What Is a Personal Voice Amplifier?
An audio amplifier is a device that reconstructs the input audio signal on the output element that produces the sound. The reconstructed signal volume and power level must be ideal-truthful, effective, and low distortion. The audio range is about 20Hz ~ 20kHz, so the amplifier must have a good frequency response in this range (smaller speakers with limited frequency bands, such as woofer or tweeter). Depending on the application, the power varies widely, from milliwatts of headphones to watts of TV or PC audio, to tens of watts of "mini" home stereo and car audio, to more powerful home and business audio With hundreds of watts or more, the system is large enough to meet the sound requirements of the entire movie theater or auditorium.
- Audio amplifier is one of the important components of multimedia products and is widely used in the field of consumer electronics. Linear audio power factor
- There are many types of audio power amplifiers. There are more than ten types of A, B, AB, C, D, E, F, G, H, S, etc., but only suitable for audio applications. There are four types: A, B, AB and D.
- The purpose of audio amplification is to reproduce the audio input signal with high efficiency and low distortion on the sound output element at the required volume and power level. The frequency range of the audio signal is 20Hz ~ 20KHz, so the audio amplifier must have a good frequency response. Audio amplifiers are usually made up of
- The following is a brief introduction of AN7115 audio power amplifier circuit.
- AN7115 under V = 9.0V, THD = 10%, RL = 8, the output power can reach 2.1W, and the noise output is 3mV.
- Limit parameters: Vcc = 13V, dissipated power (without heat sink) is 1.2W, and with heat sink is 2.25W. Working temperature: -20-70 , suitable for small portable radio cassette recorders and audio equipment as power amplifiers.
- Figure 4.AN7115 application circuit
- TDA2030 uses a V-shaped 5-pin single in-line plastic package structure. As shown in Figure 3, according to the shape of the pin can be divided into H-type and V-type. The integrated circuit is widely used in car stereo radio recorders and mid-power audio equipment, and has the characteristics of small size, large output power, and small distortion. And has internal protection circuit. The Italian SGS company, the American RCA company, the Japanese Hitachi company, and the NEC company all produce similar products. Although the internal circuits are slightly different, the lead pin positions and functions are the same and can be interchanged.
- Circuit characteristics:
- 1) Very few external components.
- 2) The output power is large, Po = 18W (RL = 4).
- 3) Ultra-small package (TO-220) can be used to increase assembly density.
- 4) Startup impact is minimal.
- 5) Contains various protection circuits, so the work is safe and reliable. The main protection circuits are: short circuit protection, thermal protection, accidental open ground, reverse polarity of power supply (Vsmax = 12V), and load dump voltage recoil.