Hello!
I have designed a 14V/700mA power supply using TNY277PN for a High power LED module. No bias winding has been used and a 13V Zener feedback is used with a bypass cap of 0.1uF. I observe that when i connect a 350mA load it functions normally, but when i give it a 700mA load, it does not switch on at all. All component values are as per 14V/700mA design only. Also for the 350mA load, if i switch the input on/off 2-3 times, the power supply does not switch on after the first time. It then has to be switched off for about a 1-2 min, then it comes on again. What could be the problem? Please advise. Thanks!
Benjamin.