CN203151434U - Power amplifier protective circuit - Google Patents
Power amplifier protective circuit Download PDFInfo
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- CN203151434U CN203151434U CN 201320202730 CN201320202730U CN203151434U CN 203151434 U CN203151434 U CN 203151434U CN 201320202730 CN201320202730 CN 201320202730 CN 201320202730 U CN201320202730 U CN 201320202730U CN 203151434 U CN203151434 U CN 203151434U
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- power amplifier
- detection module
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- module
- protective circuit
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Abstract
The utility model discloses a power amplifier protective circuit, which comprises an overvoltage detection module connected with the output end of a power amplifier. The output end of the overvoltage detection module is connected with a microprocessor module; the microprocessor module is connected with the power amplifier to control the working condition of the power amplifier; and the overvoltage detection module comprises a positive direct-current voltage detection module and a negative direct-current voltage detection module. The power amplifier protective circuit also comprises a temperature detection module; and the output end of the temperature detection module is connected with the microprocessor module. According to the power amplifier protective circuit, the overvoltage protective circuit consists of commonly used discrete components such as a triode, the power amplifier circuit is subjected to positive level overvoltage protection and negative level overvoltage protection, the design is simple and the cost is low.
Description
Technical field
The utility model relates to power amplifier, particularly a kind of power amplifier protective circuit.
Background technology
Power amplifier is called for short power amplifier, is commonly called as " sound amplifier ", is equipment the most basic in the sound system, and its task is the ultra-weak electronic signal from signal source (then being from sound console in the professional sound system) to be amplified to drive loud speaker sound.Power tube is the easiest device that is damaged in the power amplification circuit, and most of reason of damage is because the actual dissipation power of pipe has surpassed rating number.In addition, if power amplifier and loud speaker mismatch or loud speaker use medium-term and long-term overload, also very easily damage loud speaker (or audio amplifier); therefore; in stereo set, the purpose of protection is expensive power amplifier and loud speaker of protection, so be necessary fully to overvoltage or the high temperature protection of power amplifier.
At present, the overvoltage protection that power amplifier is exported mainly is to realize by hardware circuit or software, but common hardware designs relative complex causes cost to increase, and software implementation method also can increase the complexity of software design, prolongs the design cycle.
The utility model content
For overcoming the defective of above-mentioned prior art, the utility model provides a kind of power amplifier protective circuit.
The technical solution adopted in the utility model is:
A kind of power amplifier protective circuit; comprise the overvoltage detection module that is connected with the power amplifier output; overvoltage detection module output connects microprocessor module; described microprocessor module connects power amplifier; control its operating state, described overvoltage detection module comprises positive direct-current voltages detection module and negative dc voltage detection module.
Preferably, the output of described positive direct-current voltages detection module and negative dc voltage detection module all is connected microprocessor module by the signaling switch module.
Preferably, also comprise temperature detecting module, described temperature sensing circuit output connects the signaling switch module.
Preferably, described microprocessor module adopts dsp processor.
Preferably, also be connected with filter circuit between described overvoltage detection module and the power amplifier output.
Further preferred, also be connected to indicator light circuit between described signaling switch module and the microprocessor module.
Concrete, described positive direct-current voltages detection module comprises NPN triode Q1, b1 is as input for its base stage, emitter e 1 ground connection, collector electrode c1 connects positive high level by resistance R 3, the R4 of series connection, and the series connection contact between described resistance R 3, the R4 connects the base stage b3 of PNP triode Q3, and the emitter e 3 of triode Q3 connects positive high level, collector electrode c3 connects negative high level by resistance R 8, the R9 of series connection, and collector electrode c3 is as the output of positive direct-current voltages detection module; Described negative dc voltage detection module comprises PNP triode Q2, and b2 is as input for its base stage, emitter e 2 ground connection, and collector electrode c2 connects negative high level by resistance R 5, the R9 of series connection, and collector electrode c2 is as the output of negative dc voltage detection module.
Concrete, described temperature detecting module comprises thermistor TR1 and the resistance R 10 that is connected between the positive and negative level, series connection contact between thermistor TR1 and the resistance R 10 connects the base stage b4 of PNP triode Q4, the emitter e 4 of triode Q4 connects positive high level by resistance R 11, and collector electrode c4 is as the output of temperature detecting module.
Concrete, described signaling switch module comprises the total radio amplifier that is connected with the temperature detecting module output with the overvoltage detection module, the collector electrode of described total radio amplifier and the light-emitting diode OP1 that just connects between the high level, light-emitting diode OP1 negative pole connects collector electrode, and collector electrode connects microprocessor module as output.
Concrete, described filter circuit is electrochemical capacitor C1, the C2 that comprises that two negative poles link to each other, the positive pole of electrochemical capacitor C1, C2 connects input and the ground of overvoltage detection module respectively.
Compared with prior art, the beneficial effects of the utility model have:
(1) power amplifier protective circuit described in the utility model is utilized discrete component formation overvoltage crowbars commonly used such as triode, realizes positive level overvoltage protection and negative level overvoltage protection to power amplifier, simplicity of design, and cost is low;
(2) power amplifier protective circuit described in the utility model also comprises temperature detecting module, realizes high temperature protection, and is practical.
Description of drawings
Fig. 1 is the functional-block diagram of power amplifier protective circuit described in the utility model;
Fig. 2 is the circuit theory diagrams of the embodiment of power amplifier protective circuit described in the utility model.
Embodiment
For making things convenient for those skilled in the art to understand technology contents of the present utility model, be described in further detail below in conjunction with the utility model of embodiment.
As shown in Figure 1, the utility model discloses a kind of power amplifier protective circuit, comprise the overvoltage detection module that is connected with the power amplifier output, overvoltage detection module output connects microprocessor module, described microprocessor module connects power amplifier, control its operating state, described overvoltage detection module comprises positive direct-current voltages detection module and negative dc voltage detection module; The output of described positive direct-current voltages detection module and negative dc voltage detection module all is connected microprocessor module by the signaling switch module; The utility model also comprises temperature detecting module, and described temperature sensing circuit output connects the signaling switch module; Also be connected with filter circuit between described overvoltage detection module and the power amplifier output.
Concrete, as shown in Figure 2, described positive direct-current voltages detection module comprises NPN triode Q1, b1 is as input for its base stage, emitter e 1 ground connection, collector electrode c1 connects positive high level A5V_PM by resistance R 3, the R4 of series connection, node between described resistance R 3, the R4 connects the base stage b3 of PNP triode Q3, the emitter e 3 of triode Q3 connects positive high level A5V_PM, collector electrode c3 connects negative high level A-5V_PM by resistance R 8, the R9 of series connection, and collector electrode c3 is by connecting resistance R 6 as the output of positive direct-current voltages detection module; Described negative dc voltage detection module comprises PNP triode Q2, b2 is as input for its base stage, emitter e 2 ground connection, collector electrode c2 connects negative high level A-5V_PM by resistance R 5, the R9 of series connection, and collector electrode c2 is by connecting resistance R 7 as the output of negative dc voltage detection module.
Described temperature detecting module comprises thermistor TR1 and the resistance R 10 that is connected between the positive and negative high level, node between thermistor TR1 and the resistance R 10 connects the base stage b4 of PNP triode Q4, the emitter e 4 of triode Q4 connects positive high level A5V_PM by resistance R 11, be connected with capacitor C 3 between collector electrode c4 and the base stage b4, collector electrode c4 is as the temperature detecting module output.
Described signaling switch module comprises voltage sampling and the filter circuit 2 be made up of resistance R 12, R13 and capacitor C 4 that is connected with the temperature detecting module output with the overvoltage detection module, its output connects total radio amplifier, described total radio amplifier comprises NPN switch triode Q5, the collector electrode c5 of triode Q5 and just connect between the high level A5V_PM light-emitting diode OP1 and resistance R 14, light-emitting diode OP1 negative pole meets collector electrode c5, emitter e 5 connects negative high level A-5V_PM, and collector electrode connects microprocessor module as output; Described microprocessor module adopts dsp processor.
Also be connected resistance R 1, R2 that voltage sample circuit and the described voltage sample circuit of filter circuit comprise the ground connection of connecting between described overvoltage detection module and the power amplifier output, node between resistance R 1, the R2 is as the output of voltage sample circuit, described filter circuit is electrochemical capacitor C1, the C2 that comprises that two negative poles link to each other, and the positive pole of electrochemical capacitor C1, C2 connects output and the ground of voltage sample circuit respectively.
The utility model is in the specific implementation in the following several ways:
(1) power amplifier output DC INPUT is in the normal voltage scope, triode QI ends, the base stage of Q3 is high level, so Q3 ends, collector electrode e3 is output as low level, and switch triode Q5 ends, and the collector electrode c5 that DSP detects Q5 is high level, be judged to be normal operating conditions, light-emitting diode OP1 indicator light does not work simultaneously.
(2) when power amplifier output DC INPUT direct current positive level is too high; triode Q1 conducting; the base stage b3 of Q3 is low level, so the Q3 conducting, collector electrode e3 is output as high level; the base stage b5 of Q5 is high level; the Q5 conducting makes that by regulating R14 the collector electrode c5 of Q5 is low level, sends to DSP; the transmission out code was protected power amplifier after DSP detected low level, and at this moment light-emitting diode OP1 indicator light is lighted.
(3) when power amplifier output DC INPUT direct current negative level is too high; the B collection of triode Q2 collector electrode c2 output high level Q5 is high level; the base stage b5 of Q5 is high level; the Q5 conducting; make that by regulating R14 the collector electrode c5 of Q5 is low level; send to DSP, the transmission out code was protected power amplifier after DSP detected low level, and at this moment light-emitting diode OP1 indicator light is lighted.
(4) be in below the limiting temperature (limiting temperature can be regulated by thermistor TR1) when temperature, the TR1 resistance is less, resistance R 10 accounts for the pressure ratio height, the base stage b4 of switch triode Q4 is high level, Q4 is in cut-off state, switch triode Q5 ends, and the collector electrode c5 that DSP detects Q5 is that high level is judged to be normal operating conditions, and light-emitting diode OP1 indicator light does not work.
(5) when temperature surpasses limiting temperature; thermistor TR1 resistance increases; resistance R 10 accounts for pressure ratio and diminishes, and the base stage b4 of switch triode Q4 is low level, the Q4 conducting; the B collection of Q5 is high level; the C collection of Q5 and the conducting of E collection make that by regulating R14 the collector electrode c5 of Q5 is low level, send to DSP; the transmission out code was protected power amplifier after DSP detected low level, and at this moment light-emitting diode OP1 indicator light is lighted.
Above-described embodiment only is wherein specific implementation of the present utility model, and it describes comparatively concrete and detailed, but can not therefore be interpreted as the restriction to the utility model claim.Should be pointed out that for the person of ordinary skill of the art under the prerequisite that does not break away from the utility model design, can also make some distortion and improvement, these apparent replacement forms all belong to protection range of the present utility model.
Claims (10)
1. power amplifier protective circuit; comprise the overvoltage detection module that is connected with the power amplifier output; overvoltage detection module output connects microprocessor module; described microprocessor module connects power amplifier; control its operating state, it is characterized in that: described overvoltage detection module comprises positive direct-current voltages detection module and negative dc voltage detection module.
2. power amplifier protective circuit according to claim 1, it is characterized in that: the output of described positive direct-current voltages detection module and negative dc voltage detection module all is connected microprocessor module by the signaling switch module.
3. power amplifier protective circuit according to claim 2 is characterized in that: also comprise temperature detecting module, described temperature sensing circuit output connection signaling switch module.
4. power amplifier protective circuit according to claim 1 is characterized in that: described microprocessor module employing dsp processor.
5. power amplifier protective circuit according to claim 1 is characterized in that: also be connected with filter circuit between described overvoltage detection module and the power amplifier output.
6. power amplifier protective circuit according to claim 2 is characterized in that: also be connected to indicator light circuit between described signaling switch module and the microprocessor module.
7. power amplifier protective circuit according to claim 1, it is characterized in that: described positive direct-current voltages detection module comprises NPN triode Q1, b1 is as input for its base stage, emitter e 1 ground connection, collector electrode c1 connects positive high level by resistance R 3, the R4 of series connection, series connection contact between described resistance R 3, the R4 connects the base stage b3 of PNP triode Q3, the emitter e 3 of triode Q3 connects positive high level, collector electrode c3 connects negative high level by resistance R 8, the R9 of series connection, and collector electrode c3 is as the output of positive direct-current voltages detection module;
Described negative dc voltage detection module comprises PNP triode Q2, and b2 is as input for its base stage, emitter e 2 ground connection, and collector electrode c2 connects negative high level by resistance R 5, the R9 of series connection, and collector electrode c2 is as the output of negative dc voltage detection module.
8. power amplifier protective circuit according to claim 3; it is characterized in that: described temperature detecting module comprises thermistor TR1 and the resistance R 10 that is connected between the positive and negative level; series connection contact between thermistor TR1 and the resistance R 10 connects the base stage b4 of PNP triode Q4; the emitter e 4 of triode Q4 connects positive high level by resistance R 11, and collector electrode c4 is as the output of temperature detecting module.
9. power amplifier protective circuit according to claim 2; it is characterized in that: described signaling switch module comprises the total radio amplifier that is connected with the temperature detecting module output with the overvoltage detection module; the collector electrode of described total radio amplifier and the light-emitting diode OP1 that just connects between the high level; light-emitting diode OP1 negative pole connects collector electrode, and collector electrode connects microprocessor module as output.
10. power amplifier protective circuit according to claim 2 is characterized in that: described filter circuit is electrochemical capacitor C1, the C2 that comprises that two negative poles link to each other, and the positive pole of electrochemical capacitor C1, C2 connects input and the ground of overvoltage detection module respectively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320202730 CN203151434U (en) | 2013-04-22 | 2013-04-22 | Power amplifier protective circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320202730 CN203151434U (en) | 2013-04-22 | 2013-04-22 | Power amplifier protective circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203151434U true CN203151434U (en) | 2013-08-21 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201320202730 Expired - Fee Related CN203151434U (en) | 2013-04-22 | 2013-04-22 | Power amplifier protective circuit |
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| Country | Link |
|---|---|
| CN (1) | CN203151434U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103648075A (en) * | 2013-12-16 | 2014-03-19 | 惠州华阳通用电子有限公司 | Device and method for automatically detecting abnormality of power amplifier |
| CN104270106A (en) * | 2014-09-16 | 2015-01-07 | 广州杰士莱电子有限公司 | Power amplifier circuit |
-
2013
- 2013-04-22 CN CN 201320202730 patent/CN203151434U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103648075A (en) * | 2013-12-16 | 2014-03-19 | 惠州华阳通用电子有限公司 | Device and method for automatically detecting abnormality of power amplifier |
| CN104270106A (en) * | 2014-09-16 | 2015-01-07 | 广州杰士莱电子有限公司 | Power amplifier circuit |
| CN104270106B (en) * | 2014-09-16 | 2017-09-26 | 广州杰士莱电子有限公司 | Power amplifier |
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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: 20130821 Termination date: 20140422 |