CN101924970A - Circuit for eliminating earphone plosion of liquid crystal display television - Google Patents
Circuit for eliminating earphone plosion of liquid crystal display television Download PDFInfo
- Publication number
- CN101924970A CN101924970A CN2010101926894A CN201010192689A CN101924970A CN 101924970 A CN101924970 A CN 101924970A CN 2010101926894 A CN2010101926894 A CN 2010101926894A CN 201010192689 A CN201010192689 A CN 201010192689A CN 101924970 A CN101924970 A CN 101924970A
- Authority
- CN
- China
- Prior art keywords
- earphone
- switch unit
- current switch
- liquid crystal
- plosion
- 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.)
- Pending
Links
Images
Abstract
The invention discloses a circuit for eliminating the earphone plosion of a liquid crystal display television, which comprises a power supply VCC, a current switch unit, a linear control unit and an earphone power amplifying and energy storing capacitor C, wherein the current switch unit and the linear control unit are respectively connected with the power supply VCC; the earphone power amplifying and energy storing capacitor C is connected with the current switch unit; the control unit is used for outputting a linear control signal VK to the current switch unit; the current switch unit is used for outputting voltage VCC1 under the action of the linear control signal VK for supplying power for earphone power amplification; and the energy storing capacitor C is used for storing the voltage VCC1 and slowly changing the voltage VCC1 while turning on and off by alternating current for eliminating the earphone plosion. The invention has simple structure, low cost and high reliability and can effectively solve the problem of plosion of the liquid crystal display television, which is generated while turning on and off by alternating current.
Description
Technical field
The invention belongs to the liquid crystal tv technology field, relate in particular to a kind of circuit of eliminating earphone plosion of liquid crystal display television.
Background technology
At present, most of LCD TV all has earphone, and especially earphone has become a basic output function concerning the LCD TV below 32 cun.Because the audio signal of LCD TV earphone is generally by coupling capacitance output, therefore earphone power amplifier power supply transient change will produce a very big peak current when exchanging start and ac dump.When the peak current of this output passes through earphone, will produce a very big plosive, this has had a strong impact on the overall image and the performance of LCD TV product.The method that prior art solves earphone plosion of liquid crystal display television mainly is to adopt negative and positive dual power to give the power supply of earphone power amplifier, perhaps the output of earphone power amplifier is handled, so that delay or cuts off earphone and export in the moment that exchanges startup and shutdown.Yet all there is the cost height in these methods, handles defectives such as complexity and poor reliability.So be necessary to research and develop, a kind of cost is low, simple in structure to provide, reliability is high, can effectively solve the plosive scheme that produces when liquid crystal TV set exchanges startup and shutdown.
Summary of the invention
The purpose of the embodiment of the invention is to provide a kind of circuit of eliminating earphone plosion of liquid crystal display television.
The embodiment of the invention is to realize like this, a kind of circuit of eliminating earphone plosion of liquid crystal display television, include power supply VCC, current switch unit that is connected with power supply VCC and Linear Control unit respectively, and the earphone power amplifier and the storage capacitor C that connect the current switch unit, wherein control unit output linear control signal VK is to the current switch unit, current switch unit output voltage V CC1 under the effect of linear control signal VK is the power supply of earphone power amplifier, storage capacitor C is used for storage voltage VCC1, and voltage VCC1 is slowly changed to eliminate earphone plosion.
Compared to prior art, the circuit structure that the present invention eliminates earphone plosion of liquid crystal display television is simple, cost is low, reliability is high, can effectively solve the plosive that produces when liquid crystal TV set exchanges startup and shutdown.
Description of drawings
Fig. 1 is a theory diagram of the present invention.
Fig. 2 is circuit theory diagrams of the present invention.
Embodiment
In order to make purpose of the present invention, technical scheme and advantage clearer,, the present invention is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.
With reference to shown in Figure 1, the present invention eliminates the circuit of earphone plosion of liquid crystal display television, the current switch unit that include power supply VCC, is connected respectively with power supply VCC and Linear Control unit and the earphone power amplifier and the storage capacitor C that are connected the current switch unit.Wherein, control unit output linear control signal VK is to the current switch unit, current switch unit output voltage V CC1 under the effect of linear control signal VK is the power supply of earphone power amplifier, storage capacitor C is used for storage voltage VCC1, and VCC1 is slowly changed to eliminate earphone plosion.When LCD TV exchanged start, power supply provided voltage VCC, and this voltage is exported to Linear Control unit and current switch unit respectively.VK was controlled in the output of Linear Control unit after VCC imported linear control unit, and the amplitude of this signal descended linearity after start a period of time.Conducting is until saturation conduction gradually under the control of VK in the current switch unit, and VCC makes linear gradually the rising until remaining unchanged of voltage VCC1 of output to storage capacitor C charging in this process.VCC1 is the power supply of earphone power amplifier, owing to the not sudden change of VCC1 voltage, has effectively avoided exchanging the plosive of start moment generation.During the LCD TV ac dump, the current switch unit is closed, and provides VCC1 to the power supply of earphone power amplifier by storage capacitor C, and VCC1 descends gradually, has effectively avoided the plosive of ac dump moment generation.
Fig. 2 eliminates the circuit theory diagrams of earphone plosion of liquid crystal display television circuit for the present invention, wherein, the 6th capacitor C 6 that described Linear Control unit includes the 3rd diode D3 that is connected in parallel in together and the 7th resistance R 7 and is connected power supply VCC, R7 is the thermistor of negative temperature coefficient.The triode Q3 that described current switch unit includes the second diode D2, the 8th resistance R 8 that is connected with the second diode D2 and connects the 8th resistance R 8, described triode Q3 is the positive-negative-positive triode, the emitter of triode Q3 connects power supply VCC, base stage is connected with the 8th resistance R 8, and collector electrode output voltage V CC1 is to the earphone power amplifier.
It is instantaneous that LCD TV exchanges start, power supply output voltage V CC, because the electric capacity both end voltage can not be suddenlyd change, the pressure drop at the 6th capacitor C 6 two ends is 0, and the magnitude of voltage of control signal VK is VCC.Voltage is VCC to the emitter (the E utmost point) of triode Q3 at this moment, and the magnitude of voltage of VK is VCC, and triode Q3 ends, and does not have electric current to flow out from the collector electrode (the C utmost point) of triode Q3, and the magnitude of voltage of VCC1 is 0.After the LCD TV start, the 6th capacitor C 6 begins charging by the 7th resistance R 7, and the magnitude of voltage of VK descends gradually; And the 7th resistance R 7 is the thermistor of negative temperature coefficient, and its resistance value will reduce gradually, and the 6th capacitor C 6 charging rates are accelerated, and the magnitude of voltage of VK almost is linear decline.The magnitude of voltage of VK drops to VCC-UD2-UEB, and (wherein UD2 is the conduction voltage drop of the second diode D2, UEB is the conduction voltage drop of triode Q3) time, the triode Q3 and the second diode D2 conducting, VCC begins the charging to storage capacitor C by triode Q3, and the voltage of VCC1 rises gradually.Because the magnitude of voltage of VK almost is linear decline, the electric current of the E of triode Q3, C interpolar almost is linear increasing, and the pressure drop of the E of triode Q3, C interpolar almost is linear decline, and VCC1 almost is linear the rising.VK drops to certain voltage value after the 6th resistance C6 charging a period of time, triode Q3 saturation conduction, and the pressure drop of the E of triode Q3, C interpolar is basicly stable, and VCC1 is basicly stable.The no longer influence of suspension control signal VK of the pressure drop of its E, C interpolar behind the triode Q3 saturation conduction, VCC1 is the normal working voltage of earphone power amplifier.Because the supply power voltage VCC1 of earphone power amplifier suddenly change, thus the earphone plosion when effectively having avoided LCD TV to exchange start, and VCC1 is linear rising simultaneously, has reduced the stabilization time of VCC1, has effectively shortened the start-up time of earphone power amplifier.
The LCD TV ac dump is instantaneous, power supply output voltage V CC is 0, the 6th capacitor C 6 is discharged rapidly by the 3rd diode D3, the 3rd diode D3 with the magnitude of voltage clamper of VK be diode turn-on voltage negative value (UD3), triode Q3 ends, storage capacitor C provides power supply for the earphone power amplifier and discharges gradually by the earphone power amplifier, has avoided earphone power amplifier supply power voltage VCC1 moment to suddenly change the earphone plosion when effectively having eliminated the LCD TV ac dump.
The above only is preferred embodiment of the present invention, not in order to restriction the present invention, all any modifications of being done within the spirit and principles in the present invention, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.
Claims (4)
1. circuit of eliminating earphone plosion of liquid crystal display television, include power supply VCC, and earphone power amplifier, it is characterized in that: also include the current switch unit and the Linear Control unit that are connected with power supply VCC respectively, and the storage capacitor (C) that connects the current switch unit, wherein control unit output linear control signal VK is to the current switch unit, current switch unit output voltage V CC1 under the effect of linear control signal VK is the power supply of earphone power amplifier, storage capacitor (C) is used for storage voltage VCC1, and voltage VCC1 is slowly changed to eliminate earphone plosion.
2. eliminate the circuit of earphone plosion of liquid crystal display television according to claim 1, it is characterized in that: the 6th electric capacity (C6) that described Linear Control unit includes the 3rd diode (D3) that is connected in parallel in together and the 7th resistance (R7) and is connected power supply VCC; Described the 7th resistance (R7) is the thermistor of negative temperature coefficient.
3. as the circuit of elimination earphone plosion of liquid crystal display television as described in the claim 2, it is characterized in that: the triode (Q3) that described current switch unit includes second diode (D2), the 8th resistance (R8) that is connected with second diode (D2) and connects the 8th resistance (R8).
4. as the circuit of elimination earphone plosion of liquid crystal display television as described in the claim 3, it is characterized in that: described triode (Q3) is the positive-negative-positive triode, the emitter of triode (Q3) connects power supply VCC, and base stage is connected with the 8th resistance (R8), and collector electrode output voltage V CC1 is to the earphone power amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010101926894A CN101924970A (en) | 2010-06-04 | 2010-06-04 | Circuit for eliminating earphone plosion of liquid crystal display television |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010101926894A CN101924970A (en) | 2010-06-04 | 2010-06-04 | Circuit for eliminating earphone plosion of liquid crystal display television |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101924970A true CN101924970A (en) | 2010-12-22 |
Family
ID=43339560
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010101926894A Pending CN101924970A (en) | 2010-06-04 | 2010-06-04 | Circuit for eliminating earphone plosion of liquid crystal display television |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101924970A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102572643A (en) * | 2010-12-29 | 2012-07-11 | 佛山普立华科技有限公司 | Plosive eliminating circuit |
| CN102769729A (en) * | 2012-06-21 | 2012-11-07 | 深圳创维－Rgb电子有限公司 | Television and audio external play control circuit thereof |
| CN114125660A (en) * | 2021-11-23 | 2022-03-01 | 深圳市长丰影像器材有限公司 | Audio system for eliminating startup plosive and power supply control method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5043637A (en) * | 1990-12-14 | 1991-08-27 | Thomson Consumer Electronics, Inc. | Transformer coupled voltage clamp for pincushion correction circuit |
| CN200962639Y (en) * | 2006-10-22 | 2007-10-17 | 青岛海信电器股份有限公司 | TV set standby low power consumption circuit |
| CN201001104Y (en) * | 2007-01-12 | 2008-01-02 | 深圳创维－Rgb电子有限公司 | Impact sound preventing circuit |
-
2010
- 2010-06-04 CN CN2010101926894A patent/CN101924970A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5043637A (en) * | 1990-12-14 | 1991-08-27 | Thomson Consumer Electronics, Inc. | Transformer coupled voltage clamp for pincushion correction circuit |
| CN200962639Y (en) * | 2006-10-22 | 2007-10-17 | 青岛海信电器股份有限公司 | TV set standby low power consumption circuit |
| CN201001104Y (en) * | 2007-01-12 | 2008-01-02 | 深圳创维－Rgb电子有限公司 | Impact sound preventing circuit |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102572643A (en) * | 2010-12-29 | 2012-07-11 | 佛山普立华科技有限公司 | Plosive eliminating circuit |
| CN102572643B (en) * | 2010-12-29 | 2014-03-05 | 佛山普立华科技有限公司 | Plosive eliminating circuit |
| CN102769729A (en) * | 2012-06-21 | 2012-11-07 | 深圳创维－Rgb电子有限公司 | Television and audio external play control circuit thereof |
| CN102769729B (en) * | 2012-06-21 | 2014-08-13 | 深圳创维－Rgb电子有限公司 | Television and audio external play control circuit thereof |
| CN114125660A (en) * | 2021-11-23 | 2022-03-01 | 深圳市长丰影像器材有限公司 | Audio system for eliminating startup plosive and power supply control method |
| CN114125660B (en) * | 2021-11-23 | 2023-08-15 | 深圳市长丰影像器材有限公司 | Audio system for eliminating startup plosive and power supply control method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN201274406Y (en) | Overheat protection circuit and electric power system | |
| CN202586329U (en) | Self-discharge circuit | |
| CN201629569U (en) | Over-voltage protection circuit of USB interface | |
| CN101924970A (en) | Circuit for eliminating earphone plosion of liquid crystal display television | |
| CN101685961B (en) | Power supply circuit of audio frequency power amplifier | |
| CN103312166A (en) | Power management circuit and electronic device | |
| CN202014197U (en) | USB power source management device and USB loudspeaker system | |
| CN101789765A (en) | Low power consumption high efficiency operational amplifier circuit and operating method thereof | |
| CN101599756A (en) | A kind of high voltage fast electronic switch device | |
| CN208369280U (en) | A kind of lithium battery protection circuit | |
| CN202652374U (en) | Television and mute auxiliary control circuit thereof | |
| CN206332606U (en) | FET drive circuit | |
| CN103475205A (en) | Protective circuit | |
| CN202496002U (en) | Audio signal outputting and processing circuit and television | |
| CN203026929U (en) | Spark limiting device of intrinsically safe power supply | |
| CN102201791B (en) | AB-class audio amplifier power protector | |
| CN201639752U (en) | Voice control device of AV (audio and video) output and player | |
| CN206834739U (en) | A kind of vehicle-mounted cloud mirror for preventing instantaneous pressure from impacting | |
| CN204065896U (en) | A kind of mu balanced circuit | |
| CN204886132U (en) | Prevent voltage pulse circuit | |
| CN104639057A (en) | Audio amplification circuit provided with simple structure and used for computer | |
| CN104660231A (en) | Loudspeaker protection circuit of active sound box | |
| CN101453658B (en) | Degaussing control circuit, degaussing control apparatus and television set | |
| CN209402715U (en) | A kind of audio power amplifier circuit | |
| CN218240761U (en) | Current-expanding voltage stabilizing circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20101222 |