EPR-8 - 1.2 W, universal input, non-isolated power supply

This document presents the specifications, schematic and BOM, inductor calculations, test data and waveforms of a low-cost non-isolated converter for home appliance applications (triac driven). This power supply has three specific requirements: 1. To provide power for the driving test, the output power is required to be based on the input line (L), with no series impedance, so only 1/2 wave rectification is allowed, and the switch must be located on the return side of the primary switching circuit. If necessary, EMI filtering must be implemented at the system level. 2. The device must operate at an ambient temperature of 85°C. 3. The device must be able to withstand input surge voltages of 2 kV (configuration "1", page 4) and 6 kV (configuration "2", page 5) as defined by IEC 1000-4-5 (1.2/50 s) . Surge protection added to meet these requirements can reduce converter efficiency. It would be more beneficial (lower costs, higher efficiency) if surge protection was implemented at the system (equipment) level.