CN101174824A - Silencing circuit for start-up and close-down - Google Patents
Silencing circuit for start-up and close-down Download PDFInfo
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- CN101174824A CN101174824A CNA2006100700199A CN200610070019A CN101174824A CN 101174824 A CN101174824 A CN 101174824A CN A2006100700199 A CNA2006100700199 A CN A2006100700199A CN 200610070019 A CN200610070019 A CN 200610070019A CN 101174824 A CN101174824 A CN 101174824A
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Abstract
The present invention discloses an on-off mute circuit, including a DC power supply, a power amplifier circuit, a comparator and two energy storage capacitors. The first input end of the comparator is connected with the first energy storage capacitor and the DC power supply, the second input end is connected with the DC power supply through a divider resistor and with the negative electrode through the diode of a first switch. The positive electrode of the diode of the first switch is connected with the second capacitor and the DC power supply through a resistor, and the output end of the comparator output high or low level control signals to the power amplifier circuit. The present invention realizes the accurate mute switching on or off of the power amplifier circuit with a simple circuit structure, effectively solves the problem of the momentary on-off noise of electrical appliances such as television set, audio device, strengthens the universality of the mute circuit and improves the reaction rate, reliability and anti-interference ability of the mute circuit.
Description
Technical field
The invention belongs to the mute circuit technical field, specifically, relate to a kind of switching on and shutting down muting control circuit of power amplifier.
Background technology
When television set has just powered on or during the firm power down of television set, because the input signal noise that prime Audio Processing chip power or power down noise cause, and power amplifier chip itself is because the noise that power or power-down causes all produces the unusual sound in loudspeaker, form on-off noise, had a strong impact on the complete machine quality of tv product.Along with improving constantly of consumer spending level, people require also to improve constantly to the soften of sound accompaniment, and this just makes the realization of mute circuit and improvement become more and more important.At present, though realizing the quiet circuit of TV power on and off has a variety of, but, generally all can only realize powering on quiet or power down static, and ubiquity circuit reaction speed is slow, difficulty of parameter tuning, poor anti jamming capability, depend on powering on and the bad adaptability of power down reaction speed, system, being difficult to satisfy shortcoming such as system requirements of main power source and standby power unduly; And can not be applicable in all TV set circuit, usually be formed on successful Application on the tv product of a model, and after system changed a little, this mute circuit was the situation of cisco unity malfunction.
Summary of the invention
Mute circuit for open and close reaction speed in the prior art is slow, the defective of bad adaptability in order to overcome in the present invention, a kind of novel mute circuit for open and close is provided, realize the purpose that TV power on and off is quiet with simple circuit configuration, improved the applicability of mute circuit in different power amplifiers.
For solving the problems of the technologies described above, the present invention is achieved by the following technical solutions:
A kind of mute circuit for open and close comprises DC power supply, power amplifier, comparator and two storage capacitors, and the first input end of described comparator connects first storage capacitor on the one hand, connects described DC power supply on the other hand; Second input of described comparator connects described DC power supply through divider resistance on the one hand, the negative electrode that connects first switching diode on the other hand, the anode of described first switching diode connects described second storage capacitor on the one hand, connects described DC power supply through resistance on the other hand; The output of described comparator is to the quiet end output high level or the low level control signal of power amplifier.
When being implemented in power supply power-fail, electric charge in first storage capacitor can be fallen by timely bleed off, between the first input end of described comparator and DC power supply, be connected with a parallel branch of forming by divider resistance and second switch diode, the anode of described second switch diode connects the first input end of described comparator, and negative electrode connects described DC power supply.
When being implemented in power supply power-fail, electric charge in second storage capacitor is by the described first switching diode bleed off, described DC power supply connects the anode of the 3rd switching diode through described resistance, and the negative electrode of described the 3rd switching diode links to each other with the anode of described second storage capacitor and first switching diode respectively.
Wherein a kind of method of attachment of comparator is: the first input end of described comparator is the in-phase input end of comparator, second input is the inverting input of comparator, adopt this syndeton, when the electric equipment switching on and shutting down, the output output low level signal of comparator.In order to satisfy the different requirements of different power amplifiers to the mute signal high-low level, for the power amplifier that needs the low level mute signal, the quiet end that the output of described comparator is directly connected power amplifier gets final product; And for the power amplifier that needs the high level mute signal, the output of described comparator need connect the quiet end of power amplifier through negater circuit.
Another method of attachment of comparator is: the first input end of described comparator is the inverting input of comparator, second input is the in-phase input end of comparator, adopt this syndeton, when the electric equipment switching on and shutting down, the output of comparator output high level signal.Quiet for the switching on and shutting down that realize electric equipment, the output of comparator directly connected the quiet end of the quiet effective power amplifier of high level or connect the quiet end of the quiet effective power amplifier of low level through negater circuit.
When adopting second kind of comparator connected mode, and the mute signal of the power amplifier of selecting for use is low level when effective, the output of comparator connected the quiet end of described power amplifier by negater circuit.In the present invention, described negater circuit adopts a NPN type triode to cooperate peripheral circuit to realize, the base stage of a described NPN type triode connects the output of comparator, grounded emitter, collector electrode connects standby power on the one hand, connects the quiet end of described power amplifier on the other hand.
In order to realize that electric equipment is in stable back response user's the quiet operation that powers on, affact the base stage of the 2nd NPN type triode by the quiet control signal of motherboard circuit output, the grounded emitter of described the 2nd NPN type triode, collector electrode connects described standby power on the one hand, connects the base stage of a described NPN type triode on the other hand through a resistance.
For the normal quiet operation after guaranteeing to start shooting, prevent that simultaneously late-class circuit from impacting the prime comparator, between the base stage of the output of described comparator and a described NPN type triode, be connected with the 4th switching diode, the anode of described the 4th switching diode connects the output of comparator, and negative electrode connects the base stage of a described NPN type triode.
In order to realize comparator circuit operate as normal when the electric equipment switching on and shutting down, described comparator provides direct current supply by the standby power of electric equipment for it; The DC power supply that is connected its input is the electric equipment main power source, has characteristics such as the load capacity of driving is big, power down speed is fast.
Compared with prior art, advantage of the present invention and good effect are: the present invention has realized the accurately quiet of power amplifier switching on and shutting down by adopting simple circuit configuration, can be widely applied in the power amplifier switch machine mute circuit design of all television systems, efficiently solve the problem of television system switching on and shutting down moment noise, versatility, reaction speed and the antijamming capability of mute circuit under the prerequisite that increases few cost, have been strengthened, effectively improve the reliability and the antijamming capability of tv product, satisfied consumer's appreciation demand.
Description of drawings
Fig. 1 is the schematic diagram of TV power on and off mute circuit among the present invention.
Embodiment
The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.
Power amplifier of the present invention adopts a power amplifier chip to realize, in order to reach the quiet purpose of TV power on and off, has set up mute circuit for open and close as shown in Figure 1 at the quiet end of described power amplifier chip.In described mute circuit for open and close, include a comparator U1A, can operate as normal when the TV power on and off in order to realize it, described comparator U1A provides direct current supply by the standby power VCC_STB in the TV set circuit plate for it.
Embodiment one, and as shown in Figure 1, the inverting input of described comparator U1A connects DC power supply VCC on the one hand; On the other hand by storage capacitor C1 ground connection.Specifically, the inverting input of described comparator U1A connects described DC power supply VCC through divider resistance R3, and through another divider resistance R4 ground connection.Described DC power supply VCC is the television set main power source, has characteristics such as the load capacity of driving is big, power down speed is fast.When being implemented in power supply power-fail, be that DC power supply VCC is equivalent to be shorted to when ground, electric charge among the storage capacitor C1 can be fallen by timely bleed off, between the inverting input of described comparator U1A and DC power supply VCC, be connected with a switching diode D1, the anode of described switching diode D1 connects the inverting input of comparator U1A, and negative electrode connects described DC power supply VCC.The in-phase input end of described comparator U1A connects described DC power supply VCC through divider resistance R1 on the one hand, through another divider resistance R2 ground connection; The negative electrode that connects a switching diode D4 on the other hand, the anode of described switching diode D4 connect described DC power supply VCC by resistance R 11 on the other hand on the one hand by another storage capacitor C2 ground connection.In order to realize that DC power supply VCC passes through resistance R 11 when television boot-strap powers on is storage capacitor C2 charging, and when power supply power-fail or television set shutdown, the electric charge among the storage capacitor C2 is by switching diode D4 bleed off.Be connected with a switching diode D3 between described storage capacitor C2 and DC power supply VCC, the negative electrode of described switching diode D3 connects described storage capacitor C2, and anode connects described DC power supply VCC by the resistance R 11 of series connection with it.
When television boot-strap powered on, DC power supply VCC made the normal phase input end voltage of comparator U1A be in high level state when start just through the normal phase input end that resistor voltage divider network R1, R2 affact comparator U1A.And the inverting input of comparator U1A is because the existence of storage capacitor C1, the principle that can not suddenly change according to capacitor C 1 both end voltage, make its inverting input voltage when start just, be in low level state, and be elevated to gradually on the current potential of DC power supply VCC with the prolongation of start process.Like this, in start process, inverting input voltage ratio normal phase input end voltage delay a period of time of comparator U1A, therefore, and when inverting input voltage does not also surpass normal phase input end voltage, the output output high level of comparator U1A.In order to satisfy the different requirements of different power amplifier chips to the mute signal high-low level, for the power amplifier chip that needs the high level mute signal, the quiet end that the output of described comparator U1A is directly connected the power amplifier chip gets final product; And for the power amplifier chip that needs the low level mute signal, the output of described comparator U1A need connect the quiet end of power amplifier chip through negater circuit.
In the present invention, the mute signal of selected power amplifier chip is that low level is effective, therefore, need connect negater circuit at the output of comparator U1A.In order to simplify circuit structure, described negater circuit adopts a NPN type triode Q1 to cooperate peripheral circuit to realize.In order to prevent that late-class circuit from impacting prime comparator U1A, the output of described comparator U1A connects described negater circuit by a switching diode D2.Wherein, the anode of switching diode D2 connects the output of comparator U1A, and negative electrode connects the base stage of NPN type triode Q1, the grounded emitter of described NPN type triode Q1, and collector electrode connects described standby power VCC_STB by resistance R 6 on the one hand; The quiet end that connects the power amplifier chip on the other hand by resistance R 10.In the television boot-strap process, the high level signal of described comparator U1A output affacts the base stage of triode Q1 through switching diode D2, make triode Q1 conducting, drag down the current potential of its collector electrode, thereby put the voltage of the quiet end of power amplifier chip low, control power amplifier chip is quiet, to realize the quiet purpose of television boot-strap.
After the television set startup is finished, enter normal operating conditions, at this moment, storage capacitor C1 finishes charging process, make comparator U1A inverting input voltage be higher than in-phase input end voltage, comparator U1A output low level signal, diode D2 ends, and triode Q1 is ended, standby power VCC_STB affacts the quiet end of power amplifier chip by resistance R 6, R10, making its quiet terminal potential is high level, and quiet invalid, the power amplifier chip is normally exported audio signal.
In the television set course of normal operation, the mute signal output of TV SKD circuit is exported high level signal MUTE_SYSTEM, affacts the base stage of NPN type triode Q2, controls its conducting.The grounded emitter of described NPN type triode Q2, collector electrode connect standby power VCC_STB by resistance R 7 on the one hand, connect the base stage of described NPN type triode Q1 on the other hand by resistance R 8.At this moment, because the collector potential of triode Q2 is dragged down, the base potential that makes triode Q1 is low, and triode Q1 ends, and the quiet terminal potential of power amplifier chip is a high level, and is quiet invalid, and the power amplifier chip is normally exported audio signal.When the user need carry out quiet operation to television set, can send quiet control signal by remote controller, after the TV SKD circuit receives this control signal, by its mute signal output output low level mute signal MUTE_SYSTEM, triode Q2 ends, standby power VCC_STB affacts the base stage of triode Q1 by resistance R 7, R8, make triode Q1 conducting, drag down the current potential of its collector electrode, thereby put the voltage of the quiet end of power amplifier chip low, control power amplifier chip is quiet, with response user's quiet operation.
When unexpected power down of television set or shutdown, the electric charge on the storage capacitor C1 discharges rapidly by switching diode D1; Electric charge on the storage capacitor C2 is by switching diode D4, through resistance R 1, R2 bleed off.Because the time constant of the RC network that capacitor C 2 and resistance R 1, R2 form is far longer than the time constant of diode D1 and capacitor C 1, therefore, the voltage of comparator U1A in-phase input end is higher than the voltage of inverting input, comparator U1A exports high level signal, after the negater circuit negate of triode Q1 and its peripheral circuit composition, to the quiet pulse signal of power amplifier chip output low level, control power amplifier chip is quiet, thereby realizes the quiet purpose of television set shutdown.
In mute circuit for open and close of the present invention, switching diode D1 can obviously improve the antijamming capability of circuit as quick bleed off circuit, and particularly continuously during switching on and shutting down, circuit still can reliably working.This circuit can respond when acute variation such as surge occurring in system power supply fast, in time sends mute signal, guarantees that violent noise output can not appear in television system.
Embodiment two, and the peripheral circuit that is connected on comparator U1A in-phase input end and the inverting input is exchanged, and can also realize the purpose that TV power on and off is quiet.Adopt this circuit structure, in the TV power on and off process, comparator U1A output low level signal, can directly connect the quiet end of the quiet effective power amplifier chip of low level or connect the quiet end of the quiet effective power amplifier chip of high level, can realize the purpose that the power amplifier switch machine is quiet equally through negater circuit.
The present invention is by adopting above-mentioned simple circuit configuration, accurately quiet when having realized the power amplifier switch machine with lower cost, can be widely used in effectively having improved the reliability and the antijamming capability of mute circuit in the power amplifier of electric equipments such as television set, sound equipment.
Certainly; above-mentioned explanation is not to be limitation of the present invention; the present invention 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 invention also should belong to protection scope of the present invention.
Claims (10)
1. mute circuit for open and close, comprise DC power supply (VCC) and power amplifier, it is characterized in that: also comprise a comparator (U1A) and two storage capacitors (C1, C2), the first input end of described comparator (U1A) connects first storage capacitor (C1) on the one hand, connects described DC power supply (VCC) on the other hand; Second input of described comparator (U1A) connects described DC power supply (VCC) through divider resistance (R1) on the one hand, the negative electrode that connects first switching diode (D4) on the other hand, the anode of described first switching diode (D4) connects described second storage capacitor (C2) on the one hand, connects described DC power supply (VCC) through resistance (R11) on the other hand; The output of described comparator (U1A) is to the quiet end output high level or the low level control signal of power amplifier.
2. mute circuit for open and close according to claim 1, it is characterized in that: between the first input end of described comparator (U1A) and DC power supply (VCC), be connected with a parallel branch of forming by divider resistance (R3) and second switch diode (D1), the anode of described second switch diode (D1) connects the first input end of described comparator (U1A), and negative electrode connects described DC power supply (VCC).
3. mute circuit for open and close according to claim 1, it is characterized in that: described DC power supply (VCC) is through the anode of described resistance (R11) connection the 3rd switching diode (D3), and the negative electrode of described the 3rd switching diode (D3) links to each other with the anode of described second storage capacitor (C2) with first switching diode (D4) respectively.
4. according to claim 1 or 2 or 3 described mute circuit for open and close, it is characterized in that: the first input end of described comparator (U1A) is the in-phase input end of comparator (U1A), second input is the inverting input of comparator (U1A), and output connects the quiet end of the quiet effective power amplifier of low level or connects the quiet end of the quiet effective power amplifier of high level through negater circuit.
5. according to claim 1 or 2 or 3 described mute circuit for open and close, it is characterized in that: the first input end of described comparator (U1A) is the inverting input of comparator (U1A), second input is the in-phase input end of comparator (U1A), and output connects the quiet end of the quiet effective power amplifier of high level or connects the quiet end of the quiet effective power amplifier of low level through negater circuit.
6. mute circuit for open and close according to claim 5 is characterized in that: the mute signal low level of described power amplifier is effective, and the output of described comparator (U1A) connects the quiet end of described power amplifier by negater circuit; In described negater circuit, include a NPN type triode (Q1), the base stage of a described NPN type triode (Q1) connects the output of comparator (U1A), grounded emitter, collector electrode connect standby power (VCC_STB) on the one hand, connect the quiet end of described power amplifier on the other hand.
7. mute circuit for open and close according to claim 6, it is characterized in that: between the base stage of the output of described comparator (U1A) and a described NPN type triode (Q1), be connected with the 4th switching diode (D2), the anode of described the 4th switching diode (D2) connects the output of comparator (U1A), and negative electrode connects the base stage of a described NPN type triode (Q1).
8. mute circuit for open and close according to claim 7, it is characterized in that: electric equipment power on stable after, affact the base stage of the 2nd NPN type triode (Q2) by the quiet control signal (MUTE_SYSTEM) of motherboard circuit output, the grounded emitter of described the 2nd NPN type triode (Q2), collector electrode connects described standby power (VCC_STB) on the one hand, connects the base stage of a described NPN type triode (Q1) on the other hand through a resistance (R8).
9. mute circuit for open and close according to claim 1 is characterized in that: the feeder ear of described comparator (U1A) connects described standby power (VCC_STB).
10. mute circuit for open and close according to claim 1 is characterized in that: described DC power supply is the electric equipment main power source, and described main power source driving load is big, power down speed is fast.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100700199A CN100546186C (en) | 2006-10-30 | 2006-10-30 | Mute circuit for open and close |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100700199A CN100546186C (en) | 2006-10-30 | 2006-10-30 | Mute circuit for open and close |
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| CN101174824A true CN101174824A (en) | 2008-05-07 |
| CN100546186C CN100546186C (en) | 2009-09-30 |
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| CNB2006100700199A Active CN100546186C (en) | 2006-10-30 | 2006-10-30 | Mute circuit for open and close |
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| CN102801388A (en) * | 2011-05-27 | 2012-11-28 | 康佳集团股份有限公司 | Headphone amplification circuit capable of removing noise |
| CN103975528A (en) * | 2011-11-30 | 2014-08-06 | Abb技术有限公司 | An electronic system for an electrical apparatus and related method |
| CN107580278A (en) * | 2017-10-17 | 2018-01-12 | 怀集县正华电器有限公司 | A kind of Stereo Switch machine protecting against shock sound and output short circuit protection circuit |
| WO2018045770A1 (en) * | 2016-09-12 | 2018-03-15 | 京东方科技集团股份有限公司 | Control circuit, control method and electronic device |
| WO2019029563A1 (en) * | 2017-08-10 | 2019-02-14 | 捷开通讯(深圳)有限公司 | Mute control circuit used upon power-on or power-of, control method, and audio device |
| CN109884927A (en) * | 2019-03-21 | 2019-06-14 | 高创(苏州)电子有限公司 | A kind of control circuit and its control method, electronic equipment |
| CN110677778A (en) * | 2019-10-10 | 2020-01-10 | 深圳市九洲电器有限公司 | Audio mute control circuit and electronic equipment |
| CN111142425A (en) * | 2019-12-05 | 2020-05-12 | 芜湖宏景电子股份有限公司 | Vehicle-mounted multimedia power amplifier IC mute control circuit |
| CN113824470A (en) * | 2021-09-26 | 2021-12-21 | 海南宝通实业公司 | Method and device for improving frequency hopping receiving voice quality |
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| CN102801388B (en) * | 2011-05-27 | 2016-03-16 | 康佳集团股份有限公司 | The earphone amplifying circuit of noise can be removed |
| CN102801388A (en) * | 2011-05-27 | 2012-11-28 | 康佳集团股份有限公司 | Headphone amplification circuit capable of removing noise |
| CN103975528A (en) * | 2011-11-30 | 2014-08-06 | Abb技术有限公司 | An electronic system for an electrical apparatus and related method |
| CN103975528B (en) * | 2011-11-30 | 2017-06-23 | Abb技术有限公司 | The method of electronic system and correlation for electrical equipment |
| EP3512095A4 (en) * | 2016-09-12 | 2020-02-26 | BOE Technology Group Co., Ltd. | Control circuit, control method and electronic device |
| WO2018045770A1 (en) * | 2016-09-12 | 2018-03-15 | 京东方科技集团股份有限公司 | Control circuit, control method and electronic device |
| CN107817699A (en) * | 2016-09-12 | 2018-03-20 | 京东方科技集团股份有限公司 | Control circuit, control method and electronic equipment |
| US10298180B2 (en) | 2016-09-12 | 2019-05-21 | Boe Technology Group Co., Ltd. | Control circuit, control method, and electronic device |
| CN107817699B (en) * | 2016-09-12 | 2023-11-17 | 高创(苏州)电子有限公司 | Control circuit, control method and electronic equipment |
| WO2019029563A1 (en) * | 2017-08-10 | 2019-02-14 | 捷开通讯(深圳)有限公司 | Mute control circuit used upon power-on or power-of, control method, and audio device |
| US10826455B2 (en) | 2017-08-10 | 2020-11-03 | JRD Communication (Shenzhen) Ltd. | Mute control circuit used upon power-on or power-of, control method, and audio device |
| CN107580278A (en) * | 2017-10-17 | 2018-01-12 | 怀集县正华电器有限公司 | A kind of Stereo Switch machine protecting against shock sound and output short circuit protection circuit |
| CN109884927A (en) * | 2019-03-21 | 2019-06-14 | 高创(苏州)电子有限公司 | A kind of control circuit and its control method, electronic equipment |
| CN110677778A (en) * | 2019-10-10 | 2020-01-10 | 深圳市九洲电器有限公司 | Audio mute control circuit and electronic equipment |
| CN111142425A (en) * | 2019-12-05 | 2020-05-12 | 芜湖宏景电子股份有限公司 | Vehicle-mounted multimedia power amplifier IC mute control circuit |
| CN113824470A (en) * | 2021-09-26 | 2021-12-21 | 海南宝通实业公司 | Method and device for improving frequency hopping receiving voice quality |
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Address after: 266071 Shandong city of Qingdao province Jiangxi City Road No. 11 Patentee after: Hisense Video Technology Co.,Ltd. Address before: 266071 Shandong city of Qingdao province Jiangxi City Road No. 11 Patentee before: HISENSE ELECTRIC Co.,Ltd. |
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