CN2859965Y - Audio commutation circuit - Google Patents
Audio commutation circuit Download PDFInfo
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- CN2859965Y CN2859965Y CN 200520126704 CN200520126704U CN2859965Y CN 2859965 Y CN2859965 Y CN 2859965Y CN 200520126704 CN200520126704 CN 200520126704 CN 200520126704 U CN200520126704 U CN 200520126704U CN 2859965 Y CN2859965 Y CN 2859965Y
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Abstract
The utility model discloses an audio switch circuit comprising audio channels and a CPU whose I/O port is connected to a control pin of a relay by a switch control circuit, a power supply end of the relay is connected to a DC power, a usually opend contact is connected to an audio channel and a usually closed contact is connected to another audio channel, a common point of the relay is connected with an audio signal output end, and the relay outputs the switched audio signal. The utility model controls power turned-on and power cut-off of a relay coil according to a high/low voltage level signal transmitted from the I/O port of the CPU by adding a relay control circuit on an original power amplifying circuit, so as to selectively switch the audio signals of two channels connected on the usually opend contact and the usually closed contact, and output the signals from a speaker or an earphone via the common point, thereby the audio output being switched between the two different audio can be achieved, the audio switch circuit can be widely used in a vehicular mobile TV system for achieving free switch between TV audio and redio receiver voice.
Description
Technical field
The utility model relates to a kind of improvement of power amplifier, specifically, relates to a kind of power amplifier that is used for and is implemented in the control circuit that freely switches between the two-way different audio signals.
Background technology
The audio power amplifier circuit of generally using all is directly to build with common power amplifier chip such as TDA2003, and its circuit connecting relation is referring to shown in Figure 1.Audio signal is connected to the input IN+ of power amplifier chip TDA2003 by capacitor C 101, resistance R 101, coupling capacitance C103, audio signal is carried out after the processing and amplifying by its output OUTPUT output, and then drive loud speaker or the earphone signal of sounding.This power amplifier just simply carries out power amplification to audio signal, to obtain bigger audio frequency output.But, in some system, in for example vehicle-mounted mobile TV-system, audio frequency output need be switched between the different audio frequency of two-way sometimes back and forth, as video sound SR and broadcast receiver sound FMR, common power amplifier just can not be realized this function, thereby makes troubles for listening to of people.
Summary of the invention
The utility model can not realize that in order to solve common power amplifier in the prior art selection of audio signal switches, thereby give people's the problem of making troubles of listening to, a kind of novel audio signal commutation circuit is provided, by on the basis of original power amplifier, increasing control relay circuit, output channel to sound is controlled, thereby, realized the free handoff functionality of audio frequency output between the two-way different audio signals with simple circuit configuration.
For solving the problems of the technologies described above, the utility model is achieved by the following technical solutions:
A kind of frequency switch circuit, comprise voice-grade channel and CPU, the I/O mouth of described CPU connects the control pin of a relay through ON-OFF control circuit, the power end of described relay connects a direct current power supply, normally opened contact connects one road voice-grade channel, normally-closed contact connects another road voice-grade channel, and its common point connects audio signal output end, the audio signal after output is switched.
As further qualification to technique scheme, described ON-OFF control circuit is realized that by a NPN type triode base stage of described triode connects the I/O mouth of CPU, grounded emitter, collector electrode links to each other with DC power supply through resistance on the one hand, connects the control pin of described relay on the other hand.
As the further qualification again to technique scheme, the normally opened contact of described relay connects from wireless voice signal, and normally-closed contact connects the audio signal from audio-visual playback equipment output.The audio signal of described audio-visual playback equipment output is through the input of coupling capacitance connection power amplifier chip, and the output of power amplifier chip connects the normally-closed contact of described relay through coupling capacitance.The common point of described relay connects loud speaker or earphone.
Compared with prior art, advantage of the present utility model and good effect are: the utility model is by adding control relay circuit on the basis of original power amplifier, the high-low level signal control relay coil that sends according to the I/O mouth of CPU electric and dead electricity, and then the two-way audio signal that will be connected on its normally opened contact and the normally-closed contact is selected to switch, export by loud speaker or earphone through its common point, thereby reached the handoff functionality of system audio output between the different audio frequency of two-way, convenient for users to use, can be widely used in the vehicle-mounted mobile TV-system, realize freely switching of television audio and broadcast receiver sound.
Description of drawings
Fig. 1 is the schematic diagram of power amplifier in the prior art;
Fig. 2 is an audio signal control switching circuit schematic diagram of the present utility model.
Embodiment
Below in conjunction with the drawings and specific embodiments the utility model is described in further detail.
The utility model has been set up control relay circuit in order to realize the handoff functionality of audio signal on the basis of original power amplifier, its concrete annexation is referring to shown in Figure 2.
Among Fig. 2, the AUDIOCONTROL signal is the control signal of switch audio output, is provided by the I/O mouth of system CPU, provides high level or low level signal in the different time.The I/O mouth of CPU connects the base stage of NPN type triode VT101 through resistance R 133, and through pull-up resistor R132 connection+5V DC power supply, the grounded emitter of described NPN type triode VT101, collector electrode connects control pin 1 pin of relay R EL102 on the other hand on the one hand through resistance R 130 connection+12V DC power supply through resistance R 131.The 2 pin connection+12V DC power supply of described relay R EL102, normally opened contact 3 pin connect from wireless audio signal FMR, normally-closed contact 4 pin connect the voice signal SR from audio-visual playback equipment output, audio signal OUT PUTR after its common point 0 pin output is switched, and then through loud speaker or earphone output sound.The voice signal SR of described audio-visual playback equipment output outputs to normally-closed contact 4 pin of relay R EL102 after the process power amplification, its concrete syndeton is: the voice signal SR of audio-visual playback equipment output is through 1 pin of interface XP102, by capacitor C 101, resistance R 101, coupling capacitance C103 is connected to the input IN+ of power amplifier chip TDA2003, the audio signal of the output OUTPUT of described power amplifier chip TDA2003 after coupling capacitance C107 output is amplified is to normally-closed contact 4 pin of relay R EL102, + 12V DC power supply is by inductance L 105 and capacitor C 105, C106, after the filter network that C108 forms is handled, connect the power end VSS of power amplifier chip TDA2003, TDA2003 provides stable direct current supply for the power amplifier chip.Be connected with an inductance L 103 between 2 pin of interface XP102 and ground, described inductance L 103 strobes, and can prevent that noise from being sealed in by ground.
When selecting to listen to radio programs, the I/O mouth level of CPU is put height, + 5V DC power supply is by resistance R 132, R133 affacts the base stage of NPN type triode VT101, control its conducting, and then make the control pin of relay R EL102 pass through resistance R 131 ground connection, the coil of relay R EL102 gets, normally opened contact 3 pin closures, normally-closed contact 4 pin disconnect, common point 0 pin of relay R EL102 is communicated with broadcast receiver voice-grade channel FMR, from wireless voice signal, after power amplifier chip TDA2003 carries out power amplification, play radio programs to the user to power amplifier chip TDA2003 output by loud speaker or earphone.
When selecting to listen to television audio, put the I/O mouth level of CPU low, triode VT101 ends, + 12V DC power supply is through resistance R 130, R131 affacts control pin 1 pin of relay R EL102, the coil of relay R EL102 is not owing to constitute power circuit, therefore, its normally opened contact 3 pin disconnect, normally-closed contact 4 pin closures, and then common point 0 pin that makes relay R EL102 is communicated with tv audio passage SR, described audio signal by relay R EL102, drives loud speaker or earphone and plays television audio to the user after power amplifier chip TDA2003 carries out power amplification.
The utility model freely switches output by what adopt that above-mentioned simple circuit configuration realized the two-way different audio signals, wherein, high-low level control to the AUDIOCONTROL signal can specifically be provided with by software according to the difference of switching mutually between the sound channel.Fig. 2 only shows the switching output circuit to right channel audio signal, can adopt same circuit structure to realize that the utility model does not repeat them here for the selection output of left channel audio signal.
Certainly; above-mentioned explanation is not to be to restriction of the present utility model; the utility model also is not limited in above-mentioned giving an example, and variation, remodeling, interpolation or replacement that those skilled in the art are made in essential scope of the present utility model also should belong to protection range of the present utility model.
Claims (5)
1. frequency switch circuit, comprise voice-grade channel and CPU, it is characterized in that: the I/O mouth of described CPU connects the control pin of a relay through ON-OFF control circuit, the power end of described relay connects a direct current power supply, normally opened contact connects one road voice-grade channel, normally-closed contact connects another road voice-grade channel, and its common point connects audio signal output end, the audio signal after output is switched.
2. frequency switch circuit according to claim 1, it is characterized in that: described ON-OFF control circuit is realized by a NPN type triode, the base stage of described triode connects the I/O mouth of CPU, grounded emitter, collector electrode links to each other with described DC power supply through resistance on the one hand, connects the control pin of described relay on the other hand.
3. frequency switch circuit according to claim 2 is characterized in that: the common point of described relay connects loud speaker or earphone.
4. according to claim 2 or 3 described frequency switch circuits, it is characterized in that: the normally opened contact of described relay connects from wireless voice signal, and normally-closed contact connects the audio signal from audio-visual playback equipment output.
5. frequency switch circuit according to claim 4 is characterized in that: the audio signal of described audio-visual playback equipment output is through the input of coupling capacitance connection power amplifier chip, and the output of power amplifier chip connects the normally-closed contact of described relay through coupling capacitance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200520126704 CN2859965Y (en) | 2005-12-28 | 2005-12-28 | Audio commutation circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200520126704 CN2859965Y (en) | 2005-12-28 | 2005-12-28 | Audio commutation circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2859965Y true CN2859965Y (en) | 2007-01-17 |
Family
ID=37612820
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200520126704 Expired - Fee Related CN2859965Y (en) | 2005-12-28 | 2005-12-28 | Audio commutation circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2859965Y (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112243066A (en) * | 2020-10-20 | 2021-01-19 | Oppo广东移动通信有限公司 | Method for selecting FM (frequency modulation) playing mode of electronic equipment and electronic equipment |
-
2005
- 2005-12-28 CN CN 200520126704 patent/CN2859965Y/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112243066A (en) * | 2020-10-20 | 2021-01-19 | Oppo广东移动通信有限公司 | Method for selecting FM (frequency modulation) playing mode of electronic equipment and electronic equipment |
| CN112243066B (en) * | 2020-10-20 | 2021-07-23 | Oppo广东移动通信有限公司 | Method for selecting FM (frequency modulation) playing mode of electronic equipment and electronic equipment |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |