CN208623634U - A kind of power amplification circuit - Google Patents

Abstract

The utility model discloses a kind of power amplification circuits, the power amplification circuit is on the basis of patent 2014102378062 that I has applied, further there is significant improvement, first item significant improvement is, this circuit is on the basis of primary circuit, it added two concatenated diodes between symmetrical two NPN and the base stage of PNP triode of emitter input, it is ensured that the static working current of circuit is highly stable；Section 2 significant improvement is, in power amplifying part, since the output impedance of the collector of symmetrical two NPN and PNP triode of emitter input is very big, the input impedance of its this circuit driven is also very big, thousand times or more are improved than former 2014102378062 impedance of patent, has achieved the purpose that impedance matching.

Description

A kind of power amplification circuit

Technical field

The utility model is for a kind of electronic circuit, it can be achieved that the power amplification of AC signal.

Background technique

The utility model is significant improvement on the basis of publication (patent No. 2014102378062).Attached drawing 1 is The circuit of published patent 2014102378062, the circuit are made of a series of symmetrical transistors, can be AC signal one It is divided into two for the current signal of upper lower half, then upper lower half carries out Current amplifier respectively, is finally combined into one in output stage Complete signal.The Static Electro potential difference at circuit input both ends is easily done within 1 millivolt, and is changed in input signal When, the Static Electro potential difference for inputting both ends varies less, so can replace amplifier in certain occasions.But there are two for the circuit Problem.First problem is that the static working current of the circuit is unstable, in practice it has proved that, circuit NPN the pipe Q7 and PNP of attached drawing 1 The quiescent current of pipe Q8 only may be just used with the triode of higher collector pressure resistance there are unstable, but higher collector is pressure-resistant Triode be not appropriate for sometimes for certain occasions, for example audio frequency power amplifier, practicability are restricted.Second Problem is NPN The output impedance of the collector of pipe Q7 and PNP pipe Q8 is very high, and the base stage of power amplification triode NPN pipe Q5 and PNP pipe Q6 are defeated It is very low to enter impedance, impedance mismatch, for audio frequency power amplifier, this also affects sound quality.The utility model can be solved perfectly Above-mentioned two problems.

Utility model content

The purpose of this utility model is to provide a kind of power amplification circuits, to solve the above problems.

To achieve the above object, the utility model provides the following technical solutions a kind of power amplification circuit, it is characterised in that: Big resistance R9 is connected using 220V positive voltage, the other end of R9 connects the collector of NPN pipe Q7, while connecting zener diode D1 Negative terminal, big resistance R10 is connected using 220V negative voltage, the other end of R10 connects the collector of PNP pipe Q8, while connecting steady The anode of diode D2 is pressed, the value of R9, R10 will guarantee collector electricity of the electric current thereon greater than NPN pipe Q7 and PNP pipe Q8 Stream, the anode of zener diode D1 connect the emitter follower by pushing NPN pipe Q10 and power NPN pipe Q12 to constitute, pressure stabilizing two The negative terminal of pole pipe D2 connects the emitter follower being made of promotion PNP pipe Q11 and power P NP pipe Q13, be finally synthesizing one it is defeated Voltage out is added on load Rload, two concatenated diodes is added between the base stage of NPN pipe Q7 and PNP pipe Q8, and go here and there Join two resistance, a resistance has respectively been concatenated on the emitter of NPN pipe Q7 and PNP pipe Q8.

Preferably, the positive current being added on the emitter of NPN pipe Q7 and PNP pipe Q8, it is ensured that the emitter of NPN pipe Q7 Electric current reduce and the electric current of the emitter of PNP pipe Q8 increase it is very close.

Preferably, the negative current being added on the emitter of NPN pipe Q7 and PNP pipe Q8, it is ensured that the emitter of NPN pipe Q7 Electric current increase and the reduction of the emitter of PNP pipe Q8 increase it is very close.

Preferably, the base stage input impedance of the base stage input impedance of the NPN pipe Q10 of shown circuit and PNP pipe Q11, it is long-range In resistance R9, R10.

Compared with prior art, the utility model has the beneficial effects that the power amplification circuit is in published patent On the basis of (patent No. 2014102378062), further there is significant improvement, first item significant improvement is that this circuit is in former electricity On the basis of road, it added two concatenated two poles between symmetrical two NPN and the base stage of PNP triode of emitter input Pipe, it is ensured that the static working current of circuit is highly stable；Section 2 significant improvement is, in power amplifying part, due to transmitting The output impedance of the collector of symmetrical two NPN and PNP triode of pole input is very big, the input of this circuit of driving Impedance is also very big, improves thousand times or more than former patent (patent No. 2014102378062) impedance, has reached the mesh of impedance matching , this circuit connects two big resistance using higher generating positive and negative voltage respectively, and the other end of two big resistance connects transmitting respectively The collector of symmetrical two NPN and PNP triode of pole input, while a zener diode is respectively connected, two pressure stabilizings two The other end of pole pipe drives two symmetrical emitter followers, an output voltage is finally synthesizing, using the audio function of this circuit Sound reproduction sound articulation and clear, it is very really, thick and heavy, it is graceful.

Detailed description of the invention

Fig. 1 is the circuit diagram 1 of published patent 2014102378062；

Fig. 2 is the utility model circuit connection diagram.

Specific embodiment

The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are without making creative work Every other embodiment obtained, fall within the protection scope of the utility model.

Referring to FIG. 1-2, as shown in Figure of description 1, it has been disclosed that patent 2014102378062 circuit, NPN pipe Q7 There are two concatenated diodes between the base stage of PNP pipe Q8, this causes the quiescent current of Q7 and Q8 unstable, moreover, The output impedance of the collector of NPN pipe Q7 and PNP pipe Q8 is very high, and the base stage input impedance of power amplification triode is very low, resistance Anti- mismatch, therefore, the utility model provide a kind of technical solution: a kind of power amplification circuit, it is characterised in that: use 220V Positive voltage connects big resistance R9, and the other end of R9 connects the collector of NPN pipe Q7, while connecting the negative terminal of zener diode D1, Big resistance R10 is connected using 220V negative voltage, the other end of R10 connects the collector of PNP pipe Q8, while connecting zener diode The anode of D2, the value of R9, R10 will guarantee that electric current thereon is greater than the collector current of NPN pipe Q7 and PNP pipe Q8, pressure stabilizing two The anode of pole pipe D1 connects the emitter follower by pushing NPN pipe Q10 and power NPN pipe Q12 to constitute, zener diode D2's Negative terminal connects the emitter follower being made of promotion PNP pipe Q11 and power P NP pipe Q13, is finally synthesizing an output voltage, adds On load Rload, two concatenated diodes are added between NPN pipe Q7 and the base stage of PNP pipe Q8, and two electricity of connecting Resistance, has respectively concatenated a resistance, this can guarantee NPN pipe Q7's and PNP pipe Q8 on the emitter of NPN pipe Q7 and PNP pipe Q8 Collector current is stablized, and circuit is added in the positive current on the emitter of NPN pipe Q7 and PNP pipe Q8, it is ensured that the transmitting of NPN pipe Q7 The electric current of pole is reduced and the electric current of the emitter of PNP pipe Q8 increases closely, and circuit is added in the hair of NPN pipe Q7 and PNP pipe Q8 Negative current on emitter-base bandgap grading, it is ensured that the electric current of the emitter of NPN pipe Q7 increases and the reduction of the emitter of PNP pipe Q8 increase is non- Very close to, just can guarantee the voltage for being added in the emitter follower of lower half in this way, that is, NPN pipe Q10 base voltage and The base voltage of PNP pipe Q11 increases simultaneously or reduces the same amplitude, since triode is nonlinear device, in order to guarantee The curent change of upper lower half is very close, and the utility model has respectively concatenated one on the emitter of NPN pipe Q7 and PNP pipe Q8 The resistance in several hundred Europe, the base stage input impedance of the NPN pipe Q10 of shown circuit and the base stage input impedance of PNP pipe Q11, are much larger than Resistance R9, R10, by can be calculated, the load impedance of the collector of upper lower half NPN pipe Q7 and PNP pipe Q8 is very high, reachable Tens kilo-ohms, fundamentally solves the problems, such as impedance mismatch, simultaneously because the Current amplifier of upper lower half emitter follower Multiple is difficult equally in practice, but the input impedance of upper lower half emitter follower, that is, the base stage of NPN pipe Q10 are defeated Enter impedance and the base stage input impedance of PNP pipe Q11, is much larger than resistance R9, R10, therefore upper lower half NPN pipe Q7 and PNP pipe Q8 The curent change of collector is mainly reflected in resistance R9, the voltage change on R10, so this circuit can guarantee upper lower half Voltage gain is essentially the same.

Although the utility model is described in detail with reference to the foregoing embodiments, come for those skilled in the art Say, it is still possible to modify the technical solutions described in the foregoing embodiments, or to part of technical characteristic into Row equivalent replacement, within the spirit and principle of the utility model, any modification, equivalent replacement, improvement and so on should all It is included within the scope of protection of this utility model.

Claims (4)

1. a kind of power amplification circuit, it is characterised in that: connect big resistance R9 using 220V positive voltage, the other end of R9 connects The collector of NPN pipe Q7, while the negative terminal of zener diode D1 is connected, big resistance R10 is connected using 220V negative voltage, R10's The other end connects the collector of PNP pipe Q8, while connecting the anode of zener diode D2, and the value of R9, R10 will guarantee thereon Electric current be greater than NPN pipe Q7 and PNP pipe Q8 collector current, the anode of zener diode D1, connect by push NPN pipe Q10 and The emitter follower that power NPN pipe Q12 is constituted, the negative terminal of zener diode D2 are connected by promotion PNP pipe Q11 and power P NP pipe The emitter follower that Q13 is constituted, is finally synthesizing an output voltage, is added on load Rload, NPN pipe Q7's and PNP pipe Q8 Two concatenated diodes are added between base stage, and two resistance of connecting, respectively go here and there on the emitter of NPN pipe Q7 and PNP pipe Q8 A resistance is connect.

2. power amplification circuit as described in claim 1, it is characterised in that: be added on the emitter of NPN pipe Q7 and PNP pipe Q8 Positive current, it is ensured that the electric current of the emitter of NPN pipe Q7 is reduced and the electric current of the emitter of PNP pipe Q8 increase it is very close.

3. power amplification circuit as described in claim 1, it is characterised in that: be added on the emitter of NPN pipe Q7 and PNP pipe Q8 Negative current, it is ensured that the electric current of the emitter of NPN pipe Q7 increases and the reduction of the emitter of PNP pipe Q8 increase it is very close.

4. power amplification circuit as described in claim 1, it is characterised in that: the base stage of the NPN pipe Q10 of shown circuit inputs resistance Anti- and PNP pipe Q11 base stage input impedance, is much larger than resistance R9, R10.