CN203984652U - Power amplifier amplitude limiter circuit - Google Patents
Power amplifier amplitude limiter circuit Download PDFInfo
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- CN203984652U CN203984652U CN201420429278.6U CN201420429278U CN203984652U CN 203984652 U CN203984652 U CN 203984652U CN 201420429278 U CN201420429278 U CN 201420429278U CN 203984652 U CN203984652 U CN 203984652U
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Abstract
A kind of power amplifier amplitude limiter circuit, the large-signal of positive half cycle produces pressure drop at R138, voltage is through R122, the B utmost point that enters Q119 after R153 dividing potential drop, makes triode conducting, the diode D132 conducting that makes again triode C extremely be connected after conducting, thereby make to drive the base voltage of triode Q108 to reduce, make the base voltage of efferent duct Q115 lower again, finally make output signal reduce, output is not increasing; Otherwise the large-signal of negative half period is by R149, R177, R133; Q120, the amplitude limiter circuit of D133 composition is controlled the base voltage of Q109, then reduces the voltage of Q116 base stage, and output signal is lowered; reach the object of controlling output, can effectively protect loud speaker not damaged, and self structure is simple.
Description
Technical field
The utility model relates to power amplifier field, relates in particular to a kind of power amplifier amplitude limiter circuit that can limit power amplifier voltage amplitude.
Background technology
Present power amplifier or loudspeaker are all to convert voice signal to the signal of telecommunication, through after amplification again with the output sound of high-fidelity, but for power amplifier or loudspeaker, the amplifying power multiple of himself is limited, in actual application, due to the complexity of whole circuit, be difficult to guarantee that voltage or electric current exceed maximum, may directly damage thus power amplifier.In prior art, solving the normal means that adopt of problems is to adopt amplitude limiter circuit.Existing amplitude limiter circuit is directly to arrive ground at advance signal path two diode 1N4148 in parallel, and principle is to be 0.7V left and right by the forward conduction voltage of diode, so amplitude limit inaccuracy, and the distortion factor is very large, make the sound of power amplifier, be difficult to listen, affect consumer's hearing effect.And the most IC of use of the amplitude limiter circuit of the high-power power amplifier of automobile application at present control, circuit structure complexity.
Utility model content
The technical problems to be solved in the utility model is to overcome the deficiency that above-mentioned prior art exists, and proposes a kind of power amplifier amplitude limiter circuit, and it is simple in structure, implements easily, and element is few, and wiring is simple, successful amplitude limit.
For solving the problems of the technologies described above, the utility model adopts following technical scheme:
A kind of power amplifier amplitude limiter circuit, it comprises: triode Q119, Q120, Q108, Q109, resistance R 118, R117, R122, R153, R138, R133, R149, R148, R119, R121, R126, R127, diode D132, D133;
Wherein, the collector electrode of described triode Q119 is connected in the negative pole of described diode D132, described diode D132 is connected in external power source V++, the emitter of described triode Q119 connects the emitter of described triode Q120, described in its base stage series connection one, after resistance R 122, be connected in described triode Q108, resistance R 153 described in being in series with one between the emitter of described triode Q119 and base stage, between described triode Q119 emitter and resistance R 153, node is connected and described in one, after resistance R 133, is connected in the base stage of triode Q120, the emitter of described triode Q108 is connected in the emitter of described triode Q109 after connecting with described resistance R 138 and resistance R 149, the base stage of described triode Q120 is connected and is connected in the emitter of triode Q109 after a resistance R 121, node between wherein said resistance R 153 and resistance R 133 is directly connected in the node between resistance R 138 and resistance R 149 by wire, the collector electrode of described triode Q120 be connected in one described in diode D133 positive pole, described diode D133 is connected in external power source V--, the base stage of described triode Q109 is connected after a resistance R 148 and is connected in external power source V--, and the collector electrode of described triode Q109 is connected after a resistance R 119 and is connected in external power source V--, the collector electrode of described triode Q108 is connected after a resistance R 118 and is connected in external power source V++, and its base stage is connected after a resistance R 117 and is connected in external power source V++, node between described resistance R 138 and resistance R 149 is connected in the positive terminal of a loud speaker, the negative pole end ground connection of described loud speaker by wire.
Wherein, the emitter of described triode Q108 is also in series with the base stage that is connected in again triode Q115 after a resistance R 120, the collector electrode of triode Q115 is connected in external power source V++, is connected in the emitter of triode Q116 after its emitter is connected with the series circuit being made up of resistance R 126 and resistance R 127; The collector electrode of described triode Q116 is connected in external power source V--, and its base stage is connected in the node between described resistance R 149 and triode Q109 emitter after being series at a resistance R 125.
Wherein, the positive terminal of described loud speaker is also provided with an anti-jamming circuit, and described anti-jamming circuit comprises that one is connected in a capacitor C 110 of loud speaker positive terminal, and described capacitor C 110 other ends are connected in a resistance R 137 ground connection afterwards.
Compared with prior art; the utility model power amplifier amplitude limiter circuit; the amplitude of controlling power amplifier driving signal voltage by the size of power amplifier final stage output signal reaches control power amplifier final stage output voltage, output amplitude is limited within the specific limits, protection power amplifier and loud speaker.
Brief description of the drawings
Fig. 1 is the circuit diagram of the utility model power amplifier amplitude limiter circuit.
Embodiment
The exemplary embodiment that embodies the utility model feature & benefits will describe in detail in the following description.Be understood that the utility model can have various variations on different execution modes, it neither departs from scope of the present utility model, and explanation wherein and to be shown in be the use when explaining in essence, but not in order to limit the utility model.
Consult accompanying drawing 1, in the present embodiment, a kind of power amplifier amplitude limiter circuit, it comprises: triode Q119, Q120, Q108, Q109, resistance R 118, R117, R122, R153, R138, R133, R149, R148, R119, R121, R126, R127, diode D132, D133;
Wherein, the collector electrode of described triode Q119 is connected in the negative pole of described diode D132, described diode D132 is connected in external power source V++, the emitter of described triode Q119 connects the emitter of described triode Q120, described in its base stage series connection one, after resistance R 122, be connected in described triode Q108, resistance R 153 described in being in series with one between the emitter of described triode Q119 and base stage, between described triode Q119 emitter and resistance R 153, node is connected and described in one, after resistance R 133, is connected in the base stage of triode Q120, the emitter of described triode Q108 is connected in the emitter of described triode Q109 after connecting with described resistance R 138 and resistance R 149, the base stage of described triode Q120 is connected and is connected in the emitter of triode Q109 after a resistance R 121, node between wherein said resistance R 153 and resistance R 133 is directly connected in the node between resistance R 138 and resistance R 149 by wire, the collector electrode of described triode Q120 be connected in one described in diode D133 positive pole, described diode D133 is connected in external power source V--, the base stage of described triode Q109 is connected after a resistance R 148 and is connected in external power source V--, and the collector electrode of described triode Q109 is connected after a resistance R 119 and is connected in external power source V--, the collector electrode of described triode Q108 is connected after a resistance R 118 and is connected in external power source V++, and its base stage is connected after a resistance R 117 and is connected in external power source V++, node between described resistance R 138 and resistance R 149 is connected in the positive terminal of a loud speaker, the negative pole end ground connection of described loud speaker by wire.
Further, the emitter of described triode Q108 is also in series with the base stage that is connected in again triode Q115 after a resistance R 120, the collector electrode of triode Q115 is connected in external power source V++, is connected in the emitter of triode Q116 after its emitter is connected with the series circuit being made up of resistance R 126 and resistance R 127; The collector electrode of described triode Q116 is connected in external power source V--, and its base stage is connected in the node between described resistance R 149 and triode Q109 emitter after being series at a resistance R 125.
Preferably, the positive terminal of described loud speaker is also provided with an anti-jamming circuit, and described anti-jamming circuit comprises that one is connected in a capacitor C 110 of loud speaker positive terminal, and described capacitor C 110 other ends are connected in a resistance R 137 ground connection afterwards.
The utility model, by element Q119, Q120, D132, D133, R122, R153, R117, R133 forms amplitude limiter circuit jointly.Its operation principle is as follows: the large-signal of positive half cycle produces pressure drop at R138, voltage is through R122, after R153 dividing potential drop, enter the B utmost point of Q119, make triode conducting, the diode D132 conducting that makes again triode C extremely be connected after conducting, thus make to drive the base voltage of triode Q108 to reduce, then the base voltage of efferent duct Q115 is lowered, finally make output signal reduce, output is not increasing; Otherwise the large-signal of negative half period is passed through R149, R177, R133, Q120, the amplitude limiter circuit of D133 composition is controlled the base voltage of Q109, then reduces the voltage of Q116 base stage, and output signal is lowered, and reaches the object of controlling output.
It should be noted that; these are only better possible embodiments of the present utility model; and unrestricted protection range of the present utility model, the equivalent structure that all utilization the utility model specifications and accompanying drawing content have been done changes, and is all included in protection range of the present utility model.
Claims (3)
1. a power amplifier amplitude limiter circuit, is characterized in that, comprising: triode Q119, Q120, Q108, Q109, resistance R 118, R117, R122, R153, R138, R133, R149, R148, R119, R121, R126, R127, diode D132, D133;
Wherein, the collector electrode of described triode Q119 is connected in the negative pole of described diode D132, described diode D132 is connected in external power source V++, the emitter of described triode Q119 connects the emitter of described triode Q120, described in its base stage series connection one, after resistance R 122, be connected in described triode Q108, resistance R 153 described in being in series with one between the emitter of described triode Q119 and base stage, between described triode Q119 emitter and resistance R 153, node is connected and described in one, after resistance R 133, is connected in the base stage of triode Q120, the emitter of described triode Q108 is connected in the emitter of described triode Q109 after connecting with described resistance R 138 and resistance R 149, the base stage of described triode Q120 is connected and is connected in the emitter of triode Q109 after a resistance R 121, node between wherein said resistance R 153 and resistance R 133 is directly connected in the node between resistance R 138 and resistance R 149 by wire, the collector electrode of described triode Q120 be connected in one described in diode D133 positive pole, described diode D133 is connected in external power source V--, the base stage of described triode Q109 is connected after a resistance R 148 and is connected in external power source V--, and the collector electrode of described triode Q109 is connected after a resistance R 119 and is connected in external power source V--, the collector electrode of described triode Q108 is connected after a resistance R 118 and is connected in external power source V++, and its base stage is connected after a resistance R 117 and is connected in external power source V++, node between described resistance R 138 and resistance R 149 is connected in the positive terminal of a loud speaker, the negative pole end ground connection of described loud speaker by wire.
2. power amplifier amplitude limiter circuit as claimed in claim 1, it is characterized in that, the emitter of described triode Q108 is also in series with the base stage that is connected in again triode Q115 after a resistance R 120, the collector electrode of triode Q115 is connected in external power source V++, is connected in the emitter of triode Q116 after its emitter is connected with the series circuit being made up of resistance R 126 and resistance R 127; The collector electrode of described triode Q116 is connected in external power source V--, and its base stage is connected in the node between described resistance R 149 and triode Q109 emitter after being series at a resistance R 125.
3. power amplifier amplitude limiter circuit as claimed in claim 1, it is characterized in that, the positive terminal of described loud speaker is also provided with an anti-jamming circuit, and described anti-jamming circuit comprises that one is connected in a capacitor C 110 of loud speaker positive terminal, and described capacitor C 110 other ends are connected in a resistance R 137 ground connection afterwards.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420429278.6U CN203984652U (en) | 2014-07-31 | 2014-07-31 | Power amplifier amplitude limiter circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420429278.6U CN203984652U (en) | 2014-07-31 | 2014-07-31 | Power amplifier amplitude limiter circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203984652U true CN203984652U (en) | 2014-12-03 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420429278.6U Active CN203984652U (en) | 2014-07-31 | 2014-07-31 | Power amplifier amplitude limiter circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203984652U (en) |
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2014
- 2014-07-31 CN CN201420429278.6U patent/CN203984652U/en active Active
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|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |