CN204392540U - Audio-frequency multiplex circuit and audio-frequency multiplex system - Google Patents
Audio-frequency multiplex circuit and audio-frequency multiplex system Download PDFInfo
- Publication number
- CN204392540U CN204392540U CN201420848353.2U CN201420848353U CN204392540U CN 204392540 U CN204392540 U CN 204392540U CN 201420848353 U CN201420848353 U CN 201420848353U CN 204392540 U CN204392540 U CN 204392540U
- Authority
- CN
- China
- Prior art keywords
- audio
- circuit
- output
- input
- signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn - After Issue
Links
Landscapes
- Amplifiers (AREA)
- Circuit For Audible Band Transducer (AREA)
Abstract
The utility model proposes a kind of audio-frequency multiplex circuit and audio-frequency multiplex system, audio-frequency multiplex circuit comprises audio-frequency power amplifier, difference audio input circuit, single-ended audio input circuit, audio detection circuit, audio switch circuit and audio output; Difference audio input circuit is all connected the signal input part of audio switch circuit with the output of single-ended audio input circuit; The signal output part of audio switch circuit connects the audio signal input end of audio-frequency power amplifier; The test side of audio detection circuit connects single-ended audio input circuit, and its control end connects audio switch circuit; The audio signal output end of audio-frequency power amplifier connects audio output; In above-mentioned audio-frequency multiplex circuit, adopt audio switch circuit difference audio signal and single-ended audio signal to be carried out selection and switch rear output, by audio-frequency power amplifier unified adjustment gain, achieve and avoid output volume to suddenly change and reduce the technique effect that audio frequency exports application circuit design complexities.
Description
Technical field
The present invention relates to technical field of circuit design, be specifically related to a kind of the audio-frequency multiplex circuit and the audio-frequency multiplex system that relate to difference audio signal and single-ended audio signal.
Background technology
In the voicefrequency circuit of the such as multimedia playing apparatus such as TV, Set Top Box, audio frequency as shown in Figure 1 is usually used to export application circuit; Application circuit shown in Fig. 1 comprises audio-frequency power amplifier U1, difference audio signal SPK_RN, SPK_RP, SPK_LN and SPK_LP, and single-ended audio signal L and R; Difference audio signal comes from the audio signal output end of modulator-demodulator or the audio signal output end of master chip usually, and single-ended audio signal comes from the audio input signals such as external AV audio frequency input or the input of component audio frequency usually.
Above-mentioned application circuit Problems existing is: difference audio signal exports from loud speaker SPK after audio frequency power amplifier U1 amplifies, and single-ended audio signal directly exports from loud speaker, the output channel of these two kinds of audio signals is different, make the output gain of two kinds of audio signals inconsistent, this can cause the output volume of two kinds of audio signals inconsistent, after the audio frequency broadcast mode of user's switching multi-media playing device, there will be the situation of sound volume mutation, this affects the experience sense of user; And in order to avoid this sudden change situation as far as possible, usually need the output gain that different audio signals output channel is set respectively, which increase the design complexities that audio frequency exports application circuit.
Summary of the invention
The embodiment of the present application by providing a kind of audio-frequency multiplex circuit and system, to realize reducing the technique effect that audio frequency exports application circuit design complexities.
For solving the problems of the technologies described above, the present invention is achieved by the following technical solutions:
Propose a kind of audio-frequency multiplex circuit, comprise audio-frequency power amplifier, difference audio input circuit, single-ended audio input circuit and audio output; Also comprise audio detection circuit and audio switch circuit; Output and the output of described single-ended audio input circuit of described difference audio input circuit are all connected the signal input part of described audio switch circuit; The signal output part of described audio switch circuit connects the audio signal input end of described audio-frequency power amplifier; Described audio detection circuit comprises test side and control end, and described test side connects described single-ended audio input circuit, and described control end connects described audio switch circuit; The audio signal output end of described audio-frequency power amplifier connects described audio output; Described audio detection circuit when detecting that described single-ended audio input circuit exists audio input signal, to described audio switch circuit output audio switch controlling signal; Described audio switch circuit, after receiving described audio switch control signal, exports single-ended audio signal with its audio signal output end; Described audio-frequency power amplifier amplifies the single-ended audio signal of its audio signal input end input.
Further, described audio-frequency multiplex circuit also comprises gain setting circuit; Described gain setting circuit arranges pin with the gain of described audio-frequency power amplifier and is connected.
Further, described gain setting circuit comprises the first switching tube, second switch pipe; Described first switching tube is connected described audio switch control signal with the control end of described second switch pipe; Input one tunnel of described first switching tube connects working power, and the first gain that a road connects described audio-frequency power amplifier arranges pin, its output head grounding; The input of described second switch pipe connects described working power, and the second gain that its output one tunnel connects described audio-frequency power amplifier arranges pin, another road ground connection.
Further, described audio-frequency multiplex circuit also comprises volume Circuit tuning; Described volume Circuit tuning is connected with the audio signal output end of described audio-frequency power amplifier.
Further, described volume Circuit tuning comprises the first adjustable resistance and the second adjustable resistance; Described audio output comprises the first audio output and the second audio output; ; Described first adjustable resistance is connected between the first audio signal output pin of described audio-frequency power amplifier and described first audio output; Described second adjustable resistance is connected between the second audio signal output pin of described audio-frequency power amplifier and described second audio output.
Further, described audio detection circuit and described single-ended audio input circuit are integrated in a single-ended audio input terminal; Described single-ended audio input terminal comprises the first audio signal input pin, the second audio signal input pin; The test side of described audio detection circuit and control end are all connected on described first audio signal input pin or described second audio signal input pin.
Further, described first switching tube and described second switch pipe are NPN triode, and described control end is the base stage of described NPN triode, and described input is the collector electrode of described NPN triode, and described output is the emitter of described NPN triode.
Further, described first switching tube and described second switch pipe are NMOS tube, and described control end is the grid of described NMOS tube, and described input is the source electrode of described NMOS tube, and described output is the drain electrode of described NMOS tube.
Propose a kind of audio-frequency multiplex system, comprise loud speaker and above-mentioned audio-frequency multiplex circuit; Described audio output connects described loud speaker.
Compared with prior art, the technical scheme that the present patent application embodiment proposes, the technique effect had or advantage are: the embodiment of the present application propose audio-frequency multiplex circuit and system in, adopt audio switch circuit difference audio input signal and single-ended audio input signal to be carried out selection and switch rear output, the audio signal unification exported by audio switch circuit adjusts gain through audio-frequency power amplifier, by audio detection circuit, this wherein detects that single-ended audio input circuit exports after there is audio input signal for the audio switch control signal switched; This volume that audio signal is exported can be consistent, after the audio frequency broadcast mode of user's switching multi-media playing device, there will not be the situation of sound volume mutation, which increase the experience sense of user; Because all audio input signal unifications adjust gain by audio-frequency power amplifier, this eliminate the gain adjusting part of each audio signal output channel, also eliminate balance each passage adjustment gain with the step avoiding output volume to suddenly change, thus simplify the design that audio signal exports application circuit, achieve and reduce the technique effect that audio frequency exports application circuit design complexities.
Accompanying drawing explanation
Fig. 1 is the circuit diagram that prior art sound intermediate frequency signal exports application circuit;
Fig. 2 is the audio-frequency multiplex circuit frame figure that the embodiment of the present application proposes;
Fig. 3 is the audio-frequency multiplex circuit specific embodiment circuit diagram that the embodiment of the present application proposes.
Embodiment
The embodiment of the present application by providing a kind of audio-frequency multiplex circuit and audio-frequency multiplex system, to realize reducing the technique effect that audio frequency exports application circuit design complexities.
In order to better understand technique scheme, below in conjunction with Figure of description and concrete execution mode, technique scheme is described in detail.
As shown in Figure 2, be the circuit framework figure of the audio-frequency multiplex circuit that the embodiment of the present application proposes, comprise sound
Frequently power amplifier U1, difference audio input circuit SPK_IN, single-ended audio input circuit LINE_IN and audio output OUT, and audio detection circuit Detect and audio switch circuit Switch; Output and the output of single-ended audio input circuit LINE_IN of difference audio input circuit SPK_IN are all connected the signal input part of audio switch circuit Switch; The signal output part of audio switch circuit Switch connects the audio signal input end of audio-frequency power amplifier U1; Audio detection circuit Detect comprises test side Plug and control end ctl, and test side Plug connects single-ended audio input circuit LINE_IN, and control end ctl connects audio switch circuit Switch; The audio signal output end of audio-frequency power amplifier U1 connects audio output OUT.
Audio detection circuit when detecting that single-ended audio input circuit exists audio input signal, by control end ctl to audio switch circuit output audio switch controlling signal Plug_in_Control; Audio switch circuit, after receiving audio switch control signal Plug_in_Control, exports single-ended audio signal with its audio signal output end; Audio-frequency power amplifier amplifies the single-ended audio signal of its audio signal input end input.
Concrete, as shown in Figure 2, difference audio signal SPK_LP, SPK_LN and SPK_RP, SPK_RN connects the input of audio switch circuit, simultaneously, single-ended audio signal LINE_IN_L with LINE_IN_R is also connected the input of audio switch circuit, when not having single-ended audio signal to input, the output output difference multi-voice frequency signal of audio switch circuit, and the difference audio signal of output is input to the INL_P of audio-frequency power amplifier, INL_N, INR_P and INR_N tetra-pins, by audio-frequency power amplifier after Gain tuning, audio output OUT is exported to from its audio signal output end pin OUTL and OUTR, when single-ended audio input circuit input single-ended audio signal, audio detection circuit detects that single-ended audio input circuit has audio input signal, then produce an audio switch control signal, and this audio switch control signal is exported to audio switch circuit, the passage bridge of the output channel of audio signal from output difference multi-voice frequency signal comes to the path exporting single-ended audio signal by audio switch circuit, thus exports single-ended audio signal LINE_IN_L and LINE_IN_R at its output, single-ended audio signal LINE_IN_L and LINE_IN_R exported is input on INL_P, INR_P pin of audio-frequency power amplifier, and the audio input end INL_N of audio-frequency power amplifier and INR_N ground connection, then single-ended audio signal is after the Gain tuning of audio-frequency power amplifier, exports to audio output OUT from its audio signal output pin OUTL and OUTR.
Above-mentioned visible, adopt audio switch circuit difference audio input signal and single-ended audio input signal to be carried out selection and switch rear output, the audio signal unification exported by audio switch circuit adjusts gain through audio-frequency power amplifier, wherein, by audio detection circuit, the audio switch control signal for switching detects that single-ended audio input circuit exports after there is audio input signal; This volume that audio signal is exported can be consistent, after the audio frequency broadcast mode of user's switching multi-media playing device, there will not be the situation of sound volume mutation, which increase the experience sense of user; Because all audio input signal unifications adjust gain by audio-frequency power amplifier, this eliminate the gain adjusting part of each audio signal output channel, also eliminate balance each passage adjustment gain with the step avoiding output volume to suddenly change, thus simplify the design that audio signal exports application circuit, achieve and reduce the technique effect that audio frequency exports application circuit design complexities.
Usually, the amplitude of the difference audio signal of input audio-frequency power amplifier, not identical with the amplitude of single-ended audio signal of input audio-frequency power amplifier, therefore for audio-frequency power amplifier, its Gain tuning amplitude for difference audio signal is also different from the Gain tuning amplitude to single-ended audio signal, for the input of different audio signals, different Gain tuning need be implemented.
In concrete embodiment application, audio detection circuit and single-ended audio input circuit are integrated in a single-ended audio input terminal; As shown in Figure 3, this single-ended audio input terminal generally includes the first audio signal input pin L and the second audio signal input pin R and grounding pin GND; First audio signal input pin introduces single-ended audio signal LINE_IN_L, and the second audio signal input pin introduces single-ended audio signal LINE_IN_R; The test side of audio detection circuit and control end are all connected on the first audio signal input pin (or second audio signal input pin); Working power VCC connects a probe by resistance R26, this probe is against on the first audio signal input pin (or second audio signal input pin), makes the first audio signal input pin (or second audio signal input pin) be high level state when not having the audio signal splicing ear of external audio frequency input equipment to insert.
This single-ended audio input terminal, in multimedia play terminal, be generally the such as earphone terminal that is introduced audio frequency input, the audio frequency such as audio frequency access terminal introduce connector, when inserting the audio signal splicing ear of external audio frequency input equipment in this single-ended audio input terminal, first audio signal input pin and the second audio signal input pin introduce the single-ended audio signal of external audio frequency input equipment input, simultaneously, the audio signal splicing ear being connected to the external audio frequency input equipment that the upper probe of the first audio signal input pin (or second audio signal input pin) is inserted into backs down, the first audio signal input pin (or second audio signal input pin) is made to be converted to high-impedance state from high level state, then be connected to test side on the first audio signal input pin (or second audio signal input pin) and control end and be also converted to high-impedance state from also high level state, namely this high level state and high-impedance state can be used as audio switch control signal, control audio switch circuit path to switch, and gain arranges change etc., such as, when test side becomes high level state, illustrate and do not have the audio signal splicing ear of external audio frequency input equipment to insert in this single-ended audio input terminal, then the high level of control end is used to refer to audio switch circuit and remains on the passage of output difference multi-voice frequency signal, and when test side is high-impedance state, illustrate that the audio signal splicing ear of external audio frequency input equipment inserts in this single-ended audio input terminal, then the high-impedance state of control end be used to refer to audio switch circuit be switched to export single-ended audio signal passage on.
As shown in Figure 2, audio-frequency multiplex circuit also comprises gain setting circuit Gain Setting; This gain setting circuit arranges pin with the gain of audio-frequency power amplifier and is connected; Switching the Audio conversion control signal of output channel for controlling audio switch circuit, can also be used to the control signal changing gain setting as gain setting circuit.
As shown in Figure 3, for the application implements a specific embodiment circuit diagram of the audio-frequency multiplex circuit proposed, this wherein, gain setting circuit comprises the first switching tube and second switch pipe shown in the first switching tube Q1, second switch pipe Q2(figure is NPN triode); First switching tube Q1 is connected audio switch control signal Plug_in_Control with the control end of second switch pipe Q2; The input of the first switching tube is leaded up to resistance R3 and is connected working power VCC, and the first gain that a road connects audio-frequency power amplifier arranges pin G0, its output head grounding; The input of second switch pipe connects working power VCC, and the second gain that its output one tunnel connects audio-frequency power amplifier arranges pin G1, separately leads up to resistance R5 ground connection.
First switching tube and second switch pipe can be NPN triode, then the control end of the first switching tube and second switch pipe is the base stage of NPN triode, and input is the collector electrode of NPN triode, and output is the emitter of NPN triode; First switching tube and second switch pipe can also be NMOS tube, then the control end of the first switching tube and second switch pipe is the grid of NMOS tube, and input is the source electrode of NMOS tube, and output is the drain electrode of NMOS tube.
As mentioned above, when the audio signal output end output difference multi-voice frequency signal of audio switch circuit, audio switch control signal is high level, then the first switching tube and the conducting of second switch pipe, first gain is arranged, and state that pin G0 and the second gain arrange pin G1 is (0,1), corresponding gain is Ga; When after the audio signal splicing ear inserting external audio frequency input equipment, audio switch control signal is high-impedance state, and it is (1,0) that now the first gain arranges the state that pin G0 and the second gain arrange pin G1, and corresponding gain is Gb; The amplitude generally ratio multi-voice frequency signal due to single ended input audio signal is large, and undistorted in order to ensure that audio-frequency power amplifier exports the audio signal of amplifying as far as possible, usual gain G a is greater than gain G b.
As shown in Figure 2, the audio-frequency multiplex circuit that the embodiment of the present application proposes also comprises volume Circuit tuning Volum_ad; This volume Circuit tuning is connected with the audio signal output end of audio-frequency power amplifier U1.
A concrete embodiment is shown in Fig. 3, and this volume Circuit tuning comprises the first adjustable resistance RT1 and the second adjustable resistance RT2, and audio output correspondence comprises the first audio output SPK_L and the second audio output SPK_R; First adjustable resistance RT1 is connected between the first audio signal output pin OUTL of audio-frequency power amplifier and the first audio output SPK_L; Second adjustable resistance RT2 is connected between the second audio signal output pin OUTR second audio output SPK_R of audio-frequency power amplifier.By the adjustment of adjustable resistance, output volume can be avoided further to produce sudden change and reduce Consumer's Experience sense.
The audio-frequency multiplex circuit that the embodiment of the present application proposes, is not limited to the multiplexing of difference audio signal and single-ended audio signal; As long as by this audio-frequency multiplex circuit, can realize avoiding volume to export and produce sudden change, and reduce the technique effect that audio frequency exports application circuit design complexities, the audio-frequency multiplex circuit that the multiplexing output of any different types of audio signal all can adopt the embodiment of the present application to propose.
Based on above-mentioned, the embodiment of the present application proposes a kind of audio-frequency multiplex system, comprise loud speaker and above-mentioned audio-frequency multiplex circuit, audio output SPK_L with SPK_R in audio-frequency multiplex circuit is connected this loud speaker, can not undergo mutation and reduce Consumer's Experience sense when the audio signal exported through audio-frequency multiplex circuit is played back from loud speaker, and circuit design is simple.
Above-mentioned, if audio detection circuit does not detect that single-ended audio inputs, then do not produce audio switch control signal, audio switch circuit remains on the passage of output difference multi-voice frequency signal, output difference multi-voice frequency signal is to audio-frequency power amplifier, and audio-frequency power amplifier amplifies this difference audio signal and exports, and the audio signal of output can be difference audio signal, also can be single-ended audio signal, be determined by the output audio signal kind of audio-frequency power amplifier.
The audio-frequency multiplex circuit proposed by the embodiment of the present application and audio-frequency multiplex system, adopt audio switch circuit difference audio input signal and single-ended audio input signal to be carried out selection and switch rear output, the audio signal unification exported by audio switch circuit exports after audio-frequency power amplifier adjustment gain; This volume that audio signal is exported can be consistent, after the audio frequency broadcast mode of user's switching multi-media playing device, there will not be the situation of sound volume mutation, which increase the experience sense of user; Because all audio input signal unifications adjust gain by audio-frequency power amplifier, this eliminate the gain adjusting part of each audio signal output channel, also eliminate balance each passage adjustment gain with the step avoiding output volume to suddenly change, thus simplify the design that audio signal exports application circuit, achieve and reduce the technique effect that audio frequency exports application circuit design complexities.
It should be noted that; above-mentioned explanation is not limitation of the present invention; the present invention is also not limited in above-mentioned citing, the change that those skilled in the art make in essential scope of the present invention, modification, interpolation or replacement, also should belong to protection scope of the present invention.
Claims (9)
1. an audio-frequency multiplex circuit, comprises audio-frequency power amplifier, difference audio input circuit, list
End audio input circuit and audio output, is characterized in that, also comprise audio detection circuit and audio switch circuit;
The output of described difference audio input circuit is all connected the signal input part of described audio switch circuit with the output of single-ended audio input circuit; The signal output part of described audio switch circuit connects the audio signal input end of described audio-frequency power amplifier; Described audio detection circuit comprises test side and control end, and described test side connects described single-ended audio input circuit, and described control end connects described audio switch circuit; The audio signal output end of described audio-frequency power amplifier connects described audio output;
Described audio detection circuit when detecting that described single-ended audio input circuit exists audio input signal, to described audio switch circuit output audio switch controlling signal; Described audio switch circuit, after receiving described audio switch control signal, exports single-ended audio signal with its audio signal output end; Described audio-frequency power amplifier amplifies the single-ended audio signal of its audio signal input end input.
2. audio-frequency multiplex circuit according to claim 1, is characterized in that, described audio-frequency multiplex circuit also comprises gain setting circuit; Described gain setting circuit arranges pin with the gain of described audio-frequency power amplifier and is connected.
3. audio-frequency multiplex circuit according to claim 2, is characterized in that, described gain setting circuit comprises the first switching tube, second switch pipe; Described first switching tube is connected described audio switch control signal with the control end of described second switch pipe; Input one tunnel of described first switching tube connects working power, and the first gain that a road connects described audio-frequency power amplifier arranges pin, its output head grounding; The input of described second switch pipe connects described working power, and the second gain that its output one tunnel connects described audio-frequency power amplifier arranges pin, another road ground connection.
4. audio-frequency multiplex circuit according to claim 1, is characterized in that, described audio-frequency multiplex circuit also comprises volume Circuit tuning; Described volume Circuit tuning is connected with the audio signal output end of described audio-frequency power amplifier.
5. audio-frequency multiplex circuit according to claim 4, is characterized in that, described volume Circuit tuning comprises the first adjustable resistance and the second adjustable resistance; Described audio output comprises the first audio output and the second audio output;
Described first adjustable resistance is connected between the first audio signal output pin of described audio-frequency power amplifier and described first audio output; Described second adjustable resistance is connected between the second audio signal output pin of described audio-frequency power amplifier and described second audio output.
6. audio-frequency multiplex circuit according to claim 1, is characterized in that, described audio detection circuit and described single-ended audio input circuit are integrated in a single-ended audio input terminal; Described single-ended audio input terminal comprises the first audio signal input pin, the second audio signal input pin; The test side of described audio detection circuit and control end are all connected on described first audio signal input pin or described second audio signal input pin.
7. audio-frequency multiplex circuit according to claim 3, it is characterized in that, described first switching tube and described second switch pipe are NPN triode, described control end is the base stage of described NPN triode, described input is the collector electrode of described NPN triode, and described output is the emitter of described NPN triode.
8. audio-frequency multiplex circuit according to claim 3, it is characterized in that, described first switching tube and described second switch pipe are NMOS tube, and described control end is the grid of described NMOS tube, described input is the source electrode of described NMOS tube, and described output is the drain electrode of described NMOS tube.
9. an audio-frequency multiplex system, comprises loud speaker, it is characterized in that, also comprises the audio-frequency multiplex circuit as described in any one of claim 1-8 claim; Described audio output connects described loud speaker.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420848353.2U CN204392540U (en) | 2014-12-29 | 2014-12-29 | Audio-frequency multiplex circuit and audio-frequency multiplex system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420848353.2U CN204392540U (en) | 2014-12-29 | 2014-12-29 | Audio-frequency multiplex circuit and audio-frequency multiplex system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204392540U true CN204392540U (en) | 2015-06-10 |
Family
ID=53365217
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420848353.2U Withdrawn - After Issue CN204392540U (en) | 2014-12-29 | 2014-12-29 | Audio-frequency multiplex circuit and audio-frequency multiplex system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204392540U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104768101A (en) * | 2014-12-29 | 2015-07-08 | 青岛歌尔声学科技有限公司 | Audio multiplexing circuit, audio multiplexing system and audio multiplexing method |
| CN107396217A (en) * | 2017-05-11 | 2017-11-24 | 博兴电子（恩平）有限公司 | A kind of wireless microphone reception device |
-
2014
- 2014-12-29 CN CN201420848353.2U patent/CN204392540U/en not_active Withdrawn - After Issue
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104768101A (en) * | 2014-12-29 | 2015-07-08 | 青岛歌尔声学科技有限公司 | Audio multiplexing circuit, audio multiplexing system and audio multiplexing method |
| CN104768101B (en) * | 2014-12-29 | 2018-08-24 | 青岛歌尔声学科技有限公司 | Audio-frequency multiplex circuit and system |
| CN107396217A (en) * | 2017-05-11 | 2017-11-24 | 博兴电子（恩平）有限公司 | A kind of wireless microphone reception device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101179871B (en) | Earphone and audio play device | |
| CN104768101A (en) | Audio multiplexing circuit, audio multiplexing system and audio multiplexing method | |
| CN201349247Y (en) | Earphone interface circuit and movable termination | |
| TWI539830B (en) | Electronic device and audio output control method | |
| CN101129088B (en) | Portable device with enhanced stereo image | |
| US8320587B2 (en) | Audio device and volume adjusting circuit for the audio device | |
| US20060222191A1 (en) | Surround sound system | |
| CN104717588A (en) | Low-power-consumption in-ear type active noise reduction earphone and noise reduction method | |
| CN102769729B (en) | Television and audio external play control circuit thereof | |
| CN105554606A (en) | Digital earphone and electronic device | |
| CN101383595A (en) | Electronic volume ajuster and audio device using thereof and abnormity detection method | |
| CN204392540U (en) | Audio-frequency multiplex circuit and audio-frequency multiplex system | |
| CN202799071U (en) | Multifunctional sound box | |
| CN109842836B (en) | Method, circuit and equipment for eliminating crosstalk between audio signal playing paths | |
| CN107635171B (en) | Circuit for improving earphone compatibility | |
| CN106231460B (en) | The multiplexing method and device of earphone interface | |
| CN105142072A (en) | Audio apparatus with externally connected player and audio playing method thereof | |
| US20130003985A1 (en) | Audio output controller and control method | |
| CN202395884U (en) | Television sound signal modulation circuit and television | |
| CN208971820U (en) | A kind of earphone insertion detection circuit, earphone isolation circuit and electronic equipment | |
| CN205232334U (en) | Audio frequency noise suicide circuit and audio -visual equipment | |
| CN208905194U (en) | Silent sound reverberation one power amplifier | |
| CN203027365U (en) | Audio output control circuit and TV set | |
| CN102340563A (en) | Method for eliminating TDD (time division duplex) noise of FM (frequency modulation)-GSM (global system for mobile communications) mobile phone | |
| CN207399486U (en) | A kind of microphone device extended by ear microphone jack |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20150610 Effective date of abandoning: 20180824 |