The invention discloses a power amplifying circuit. The circuit is further improved on the basis of the patent (patent number 2014102378062) that I have applied for. The first major improvement is that, on the basis of the original circuit, the circuit adds two series diodes to the base of the two symmetrical NPN inputs and the PNP triode, which can ensure the quiescent current of the circuit is very stable. Second major changes, in part because of the power amplifier, the output impedance of two NPN and PNP Emission Triode symmetrical polar input tube collector, the driving circuit of the input impedance is also great, than the original patent (Patent No. 2014102378062) to enhance the impedance of thousands of times, reached the purpose of impedance matching. This circuit uses the positive and negative high voltage are respectively connected with two large resistance, the other side of the two large resistor are respectively connected with the input of the symmetrical polar emission of two NPN PNP and the collector electrode of the triode, and each connected to a zener diode, the other end of the two zener diode driving two symmetrical emitter follower, the final synthesis of an output voltage. The audio power amplifier circuit voice clear, very real, thick, beautiful.
【技术实现步骤摘要】
一种功率放大电路
本专利技术为一种电子线路,可实现交流信号的功率放大。
技术介绍
本专利技术是在本人已公开专利(专利号2014102378062)基础上的重大改进。附图1为已公开的专利2014102378062的电路,该电路由一系列对称的晶体管构成,可把交流信号一分为二为上下半周的电流信号,然后上下半周分别进行电流放大,最后在输出级合二为一完整的信号。该电路输入两端的静态电势差很容易做到1毫伏以内,并且在输入信号变化时,输入两端的静态电势差变化很小,所以在某些场合可以代替运放。但是该电路存在两个问题。第一个问题是该电路的静态工作电流不稳定,实践证明,附图1的电路NPN管Q7和PNP管Q8的静态电流存在不稳定,只有用较高集电极耐压的三极管才堪用,但较高集电极耐压的三极管有时并不适合用于某些场合,比如音频功放,实用性受到限制。第二个问题是,NPN管Q7和PNP管Q8的集电极的输出阻抗很高,而功率放大三极管NPN管Q5和PNP管Q6的基极输入阻抗很低,阻抗不匹配,对于音频功放而言,这也影响了音质。本专利技术可以完美解决上述两个问题。
技术实现思路
附图1是已公开专利(专利号2014102378062)的电路示意图,附图2是本次重大改进后的电路示意图。如说明书附图2所示,已公开的专利2014102378062的电路,NPN管Q7和PNP管Q8的基极之间并没有两个串联的二极管,这导致Q7和Q8的静态电流不稳定。本专利技术在NPN管Q7和PNP管Q8的基极之间加上两个串联的二极管,并串联两个电阻。R2的阻值远小于R1,R4的阻值远小于R3。这可以保证NPN管Q7和PNP管 ...
【技术保护点】
如附图2所示,电路特征是:在NPN管Q7和PNP管Q8的基极之间加上两个串联的二极管,并串联两个电阻,在NPN管Q7和PNP管Q8的发射极上各串接了一个电阻,R2的阻值远小于R1,R4的阻值远小于R3,这可以保证NPN管Q7和PNP管Q8的集电极电流稳定。
【技术特征摘要】
1.如附图2所示,电路特征是:在NPN管Q7和PNP管Q8的基极之间加上两个串联的二极管,并串联两个电阻,在NPN管Q7和PNP管Q8的发射极上各串接了一个电阻,R2的阻值远小于R1,R4的阻值远小于R3,这可以保证NPN管Q7和PNP管Q8的集电极电流稳定。2.如附图2所示,电路特征是:采用较高的正电压接上大电阻R9,R9的另一端接上NPN管Q7的集电极,同时接上...
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