I want to generate a 120V DC output voltage based on the reference design in LinkSwitch-HP datasheet. The related schematic is attached. Now, when there is 110 V ac 50 Hz input, the output voltage rise to around 50 V then it will slowly go down to zero. Then will rise again. The related figure is also attached. However, when there is 220 V ac 50 Hz input, the output voltage will maintain zero.
Can anybody explain what happened to my circuit? Thank you for your help.