Introduction to the working principle of the power

Abstract: Amplifier is an important part of home theater, and its working principle is not complicated. Intuitively, it is to amplify various sound signals played by the sound source to promote the sound from the speaker. The main parameters of the power amplifier are output power, signal-to-noise ratio, input sensitivity, harmonic distortion, frequency response, damping coefficient, slew rate, etc. Let's take a look with Xiaobian next. Introduction to the working principle of power amplifier The working principle of the amplifier is actually very simple. Intuitively, it is to amplify various sound signals played by the sound source to promote the sound from the speaker. From a technical point of view, the power amplifier is like a current modulator. It converts AC power to DC power, and is controlled by the sound signal played by the sound source. It transmits different currents to the speakers at different frequencies, so that the speakers emit corresponding sizes. The sound of the corresponding frequency. Amplifier This picture was provided by registered user '蹇楀＋ 璞澃', copyright statement feedback Due to the consideration of power, impedance, distortion, dynamics, and different use ranges and control adjustment functions, different power amplifiers also have different signal processing, circuit design, and production processes. Traditional amplifiers have undergone decades of development, and there has been no special classification. Until recent years, with the development of audio and video playback equipment and the enrichment of film and television software, many audio manufacturers have made reference to the real cinemas on the basis of traditional amplifiers. The characteristics of sound playback, designed and produced a comprehensive type of power amplifier with different types and different technical characteristics. People call it AV amplifier, and accordingly the power amplifier that is simply used to enjoy music is called pure music power amplifier. According to the current consumer demand for audio, the amplifiers in civilian audio have basically been shaped into two categories, namely pure music amplifiers and home theater AV amplifiers. The main parameters of the power amplifier 1.Output power There are many output powers. Different manufacturers have different measurement methods and different names. Common ones include rated output power, average power, peak output power, and so on. The rated output power refers to the maximum power that the audio signal output by the amplifier can output within the total harmonic distortion range. The average power generally refers to the average power consumption at each frequency point, and the peak output power refers to the power from the peak of the positive voltage to the peak of the negative voltage. 2.Signal to noise ratio The larger the value of the signal-to-noise ratio, the better, indicating that the noise mixed in the signal is smaller and the playback quality is better, which is generally expressed as (S / N). As the signal-to-noise ratio and input signal level increase, the signal-to-noise ratio also gradually increases, but when the input signal level reaches a certain value, the signal-to-noise ratio remains basically unchanged. According to the current high-fidelity requirements, the signal-to-noise ratio should be more than 90dB, and imported high-end power amplifiers often reach 110-120dB. 3.Input sensitivity Input sensitivity refers to the minimum input signal level required by the power amplifier, and it is a necessary condition required to amplify the sound source signal enough to drive the subsequent power amplifier. 4. Harmonic distortion Harmonic distortion is an extremely important indicator of power amplifiers. It is caused by the non-linear characteristics of the amplifier during operation. The distortion results in the generation of new harmonic components, causing the sound to lose its original timbre. Broken and harsh. The biggest influence on the power amplifier is the degree of harmonic distortion. Generally high-fidelity requires that the harmonic distortion is below 0.05%, the lower the better. 5.Frequency response Frequency response refers to the half of the rated power frequency band width of the power amplifier when the harmonic distortion does not exceed the specified value, that is, the frequency band included between the two frequency points where the high and low ends fall by -3dB, also known as the power bandwidth . 6, damping coefficient The damping coefficient is a very important technical parameter that directly affects the sound quality of the bass. The damping coefficient can respond to the inertial movement of the speaker and generate a 'resistance' effect, so that the movement of the sound basin and the audio signal are synchronized. Quickly returned to zero. The larger the damping coefficient, the better the synchronization between the cone and the signal, the purer and cleaner the bass, and the better the playback effect. 7, conversion rate The conversion rate of the power amplifier greatly affects the quality and performance of treble playback. The faster the conversion rate, the better the treble sound quality, and the more accurately it can capture transient high-frequency information.