CN201699662U - Amplitude limiting circuit for audio power amplifier - Google Patents
Amplitude limiting circuit for audio power amplifier Download PDFInfo
- Publication number
- CN201699662U CN201699662U CN200920261928XU CN200920261928U CN201699662U CN 201699662 U CN201699662 U CN 201699662U CN 200920261928X U CN200920261928X U CN 200920261928XU CN 200920261928 U CN200920261928 U CN 200920261928U CN 201699662 U CN201699662 U CN 201699662U
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- circuit
- amplitude limiting
- amplitude
- audio
- amplitude limiter
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- 230000005236 sound signal Effects 0.000 claims abstract description 14
- 239000003990 capacitor Substances 0.000 abstract 2
- 238000010586 diagram Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012797 qualification Methods 0.000 description 1
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- Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
Abstract
The utility model relates to an amplitude limiting circuit for an audio power amplifier, which comprises an amplifying circuit A, an amplitude limiting circuit B and an adjusting circuit C, wherein the amplifying circuit A comprises a transistor amplifying circuit, and audio input signal is transmitted to the base electrode of a transistor through a series capacitor and a resistance divider, and is then sent to the amplitude limiting circuit B from the collector electrode of the transistor through the series capacitor; the amplitude limiting circuit B comprises two diodes which are connected in parallel reversely and have one end connected with the ground; the audio signal from the amplifying circuit A is added to one end of the diodes through a serial resistance, and is output to the adjusting circuit C; and the adjusting circuit C regulates the audio signal from the amplitude limiting circuit B through two divider resistances. The utility model adds a first-level amplifying circuit before the common diode, realizes free adjustment of clip level through adjusting amplifier gain, and has low cost and reliable work.
Description
Technical field the utility model relates to a kind of amplitude limiter circuit that is used for audio-frequency power amplifier.
Background technology is in the application of audio-frequency power amplifier, under some special state such as input non-standard signal, the audio input signal amplitude can be much larger than specified input voltage, the peak power output that causes the sound accompaniment power amplifier output power surpass to be set can be burnt the loud speaker of connection when serious or be made the sound accompaniment power amplifier overheated and break down.Solving this way in the prior art comprises:
1, the input at audio-frequency power amplifier increases the automatic volume control circuit, adjusts gain automatically with the audio amplitude of input.Automatic volume control circuit more complicated need be realized that generally cost is higher by integrated circuit; And its operation principle is based on the average voltage that detects input audio signal, and response speed is slower
2, increase sound accompaniment power amplifier and speaker design allowance, this method can cause cost significantly to increase.
3, use simple diode limiting circuit to prevent to transship in addition, but the limiting voltage of diode fixes, use and inconvenient, also can not realize the amplitude limit function for the small-signal of millivolt level, nor can adjust the threshold values of limiting voltage flexibly.
The summary of the invention the purpose of this utility model is to provide a kind of amplitude limiter circuit that is used for audio-frequency power amplifier, makes audio signal automatic amplitude limit when amplitude is excessive of input, has guaranteed the sound accompaniment power amplifier of back level and the trouble free service of loud speaker.
The utility model discloses a kind of amplitude limiter circuit that is used for audio-frequency power amplifier, comprise amplifying circuit A, amplitude limiter circuit B and adjust circuit C;
Described amplitude limiter circuit B comprises the diode of two reverse parallel connections of an end ground connection; Be added to an end of described diode from the audio signal of amplifying circuit A after through a series resistance, and output to described adjustment circuit C;
Described adjustment circuit C is by the audio signal of two divider resistance adjustment from described amplitude limiter circuit B.
In the disclosed amplitude limiter circuit of the utility model, described amplifying circuit A is a kind of transistor amplifier circuit.
The multiplication factor of described amplifying circuit A, the amplitude that can amplify the audio input signal that needs amplitude limit, the turn-on voltage of the diode in the described amplitude limiter circuit B.
The disclosed a kind of amplitude limiter circuit that is used for audio-frequency power amplifier of the utility model, use the nonlinear characteristic of diode, make audio signal automatic amplitude limit when amplitude is excessive of input, the sound accompaniment power amplifier and the loud speaker trouble free service of back level have been guaranteed, circuit is simple and reliable, and the cost of increase is extremely low.
Description of drawings
Fig. 1 is an amplitude limiter circuit schematic diagram of the present utility model.
Embodiment is described in further detail the utility model below in conjunction with the drawings and specific embodiments.Specific embodiment described herein is not to qualification of the present utility model, but to explanation of the present utility model.
Be amplitude limiter circuit schematic diagram of the present utility model as shown in Figure 1, comprise amplifying circuit A, amplitude limiter circuit B and adjust three parts of circuit C that audio signal is partly imported from amplifying circuit A, adjusts circuit C and partly exports.
Amplifying circuit A partly is a transistor amplifier circuit among Fig. 1; The sound accompaniment power amplifier is after the utility model, because the gain amplifier higher (tens of times approximately of gain amplifiers) of general sound accompaniment power amplifier, because the gain of the sound accompaniment power amplifier of back level is higher, generally have about 40 times, the audio frequency signal amplitude of input is lower, conducting voltage from diode differs far away, so need to use amplifier A amplifying signal.
Amplitude limiter circuit B is the amplitude limiter circuit that two diodes are formed; According to the voltage-current characteristic of diode, when audio signal peak-to-peak value voltage during greater than the conducting voltage of diode, the audio signal peak-to-peak value is limited on the diode turn-on voltage; When the little diode turn-on voltage of audio signal peak-to-peak value voltage, signal is not affected.
Adjusting circuit C is the output voltage circuit, is used for audio output signal is adjusted to the required voltage value.
When the gain amplifier of adjusting amplifying circuit A, the input audio signal amplitude that makes process is when just reaching the magnitude of voltage that needs amplitude limit, and the diode among the amplitude limiter circuit B just begins conducting.
Based on same principle, amplifying circuit A also can use other known amplifying circuits, realizes as using operational amplifier, perhaps uses the transistor grounded emitter amplifier of standard etc.
By the utility model, use the nonlinear characteristic of diode, make audio frequency automatic amplitude limit when amplitude is excessive, guaranteed the sound accompaniment power amplifier and the loud speaker trouble free service of back level, circuit is simple and reliable, and the cost of increase is extremely low.The utility model increases the one-level amplifying circuit before the general-purpose diode amplitude limiter circuit, by adjusting amplifier gain, realize the free adjustment of clip level, and cost is low, reliable operation.
The above only is preferred embodiment of the present utility model; not in order to restriction the utility model; all any modifications of within spirit of the present utility model and principle, being done, be equal to and replace and improvement etc., all should be included within the protection range of the present utility model.
Claims (3)
1. an amplitude limiter circuit that is used for audio-frequency power amplifier is characterized in that, comprises amplifying circuit A, amplitude limiter circuit B and adjusts circuit C;
Described amplitude limiter circuit B comprises the diode of two reverse parallel connections of an end ground connection; Be added to an end of described diode from the audio signal of amplifying circuit A after through a series resistance, and output to described adjustment circuit C;
Described adjustment circuit C is by the audio signal of two divider resistance adjustment from described amplitude limiter circuit B.
2. amplitude limiter circuit as claimed in claim 1 is characterized in that, described amplifying circuit A is a kind of transistor amplifier circuit.
3. amplitude limiter circuit as claimed in claim 2 is characterized in that, the multiplication factor of described amplifying circuit A, the amplitude that can amplify the audio input signal that needs amplitude limit, the turn-on voltage of the diode in the described amplitude limiter circuit B.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200920261928XU CN201699662U (en) | 2009-12-23 | 2009-12-23 | Amplitude limiting circuit for audio power amplifier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200920261928XU CN201699662U (en) | 2009-12-23 | 2009-12-23 | Amplitude limiting circuit for audio power amplifier |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201699662U true CN201699662U (en) | 2011-01-05 |
Family
ID=43400907
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200920261928XU Expired - Fee Related CN201699662U (en) | 2009-12-23 | 2009-12-23 | Amplitude limiting circuit for audio power amplifier |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201699662U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102655434A (en) * | 2011-03-02 | 2012-09-05 | 苏州英诺迅科技有限公司 | Power detector of radio frequency power amplifier |
-
2009
- 2009-12-23 CN CN200920261928XU patent/CN201699662U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102655434A (en) * | 2011-03-02 | 2012-09-05 | 苏州英诺迅科技有限公司 | Power detector of radio frequency 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: 20110105 Termination date: 20121223 |