It is used as a component of voltage amplification, power output and other circuits in radio communication, broadcasting and television, and automatic control. The audio transformer has a uniform frequency response in the working frequency band, and its core is made of high-permeability materials. The primary and secondary windings are closely coupled, so that almost all the magnetic flux passing through the primary winding is linked with the secondary winding, and the coupling coefficient is close to 1. The lowest frequency of the passband is determined by the original winding inductance, and the highest frequency is determined by the transformer leakage inductance. To ensure that the transformer has enough pass band, the original winding inductance should be large and the leakage inductance should be small. The core's hysteresis loss and magnetic circuit saturation will cause signal distortion. Properly configure the load and increase the load current to reduce the effect of hysteresis loss; increase the core section and leave an air gap to prevent the magnetic circuit from being saturated, which can reduce signal distortion.

Audio transformer manufacturers transformers can be divided into 3 categories.

The one connected between the output circuit and the load is called the output transformer;

The one connected between the signal source and the amplifier input is called the input transformer;

The one connected between the output circuit of the previous stage and the input circuit of the next stage is called an interstage transformer.

Pay attention to the matching of the front and rear impedance when using it to avoid signal distortion due to reflection. In order to make the load obtain the maximum power, the load impedance should be the same as the impedance required by the power amplifier stage after transformation through the impedance of the output transformer, and it should not be too large or too small. After the audio signal is amplified by the audio transformer, the voltage can be increased, but the power is reduced due to the loss of the transformer. In this way, it cannot drive a larger load. Therefore, audio transformers cannot replace electronic audio signal amplifiers.

Audio transformer manufacturers tell you what are the functions

1. Audio signal coupling;

2. Realize the impedance matching of the front and rear stages;

3. Isolation of front and rear DC power supply circuits.

Generally the first two functions are commonly used. Due to the characteristics of the audio transformer itself, it is generally not used in high-quality audio amplifiers, but in circuits such as amplifier circuits and early electronic tubes, transistor radios and other circuits that do not require high sound quality.

It is necessary to understand the circuit's requirements for audio transformers when using it. For example, the input end of the Class A and B power amplifier circuit of the early transistor radios requires the completion of the phase inversion of the two half waves of the audio signal in order to amplify the power of the two half waves respectively. This is the input transformer; at the output end, the two half-waves must be synthesized, and finally fed to the speaker, this is the output transformer.

No matter which effect is achieved, the effect of the transformer reflecting (converting) the input impedance of the subsequent stage to the previous stage must be considered. When all these are taken into consideration, a suitable transformer can be selected or self-made to realize the function of the circuit.

Let me explain to you, when the transformer is in the circuit output, and then generate current, the equipment used in this entire transmission process is called the output transformer. We go from ce2 to rc2 to uo, these are all the processes of a transmission, ce1 and cb and re1 are connected, so that the t1, ri2/ui on the left follow the output and pass to B1, r21, r22 , B2 and ucc can be output directly, and streamed to the equipment you want to use.