the signal P1 is at a high level.
When the plug 6 is inserted into the first socket 1, but the plug 7 is inserted into the second socket 2 or not, the audio signal without dc bias is output through the audio signal output terminal b and the audio signal output terminal a, the first elastic pin 14 and the second elastic pin 16 are disconnected from the audio signal output terminal b and the audio signal output terminal a, and the audio signal without dc bias input into the first socket 1 is transmitted to the first end e and the second end f of the third output terminal, and then transmitted to the playing module 3 through the dc blocking capacitors C2 and C3. The first terminal e of the third output terminal charges the capacitor C1 through the resistor R1, and the second terminal f of the third output terminal charges the capacitor C1 through the resistor R3, but since the audio signal without dc bias is input, no high level is generated on the capacitor C1, and the signal P1 is low.
The control module 4 is, for example, a digital controller, which digitally filters the I/O port or AD port sampling signal P1 to identify whether the audio signal played by the playing module 3 originates from the first socket 1 or the second socket 2, if the signal P1 is high, the audio signal originates from the second socket 2, and if the signal P1 is low, the audio signal originates from the first socket 1.
As shown in fig. 2, different from the embodiment shown in fig. 1, if the audio signal decoded by the audio signal demodulation module 21 does not contain dc offset, an offset voltage may be respectively applied to the output terminals OR and OL of the audio signal demodulation module 21, as shown in fig. 2, a dc voltage V1 is applied to the output terminal OL, and a dc voltage V2 is applied to the output terminal OR. Therefore, the audio signals output from the two audio signal output terminals of the second jack 2 contain a dc offset. Please refer to fig. 6 again.
As shown in fig. 3, the detection module 5 includes resistors R1, R2, R3, a capacitor C1, and a switch Q1, a first end e of the third output end is sequentially connected in series with the resistor R1 and the capacitor C1 and then grounded, a second end f of the third output end is sequentially connected in series with the resistor R3 and the capacitor C1 and then grounded, a resistor R2 is connected in parallel with the capacitor C1, and a control end of the switch Q1 is connected to a midpoint of a series connection between the resistor R3 and the capacitor C1. In this embodiment, the switch Q1 is an NPN transistor, a collector of which is connected to the control module 4, an emitter of which is grounded, and a base of which is connected to a series midpoint of the resistor R3 and the capacitor C1, that is, the base and the emitter of the switch Q1 are connected in parallel to the capacitor C1. The switch Q1 is not limited to the NPN transistor shown in fig. 3, but may be another switch, such as a MOSFET shown in fig. 4. In this embodiment, the switch Q1 is an NPN transistor, a collector of which is connected to the control module 4, an emitter of which is grounded, and a base of which is connected to a series midpoint of the resistor R3 and the capacitor C1, that is, the base and the emitter of the switch Q1 are connected in parallel to the capacitor C1. The control module 4 is a control chip, such as a PLC chip, which has a strong data processing capability, and can detect a level change of the collector of the switch Q1, and determine whether the plug 6 is inserted into the first outlet 1 according to the level.
As shown in fig. 3, when the plug 6 is not inserted into the first socket 1, the audio transmitted by the MP3 or the SD card is decoded by the second socket 2, and then the audio signal with dc offset is output through the audio signal output terminal C and the audio signal output terminal d, and then the audio signal is transmitted to the first end e and the second end f of the third output terminal through the first elastic pin 14 and the second elastic pin 16 in the first socket 1, and then transmitted to the playing module 3 through the dc blocking capacitors C2 and C3, so as to play the audio in the MP3 or the SD card. The audio signal decoded by the second socket 2 contains a dc offset, the first terminal e of the third output terminal charges the capacitor C1 through the resistor R1, the second terminal f of the third output terminal charges the capacitor C1 through the resistor R3, a dc voltage is generated on the capacitor C1, the switch Q1 is turned on, a low level signal is generated on the collector thereof, and the control module 4 detects the low level signal and displays the low level signal through the display screen. When the plug 6 is not inserted into the first jack 1, the audio played by the playing module 4 is input from the second jack 2.
When the plug 6 with an external audio line is inserted into the first socket 1, the audio signal output end a of the first socket 1 is disconnected from the first elastic pin 14, the audio signal output end b is disconnected from the second elastic pin 16, and audio signals transmitted by the external audio line are output from the audio signal output ends a and b after passing through the first socket 1, transmitted to the first end e and the second end f of the third output end, and transmitted to the playing module 3 for playing after passing through the blocking capacitors C2 and C3. The audio signal transmitted by the external audio line does not contain direct current bias after being transmitted by the first socket 1, in the detection module 5, the capacitor C1 discharges through the resistor R2, the voltage on the capacitor C1 is zero, the switch Q1 is turned off, a high level signal is generated on the collector of the switch Q1, and the control module 4 detects the high level signal and displays the high level signal through the display screen. When the plug 6 is plugged into the first socket 1, the audio played by the playing module 4 is input from the external audio line through the first socket 1.
As shown in fig. 5, the detection module 5 includes resistors R1, R2, R3, a capacitor C1, and a comparator COM, a first end e of a third output end is sequentially connected in series with the resistor R1 and the capacitor C1 and then grounded, a second end f of the third output end is sequentially connected in series with the resistor R3 and the capacitor C1 and then grounded, the resistor R2 is connected in parallel with the capacitor C1, a series midpoint of the resistor R3 and the capacitor C1 is connected to one end of the comparator COM, the other end of the comparator COM is connected to a reference level Vref, and the voltage VC1 is compared with the reference level Vref to output a signal P1. In the present embodiment, the positive input voltage VC1 of the comparator COM, and the negative input terminal of the comparator COM is referenced to the level Vref. Signal P1 is high when voltage VC1 is greater than reference level Vref. The control module 4 determines from the level of the signal P1 which socket the audio signal originates from.
As mentioned above, the switch Q1 shown in fig. 1 may also be a PNP type triode, when the external audio line plug 6 is not plugged into the first socket 1, the decoded audio signal with dc bias of the second socket 2 is transmitted to the playing module 3 through the first end e and the second end f of the third output terminal for playing, the first end e charges the capacitor C1 through the resistor R1, the second end f charges the capacitor C1 through the resistor R3, the capacitor C1 generates a dc voltage, the switch Q1 is turned off, a high level signal is generated on its collector, and the control module 4 detects the high level signal; when the plug 6 with the external audio line is plugged into the first jack 1, the audio signal without dc bias output from the first jack 1 is transmitted to the playing device 3 through the first terminal e and the second terminal f of the third output terminal to play audio, the capacitor C1 discharges through the resistor R2, the voltage on the capacitor C1 is zero, the switch Q1 is turned on, a low level signal is generated on the collector thereof, and the control module 4 detects the low level signal.
The invention also provides a fire control switchboard which is provided with the audio input interface circuit, the fire control switchboard can be used for playing the audio signal which is transmitted from the MP3 or the SD card and contains the DC bias, can also play the audio signal which is transmitted from the external audio line and does not contain the DC bias, and can detect whether the played audio signal is from the MP3 or the SD card or from the external audio line.
It should be understood that the detailed description of the present invention is only for illustrating the present invention and is not limited by the technical solutions described in the embodiments of the present invention, and those skilled in the art should understand that the present invention can be modified or substituted equally to achieve the same technical effects; as long as the use requirements are met, the method is within the protection scope of the invention.
Claims (10)
1. An audio input interface circuit is characterized by comprising a first socket, a second socket, a playing module and a detection module, wherein the first socket and the second socket are connected in parallel and then are connected with the playing module, the detection module is connected with the input end of the playing module in parallel, an audio signal output by the second socket contains a direct current offset signal, the audio signal output by the first socket does not contain the direct current offset signal, and the detection module detects the direct current offset signal.
2. The audio input interface circuit of claim 1, wherein two terminals of a third output terminal of the first socket and the second output terminal of the second socket connected in parallel are respectively connected to the playing module through a second capacitor and a third capacitor.
3. The audio input interface circuit of claim 2, wherein the detection module comprises a first resistor, a second resistor, a third resistor, and a first capacitor, the second resistor is connected in parallel with the first capacitor, the first resistor and the first capacitor are connected in series and then connected to a first terminal of the third output terminal, and the third resistor and the first capacitor are connected in series and then connected to a second terminal of the third output terminal.
4. The audio input interface circuit of claim 3, wherein the detection module further comprises a first switch, a control terminal of the first switch is connected to the first capacitor, the first switch is an NPN transistor, a base and an emitter of the first switch are connected in parallel to the first capacitor, and a collector of the first switch outputs the detection signal.
5. The audio input interface circuit of claim 3, wherein the detection module further comprises a comparator, a first input terminal of the comparator is connected to the positive pole of the first capacitor, a second input terminal of the comparator is connected to a reference level, and an output terminal of the comparator outputs the detection signal.
6. The audio input interface circuit of claim 2, wherein the first output terminal of the first socket comprises a first audio signal output terminal and a second audio signal output terminal, the first audio signal output terminal is connected to the first resilient pin, the second audio signal output terminal is connected to the second resilient pin, and when the plug is inserted into the first socket, the first resilient pin is disconnected from the first audio signal output terminal and the second resilient pin is disconnected from the second audio signal output terminal.
7. The audio input interface circuit of claim 6, wherein a third audio signal output terminal and a fourth audio signal output terminal of the second socket are connected to the first resilient pin and the second resilient pin, respectively.
8. The audio input interface circuit of claim 7, wherein the second socket comprises an audio signal demodulation module, an output signal of the audio signal demodulation module comprises a DC offset, and an output of the audio signal demodulation module is connected in parallel with the second output.
9. The audio input interface circuit of claim 7, wherein the two terminals of the second output of the second socket are connected in parallel with a first voltage and a second voltage, respectively.
10. A fire fighting system control station comprising the audio input interface circuit of any of claims 1-9.
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| CN202111677920.3A CN114302300A (en) | 2021-12-31 | 2021-12-31 | Audio input interface circuit and fire extinguishing system control center |
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| CN202111677920.3A CN114302300A (en) | 2021-12-31 | 2021-12-31 | Audio input interface circuit and fire extinguishing system control center |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103220614A (en) * | 2012-01-20 | 2013-07-24 | 天地融科技股份有限公司 | Audio interface type detection device |
| CN106231495A (en) * | 2016-08-31 | 2016-12-14 | 浙江大华技术股份有限公司 | A kind of audio identification methods and device |
| CN209170638U (en) * | 2018-12-29 | 2019-07-26 | Tcl通力电子（惠州）有限公司 | Audio interface adaptive circuit, device and electronic equipment |
| CN112995850A (en) * | 2021-01-28 | 2021-06-18 | 杭州涂鸦信息技术有限公司 | Self-adaptive audio circuit and self-adaptive audio device |
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2021
- 2021-12-31 CN CN202111677920.3A patent/CN114302300A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103220614A (en) * | 2012-01-20 | 2013-07-24 | 天地融科技股份有限公司 | Audio interface type detection device |
| US20150016619A1 (en) * | 2012-01-20 | 2015-01-15 | Tendyron Corporation | Apparatus for detecting type of audio interface |
| CN106231495A (en) * | 2016-08-31 | 2016-12-14 | 浙江大华技术股份有限公司 | A kind of audio identification methods and device |
| CN209170638U (en) * | 2018-12-29 | 2019-07-26 | Tcl通力电子（惠州）有限公司 | Audio interface adaptive circuit, device and electronic equipment |
| CN112995850A (en) * | 2021-01-28 | 2021-06-18 | 杭州涂鸦信息技术有限公司 | Self-adaptive audio circuit and self-adaptive audio device |
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