Audio transformer is a transformer that works in the audio range, also known as a low-frequency transformer. Operating frequency range - generally from 10-20000Hz. It is often used to change the impedance of voltage or load. In radio communication, radio and television, automatic control as a voltage amplifier, power output circuit components. Audio transformers can be divided into three categories according to their position in the electronic circuit. 1: connected between the output circuit and the load is called the output transformer :2: connected between the signal source and the amplifier input is called the input transformer :3: connected between the upper level output circuit and the next level of the input circuit is called the interstage transformer. When used, attention should be paid to the matching of the impedance of the front and back stages to avoid signal distortion due to reflection. Audio transformers do not replace electronic audio signal amplifiers. This is the main difference between the two. Audio transformer EI14 is suitable for electric car alarm, telephone, radio, flapper, buzzer, bird call doorbell and other products drive