Abstract
With the development of people’s living standards, the hi-fi audio system and family
video system have come into people’s life. It’s no longer a dream to establish a suitable and
favorable hi-fi audio system as people’s desires for electronic products are becoming stronger.
Under the guidance of the ratio between quality and price, considering the basic
technical index, the essay discusses the ordinary multi- media hi-fi audio amplifiers. The
content of the essay develops from shallow to profound, and is illustrated with diagrams to
introduce the structures and relative knowledge of the household audio system, and also the
detailed working procedures, including the entry of front extending circus, volume controller,
voice dealing circus, efficiency extending circus and supply circus. And meanwhile the essay
describes the features of the main chip and also on how to use and to learn from this system.
I’ve tried my best to make the language of this essay easy and simple for readers, and with
every wish that they can learn something useful from my works: how to make an audio
system, and how to choose the right materials for it.
As per techniques, the design chiefly adopts the integrated chips. In this design, I
adopted the NS’s LM4610N with 3D voice encircling function as the leading chips, by
changing the voltage of direct circus to control the volume. The front amplifier is the “Master
of amplifier” NE5532, with the typical increase 20dB. The rear efficiency amplifier also
adopts NS’s LM1875, every step two pieces, bridging into BTL push-pull circus so as to
achieve the higher efficiency and better voice. Besides, for customers’ convenience, the
system can timely be turned of f automatically when there is no signal.
At the end of my essay, I also state about the difficulties and problems during my
design and test, the ways to solves these problems and also offer some standard national
testing approaches for reader’s references.
Key words: 3D encircling; Integrated chips; Voltage controller of direct current; BTL;
Automatically turned off without signal;
