Having issue with SMPS circuit

[PriyanshuGupta]

I am currently working on a project to build a 240V AC to 5V 2A DC SMPS circuit. I have designed the circuit based on the standard flyback converter topology, but I’m facing some issues that I can't resolve. I hope someone here can guide me through troubleshooting this.

T1 -ee20 , 203T Primary 0.1mm, 4T Secondary 0.5mm
D5 - 1N4734A
R1 - 100k ohm
C5 - 103/1KV

 

[D.A.(Tony)Stewart]

Unless you define a problem, it is a problem!

 

[crutschow]

I’m facing some issues that I can't resolve. I hope someone here can guide me through troubleshooting this.

Hard to give troubleshooting advice when you haven't stated what the "issues" are.

 

[PriyanshuGupta]

the circuit keeps shorting out

 

[Easy peasy]

Oh - I can see the issue - there are unconnected pins on the control IC, Dóh !

 

[PriyanshuGupta]

Oh - I can see the issue - there are unconnected pins on the control IC, Dóh !

from the left out pins ,2 of them are NC (empty pins with no internal connections ) and 1 is OB ... i did not found any circuit using this pin.

 

[stenzer]

Hi,

what's the value of R4? Does the photocoupler gets enough current to be turned on /give feedback?

BR