CN104270106A - Power amplifier circuit - Google Patents
Power amplifier circuit Download PDFInfo
- Publication number
- CN104270106A CN104270106A CN201410470806.7A CN201410470806A CN104270106A CN 104270106 A CN104270106 A CN 104270106A CN 201410470806 A CN201410470806 A CN 201410470806A CN 104270106 A CN104270106 A CN 104270106A
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- Prior art keywords
- circuit
- power
- board
- power amplifier
- triode
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/52—Circuit arrangements for protecting such amplifiers
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F2200/00—Indexing scheme relating to amplifiers
- H03F2200/447—Indexing scheme relating to amplifiers the amplifier being protected to temperature influence
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Amplifiers (AREA)
Abstract
A power amplifier circuit comprises an input board, a left power amplifier board, a right power amplifier board, a power supply board and an indicator lamp board; the input board is connected with the left power amplifier board and the right power amplifier board; signals are displayed on the left power amplifier board and the right power amplifier board through the indicator lamp board; the power supply board is used for supplying power for the input board, the left power amplifier board, the right power amplifier board and the indicator lamp board. The voltage of two ends of a power amplifier board emitter resistor is detected through the power supply board so as to determine whether the power amplifier boards are located in the dangerous state or not and the power supply of a power cuts off through a burning machine protection circuit so as to prevent the burn-in of power amplification. Multiple circuits with the protection function, such as a pressure limiting circuit, an over-current protection circuit, a direct current circuit protection, an over temperature protection circuit and a power reduction circuit are adopted in each power amplifier board and accordingly the effective protection is performed on a power amplifier main board so as to prevent the burn-in of the power amplifier main board.
Description
Technical field
The present invention relates to power amplifier.
Background technology
Audio frequency amplifier is widely used in home theater, sound system, stereo record-player, servo amplifier isoelectronic series system.People, while pursuit hi-fi audio power amplifier, also wish that power amplifier has large power output and high efficiency.Powerful audio frequency power amplifier output current is all greater than 1A, and power is larger, and output current is also larger.When there being big current to flow through power output pipe for a long time, when especially there is output short-circuit, power output pipe can be made to burn out.Therefore current foldback circuit must be had, restriction maximum output current, protection efferent duct.Secondly under different voltage condition, the maximum output current ability of efferent duct is also different, if only limiting efferent duct electric current is a specific electric current, then when mains voltage variations, even if there is current-limiting protection circuit, power output pipe also likely burns out.Therefore power amplifier efferent duct not only needs overcurrent protection also to need under different voltage, and the electric current of this protection also will change.Therefore we are power defencive function at the protecting circuit designed of efferent duct, and namely when supply voltage height, protective current reduces; When power electric is forced down, protective current increases, and ensures that power output pipe is not burned with this.Current power board lacks effective protective circuit.
Summary of the invention
Technical problem to be solved by this invention is to provide a kind of power amplifier, has multinomial defencive function, prevents power amplifier generation burning machine phenomenon.
For solving the problems of the technologies described above, technical scheme of the present invention is: a kind of power amplifier, comprise tablet, left power board, right power board, power panel and LED Unit, described tablet is connected with left power board and right power board respectively, described left power board and right power board are by described LED Unit display, and described power panel is powered to tablet, left power board, right power board and LED Unit;
Described tablet comprises the input branch road of left power board and the input branch road of right power board; Described left power amplifier input branch road comprises the first buffer, the first filtering regulating circuit, the first sensitivity adjusting circuit, the first pressure ration the power supply road; The output of described first buffer is connected with the first filtering regulating circuit, the output of described first filtering regulating circuit is connected with the first sensitivity adjusting circuit, the output of described first sensitivity adjusting circuit is connected with left power board, and described first presses road of rationing the power supply to be connected with the first sensitivity adjusting circuit; Described right power amplifier input branch road comprises the second buffer, the second filtering regulating circuit, the second sensitivity adjusting circuit, the second pressure ration the power supply road, the output of described second buffer is connected with the second filtering regulating circuit, the output of described second filtering regulating circuit is connected with the second sensitivity adjusting circuit, the output of described second sensitivity adjusting circuit is connected with right power board, and described second presses road of rationing the power supply to be connected with the second sensitivity adjusting circuit; Described left power amplifier input branch road is connected with mode selector switch with the output of right power amplifier input branch road;
Described power panel comprises power supply branch road and detection branch, described power supply branch road comprises transforming circuit, rectification circuit and filter circuit, and external power source signal is successively by supplying left power board, right power board and tablet after transforming circuit, rectification circuit, filter circuit; Described detection branch comprises soft starting circuit, burns machine protective circuit, and outside 220V alternating current is input to transformer by soft starting circuit and burning machine protective circuit, and described burning machine protective circuit detects the both end voltage of left and right power board emitter resistance;
Described left power board and right power board include voltage amplifier circuit, current drives circuit, press and ration the power supply road, power amplifier, current foldback circuit, DC protection circuit, thermal-shutdown circuit and fall power circuit; Described voltage amplifier circuit drives loudspeaker by current drives circuit, power amplifier successively; described pressure road of rationing the power supply is connected with current drives circuit, described current foldback circuit, DC protection circuit, thermal-shutdown circuit with fall power circuit and be connected with power amplifier respectively.As improvement, described burning machine protective circuit comprises optocoupler and the relay as power circuit conducting loop, and the input of described optocoupler is connected with the two ends of left and right power board emitter resistance, and the output of optocoupler is connected with relay.
As improvement, described DC protection circuit comprises electric capacity C72, triode Q12, triode Q13, triode Q14 and controllable silicon, the input of DC protection circuit is connected with the base stage of electric capacity C72 and triode Q12 respectively, the emitter of triode Q12 is connected with the base stage of triode Q13, the collector electrode of triode Q12 is connected with the base stage of triode Q14, the emitter of triode Q13 is connected with the base stage of triode Q12, the collector electrode of triode Q13 is connected with the base stage of triode Q14, the emitter of triode Q14 is connected with 12V direct voltage, the collector electrode of triode Q14 is by SCR control power supply.
As improvement, the feedback signal line of voltage amplifier circuit is connected with tablet, and described tablet and pressure road of rationing the power supply is connected.
The beneficial effect that the present invention is compared with prior art brought is:
Tablet, by sensitivity adjusting circuit, regulates the input current size of power amplifier; After output level arrives certain value, under pressure limit circuit function, no matter how incoming level increases, and its Maximum Output Level keeps constant; Drive two power amplifiers by two-way power amplifier input branch road, and switched the operating state of two power amplifiers by mode selector switch, to obtain different output;
Power panel, by detecting the both end voltage of power board emitter resistance, to judge that whether power board is in the hole, and by burning the power supply that machine protective circuit is cut off the electricity supply, prevents power amplifier generation burning machine;
Power board have employed the multinomial circuit with defencive function and rations the power supply road, current foldback circuit, DC protection circuit, thermal-shutdown circuit as pressed and fall power circuit, effectively protects, prevent power amplifier mainboard generation burning machine phenomenon to power amplifier mainboard.
Accompanying drawing explanation
Fig. 1 is electrical diagram of the present invention.
Fig. 2 is tablet electrical diagram.
Fig. 3 is power panel electrical diagram.
Fig. 4 is power board electrical diagram.
Fig. 5 is DC protection circuit schematic diagram.
Embodiment
Below in conjunction with Figure of description, the invention will be further described.
As shown in Figure 1, a kind of power amplifier, comprise tablet, left power board, right power board, power panel and LED Unit, described tablet is connected with left power board and right power board respectively, described left power board and right power board are by described LED Unit display, and described power panel is powered to tablet, left power board, right power board and LED Unit.
As shown in Figure 2, described tablet comprises the input branch road of left power board and the input branch road of right power board; Described left power amplifier input branch road comprises the first buffer, the first filtering regulating circuit, the first sensitivity adjusting circuit, the first pressure ration the power supply road; The output of described first buffer is connected with the first filtering regulating circuit, the output of described first filtering regulating circuit is connected with the first sensitivity adjusting circuit, the output of described first sensitivity adjusting circuit is connected with left power board, and described first presses road of rationing the power supply to be connected with the first sensitivity adjusting circuit; Described right power amplifier input branch road comprises the second buffer, the second filtering regulating circuit, the second sensitivity adjusting circuit, the second pressure ration the power supply road, the output of described second buffer is connected with the second filtering regulating circuit, the output of described second filtering regulating circuit is connected with the second sensitivity adjusting circuit, the output of described second sensitivity adjusting circuit is connected with right power board, and described second presses road of rationing the power supply to be connected with the second sensitivity adjusting circuit; Described left power amplifier input branch road is connected with mode selector switch with the output of right power amplifier input branch road.By sensitivity adjusting circuit, regulate the input current size of power amplifier; After output level arrives certain value, under pressure limit circuit function, no matter how incoming level increases, and its Maximum Output Level keeps constant.The present invention drives two power amplifiers by two-way power amplifier input branch road, and is switched the operating state of two power amplifiers by mode selector switch, to obtain different output.
As shown in Figure 3, described power panel comprises power supply branch road and detection branch, described power supply branch road comprises transforming circuit, rectification circuit and filter circuit, and external power source signal is successively by supplying left power board, right power board and tablet after transforming circuit, rectification circuit, filter circuit; Described detection branch comprises soft starting circuit, burns machine protective circuit, and outside 220V alternating current is input to transformer by soft starting circuit and burning machine protective circuit, and described burning machine protective circuit detects the both end voltage of left and right power board emitter resistance.Described burning machine protective circuit comprises optocoupler and the relay as power circuit conducting loop, and the input of described optocoupler is connected with the two ends of left and right power board emitter resistance, and the output of optocoupler is connected with relay; By detecting the both end voltage of power board emitter resistance, to judge that whether power board is in the hole, and by burning the power supply that machine protective circuit is cut off the electricity supply, prevent power amplifier generation burning machine.
As shown in Figure 4, described left power board and right power board include voltage amplifier circuit, current drives circuit, press and ration the power supply road, power amplifier, current foldback circuit, DC protection circuit, thermal-shutdown circuit and fall power circuit; Described voltage amplifier circuit drives loudspeaker by current drives circuit, power amplifier successively; described pressure road of rationing the power supply is connected with current drives circuit, described current foldback circuit, DC protection circuit, thermal-shutdown circuit with fall power circuit and be connected with power amplifier respectively.As shown in Figure 5, described DC protection circuit comprises described direct current protecting testing circuit and comprises electric capacity C72, triode Q12, triode Q13, triode Q14 and controllable silicon D29, the input of DC protection circuit is connected with the base stage of electric capacity C72 and triode Q12 respectively, the emitter of triode Q12 is connected with the base stage of triode Q13, the collector electrode of triode Q12 is connected with the base stage of triode Q14, the emitter of triode Q13 is connected with the base stage of triode Q12, the collector electrode of triode Q13 is connected with the base stage of triode Q14, the emitter of triode Q14 is connected with 12V direct voltage, the collector electrode of triode Q14 controls power protecting circuit by controllable silicon D29.Electric capacity C72 can elimination input alternating current, when the direct current being input to triode Q12 base stage is high potential, triode Q12 conducting, the base stage of triode Q14 is pulled to electronegative potential, because the emitter of triode Q14 is connected with high potential, the current collection very high potential of triode Q14, thus control silicon controlled conducting, finally complete the control to power supply.Power board have employed the multinomial circuit with defencive function and rations the power supply road, current foldback circuit, DC protection circuit, thermal-shutdown circuit as pressed and fall power circuit, effectively protects, prevent power amplifier mainboard generation burning machine phenomenon to power amplifier mainboard.
Claims (4)
1. a power amplifier, it is characterized in that: comprise tablet, left power board, right power board, power panel and LED Unit, described tablet is connected with left power board and right power board respectively, described left power board and right power board are by described LED Unit display, and described power panel is powered to tablet, left power board, right power board and LED Unit;
Described tablet comprises the input branch road of left power board and the input branch road of right power board; Described left power amplifier input branch road comprises the first buffer, the first filtering regulating circuit, the first sensitivity adjusting circuit, the first pressure ration the power supply road; The output of described first buffer is connected with the first filtering regulating circuit, the output of described first filtering regulating circuit is connected with the first sensitivity adjusting circuit, the output of described first sensitivity adjusting circuit is connected with left power board, and described first presses road of rationing the power supply to be connected with the first sensitivity adjusting circuit; Described right power amplifier input branch road comprises the second buffer, the second filtering regulating circuit, the second sensitivity adjusting circuit, the second pressure ration the power supply road, the output of described second buffer is connected with the second filtering regulating circuit, the output of described second filtering regulating circuit is connected with the second sensitivity adjusting circuit, the output of described second sensitivity adjusting circuit is connected with right power board, and described second presses road of rationing the power supply to be connected with the second sensitivity adjusting circuit; Described left power amplifier input branch road is connected with mode selector switch with the output of right power amplifier input branch road;
Described power panel comprises power supply branch road and detection branch, described power supply branch road comprises transforming circuit, rectification circuit and filter circuit, and external power source signal is successively by supplying left power board, right power board and tablet after transforming circuit, rectification circuit, filter circuit; Described detection branch comprises soft starting circuit, burns machine protective circuit, and outside 220V alternating current is input to transformer by soft starting circuit and burning machine protective circuit, and described burning machine protective circuit detects the both end voltage of left and right power board emitter resistance;
Described left power board and right power board include voltage amplifier circuit, current drives circuit, press and ration the power supply road, power amplifier, current foldback circuit, DC protection circuit, thermal-shutdown circuit and fall power circuit; Described voltage amplifier circuit drives loudspeaker by current drives circuit, power amplifier successively; described pressure road of rationing the power supply is connected with current drives circuit, described current foldback circuit, DC protection circuit, thermal-shutdown circuit with fall power circuit and be connected with power amplifier respectively.
2. power amplifier according to claim 1; it is characterized in that: described burning machine protective circuit comprises optocoupler and the relay as power circuit conducting loop; the input of described optocoupler is connected with the two ends of left and right power board emitter resistance, and the output of optocoupler is connected with relay.
3. power amplifier according to claim 1, it is characterized in that: described DC protection circuit comprises electric capacity C72, triode Q12, triode Q13, triode Q14 and controllable silicon, the input of DC protection circuit is connected with the base stage of electric capacity C72 and triode Q12 respectively, the emitter of triode Q12 is connected with the base stage of triode Q13, the collector electrode of triode Q12 is connected with the base stage of triode Q14, the emitter of triode Q13 is connected with the base stage of triode Q12, the collector electrode of triode Q13 is connected with the base stage of triode Q14, the emitter of triode Q14 is connected with 12V direct voltage, the collector electrode of triode Q14 is by SCR control power supply.
4. power amplifier according to claim 1, is characterized in that: the feedback signal line of voltage amplifier circuit is connected with tablet, and described tablet and pressure road of rationing the power supply is connected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410470806.7A CN104270106B (en) | 2014-09-16 | 2014-09-16 | Power amplifier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410470806.7A CN104270106B (en) | 2014-09-16 | 2014-09-16 | Power amplifier |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104270106A true CN104270106A (en) | 2015-01-07 |
| CN104270106B CN104270106B (en) | 2017-09-26 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410470806.7A Active CN104270106B (en) | 2014-09-16 | 2014-09-16 | Power amplifier |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104270106B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109586676A (en) * | 2019-01-24 | 2019-04-05 | 江门市川琪科技有限公司 | A kind of full load automatic gain mesh power amplifier |
| CN111273076A (en) * | 2020-02-26 | 2020-06-12 | 浙江禾川科技股份有限公司 | Servo driver and buffer circuit protection circuit thereof |
Citations (6)
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| CN201383865Y (en) * | 2009-02-14 | 2010-01-13 | 中山市捷丰达电子电器有限公司 | High-power switching power supply MOSFET audio power amplifier |
| CN201490975U (en) * | 2009-05-14 | 2010-05-26 | 广州飞达音响专业器材有限公司 | Digital power amplifier |
| US20110043956A1 (en) * | 2009-08-19 | 2011-02-24 | Qualcomm Incorporated | Protection circuit for power amplifier |
| CN102195576A (en) * | 2011-02-01 | 2011-09-21 | 上海矽诺微电子有限公司 | Audio amplifier working in double modes |
| CN202587375U (en) * | 2012-03-07 | 2012-12-05 | 东莞精恒电子有限公司 | Novel power amplification module system |
| CN203151434U (en) * | 2013-04-22 | 2013-08-21 | 惠州三星电子有限公司 | Power amplifier protective circuit |
-
2014
- 2014-09-16 CN CN201410470806.7A patent/CN104270106B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201383865Y (en) * | 2009-02-14 | 2010-01-13 | 中山市捷丰达电子电器有限公司 | High-power switching power supply MOSFET audio power amplifier |
| CN201490975U (en) * | 2009-05-14 | 2010-05-26 | 广州飞达音响专业器材有限公司 | Digital power amplifier |
| US20110043956A1 (en) * | 2009-08-19 | 2011-02-24 | Qualcomm Incorporated | Protection circuit for power amplifier |
| CN102195576A (en) * | 2011-02-01 | 2011-09-21 | 上海矽诺微电子有限公司 | Audio amplifier working in double modes |
| CN202587375U (en) * | 2012-03-07 | 2012-12-05 | 东莞精恒电子有限公司 | Novel power amplification module system |
| CN203151434U (en) * | 2013-04-22 | 2013-08-21 | 惠州三星电子有限公司 | Power amplifier protective circuit |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109586676A (en) * | 2019-01-24 | 2019-04-05 | 江门市川琪科技有限公司 | A kind of full load automatic gain mesh power amplifier |
| CN111273076A (en) * | 2020-02-26 | 2020-06-12 | 浙江禾川科技股份有限公司 | Servo driver and buffer circuit protection circuit thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104270106B (en) | 2017-09-26 |
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