The main aspects that engineers need to consider for LED power supply electromagnetic interference include circuit measures, EMI filtering, component selection, shielding, and printed circuit board anti-interference design.

In terms of component selection, it is generally believed that Schottky diodes have a greater impact. What are the methods to eliminate interference?

1. Reduce interference from the switching power supply itself

        In terms of soft switching technology, inductance and capacitance components are added to the original hard switching circuit. Switching frequency modulation technology: by modulating the switching frequency fc, the energy concentrated on fc and its harmonics 2fc, 3fc... is dispersed to the surrounding frequency bands. Schottky diodes with small reverse recovery current and short recovery time are ideal devices for high-frequency rectification in switching power supplies. Installing electromagnetic interference filters in the input and output circuits of switching power supplies

2. Cut off the propagation path of interference signals

        Use power line filters to filter out power line interference, improve the electromagnetic compatibility design of PCB boards, follow the general principles of PCB design, and comply with anti-interference design requirements.

3. Enhance the anti-interference ability of the interfered body

        Various isolation measures (such as photoelectric isolation or magneto electric isolation) should be taken to block the propagation of interference. For LED power systems used outdoors or for power and signal lines introduced indoors from outside, lightning protection of the system should be considered.

The main control technologies for electromagnetic interference in LED power supply include circuit measures, EMI filtering, component selection (Schottky diodes), shielding, and anti-interference design of printed circuit boards.