CN205178996U - Audio signal amplifier circuit - Google Patents
Audio signal amplifier circuit Download PDFInfo
- Publication number
- CN205178996U CN205178996U CN201521053942.2U CN201521053942U CN205178996U CN 205178996 U CN205178996 U CN 205178996U CN 201521053942 U CN201521053942 U CN 201521053942U CN 205178996 U CN205178996 U CN 205178996U
- Authority
- CN
- China
- Prior art keywords
- amplifier
- circuit
- connects
- resistance
- output
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Amplifiers (AREA)
Abstract
The utility model discloses an audio signal amplifier circuit, including current sampling circuit and the preamplification circuit that connects gradually, power amplification circuit, audio frequency protection circuit and audio output circuit, the audio frequency protection circuit including recommend the protection circuit and with recommend first comparator and the second comparator that the protection circuit meets and is used for reducing the audio signal crossover distortion, power amplification circuit's output meets with the input of recommending the protection circuit, the input of audio output circuit and the output of recommending the protection circuit meet, current sampling circuit's input meets with the output of audio output circuit, and current sampling circuit's output meets with power amplification circuit's input, the utility model relates to a fast trigger is carried out to recommending the protection circuit respectively through first comparator and second comparator to the novelty, adopts current sampling circuit to prevent to recommend the great electric current of protection circuit output and leads to audio output circuit pressure drop increase and the audio signal crossover distortion, and the practicality is strong.
Description
Technical field
The utility model belongs to power amplifier technology field, is specifically related to a kind of amplifier circuit for sound frequency signal.
Background technology
Along with the development of science and technology, audio-frequency power amplifier has developed into a stage of ripeness, in daily life, large little of earpiece audio output to high-power audio amplifier, we enjoying in various degree audio-frequency power amplifier bring our hearing enjoying, visible audio-frequency power amplifier and our life closely related, but, the effect that audio signal exports but is not very satisfactory, and we often can hear the audio signal of distortion; It is low to there is power amplifier efficiency in existing audio-frequency power amplifier, adopts switching tube conducting more, can single tube ON operation also can symmetrical operation, transistor dissipation is large, and the direct output cross distortion of the synchronous signal of push-pull power amplifier is serious, and interference is large; In order to make audio signal output effect good, the power amplification of many employing pulse-width modulation classes, but pulse-width modulation genus audio power amplifier cost is high and control is complicated, and program is loaded down with trivial details; Therefore; nowadays the amplifier circuit for sound frequency signal that a kind of structure is simple, volume is little, cost is low, reasonable in design is lacked; analog component is adopted to improve audio-frequency power amplifier; adopt the connected mode that power amplification separates with audio signal protection; power amplification circuit adopts the mode of two panels amplifier parallel connection to export; increase output current at double; power amplifier efficiency is high; employing is recommended protective circuit and is prevented cross distortion; circuit efficiency is high; speed is fast, and precision is high, strong interference immunity and control simple.
Utility model content
Technical problem to be solved in the utility model is for above-mentioned deficiency of the prior art; a kind of amplifier circuit for sound frequency signal is provided; it is rationally novel in design; structure is simple; by arranging the first comparator and the second comparator carries out rapid triggering to two triodes of recommending in protective circuit respectively simultaneously; adopt current sampling circuit to prevent from recommending protective circuit to export larger current and cause audio output circuit pressure drop increase and audio signal cross distortion, practical, be convenient to promote the use of.
For solving the problems of the technologies described above, the technical solution adopted in the utility model is: a kind of amplifier circuit for sound frequency signal, is characterized in that: comprise current sampling circuit and the pre-amplification circuit connected successively, power amplification circuit, audio protection circuit and audio output circuit; Described audio protection circuit comprises recommends protective circuit and to connect and for the first comparator of reducing audio signal cross distortion and the second comparator with described protective circuit of recommending, the output of described power amplification circuit connects with described input of recommending protective circuit, and the input of described audio output circuit connects with described output of recommending protective circuit; The input of described current sampling circuit connects with the output of audio output circuit, the output of described current sampling circuit connects with the input of power amplification circuit, described current sampling circuit is precision resistance R14, the signal follow circuit that described pre-amplification circuit comprises signal amplification circuit and connects with described signal amplification circuit output; Described power amplification circuit comprises amplifier U3 and amplifier U4, the in-phase input end of described amplifier U3 is through electric capacity C1 and resistance R6 ground connection, the inverting input of amplifier U3 is through resistance R10 ground connection, the output of amplifier U3 divides two-way, one tunnel connects with one end of resistance R9, and another road connects with the in-phase input end of amplifier U4; The output of amplifier U4 divides two-way, and a road connects with the inverting input of amplifier U4, and another road connects with the other end of resistance R9 through resistance R3; Described amplifier U3 and amplifier U4 all adopts the dual power supply of+15V power supply and-15V power supply.
Above-mentioned a kind of amplifier circuit for sound frequency signal, it is characterized in that: described signal amplification circuit comprises amplifier U1, the in-phase input end of described amplifier U1 divides three tunnels, and a road is through resistance R4 and+15V power supply, another road is through resistance R8 ground connection, and the 3rd tunnel connects with one end of resistance R5; The inverting input of amplifier U1 is through resistance R11 ground connection, and the output of amplifier U1 divides two-way one tunnel to be the signal output part of signal amplification circuit, and another road is through resistance R13 ground connection.
Above-mentioned a kind of amplifier circuit for sound frequency signal, it is characterized in that: described signal follow circuit comprises amplifier U2, the in-phase input end of described amplifier U2 connects with the signal output part of signal amplification circuit, the output of amplifier U2 divides two-way, one tunnel connects with the link of electric capacity C1 and resistance R6 through variable resistor R7, and another road connects with the inverting input of amplifier U2.
Above-mentioned a kind of amplifier circuit for sound frequency signal, it is characterized in that: described in recommend protective circuit and comprise NPN triode Q1 and PNP triode Q2, the collector electrode of described NPN triode Q1 connects with+15V power supply through resistance R2, the emitter of NPN triode Q1 connects with the emitter of described PNP triode Q2, the collector electrode of PNP triode Q2 connects with-15V power supply through resistance R16, the base stage of NPN triode Q1 connects with the anode of diode D1, the negative electrode of diode D1 connects with the anode of diode D3, the negative electrode of diode D3 connects with the base stage of PNP triode Q2, the negative electrode of diode D1 connects with the link of the link of the anode of diode D3 with the other end of resistance R3 and resistance R9, the emitter of NPN triode Q1 connects with the inverting input of amplifier U3 through precision resistance R14 with the link of the emitter of PNP triode Q2.
Above-mentioned a kind of amplifier circuit for sound frequency signal, is characterized in that: described first comparator comprises amplifier U5, and the inverting input of described amplifier U5 divides two-way, and a road connects with+15V power supply through variable resistor R1, and another road connects with the negative electrode of voltage stabilizing didoe D2; The plus earth of voltage stabilizing didoe D2, the in-phase input end of amplifier U5 connects with the collector electrode of NPN triode Q1 and the link of resistance R2, and the output of amplifier U5 connects with the link of the base stage of NPN triode Q1 and the anode of diode D1.
Above-mentioned a kind of amplifier circuit for sound frequency signal, it is characterized in that: described second comparator comprises amplifier U6, the inverting input of described amplifier U6 connects with the link of the collector electrode of PNP triode Q2 and resistance R16, the in-phase input end of amplifier U6 divides two-way, one tunnel is through variable resistor R15 ground connection, and another road connects with the negative electrode of voltage stabilizing didoe D4; The anode of voltage stabilizing didoe D4 connects with-15V power supply, and the output of amplifier U6 connects with the link of the negative electrode of diode D3 and the base stage of PNP triode Q2.
Above-mentioned a kind of amplifier circuit for sound frequency signal, it is characterized in that: described audio output circuit comprises loud speaker LS1, one end of described loud speaker LS1 connects with the link of the emitter of NPN triode Q1, the emitter of PNP triode Q2 and precision resistance R14 through electric capacity C2, the other end ground connection of loud speaker LS1.
The utility model compared with prior art has the following advantages:
1, the utility model is by arranging power amplification circuit, adopt amplifier U3 and amplifier U4, the output of amplifier U3 and the output signal short circuit of amplifier U4 is made to realize connected mode in parallel, output current increase at double can be realized by the resistance of regulating resistance R9 and resistance R3, power amplifier efficiency is high, circuit is simple, is convenient to promote the use of.
2, the utility model recommends protective circuit by setting, the gating of high low amplitude value can be carried out to the audio signal of power amplification, during circuit working, NPN triode Q1 and PNP triode Q2 only has a conducting at every turn, the little efficiency of conduction loss is high, by the first comparator, the amplitude signal of recommending protective circuit output is gathered, when there is spiking, between the emitter of NPN triode Q1 and base stage, pressure drop increases easy distortion, the quick output low level of amplifier U5 in first comparator makes NPN triode Q1 end, and avoids distortion serious; By the second comparator, the low amplitude value signal of recommending protective circuit output is gathered; when there is suddenly signal deletion, the emitter of PNP triode Q2 increases the same easily distortion of signal with pressure drop between base stage; and amplifier U6 in comparator exports high level fast that PNP triode Q2 is ended; avoid cross distortion; reliable and stable, result of use is good.
3, the utility model is rationally novel in design, and volume is little, and cost is low, controls simple, and adopt current sampling circuit to react audio output circuit output signal in time, feedback speed is fast, and line is convenient, practical, is convenient to promote the use of.
In sum; the utility model is rationally novel in design; by arranging the first comparator and the second comparator carries out rapid triggering to recommending protective circuit respectively simultaneously; adopt current sampling circuit to prevent from recommending protective circuit to export larger current and cause audio output circuit pressure drop increase and audio signal cross distortion; there is the function of HD Audio power amplification; practical, be convenient to promote the use of.
Below by drawings and Examples, the technical solution of the utility model is described in further detail.
Accompanying drawing explanation
Fig. 1 is schematic block circuit diagram of the present utility model.
Fig. 2 is circuit theory diagrams of the present utility model.
Description of reference numerals:
1-pre-amplification circuit; 2-power amplification circuit; 3-recommend protective circuit;
4-the first comparator; 5-the second comparator; 6-audio output circuit;
7-current sampling circuit.
Embodiment
As depicted in figs. 1 and 2, the utility model comprises current sampling circuit 7 and the pre-amplification circuit 1 connected successively, power amplification circuit 2, audio protection circuit and audio output circuit 6; Described audio protection circuit comprises recommends protective circuit 3 and connects and the first comparator 4 and the second comparator 5 for reducing audio signal cross distortion with described protective circuit 3 of recommending, the output of described power amplification circuit 2 connects with described input of recommending protective circuit 3, and the input of described audio output circuit 6 connects with described output of recommending protective circuit 3; The input of described current sampling circuit 7 connects with the output of audio output circuit 6, the output of described current sampling circuit 7 connects with the input of power amplification circuit 2, described current sampling circuit 7 is precision resistance R14, the signal follow circuit that described pre-amplification circuit 1 comprises signal amplification circuit and connects with described signal amplification circuit output; Described power amplification circuit 2 comprises amplifier U3 and amplifier U4, the in-phase input end of described amplifier U3 is through electric capacity C1 and resistance R6 ground connection, the inverting input of amplifier U3 is through resistance R10 ground connection, the output of amplifier U3 divides two-way, one tunnel connects with one end of resistance R9, and another road connects with the in-phase input end of amplifier U4; The output of amplifier U4 divides two-way, and a road connects with the inverting input of amplifier U4, and another road connects with the other end of resistance R9 through resistance R3; Described amplifier U3 and amplifier U4 all adopts the dual power supply of+15V power supply and-15V power supply.
In actual use, amplifier U3 in power amplification circuit 2 adopts with amplifier U4 the operational amplifier that parameter configuration is identical, the output of amplifier U3 is connected with the in-phase input end of amplifier U4 by the mode adopting homophase to amplify, amplifier U3 and amplifier U4 is exported equal, be shorted together after a resistance and amplifier U3 and amplifier U4 output have all been connected, the resistance of the resistance R3 that the resistance R9 connected by arranging amplifier U3 output is connected with amplifier U4 output is identical, realizes the function that output current increases exponentially.
As shown in Figure 2, in the present embodiment, described signal amplification circuit comprises amplifier U1, and the in-phase input end of described amplifier U1 divides three tunnels, and a road is through resistance R4 and+15V power supply, and another road is through resistance R8 ground connection, and the 3rd tunnel connects with one end of resistance R5; The inverting input of amplifier U1 is through resistance R11 ground connection, and the output of amplifier U1 divides two-way one tunnel to be the signal output part of signal amplification circuit, and another road is through resistance R13 ground connection.
In actual use, the other end connecting terminal Port1 in succession of resistance R5, splicing ear Port1 connects the audio signal of input.
As shown in Figure 2, in the present embodiment, described signal follow circuit comprises amplifier U2, the in-phase input end of described amplifier U2 connects with the signal output part of signal amplification circuit, the output of amplifier U2 divides two-way, one tunnel connects with the link of electric capacity C1 and resistance R6 through variable resistor R7, and another road connects with the inverting input of amplifier U2.
As shown in Figure 2, in the present embodiment, described protective circuit 3 of recommending comprises NPN triode Q1 and PNP triode Q2, the collector electrode of described NPN triode Q1 connects with+15V power supply through resistance R2, the emitter of NPN triode Q1 connects with the emitter of described PNP triode Q2, the collector electrode of PNP triode Q2 connects with-15V power supply through resistance R16, the base stage of NPN triode Q1 connects with the anode of diode D1, the negative electrode of diode D1 connects with the anode of diode D3, the negative electrode of diode D3 connects with the base stage of PNP triode Q2, the negative electrode of diode D1 connects with the link of the link of the anode of diode D3 with the other end of resistance R3 and resistance R9, the emitter of NPN triode Q1 connects with the inverting input of amplifier U3 through precision resistance R14 with the link of the emitter of PNP triode Q2.
As shown in Figure 2, in the present embodiment, described first comparator 4 comprises amplifier U5, and the inverting input of described amplifier U5 divides two-way, and a road connects with+15V power supply through variable resistor R1, and another road connects with the negative electrode of voltage stabilizing didoe D2; The plus earth of voltage stabilizing didoe D2, the in-phase input end of amplifier U5 connects with the collector electrode of NPN triode Q1 and the link of resistance R2, and the output of amplifier U5 connects with the link of the base stage of NPN triode Q1 and the anode of diode D1.
As shown in Figure 2, in the present embodiment, described second comparator 5 comprises amplifier U6, the inverting input of described amplifier U6 connects with the link of the collector electrode of PNP triode Q2 and resistance R16, the in-phase input end of amplifier U6 divides two-way, one tunnel is through variable resistor R15 ground connection, and another road connects with the negative electrode of voltage stabilizing didoe D4; The anode of voltage stabilizing didoe D4 connects with-15V power supply, and the output of amplifier U6 connects with the link of the negative electrode of diode D3 and the base stage of PNP triode Q2.
As shown in Figure 2, in the present embodiment, described audio output circuit 6 comprises loud speaker LS1, and one end of described loud speaker LS1 connects with the link of the emitter of NPN triode Q1, the emitter of PNP triode Q2 and precision resistance R14 through electric capacity C2, the other end ground connection of loud speaker LS1.
When the utility model uses, input audio signal through splicing ear Port1 be sent to pre-amplification circuit 1 carry out signal amplify and signal follow, power amplification is carried out by power amplification circuit 2 pairs of audio signals, amplifier U3 in power amplification circuit 2 and amplifier U4 adopts the operational amplifier and the connected mode raising power amplifier efficiency of employing parallel connection that parameter configuration is identical, high level is exported after power amplification circuit 2 pairs of amplitude signals amplify, recommend the NPN triode Q1 conducting in protective circuit 3, PNP triode Q2 ends, the in-phase input end voltage of the amplifier U5 now in the first comparator 4 is higher than anti-phase input terminal voltage, NPN triode Q1 conducting normally runs, when there is spiking, between the emitter of NPN triode Q1 and base stage, pressure drop increases, the in-phase input end voltage of the amplifier U5 in the first comparator is lower than anti-phase input terminal voltage, the quick output low level of amplifier U5 makes NPN triode Q1 end, precision resistance R14 simultaneously in current sampling circuit 7 gathers the current signal that audio output circuit 16 flows through, by the power stage of signal back power amplification circuit 2 regulating power amplifying circuit 2,
Output low level after power amplification circuit 2 pairs of low amplitude value signals amplify, recommend the PNP triode Q2 conducting in protective circuit 3, NPN triode Q1 ends, the in-phase input end voltage of the amplifier U6 now in the second comparator 5 is lower than anti-phase input terminal voltage, PNP triode Q2 conducting normally runs, when there is signal deletion, between the emitter of PNP triode Q2 and base stage, pressure drop reduces, the in-phase input end voltage of the amplifier U6 in the second comparator is higher than anti-phase input terminal voltage, amplifier U6 exports high level fast makes PNP triode Q2 end, precision resistance R14 simultaneously in current sampling circuit 7 gathers the current signal that audio output circuit 16 flows through, by the power stage of signal back power amplification circuit 2 regulating power amplifying circuit 2, control precision is high, cost is low.
The above; it is only preferred embodiment of the present utility model; not the utility model is imposed any restrictions; every above embodiment is done according to the utility model technical spirit any simple modification, change and equivalent structure change, all still belong in the protection range of technical solutions of the utility model.
Claims (7)
1. an amplifier circuit for sound frequency signal, is characterized in that: comprise current sampling circuit (7) and the pre-amplification circuit (1) connected successively, power amplification circuit (2), audio protection circuit and audio output circuit (6); Described audio protection circuit comprises recommends protective circuit (3) and to connect and for the first comparator (4) of reducing audio signal cross distortion and the second comparator (5) with described protective circuit (3) of recommending, the output of described power amplification circuit (2) connects with described input of recommending protective circuit (3), and the input of described audio output circuit (6) connects with described output of recommending protective circuit (3); The input of described current sampling circuit (7) connects with the output of audio output circuit (6), the output of described current sampling circuit (7) connects with the input of power amplification circuit (2), described current sampling circuit (7) is precision resistance R14, the signal follow circuit that described pre-amplification circuit (1) comprises signal amplification circuit and connects with described signal amplification circuit output; Described power amplification circuit (2) comprises amplifier U3 and amplifier U4, the in-phase input end of described amplifier U3 is through electric capacity C1 and resistance R6 ground connection, the inverting input of amplifier U3 is through resistance R10 ground connection, the output of amplifier U3 divides two-way, one tunnel connects with one end of resistance R9, and another road connects with the in-phase input end of amplifier U4; The output of amplifier U4 divides two-way, and a road connects with the inverting input of amplifier U4, and another road connects with the other end of resistance R9 through resistance R3; Described amplifier U3 and amplifier U4 all adopts the dual power supply of+15V power supply and-15V power supply.
2. according to a kind of amplifier circuit for sound frequency signal according to claim 1, it is characterized in that: described signal amplification circuit comprises amplifier U1, the in-phase input end of described amplifier U1 divides three tunnels, and a road is through resistance R4 and+15V power supply, another road is through resistance R8 ground connection, and the 3rd tunnel connects with one end of resistance R5; The inverting input of amplifier U1 is through resistance R11 ground connection, and the output of amplifier U1 divides two-way one tunnel to be the signal output part of signal amplification circuit, and another road is through resistance R13 ground connection.
3. according to a kind of amplifier circuit for sound frequency signal according to claim 2, it is characterized in that: described signal follow circuit comprises amplifier U2, the in-phase input end of described amplifier U2 connects with the signal output part of signal amplification circuit, the output of amplifier U2 divides two-way, one tunnel connects with the link of electric capacity C1 and resistance R6 through variable resistor R7, and another road connects with the inverting input of amplifier U2.
4. according to a kind of amplifier circuit for sound frequency signal according to claim 1, it is characterized in that: described in recommend protective circuit (3) and comprise NPN triode Q1 and PNP triode Q2, the collector electrode of described NPN triode Q1 connects with+15V power supply through resistance R2, the emitter of NPN triode Q1 connects with the emitter of described PNP triode Q2, the collector electrode of PNP triode Q2 connects with-15V power supply through resistance R16, the base stage of NPN triode Q1 connects with the anode of diode D1, the negative electrode of diode D1 connects with the anode of diode D3, the negative electrode of diode D3 connects with the base stage of PNP triode Q2, the negative electrode of diode D1 connects with the link of the link of the anode of diode D3 with the other end of resistance R3 and resistance R9, the emitter of NPN triode Q1 connects with the inverting input of amplifier U3 through precision resistance R14 with the link of the emitter of PNP triode Q2.
5. according to a kind of amplifier circuit for sound frequency signal according to claim 4, it is characterized in that: described first comparator (4) comprises amplifier U5, the inverting input of described amplifier U5 divides two-way, one tunnel connects with+15V power supply through variable resistor R1, and another road connects with the negative electrode of voltage stabilizing didoe D2; The plus earth of voltage stabilizing didoe D2, the in-phase input end of amplifier U5 connects with the collector electrode of NPN triode Q1 and the link of resistance R2, and the output of amplifier U5 connects with the link of the base stage of NPN triode Q1 and the anode of diode D1.
6. according to a kind of amplifier circuit for sound frequency signal according to claim 4, it is characterized in that: described second comparator (5) comprises amplifier U6, the inverting input of described amplifier U6 connects with the link of the collector electrode of PNP triode Q2 and resistance R16, the in-phase input end of amplifier U6 divides two-way, one tunnel is through variable resistor R15 ground connection, and another road connects with the negative electrode of voltage stabilizing didoe D4; The anode of voltage stabilizing didoe D4 connects with-15V power supply, and the output of amplifier U6 connects with the link of the negative electrode of diode D3 and the base stage of PNP triode Q2.
7. according to a kind of amplifier circuit for sound frequency signal according to claim 4, it is characterized in that: described audio output circuit (6) comprises loud speaker LS1, one end of described loud speaker LS1 connects with the link of the emitter of NPN triode Q1, the emitter of PNP triode Q2 and precision resistance R14 through electric capacity C2, the other end ground connection of loud speaker LS1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201521053942.2U CN205178996U (en) | 2015-12-16 | 2015-12-16 | Audio signal amplifier circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201521053942.2U CN205178996U (en) | 2015-12-16 | 2015-12-16 | Audio signal amplifier circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205178996U true CN205178996U (en) | 2016-04-20 |
Family
ID=55742924
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201521053942.2U Active CN205178996U (en) | 2015-12-16 | 2015-12-16 | Audio signal amplifier circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN205178996U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109495017A (en) * | 2018-12-21 | 2019-03-19 | 滨州学院 | A kind of broadband piezoelectric vibration energy harvesting system |
| CN111343747A (en) * | 2020-04-29 | 2020-06-26 | 横店集团得邦照明股份有限公司 | Circuit for enhancing load capacity of 0-10V dimming signal and implementation method |
-
2015
- 2015-12-16 CN CN201521053942.2U patent/CN205178996U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109495017A (en) * | 2018-12-21 | 2019-03-19 | 滨州学院 | A kind of broadband piezoelectric vibration energy harvesting system |
| CN111343747A (en) * | 2020-04-29 | 2020-06-26 | 横店集团得邦照明股份有限公司 | Circuit for enhancing load capacity of 0-10V dimming signal and implementation method |
| CN111343747B (en) * | 2020-04-29 | 2024-01-19 | 横店集团得邦照明股份有限公司 | Circuit for enhancing load carrying capacity of 0-10V dimming signal and implementation method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN204615772U (en) | A kind of audio power amplifying circuit | |
| CN205178996U (en) | Audio signal amplifier circuit | |
| CN104753477A (en) | Power amplifier and gain switching circuit thereof | |
| CN204652315U (en) | A kind of high-power amplifier drive circuit | |
| CN207354224U (en) | Power amplification circuit for speaker of voice box | |
| CN209448213U (en) | A kind of drive control device of semiconductor laser | |
| CN205160478U (en) | Electrocardiogram detector electrocardio signal amplification circuit | |
| CN203071876U (en) | High-fidelity transistor audio power amplifier | |
| CN204408277U (en) | Power amplifier | |
| CN104753483A (en) | Power amplifier and gain reduction circuit thereof | |
| CN208424741U (en) | A kind of power amplifier phonograph and line level switching circuit | |
| CN207504827U (en) | A kind of super class A bias circuit | |
| CN104639057A (en) | Audio amplification circuit provided with simple structure and used for computer | |
| CN201369813Y (en) | Audio power amplification circuit with constant output power selectability | |
| CN204362004U (en) | A kind of digital audio audio-amplifying circuit | |
| CN205195667U (en) | Intercom power amplification circuit | |
| CN204886882U (en) | Preamplifier | |
| CN218482838U (en) | High-fidelity amplifying circuit | |
| CN205040008U (en) | Earphone audio input switching circuit | |
| CN204578468U (en) | A kind of circuit realizing high efficiency class-A amplifier | |
| CN201717832U (en) | Super class A biasing circuit, | |
| CN210780688U (en) | Parallel output type multi-level class-D power amplifier | |
| CN204013410U (en) | A kind of computer broadband signal amplifier | |
| CN203775031U (en) | Power supply circuit and two-wire system electronic switching circuit using the power supply circuit | |
| CN208158550U (en) | A kind of HD Audio power amplification circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |