The high frequency of LED switching power supply is the direction of its development. High frequency makes the switching power supply miniaturized, and makes the switching power supply enter a wider application field, especially in the application of high-tech fields, which promotes the miniaturization and portability of high-tech products. In addition, the development and application of switching power supply are of great significance in saving energy, saving resources and protecting the environment. The electronic devices used in LED switching power supplies are mainly: LED diodes, IGBTs and MOSFETs. SCR has a small amount of application in switching power supply input rectifier circuit and soft start circuit. GTR is difficult to drive and the switching frequency is low, so it is gradually replaced by IGBT and MOSFET.

LED switching power supply: 1. The requirement must be constant current. 2. Low temperature, low heat and long life. 3. Small size. 4. Waterproof, anti-corrosion and anti-static. 5. High frequency pollution. The high-frequency pollution of ordinary switching power supplies is serious, and the waveform of the output DC is very complicated even if it is filtered with an inductance and a large capacitor. Poor power supply, the power supply itself may not be bad, but the LED life and light decay are greatly reduced.

1. Switch: Power electronic devices work in a switch state instead of a linear state

2. High frequency: Power electronic devices work at high frequency instead of low frequency close to industrial frequency

3. DC: The switching power supply outputs DC instead of AC