mahdiiust
Junior Member level 1
Hi
I’m trying to design a 5V/1.2A (6W) switching mode power supply using TNY 255. The schematic is below. I use EE19 core with Np= 273 turns, Ns=15 turns Lg=245 micron and Lp=6mH . But it doesn’t work properly. Some results are here :
Load (ohm) Vo (V) I (mA) P (W)
No load 5.48 - -
22 5.29 240 1.26
18.9 5.23 276 1.44
15.7 5.10 324 1.65
10.5 4.98 474 2.36
7.2 4.92 683 3.36
6.1 4.86 796 3.86
5.1 4.80 941 4.51
4.1 4.73 1153 5.45
What is the problem?
Thanks!
https://obrazki.elektroda.pl/9693394400_1455600472.png
I’m trying to design a 5V/1.2A (6W) switching mode power supply using TNY 255. The schematic is below. I use EE19 core with Np= 273 turns, Ns=15 turns Lg=245 micron and Lp=6mH . But it doesn’t work properly. Some results are here :
Load (ohm) Vo (V) I (mA) P (W)
No load 5.48 - -
22 5.29 240 1.26
18.9 5.23 276 1.44
15.7 5.10 324 1.65
10.5 4.98 474 2.36
7.2 4.92 683 3.36
6.1 4.86 796 3.86
5.1 4.80 941 4.51
4.1 4.73 1153 5.45
What is the problem?
Thanks!
https://obrazki.elektroda.pl/9693394400_1455600472.png