CN202111843U - Sound for suppressing TDMA noises - Google Patents
Sound for suppressing TDMA noises Download PDFInfo
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- CN202111843U CN202111843U CN2011201891113U CN201120189111U CN202111843U CN 202111843 U CN202111843 U CN 202111843U CN 2011201891113 U CN2011201891113 U CN 2011201891113U CN 201120189111 U CN201120189111 U CN 201120189111U CN 202111843 U CN202111843 U CN 202111843U
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- resonant circuit
- isolation amplifier
- noise isolation
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- 238000002955 isolation Methods 0.000 claims abstract description 30
- 239000003990 capacitor Substances 0.000 claims description 31
- 230000001413 cellular effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
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Abstract
The utility model discloses a sound for suppressing TDMA (Time Division Multiple Address) noises. The sound comprises an RC (Resonance Circuit) and a ground noise isolation amplifier, wherein the RC comprises a first RC and a second RC; left channel signals and right channel signals inputted to the sound are respectively connected with a fourteenth pin and an eighth pin of the ground noise isolation amplifier via the first RC; negative signals inputted to the sound are respectively connected with a twelfth pin and a tenth pin of the ground noise isolation amplifier via the first RC; and a first pin and a seventh pin, respectively as the first output end and a second output end of the ground noise isolation amplifier, are respectively connected with the left and the right channels of the sound via the second RC. By adopting the sound provided by the utility model, owing to the RC and the ground noise isolation amplifier respectively arranged at the input end and the output end, the TDMA noises coupled in a voice frequency circuit can be effectively suppressed, and beautiful music can be played in a noiseless manner without being affected by incoming calls.
Description
Technical Field
The utility model relates to a stereo set especially relates to a can restrain stereo set of TDMA noise.
Background
Ordinary players sometimes receive a "hum" emitted when making a call, which we refer to as TDMA noise, which originates from the 217Hz frequency waveform generated in GSM cellular telephones, which generates audible noise when coupled into the audio path and passed to a speaker, earpiece or microphone.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a can restrain stereo set of TDMA noise.
In order to achieve the purpose, the sound capable of suppressing the TDMA noise is characterized by comprising an RC resonant circuit and a ground noise isolation amplifier U3, wherein the RC resonant circuit comprises a first RC resonant circuit and a second RC resonant circuit; wherein, the left channel signal and the right channel signal input to the sound are respectively connected with the 14 th pin and the 8 th pin of the ground noise isolation amplifier U3 through a first RC resonant circuit, and the negative signal input to the sound is respectively connected with the 12 th pin and the 10 th pin of the ground noise isolation amplifier U3 through a first RC resonant circuit; the 1 st pin and the 7 th pin which are the first output end and the second output end of the ground noise isolation amplifier U3 are respectively connected with the right channel and the left channel of the sound through a second RC resonant circuit.
Preferably, the first RC resonant circuit comprises a capacitor C1 and a resistor R1, wherein the capacitor C1 is 33PF and the resistor R1 is 1K Ω; the second RC resonant circuit includes a capacitor C2 and a resistor R2, wherein the capacitor C2 is 33PF and the resistor R2 is 33K Ω.
Preferably, the ground lead of the sound for suppressing the TDMA noise is a bifilar shield wire.
Preferably, a large-area ground plane is provided on the circuit board of the sound box that can suppress TDMA noise.
The beneficial effects of the utility model reside in that, use can restrain the stereo set of TDMA noise, set up in the RC resonant circuit and the ground noise isolation amplifier of input/output signal end through it, can restrain effectively and couple in the 217Hz TDMA noise of audio circuit, thereby can make the stereo set does not receive the influence of incoming telegram, broadcasts pleasing to the ear music noiselessly.
Drawings
Fig. 1 shows a circuit diagram of the sound system for suppressing TDMA noise according to the present invention.
Detailed Description
The invention will be described in further detail with reference to the following drawings and embodiments:
fig. 1 shows a circuit diagram of the sound equipment for suppressing TDMA noise of the present invention, and as shown in fig. 1, the sound equipment for suppressing TDMA noise comprises an RC resonant circuit and a ground noise isolation amplifier. The chip type of the ground noise isolation amplifier U3 is NJM 2794; the RC resonant circuit comprises a first RC resonant circuit, a second RC resonant circuit and a third RC resonant circuit; the input signals input to the sound include a right channel signal, a left channel signal, and a negative signal. The first RC resonant circuit comprises a capacitor C1 and a resistor R1, wherein the capacitor C1 is 33PF, and the resistor R1 is 1K omega; the second RC resonant circuit comprises a capacitor C2 and a resistor R2, wherein the capacitor C2 is 33PF, and the resistor R2 is 33K omega; the third RC resonant circuit includes a capacitor C3 and a resistor R3, wherein the capacitor C3 is 10PF and the resistor R3 is 10K Ω.
Specifically, the right channel signal inputted through the 2 nd pin of the connector XZ3 is sequentially connected to the 14 th pin of the ground noise isolation amplifier U3 through a first RC resonant circuit and the capacitor C27 of 1uF, the negative signal inputted through the 3 rd pin of the connector XZ3 is sequentially connected to the 12 th pin and the 10 th pin of the ground noise isolation amplifier U3 through a first RC resonant circuit and the capacitor C26 of 1uF, respectively, and the left channel signal inputted through the 4 th pin of the connector XZ3 is sequentially connected to the 8 th pin of the ground noise isolation amplifier U3 through a first RC resonant circuit and the capacitor C25 of 1 uF. A capacitor C58 and a capacitor C59, of which the capacitance values are 22PF, are respectively connected in parallel between the 2 nd pin and the 3 rd pin of the connector XZ3 and between the 3 rd pin and the 4 th pin; a capacitor C60 with the capacitance value of 33PF is connected in parallel between nodes after the 2 nd pin and the 3 rd pin of the connector XZ3 are respectively connected with a first RC resonant circuit, and a capacitor C66 with the capacitance value of 33PF is connected in parallel between nodes after the 3 rd pin and the 4 th pin of the connector XZ3 are respectively connected with the first RC resonant circuit.
The 1 st pin, which is the first output terminal of the ground noise isolation amplifier U3, is connected to the right channel of sound sequentially through a 4uF capacitor C54 and a second RC resonant circuit, and the 7 th pin, which is the second output terminal of the ground noise isolation amplifier U3, is connected to the left channel of sound sequentially through a 4uF capacitor C49 and a second RC resonant circuit.
The 3 rd pin as the grounding terminal of the ground noise isolation amplifier U3 is grounded, the 4 th pin as the reference voltage terminal of the ground noise isolation amplifier U3 is grounded through a capacitor C51 of 10uF, and the 5 th pin as the high voltage terminal of the ground noise isolation amplifier U3 is connected with 9V high voltage through a third RC resonant circuit; in addition, a capacitor C55 of 33PF is connected in parallel between the 1 st pin and the 3 rd pin of the ground noise isolation amplifier U3, and a capacitor C62 and a capacitor C61 which are connected in series with each other are connected in parallel between the 5 th pin and the 7 th pin of the ground noise isolation amplifier U3, wherein the capacitance values of the capacitors C62 and C61 are respectively 10uF and 22 PF; and, the 5 th pin of the ground noise isolation amplifier U3 is grounded through the capacitor C72 of 22 PF.
Further, the leads to ground in the circuit of fig. 1 all employ a twinned shield to minimize the coupling of TDMA noise signals into the audio circuit.
Further, the PCB board carrying the audio circuitry employs a large area ground plane to quickly couple potential TDMA noise signals to ground.
The working principle of the sound for inhibiting the TDMA noise is that in the ground noise isolation amplifier, because the double-differential circuit has strong inhibition capacity on the common-mode input signal, the common-mode interference coupled between the left channel signal and the right channel signal can be eliminated. In addition, the first RC resonant circuit and the second RC resonant circuit are respectively connected with the signal input end and the signal output end of the ground noise isolation amplifier, and the third RC resonant circuit is connected with the high-voltage end of the ground noise isolation amplifier, and the TDMA noise signals in the input signals and the power signals, namely 217HZ frequency signals generated in GSM cellular phones, can be bypassed due to the capacitors C1 and C2 of 33PF in the first and second RC resonant circuits and the capacitor C3 of 10PF in the third RC resonant circuit.
In summary, the preferred embodiments of the present invention are only described, and the scope of the present invention is not limited thereto. All equivalent changes and modifications made according to the content of the claims of the present invention shall fall within the technical scope of the present invention.
Claims (4)
1. A sound system for suppressing TDMA noise, comprising: comprising an RC resonant circuit and a ground noise isolation amplifier (U3), the RC resonant circuit comprising a first RC resonant circuit and a second RC resonant circuit; wherein,
the left channel signal and the right channel signal input to the sound are respectively connected with the 14 th pin and the 8 th pin of the ground noise isolation amplifier (U3) through a first RC resonant circuit, and the negative signal input to the sound is respectively connected with the 12 th pin and the 10 th pin of the ground noise isolation amplifier (U3) through a first RC resonant circuit; the 1 st pin and the 7 th pin which are the first output end and the second output end of the ground noise isolation amplifier (U3) are respectively connected with the right channel and the left channel of the sound through the second RC resonant circuit.
2. The speaker system for suppressing TDMA noise according to claim 1, wherein: the first RC resonant circuit comprises a capacitor (C1) and a resistor (R1), wherein the capacitor (C1) is 33PF, and the resistor (R1) is 1K omega; the second RC resonant circuit includes a capacitor (C2) and a resistor (R2), wherein the capacitor (C2) is 33PF and the resistor (R2) is 33K Ω.
3. A sound system for suppressing TDMA noise according to claim 1 or 2, wherein: the grounding lead is a bifilar shielding wire.
4. A sound system for suppressing TDMA noise according to claim 1 or 2, wherein: a large-area ground plane is arranged on the circuit board.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011201891113U CN202111843U (en) | 2011-06-07 | 2011-06-07 | Sound for suppressing TDMA noises |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011201891113U CN202111843U (en) | 2011-06-07 | 2011-06-07 | Sound for suppressing TDMA noises |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202111843U true CN202111843U (en) | 2012-01-11 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011201891113U Expired - Fee Related CN202111843U (en) | 2011-06-07 | 2011-06-07 | Sound for suppressing TDMA noises |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202111843U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102970396A (en) * | 2012-05-16 | 2013-03-13 | 深圳凯虹移动通信有限公司 | Audio processing circuit and communication terminal |
| CN106454641A (en) * | 2016-09-21 | 2017-02-22 | 四川长虹电器股份有限公司 | Circuit capable of inhibiting sound accompaniment noise |
-
2011
- 2011-06-07 CN CN2011201891113U patent/CN202111843U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102970396A (en) * | 2012-05-16 | 2013-03-13 | 深圳凯虹移动通信有限公司 | Audio processing circuit and communication terminal |
| CN102970396B (en) * | 2012-05-16 | 2016-01-27 | 深圳凯虹移动通信有限公司 | A kind of audio frequency processing circuit and communicating terminal |
| CN106454641A (en) * | 2016-09-21 | 2017-02-22 | 四川长虹电器股份有限公司 | Circuit capable of inhibiting sound accompaniment noise |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120111 Termination date: 20150607 |
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| EXPY | Termination of patent right or utility model |