Electronic transformer is mainly composed of high-frequency transformer core (iron core) and two or more coils. They do not change the position of each other. From one or more electrical circuits, through AC power, with the help of electromagnetic induction, it is transformed into AC voltage and current. In the electronic circuit, it plays the role of boost, step-down, isolation, rectification, frequency conversion, phase inversion, impedance matching, inverter, energy storage, filtering and so on. 2. Working principle of electronic transformer

A simple transformer consists of a closed magnet and two windings, one of which is connected to the AC power supply, called the primary winding NP, and the other winding can be connected to the load, called the secondary winding ns. If the primary winding is connected with the power supply of AC voltage UI, the transformer is in no-load state, and the alternating power IO is generated in the primary winding. IO is called no-load current.

3. Working principle of electronic transformer

Electronic transformer is a switching power supply without voltage regulation, which is actually an inverter. First of all, the alternating current is rectified into direct current, and then a high frequency oscillator composed of electronic components is used to change the direct current into high-frequency alternating current, and the required voltage is output through the switching transformer, and then the secondary rectification is used for the use of electrical appliances. Switching power supply has the advantages of small size, light weight and low price, so it is widely used in various electrical appliances. According to the different driving modes of high frequency switches, they can be divided into self-excited oscillation type and other excitation type.

4. Working principle of electronic transformer -- Application

Electronic transformer is widely used in traditional lighting, such as fluorescent lamp, desk lamp, energy-saving lamp, advertising lamp and so on. After using electronic transformer, the starter can be omitted. In LED lighting, new products also mostly use electronic transformer. The main reason is that the electronic transformer has high efficiency, low cost, saving iron and copper materials, small structure and light weight. The disadvantage is that the withstand voltage and high current impulse performance is worse than that of iron transformer.