Issue with FlyBack AC/DC Converter - Output 5V, 500mA

Thread Starter

morethegr8

Joined Feb 14, 2011
31
Hello,

Im using LinkSwitch II - LNK615DG for my design.

Problems:

When i connect this circuit to AC mains - 230VAC. Bridge diode and fuse Blows.
I replaced MB8S with General purpose diodes 1N4007 and i started circuit with series test lamp setup.
Now the circuit shows output of 1.8 ~ 2.45 VDC and is not stable.

Kindly help me debug the circuit as i don't have Variac and working at 230VAC is highly dangerous.

Thanks in advance.

Design Reference:
3.25 W CV/CC Charger Using LinkSwitchTM-II
That Meets New 2011 European Standards.


upload_2016-3-20_21-48-50.png
 

Dodgydave

Joined Jun 22, 2012
9,632
Its a Transformerless psu, so unless you want to have it closed down stick a transformer on the input first,

So what is the chip T1 doing, is it a smpsu type, also U1?
 

Thread Starter

morethegr8

Joined Feb 14, 2011
31
Its a Transformerless psu, so unless you want to have it closed down stick a transformer on the input first,

So what is the chip T1 doing, is it a smpsu type, also U1?

Its custom made Hi freq Transformer . with specs same as given in design data.
T1 is EE16 Transformer.
U1 is LNK605/615DG

Design is same as shown in image below.

upload_2016-3-20_22-18-21.png
 

Thread Starter

morethegr8

Joined Feb 14, 2011
31
Hi, Dodgydave.

I changed my transformers. Now the issue is output goes upto 8V.

I think i have problems with feedback loop of the transformer.
 
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