CN201118792Y

CN201118792Y - A silence control circuit

Info

Publication number: CN201118792Y
Application number: CNU2007202015897U
Authority: CN
Inventors: 焦春生; 卢强
Original assignee: Sichuan Changhong Electric Co Ltd
Current assignee: Sichuan Changhong Electric Co Ltd
Priority date: 2007-12-07
Filing date: 2007-12-07
Publication date: 2008-09-17
Anticipated expiration: 2017-12-07

Abstract

The utility model relates to a silencing control circuit, in particular relates to a silencing control circuit of a television. The utility model discloses the silencing control circuit having the technical proposal that: the silencing control circuit comprises a processor and a power amplification integrated circuit, and is characterized in that a clutter filtering and basic ripple circuit, a circuit control module and a start-up silencing circuit are also included, the clutter filtering and basic ripple circuit is connected with the start-up silencing circuit, the circuit control module is connected with the clutter and basic ripple circuit, the clutter filtering and basic ripple circuit is connected with silencing feet of the power amplification integrated circuit, and the start-up silencing circuit is connected with the processor. The silencing control circuit has the functional effects that the hierarchy of circuits is simple, the functions of start-up/shutdown silencing and normal silencing control are fully realized, only one I/O port resource of the processor is occupied, and the silencing control circuit can be adapted to accompanying sound integrated circuits with or without the STB stand-by energy-saving function.

Description

A kind of muting control circuit

Technical field

The utility model relates to a kind of muting control circuit, particularly the muting control circuit of television set.

Background technology

The power amplification circuit of existing color television set audio frequency processing system has the pin of a quiet controlled function specially, systematic microprocessor detects at software program that colour TV is in that TV changes that platform, TV/AV switch, during the TV no signal condition and during the mute button of user's remote controller, the I/O of microprocessor or A/D terminal will provide high level output, this moment, quiet control pin current potential was adjusted in the low level scope of power amplifier approval, so output of power amplification circuit mute speaker, loud speaker is in mute state, no longer sends any noise; Color television set is exchanging energising or standby to the secondary open state or the AC dump of start or when starting shooting holding state, power supply status transition during stable state and transient state, this moment, interference noise such as Circuits System internal noise will be superimposed upon on the sound channel and after power amplifier integrate circuit amplifies, output to external loud speaker through power amplification circuit, or because voice-grade channel power on and off sequence problem, loud speaker will send big allophone---and be VGA CARD or shutdown noise; If the above sound system design of color television set is bad, loud speaker can send switching sound when TV changes platform, TV/AV switching, or when power amplifier itself is not quiet under mute state, power amplifier can send AC noise or have the sound when alternating-current switch, not only bring acoustically uncomfortable to the user, and might cause the damage of power amplifier integrate circuit, when loud speaker sends big allophone, electric current by loud speaker also can be bigger, might damage the useful life of loud speaker or shortening loud speaker, thereby reduce system reliability.The a plurality of circuit levels of existing numerous traditional silencing systems needs make up to be realized out, quiet and the normal quiet control of shutting down, and parameter complexity, require accurately, number of devices is many, the general power amplifier of wanting earlier of numerous prior aries to the power amplifier integrate circuit that possesses the STB idle function enters well all the quiet controls of realization of STB pattern, be to increase the STB control circuit separately on the circuit level, cause control circuit level complexity, and an I/O mouth that will take system processor in addition carries out STB control, cause the higher and I/O mouth wasting of resources of system cost, simultaneously, a large amount of practical applications are because I/O mouth resource-constrained, for avoiding too much using the I/O mouth resource or the quiet state of a control switch technology of the taking into account system difficulty problem of processor, take the not quiet control measure of power amplifier, and to carrying out quiet in the audio processing section of audio system, therefore cause power amplifier integrate circuit to still have dc noise to exist when quiet in system, this type of method for designing of while, poor anti jamming capability, as easy as rolling off a log audio frequency discrepancy place at audio processing back segment and power amplifier leading portion seals in other high-frequency pulse signals of system and disturbs, tangible howling appears in dither interference signal loud speaker after power amplification circuit amplifies easily, influences the test of user's auditory effect and acoustics noiseproof feature.

The utility model content

The purpose of this utility model is to overcome the shortcoming that above-mentioned existing muting control circuit exists, and provides a kind of circuit level very simply and only to take the muting control circuit that I/O mouth of processor just can be realized purpose.

The utility model solves its technical problem, the technical scheme that adopts is, a kind of muting control circuit, comprise processor and power amplification circuit, it is characterized in that, also comprise clutter filtering and basic ripple circuit, circuit control module and turn-on muting circuit, described clutter filtering is connected with the turn-on muting circuit with basic ripple circuit, described circuit control module is connected with basic ripple circuit with clutter, described clutter filtering is connected with the quiet pin of power amplification circuit with basic ripple circuit, and described turn-on muting circuit is connected with processor.

The beneficial effects of the utility model are, the circuit level is very simple, on function, realized the quiet and normal quiet control of open and close machine fully, performance is highly stable reliable, less demanding being easy to of parameter redundancy disposed, rationally take an I/O mouth resource of processor, and adapt to the sound accompaniment integrated circuit that has STB stand-by energy-saving function and do not possess STB stand-by energy-saving function fully.

Description of drawings

Fig. 1 is the block diagram of embodiment;

Fig. 2 is the circuit diagram of embodiment.

Embodiment

Below in conjunction with drawings and Examples, describe the technical solution of the utility model in detail.

The utility model cooperates common triode, diode with less passive device, has realized the quiet and normal quiet control of open and close machine on function fully.

Embodiment

This example is with clutter filtering and basic ripple circuit, turn-on muting circuit, circuit control module and processor and power amplification circuit composition, processor is connected with the turn-on muting circuit, the turn-on muting circuit is connected with basic ripple circuit and circuit control module with the clutter filtering, clutter leaches with basic ripple circuit and is connected with power amplification circuit, its block diagram such as Fig. 1, circuit diagram such as Fig. 2.

Clutter filtering and basic ripple circuit comprise Leaded Ceramic Disc Capacitor C1, electrochemical capacitor C2, resistance R 4 and diode D1, wherein, Leaded Ceramic Disc Capacitor C1 one end is connected with the quiet pin of power amplification circuit, the other end is connected with ground wire, electrochemical capacitor C2 is anodal to be connected with the quiet pin of power amplification circuit, other end ground connection, resistance R 4 one ends are connected with the quiet pin of power amplification circuit, the other end is connected with circuit control module and turn-on muting circuit, diode D1 is in parallel with resistance R 4, and diode D1 is anodal to be connected with the quiet pin of power amplification circuit, and negative pole is connected with circuit control module and turn-on muting circuit;

The circuit control module comprises DC power supply VCC2, NPN type triode Q2, positive-negative-positive triode Q3, resistance R 5, resistance R 6, resistance R 7, resistance R 8, storage capacitor C3, diode D2 and voltage stabilizing didoe D3, wherein, the collector electrode of NPN type triode Q2 is connected with basic ripple circuit with above-mentioned clutter filtering, base stage is connected with common ground by resistance R 5, emitter is connected with common ground, resistance R 6 one ends are connected with NPN type triode Q2 base stage, the other end is connected with positive-negative-positive triode Q3 collector electrode, positive-negative-positive triode Q3 base stage is connected with DC power supply VCC2 by resistance R 7, the negative pole of diode D2 is connected with the emitter of positive-negative-positive triode Q3, positive pole is connected with the positive pole of voltage stabilizing didoe D3, voltage stabilizing didoe D3 negative pole is connected with positive-negative-positive triode Q3 base stage, storage capacitor C3 is anodal to be connected with positive-negative-positive triode Q3 emitter, negative pole is connected with common ground, resistance R 8 one ends are connected with voltage stabilizing didoe D3 positive pole and diode D2 positive pole, and the other end is connected with common ground.

The turn-on muting circuit comprises resistance R 1, resistance R 2, resistance R 3, triode Q1 and DC power supply VCC1, wherein resistance R 1 one ends are connected with I/O mouth or the A/D mouth that processor can be exported high-low level, the other end is connected with triode Q1 base stage, triode Q1 emitter be connected publicly, collector electrode is connected with resistance R 2 one ends, resistance R 2 other ends are connected with resistance R 3 one ends and are connected with basic ripple circuit with foregoing circuit control module and clutter filtering, and resistance R 3 other ends are connected with DC power supply VCC1.

When exchanging start and system energising operate as normal, DC power supply VCC2 positive voltage rises to stable state by zero volt, this moment is by after resistance R 7 current limlitings, voltage stabilizing didoe D3 reverse breakdown, DC power supply VCC2 charges to storage capacitor C3 fast by diode D2 after voltage stabilizing didoe D3 step-down, the anodal direct voltage of C3 is lied prostrate to the stable state transition by transient state zero, steady state voltage after the storage capacitor C3 charging is poor less than the voltage stabilizing value of positive direct-current power supply VCC2 and voltage stabilizing didoe D3, positive-negative-positive triode Q3 is in by state owing to base voltage is higher than emitter voltage, because positive-negative-positive triode Q3 collector electrode output current is zero, so the base stage of NPN type triode Q2 is a low level, therefore also be in by state, the collector electrode of NPN type triode Q2 does not influence the normal operating conditions of turn-on muting circuit and power amplification circuit to being high-impedance state between the ground wire.When ac dump or system standby, direct voltage VCC1, VCC2 voltage is discharged into the transient state transition period of zero volt rapidly, the electric charge that is filled on the storage capacitor C3 can not discharge by diode D2, voltage on the storage capacitor C3 becomes the supply power voltage of positive-negative-positive triode Q3, this moment, the base voltage of positive-negative-positive triode Q3 was lower than emitter voltage, positive-negative-positive triode Q3 saturation conduction, the electric current of the collector electrode output of positive-negative-positive triode Q3 is through resistance R 6, R5 forms the base bias of NPN type triode Q2, when resistance R 5 terminal voltages during greater than 0.7 volt (when NPN type triode Q2 is silicon type triode) or 0.3 volt (when NPN type triode Q2 is germanium type triode), NPN type triode Q2 saturation conduction, it between its collector and emitter Low ESR, diode D1 since the terminal voltage difference greater than 0.7 volt forward conduction, electric charge on the electrochemical capacitor C2 discharges to carry out the RC mode publicly by the very low diode D1 of impedance rapidly, when electrochemical capacitor C2 terminal voltage is reduced to the low level of power amplification circuit approval rapidly, power amplification circuit enters quiet state of a control, system reaches the shutdown mute function, has eliminated shutdown abnormal sound problem effectively.

When the moment that exchanges energising, the quiet I/O mouth of processor or A/D port are prior to the preceding output of DC power supply VCC1 energising high level pulse, after isolating, resistance R 1 makes switch triode Q1 saturation conduction, resistance R 2 connects an end of triode Q1 collector electrode because the conducting of triode Q1 is equivalent to be directly connected to common ground, this moment, resistance R 2 and R3 carried out dividing potential drop to the direct voltage VCC1 that the energising sequential postpones a little, the terminal voltage of resistance R 2 offers power amplification circuit after resistance R 4 current limliting step-downs DC level is identified as the low level of mute state by power amplification circuit, power amplification circuit enters mute state and cuts off loud speaker output, realizes turn-on muting; When system carries out that channel changes platform or during by quiet key of remote controller etc., the I/O mouth of processor or A/D mouth output high level pulse, because triode Q1 base stage is a high level, triode Q1 saturation conduction then, resistance R 2 and R3 carry out dividing potential drop for DC power supply VCC1, the terminal voltage of R2 offers power amplification circuit after the step-down of R4 current limliting DC level is put the low level that amplification circuit is identified as mute state by power, power amplification circuit enters mute state and cuts off loud speaker output, realizes changing platform or quiet by the quiet bonded state of remote controller.

Claims

1. muting control circuit, comprise processor and power amplification circuit, it is characterized in that, also comprise clutter filtering and basic ripple circuit, circuit control module and turn-on muting circuit, described clutter filtering is connected with the turn-on muting circuit with basic ripple circuit, described circuit control module is connected with basic ripple circuit with clutter, and described clutter filtering is connected with the quiet pin of power amplification circuit with basic ripple circuit, and described turn-on muting circuit is connected with processor.

2. according to the described a kind of muting control circuit of claim 1, it is characterized in that, described clutter filtering and basic ripple circuit comprise Leaded Ceramic Disc Capacitor (C1), electrochemical capacitor (C2), the 4th resistance (R4) and first diode (D1), described Leaded Ceramic Disc Capacitor (C1) end is connected with the quiet pin of power amplification circuit, the other end is connected with common ground, described electrochemical capacitor (C2) is anodal to be connected with the quiet pin of power amplification circuit, the other end is connected with Leaded Ceramic Disc Capacitor (C1) earth terminal, described the 4th resistance (R4) end is connected with the quiet pin of power amplification circuit, the other end is connected with circuit control module and turn-on muting circuit, described first diode (D1) is in parallel with the 4th resistance (R4), and first diode (D1) is anodal to be connected with the quiet pin of power amplification circuit, and negative pole is connected with circuit control module and turn-on muting circuit.

3. according to the described a kind of muting control circuit of claim 2, it is characterized in that, described circuit control module comprises second DC power supply (VCC2), NPN type triode (Q2), positive-negative-positive triode (Q3), the 5th resistance (R5), the 6th resistance (R6), the 7th resistance (R7), the 8th resistance (R8), storage capacitor (C3), second diode (D2) and voltage stabilizing didoe (D3), the collector electrode of described NPN type triode (Q2) is connected with basic ripple circuit with described clutter filtering, base stage is connected with common ground by the 5th resistance (R5), emitter is connected with common ground, described the 6th resistance (R6) end is connected with NPN type triode (Q2) base stage, the other end is connected with positive-negative-positive triode (Q3) collector electrode, described positive-negative-positive triode (Q3) base stage is connected with second DC power supply (VCC2) by the 7th resistance (R7), the negative pole of described second diode (D2) is connected with the emitter of positive-negative-positive triode (Q3), positive pole is connected with the positive pole of voltage stabilizing didoe (D3), described voltage stabilizing didoe (D3) negative pole is connected with positive-negative-positive triode (Q3) base stage, described storage capacitor (C3) is anodal to be connected with positive-negative-positive triode (Q3) emitter, negative pole is connected with common ground, the 8th resistance (R8) end is anodal with voltage stabilizing didoe (D3) and second diode (D2) is anodal is connected, and the other end is connected with common ground.

4. according to the described a kind of muting control circuit of claim 3, it is characterized in that, described turn-on muting circuit comprises first resistance (R1), second resistance (R2), the 3rd resistance (R3), triode (Q1) and first DC power supply (VCC1), described first resistance (R1) end is connected with I/O mouth or A/D mouth that processor can be exported high-low level, the other end is connected with triode (Q1) base stage, described triode (Q1) emitter be connected publicly, collector electrode is connected with second resistance (R2) end, second resistance (R2) other end is connected with the 3rd resistance (R3) end and is connected with basic ripple circuit with described circuit control module and clutter filtering, and the 3rd resistance (R3) other end is connected with first DC power supply (VCC1).