CN201185406Y - Circuit and electronic device for eliminating impulsive sound of starting up an audio power amplifier - Google Patents
Circuit and electronic device for eliminating impulsive sound of starting up an audio power amplifier Download PDFInfo
- Publication number
- CN201185406Y CN201185406Y CNU2008200934529U CN200820093452U CN201185406Y CN 201185406 Y CN201185406 Y CN 201185406Y CN U2008200934529 U CNU2008200934529 U CN U2008200934529U CN 200820093452 U CN200820093452 U CN 200820093452U CN 201185406 Y CN201185406 Y CN 201185406Y
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- circuit
- current switch
- resistor
- control
- power amplifier
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Abstract
The utility model discloses a circuit to eliminate the starting impact sound of an audio amplifier, which consists of a charging delay circuit, a high-current switch, an electronic switch and a control unit, wherein, the charging delay circuit consists of a resistor and a capacitor, the resistor is connected in series between a power source output terminal and a power source input terminal of the audio amplifier circuit; the high-current switch is connected with the resistor; the electronic switch is used to control the high-current switch and is connected with a control terminal of the high-current switch; the control unit is used to send out control signals at the time of starting to make the electronic switch to control the disconnection of the high-current switch and, after the delay time predetermined by the charging delay circuit, send out control signals to make the electronic switch to control the connection of the high-current switch. The utility model also discloses an electronic device. The utility model has the advantages of simple structure and lower cost, and is widely applicable to audio amplifier circuits of various electronic devices.
Description
Technical field
The utility model relates to noise suppression circuit, and relate in particular to a kind of delay circuit that adopts and eliminate audio frequency power amplifier produces impulsive sound when start circuit, and the electronic equipment with this circuit.
Background technology
At product scopes such as television set, DVD and sound equipments, generally adopt the audio power amplifier circuit of AC coupled output, and external loudspeaker comes output sound.In the moment of start, audio power amplifier circuit produces AC coupled during owing to start, and electrochemical capacitor quick charge is wherein sent impulsive sound by loud speaker easily.Simultaneously, the available circuit complex structure, cost is higher, therefore, is necessary to provide a kind of audio frequency power amplifier produces impulsive sound when start circuit of eliminating.
The utility model content
The purpose of this utility model is to propose a kind of delay circuit that adopts to eliminate audio frequency power amplifier produces impulsive sound when start circuit, and the electronic equipment with this circuit, to solve the technical problem that produces large impact sound when there is start in existing audio frequency power amplifier.
For solving technical problem of the present utility model, the utility model discloses a kind of circuit that is used to eliminate audio frequency power amplifier start impulsive sound, comprising:
The charging delay circuit that constitutes by resistor and capacitor, and resistor is serially connected between the power input of the output of power supply and audio power amplifier circuit;
The high-current switch that is connected in parallel with resistor;
Be used to control the electronic switch of high-current switch, it connects the control end of high-current switch;
Be used for sending control signal when starting shooting electronic switch control high-current switch is disconnected, and through after the time of delay of being scheduled to by the charging delay circuit, send the control unit that control signal makes the conducting of electronic switch control high-current switch, it connects electronic switch.
More excellent, described resistor is the thermistor of negative temperature coefficient.
More excellent, described control unit is MCU.
In addition, the utility model also discloses a kind of electronic equipment, comprising: power supply, audio power amplifier circuit and the loud speaker that is connected the audio power amplifier circuit output; The big electric current of audio power amplifier circuit output is at the circuit of loud speaker generation impulsive sound when being used for eliminating start, and this circuit comprises:
The charging delay circuit that constitutes by resistor and capacitor, and resistor is serially connected between the power input of the output of power supply and audio power amplifier circuit;
The high-current switch that is connected in parallel with resistor;
Be used to control the electronic switch of high-current switch, it connects the control end of high-current switch;
Be used for sending control signal when starting shooting electronic switch control high-current switch is disconnected, and through after the time of delay of being scheduled to by the charging delay circuit, send the control unit that control signal makes the conducting of electronic switch control high-current switch, it connects electronic switch.
Compared with prior art, the utlity model has following beneficial effect:
The utility model is provided with the charging delay circuit that delay voltage rises by the power input at audio power amplifier circuit, and it is also slower that audio power amplifier circuit output direct current is powered on, thereby has eliminated the impulsive sound that loud speaker produces when start.In addition, the utlity model has simple in structure, realize being widely used in lower-cost advantage in the audio power amplifier circuit of various electronic equipments.
Description of drawings
Fig. 1 is the structural representation of a preferred embodiment of the utility model.
Embodiment
Below in conjunction with accompanying drawing the utility model is further described:
As shown in Figure 1, circuit of the present utility model mainly be when being used for eliminating start audio power amplifier circuit 110 because AC coupled and quick charge causes being connected loud speaker with it and sends impulsive sound.Circuit of the present utility model mainly comprises: the charging delay circuit that constitutes by resistor R and capacitor C, and resistor R is serially connected between the power input Vcc2 of the output Vcc1 of power supply 120 and audio power amplifier circuit 110; The high-current switch K that is connected in parallel with resistor R; Be used to control the electronic switch S of high-current switch K, it connects the control end of high-current switch K; Being used for sending when start control signal disconnects electronic switch S control high-current switch K, and through after the time of delay of being scheduled to by the charging delay circuit, send the control unit 130 that control signal makes electronic switch S control high-current switch K conducting, it connects electronic switch S.Wherein, resistor R is the thermistor of negative temperature coefficient, and control unit 130 can adopt MCU to realize.
The output output voltage of power supply 120 is Vcc1, and the voltage that offers audio power amplifier circuit 110 power inputs is Vcc2.Operation principle of the present utility model is as follows:
When start powers on, control unit 130 is by electronic switch S control high-current switch K, make high-current switch K be in off-state, the voltage vcc 2 of audio power amplifier circuit 110 power inputs is owing to capacitor C in the charging delay circuit is in charged state, so the rising of voltage vcc 2 is comparatively slow, thereby it is also comparatively slow that audio power amplifier circuit 110 output direct currents are powered on, so external loud speaker can not produce impulsive sound.Because resistor R is the thermistor of negative temperature coefficient, its resistance is along with the heat that produces on resistor R because of the electric current that flows through resistor R reduces, so after the time of delay of delay circuit self the parameter decision of overcharging, capacitor C charging is finished, at this moment, the size of voltage vcc 2 rises to the size of the output voltage V cc1 of power supply 120, at this moment, send control signal by control unit 130, and, make electric current pass through high-current switch K and flow into by electronic switch S control high-current switch K conducting, audio power amplifier circuit 110 power inputs, the electric current that flows through resistor R is almost 0, makes resistor R cooling, so that circuit is still effective during the next time start.And, make the resistor R short circuit during owing to high-current switch K conducting, also can reduce the power consumption of power supply 120 output voltages on resistor R, thereby reduce the power consumption of entire circuit, improve the fan-out capability of audio frequency power amplifier.
Claims (6)
1, a kind of circuit that is used to eliminate audio frequency power amplifier start impulsive sound is characterized in that, comprising:
The charging delay circuit that constitutes by resistor (R) and capacitor (C), and resistor (R) is serially connected between the power input (Vcc2) of the output (Vcc1) of power supply (120) and audio power amplifier circuit (110);
The high-current switch (K) that is connected in parallel with resistor (R);
Be used to control the electronic switch (S) of high-current switch (K), it connects the control end of high-current switch (K);
Being used for sending when start control signal disconnects electronic switch (S) control high-current switch (K), and through after the time of delay of being scheduled to by the charging delay circuit, send the control unit (130) that control signal makes the conducting of electronic switch (S) control high-current switch (K), it connects electronic switch (S).
2, the circuit that is used to eliminate audio frequency power amplifier start impulsive sound according to claim 1 is characterized in that described resistor (R) is the thermistor of negative temperature coefficient.
3, the circuit that is used to eliminate audio frequency power amplifier start impulsive sound according to claim 1 is characterized in that described control unit (130) is MCU.
4, a kind of electronic equipment comprises: power supply (120), audio power amplifier circuit (110) and the loud speaker that is connected audio power amplifier circuit (110) output; It is characterized in that, also comprise: the big electric current of audio power amplifier circuit (110) output is at the circuit of loud speaker generation impulsive sound when being used for eliminating start, and this circuit comprises:
The charging delay circuit that constitutes by resistor (R) and capacitor (C), and resistor (R) is serially connected between the power input (Vcc2) of the output (Vcc1) of power supply (120) and audio power amplifier circuit (110);
The high-current switch (K) that is connected in parallel with resistor (R);
Be used to control the electronic switch (S) of high-current switch (K), it connects the control end of high-current switch (K);
Being used for sending when start control signal disconnects electronic switch (S) control high-current switch (K), and through after the time of delay of being scheduled to by the charging delay circuit, send the control unit (130) that control signal makes the conducting of electronic switch (S) control high-current switch (K), it connects electronic switch (S).
5, electronic equipment according to claim 4 is characterized in that, described resistor (R) is the thermistor of negative temperature coefficient.
6, electronic equipment according to claim 1 is characterized in that, described control unit (130) is MCU.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008200934529U CN201185406Y (en) | 2008-04-16 | 2008-04-16 | Circuit and electronic device for eliminating impulsive sound of starting up an audio power amplifier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008200934529U CN201185406Y (en) | 2008-04-16 | 2008-04-16 | Circuit and electronic device for eliminating impulsive sound of starting up an audio power amplifier |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201185406Y true CN201185406Y (en) | 2009-01-21 |
Family
ID=40273139
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2008200934529U Expired - Fee Related CN201185406Y (en) | 2008-04-16 | 2008-04-16 | Circuit and electronic device for eliminating impulsive sound of starting up an audio power amplifier |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201185406Y (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105263087A (en) * | 2015-11-18 | 2016-01-20 | 广东威创视讯科技股份有限公司 | Audio output circuit capable of eliminating startup and shutdown impact sound |
-
2008
- 2008-04-16 CN CNU2008200934529U patent/CN201185406Y/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105263087A (en) * | 2015-11-18 | 2016-01-20 | 广东威创视讯科技股份有限公司 | Audio output circuit capable of eliminating startup and shutdown impact sound |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 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: 20090121 Termination date: 20140416 |