CN201282521Y - Silent circuit for opening/closing computer and television set with the same - Google Patents
Silent circuit for opening/closing computer and television set with the same Download PDFInfo
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- CN201282521Y CN201282521Y CNU2008202252100U CN200820225210U CN201282521Y CN 201282521 Y CN201282521 Y CN 201282521Y CN U2008202252100 U CNU2008202252100 U CN U2008202252100U CN 200820225210 U CN200820225210 U CN 200820225210U CN 201282521 Y CN201282521 Y CN 201282521Y
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- switching
- squelch
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Abstract
The utility model discloses a startup & shutdown squelch circuit and a television with the squelch circuit. The startup & shutdown squelch circuit comprises an AC (Alternating Current) input terminal, a power amplification circuit, an AC detection circuit and a squelch control circuit; the AC detection circuit generates indication signals and transmits to the squelch control circuit by detecting the power-up state and power-off state of the AC power supply connected by the AC input terminal; the squelch control circuit generates squelch control signals according to the state of the received indication signals, and outputs to the power amplification circuit, so as to enable the amplification circuit to squelch when the AC is on the power-up state and the power-off state. Since the AC power is firstly powered on and powered off, the startup & shutdown squelch circuit of the utility model utilizes the indication state thereof to realize the whole machine squelch, has no need to consider the power sequence and instability of other paths of voltage, thereby avoiding the squelch ineffectiveness, improving the squelch effect and simplifying the design of startup & shutdown squelch circuit.
Description
Technical field
The utility model belongs to the mute circuit technical field, specifically, relates to a kind of switching on and shutting down squelch circuit and has the television set of described switching on and shutting down squelch circuit.
Background technology
When television boot-strap has just powered on or has shut down firm power down, the power amplifier of television set is because the sudden change (risen to 5V or dropped to 0V by 5V by 0V usually) of input signal can produce sudden change equally to the output of power amplifier, the result of this output mutation produces the unusual sound in loudspeaker, form noise.Along with improving constantly of consumer spending level, people require also improving constantly to the soften of music, and this just makes the realization of squelch circuit and improvement become more and more important.
At present, the circuit that can realize the TV power on and off noise elimination has a variety of, all is the operating state of utilizing the electrifying timing sequence of inner each the road direct voltage of television set to come control switch machine mute circuit generally speaking, to realize the noise elimination of switch machine machine.This control mode need be considered the electrifying timing sequence of each road voltage, and adjusts along with the different needs of system docks into each road voltage of quiet circuit, therefore, needs in actual mechanical process through test repeatedly, and is more loaded down with trivial details.
The utility model content
The utility model relies on the electrifying timing sequence that inserts voltage to control the technical problem of the complex operation that its operating state causes in order to solve existing switching on and shutting down squelch circuit, a kind of novel switching on and shutting down squelch circuit is provided, by detect AC power power on and power-down state is controlled the operating state of squelch circuit, thereby avoided because the problem that the noise elimination that each road voltage electrifying timing sequence and instability problem are caused lost efficacy.
For solving the problems of the technologies described above, the utility model is achieved by the following technical solutions:
A kind of switching on and shutting down squelch circuit comprises ac power input end, power amplifier, AC power testing circuit and muting control circuit; Described AC power testing circuit to the AC power that inserts by described ac power input end power on and power-down state detects, and then generate index signal and transfer to described muting control circuit; The state of the index signal that described muting control circuit basis receives generates quiet control signal and exports described power amplifier to, and is quiet when AC power powers on power down to control described power amplifier.
Wherein, in described muting control circuit, include a turn-on muting circuit and a shutdown mute circuit, its input connects the output of described AC power testing circuit, produce turn-on muting pulse and the quiet pulse of shutdown respectively according to the index signal that receives, export the quiet pin of described power amplifier to.
Further, in described turn-on muting circuit, include a storage capacitor and a switching diode, the positive pole of described storage capacitor connects the output of described AC power testing circuit, negative pole passes through grounding through resistance on the one hand, the anode that connects described switching diode on the other hand, the negative electrode of described switching diode connects the quiet pin of power amplifier.
Further again, in described shutdown mute circuit, include a positive-negative-positive triode, storage capacitor and two diodes; The output of described AC power testing circuit connects the anode of first diode on the one hand, and links to each other with the positive pole of described storage capacitor and the emitter of positive-negative-positive triode respectively by the negative electrode of first diode; The anode that connects second diode on the other hand, the negative electrode of described second diode connects the base stage of described positive-negative-positive triode, and by the bleed off grounding through resistance; The collector electrode of described positive-negative-positive triode connects the quiet pin of described power amplifier.
Further again, in described AC power testing circuit, include a switching circuit, the control end of described switching circuit connects described ac power input end by bleeder circuit, current rectifying and wave filtering circuit successively, according to its on off state output high level or low level index signal.
Wherein, in described switching circuit, include a thyristor and an optocoupler, the control end of described thyristor connects ac power input end by described bleeder circuit, current rectifying and wave filtering circuit successively, plus earth, and negative electrode connects the negative electrode of light-emitting diode in the described optocoupler; The anode of described light-emitting diode connects DC power supply, and the collector electrode of illuminated triode connects DC power supply, and emitter connects described muting control circuit.
Further, described DC power supply is voltage or standby voltage by described bleeder circuit output.
Based on above-mentioned switching on and shutting down squelch circuit structure, the utility model provides a kind of television set with described switching on and shutting down squelch circuit again, by the AC power testing circuit is set, to the AC power that inserts power on and power-down state detects, thereby control mute circuit output start or shutdown mute signal are to realize power amplifier accurately quiet when the switching on and shutting down.Because television set is when switching on and shutting down, the state variation of AC power power on and off has precedence over the variation of other each road voltages, and therefore, the output that utilizes the state variation of AC power to control mute circuit can be controlled the complete machine noise elimination timely and accurately.
Compared with prior art, advantage of the present utility model and good effect are: the state when switching on and shutting down squelch circuit of the present utility model utilizes the AC power of complete machine to power on power down is indicated the noise elimination when realizing switching on and shutting down, because AC power all is to power at first and power down when switching on and shutting down, realize the complete machine noise elimination so utilize its state to indicate, can consider the electrifying timing sequence and the instability problem of other each road voltages, thereby avoided the problems such as noise elimination inefficacy that cause thus, and can effectively improve the noise elimination effect, simplified the design of switching on and shutting down squelch circuits.
After reading the detailed description of the utility model execution mode in conjunction with the accompanying drawings, other characteristics of the present utility model and advantage will become clearer.
Description of drawings
Fig. 1 is the circuit theory diagrams of a kind of embodiment of AC power testing circuit in the switching on and shutting down squelch circuit that proposes of the utility model;
Fig. 2 is the circuit theory diagrams of a kind of embodiment of muting control circuit in the switching on and shutting down squelch circuit that proposes of the utility model.
Embodiment
Below in conjunction with accompanying drawing embodiment of the present utility model is described in detail.
Existing switching on and shutting down squelch circuit all is to utilize the electrifying timing sequence of each road direct voltage to control mute circuit work generally speaking, to realize the noise elimination of switch machine machine process.This design need be considered the electrifying timing sequence and the stability of each road direct voltage, and need test repeatedly, and is more loaded down with trivial details.The utility model is by being provided with the AC power testing circuit at ac power input end, utilize the AC power of complete machine to power on and the state during power down is indicated noise elimination when realizing switching on and shutting down, thereby need not to pay close attention to the electrifying timing sequence and the stability problem of each road direct voltage, only need to regulate the noise elimination action time of follow-up muting control circuit, the accurate noise elimination in the time that switching on and shutting down can being realized.
In the utility model, the switching on and shutting down squelch circuit mainly is made up of AC power testing circuit and muting control circuit two parts.Wherein, the AC power testing circuit is connected the input of AC power, to the AC power that inserts by described ac power input end power on and power-down state detects, and then generate index signal and transfer to follow-up muting control circuit.The required working power of described muting control circuit comes from the instructed voltage of AC power testing circuit output, be the voltage of described index signal, high-low level state according to the index signal that receives generates the start or the quiet control signal of shutting down, to export power amplifier to, control it and power on and quiet timely and accurately during power down in AC power.
Be example with the television set below, elaborate the concrete composition structure of described switching on and shutting down squelch circuit.
Embodiment one, in the present embodiment, be used to detect that AC power powers on and the AC power testing circuit of power-down state can specifically be arranged on the power panel of television set, comprise chief components such as current rectifying and wave filtering circuit, bleeder circuit and switching circuit, referring to shown in Figure 1.Wherein, current rectifying and wave filtering circuit connects the ac power input end on the TV set power plate, be ac plug SC101 shown in Figure 1, the external communication civil power that inserts by ac plug SC101 is carried out a series of filter shapes after, export stably direct voltage and carry out step-down by bleeder circuit and handle.Described bleeder circuit can adopt by the form of a plurality of divider resistance series connection to be formed, such as the series resistance R1 among Fig. 1～R4, the low-voltage direct of output is electrically connected to the control end of switching circuit, to control the on off operating mode of described switching circuit, such as conducting when AC power powers on, turn-off during power down.Described switching circuit to follow-up muting control circuit output high level or low level index signal, and then is controlled described muting control circuit output switching on and shutting down mute signal according to its on off state, to realize the accurate noise elimination of complete machine when the switching on and shutting down.
In the present embodiment, described switching circuit can specifically adopt a thyristor IC121 and an optocoupler IC102 to be formed by connecting, as shown in Figure 1.The control end of described thyristor IC121 is the control end of described switching circuit, the output that connects bleeder circuit, plus earth, negative electrode is by the negative electrode of light-emitting diode among the described optocoupler IC102 of resistance R 5 connections, and the anode of described light-emitting diode connects DC power supply VCC1.In order to ensure the electrifying timing sequence of described DC power supply VCC electrifying timing sequence, can from described bleeder circuit, draw required DC power supply VCC1 by the dividing potential drop node here, early than each the road direct voltage by power panel output.This DC power supply VCC1 sets up when AC power powers on, and disappears during power down, satisfies the work requirements of AC power testing circuit fully.In described optocoupler IC102, the collector electrode of illuminated triode connects DC power supply VCC2, and emitter connects follow-up muting control circuit, output index signal AC_DET.Described DC power supply VCC2 can adopt as the identical mode of DC power supply VCC1 by as described in bleeder circuit obtain.Certainly, some standby voltage electrifying timing sequence early than other each road voltage electrifying timing sequences, particularly system early than the required operating voltage electrifying timing sequence of power amplifier in, described DC power supply VCC1, VCC2 can also adopt standby voltage to realize.
Briefly introduce the work engineering of described AC power testing circuit below:
When television boot-strap, electric main is input on the power panel of television set by ac plug SC101, process current rectifying and wave filtering circuit and bleeder circuit are exported the control end of high level to thyristor IC121, and then are controlled its conducting after carrying out shaping, filtering, step-down processing.At this moment, 2 pin of optocoupler IC102 become low level, optocoupler IC102 conducting, and the level of the index signal AC_DET by the output of its 3 pin becomes the high level consistent with 4 pin, thereby realizes the last electro-detection of AC power.
When television set shuts down, the AC power power down, thyristor IC121 is owing to its control end current potential ends for low.At this moment, 2 pin of optocoupler IC102 are put height, and optocoupler IC102 ends, the level step-down of the index signal AC_DET by the output of its 3 pin, thus realized the detection of power loss of AC power.
Index signal AC_DET by described AC power testing circuit output transfers to follow-up muting control circuit, controls its operating state as the working power of described muting control circuit.
In described muting control circuit, comprise turn-on muting circuit and shutdown mute circuit, its input receives index signal AC_DET, produce turn-on muting pulse and the quiet pulse of shutdown respectively according to its high-low level state, export the quiet pin of power amplifier to, accurately quiet when the TV power on and off with the control power amplifier.
In the present embodiment, described muting control circuit can specifically adopt discrete component as shown in Figure 2 to form.Wherein, in the turn-on muting circuit, the positive pole of storage capacitor CE33 connects the output of index signal AC_DET, negative pole is on the one hand by resistance R 385 ground connection, the anode that connects switching diode D15 on the other hand, the negative electrode of described switching diode D15 connects the quiet pin MUTE of power amplifier, and through resistance R 392 ground connection.In the shutdown mute circuit, the output of index signal AC_DET is connected with the emitter of positive-negative-positive triode Q44 and the positive pole of storage capacitor CE34 respectively by the resistance R 384 of the first diode D16 and series connection with it on the one hand, the anode of the described first diode D16 connects the output of index signal AC_DET, negative electrode connects triode Q44 and storage capacitor CE34, the minus earth of storage capacitor CE34 through resistance R 384; The anode that connects the second diode D17 on the other hand, the negative electrode of the described second diode D17 pass through the base stage that resistance R 388 connects described positive-negative-positive triode Q44, and by capacitor C E35 parallel with one another and bleed off resistance R 390 ground connection; The collector electrode of described positive-negative-positive triode Q44 connects the quiet pin MUTE of described power amplifier on the other hand on the one hand through resistance R 391 ground connection by diode D19.
Briefly introduce the work engineering of described muting control circuit below:
When television boot-strap, the AC power testing circuit has detected alternating voltage and has inserted, output high level index signal AC_DET.At this moment, because the existence of storage capacitor CE33, the anode tap voltage of switching diode D15 can not suddenly change, its magnitude of voltage remains the magnitude of voltage (its value is greater than the conducting voltage of switching diode D15) of AC_DET, so switching diode D15 conducting, export the mute signal SP_MUTE of high level to the quiet pin MUTE of power amplifier, thereby realize the start noise elimination.Along with of the charging of AC_DET voltage to storage capacitor CE33, the anode tap voltage of switching diode D15 reduces gradually, when magnitude of voltage during less than the conducting voltage of switching diode D15, switching diode D15 ends, the voltage of SP_MUTE becomes low level, thereby decontrol the quiet pin MUTE of power amplifier, sound power amplifier operate as normal, output sound accompaniment.Change the capacitance size of storage capacitor CE33 and the resistance value size of resistance R 385, can regulate the time of its start noise elimination.
When television set shut down, the AC power testing circuit detected no alternating voltage and inserts, and then the electric position of index signal AC_DET is low.At this moment, because the existence of the storage capacitor CE34 and the first diode D16, the emitter voltage of positive-negative-positive triode Q44 can not suddenly change, and produces the voltage difference of forward between its emitter and the base stage, make the rapid saturation conduction of triode Q44, and the discharge loop that forms by resistance R 388, R390 discharges; At this moment, the second diode D17 oppositely ends, and passes through resistance R 388, R390 bleed off to guarantee the electric charge among the storage capacitor CE34.Meanwhile, the collector voltage of triode Q44 becomes high level, and control diode D19 conducting with the mute signal SP_MUTE of output high level, thereby realizes the shutdown noise elimination.Change the capacitance size of storage capacitor CE34 and the resistance value size of resistance R 388/R390, can regulate the time of its shutdown noise elimination.
Here, storage capacitor CE33 and CE34 also can adopt an electric capacity to realize, can realize the purpose of design of described muting control circuit equally.
The powering on of AC power, power-down state were controlled muting control circuit work when switching on and shutting down squelch circuit of the present utility model utilized TV power on and off, the complete machine noise elimination when realizing TV power on and off.Because the state variation of AC power has precedence over the state variation of other each road voltages, so need not to consider other voltages electrifying timing sequence each other, just can change its quiet time as long as regulate the resistance value size of the capacitance size of storage capacitor CE33, CE34 and resistance R 385, R388, R390, thus the noise problem that labile state caused when avoiding other voltage power on and off.
Accurately quiet when switching on and shutting down squelch circuit of the present utility model has been realized the power amplifier switching on and shutting down by adopting simple circuit configuration, can be widely applied in all audio output apparatus with sound power amplifier, such as television set, radio-cassette player etc., thereby efficiently solve the problem of audio output apparatus switching on and shutting down moment noise, reach perfect sound reproduction truly, satisfied consumer's appreciation demand.
Certainly; the above only is a kind of preferred implementation of the present utility model; should be understood that; for those skilled in the art; under the prerequisite that does not break away from the utility model principle; can also make some improvements and modifications, these improvements and modifications also should be considered as protection range of the present utility model.
Claims (10)
1, a kind of switching on and shutting down squelch circuit comprises ac power input end and power amplifier; It is characterized in that: in described squelch circuit, also include an AC power testing circuit and a muting control circuit; Described AC power testing circuit to the AC power that inserts by described ac power input end power on and power-down state detects, and then generate index signal and transfer to described muting control circuit; The state of the index signal that described muting control circuit basis receives generates quiet control signal and exports described power amplifier to, and is quiet when AC power powers on power down to control described power amplifier.
2, switching on and shutting down squelch circuit according to claim 1, it is characterized in that: in described muting control circuit, include a turn-on muting circuit and a shutdown mute circuit, its input connects the output of described AC power testing circuit, produce turn-on muting pulse and the quiet pulse of shutdown respectively according to the index signal that receives, export the quiet pin of described power amplifier to.
3, switching on and shutting down squelch circuit according to claim 2, it is characterized in that: in described turn-on muting circuit, include a storage capacitor and a switching diode, the positive pole of described storage capacitor connects the output of described AC power testing circuit, negative pole passes through grounding through resistance on the one hand, the anode that connects described switching diode on the other hand, the negative electrode of described switching diode connects the quiet pin of power amplifier.
4, switching on and shutting down squelch circuit according to claim 2 is characterized in that: include a positive-negative-positive triode, storage capacitor and two diodes in described shutdown mute circuit; The output of described AC power testing circuit connects the anode of first diode on the one hand, and links to each other with the positive pole of described storage capacitor and the emitter of positive-negative-positive triode respectively by the negative electrode of first diode; The anode that connects second diode on the other hand, the negative electrode of described second diode connects the base stage of described positive-negative-positive triode, and by the bleed off grounding through resistance; The collector electrode of described positive-negative-positive triode connects the quiet pin of described power amplifier.
5, according to each described switching on and shutting down squelch circuit in the claim 1 to 4, it is characterized in that: in described AC power testing circuit, include a switching circuit, the control end of described switching circuit connects described ac power input end by bleeder circuit, current rectifying and wave filtering circuit successively, according to its on off state output high level or low level index signal.
6, switching on and shutting down squelch circuit according to claim 5, it is characterized in that: in described switching circuit, include a thyristor and an optocoupler, the control end of described thyristor connects ac power input end by described bleeder circuit, current rectifying and wave filtering circuit successively, plus earth, negative electrode connect the negative electrode of light-emitting diode in the described optocoupler; The anode of described light-emitting diode connects DC power supply, and the collector electrode of illuminated triode connects DC power supply, and emitter connects described muting control circuit.
7, switching on and shutting down squelch circuit according to claim 6 is characterized in that: described DC power supply is voltage or standby voltage by described bleeder circuit output.
8, a kind of television set comprises ac power input end, power amplifier and switching on and shutting down squelch circuit; It is characterized in that: in described squelch circuit, include an AC power testing circuit and a muting control circuit; Described AC power testing circuit to the AC power that inserts by described ac power input end power on and power-down state detects, and then generate index signal and transfer to described muting control circuit; The state of the index signal that described muting control circuit basis receives generates quiet control signal and exports described power amplifier to, and is quiet when AC power powers on power down to control described power amplifier.
9, television set according to claim 8 is characterized in that: include a turn-on muting circuit and a shutdown mute circuit in described muting control circuit; Wherein, in described turn-on muting circuit, include a storage capacitor and a switching diode, the positive pole of described storage capacitor connects the output of described AC power testing circuit, negative pole passes through grounding through resistance on the one hand, the anode that connects described switching diode on the other hand, the negative electrode of described switching diode connects the quiet pin of power amplifier; In described shutdown mute circuit, include a positive-negative-positive triode, storage capacitor and two diodes; The output of described AC power testing circuit connects the anode of first diode on the one hand, and links to each other with the positive pole of described storage capacitor and the emitter of positive-negative-positive triode respectively by the negative electrode of first diode; The anode that connects second diode on the other hand, the negative electrode of described second diode connects the base stage of described positive-negative-positive triode, and by the bleed off grounding through resistance; The collector electrode of described positive-negative-positive triode connects the quiet pin of described power amplifier.
10, according to Claim 8 or 9 described television sets, it is characterized in that: in described AC power testing circuit, include a thyristor and an optocoupler, the control end of described thyristor connects described ac power input end by bleeder circuit, current rectifying and wave filtering circuit successively, plus earth, negative electrode connect the negative electrode of light-emitting diode in the described optocoupler; The anode of described light-emitting diode connects DC power supply, and the collector electrode of illuminated triode connects DC power supply, and emitter connects described muting control circuit; Described DC power supply is voltage or standby voltage by described bleeder circuit output.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008202252100U CN201282521Y (en) | 2008-11-04 | 2008-11-04 | Silent circuit for opening/closing computer and television set with the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008202252100U CN201282521Y (en) | 2008-11-04 | 2008-11-04 | Silent circuit for opening/closing computer and television set with the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201282521Y true CN201282521Y (en) | 2009-07-29 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2008202252100U Expired - Fee Related CN201282521Y (en) | 2008-11-04 | 2008-11-04 | Silent circuit for opening/closing computer and television set with the same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201282521Y (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101707477A (en) * | 2009-10-23 | 2010-05-12 | 深圳创维－Rgb电子有限公司 | Circuit for eliminating impact sound generated in switching process |
| CN101998734A (en) * | 2009-08-21 | 2011-03-30 | 东芝照明技术株式会社 | Lighting circuit and illumination 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 |
| CN110942747A (en) * | 2018-09-25 | 2020-03-31 | 青岛海信电器股份有限公司 | OLED display device and control method thereof |
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2008
- 2008-11-04 CN CNU2008202252100U patent/CN201282521Y/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101998734A (en) * | 2009-08-21 | 2011-03-30 | 东芝照明技术株式会社 | Lighting circuit and illumination device |
| US8427070B2 (en) | 2009-08-21 | 2013-04-23 | Toshiba Lighting & Technology Corporation | Lighting circuit and illumination device |
| CN101998734B (en) * | 2009-08-21 | 2014-12-24 | 东芝照明技术株式会社 | Lighting circuit and illumination device |
| CN101707477A (en) * | 2009-10-23 | 2010-05-12 | 深圳创维－Rgb电子有限公司 | Circuit for eliminating impact sound generated in switching process |
| CN101707477B (en) * | 2009-10-23 | 2013-09-25 | 深圳创维－Rgb电子有限公司 | Circuit for eliminating impact sound generated in switching process |
| 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 |
| 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 |
| CN110942747A (en) * | 2018-09-25 | 2020-03-31 | 青岛海信电器股份有限公司 | OLED display device and control method thereof |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090729 Termination date: 20111104 |