Problem with TOP247YN

Posted by: Ronaldo Lins on 07/27/2012

Hello,

Where I work we have a smps with input 85-265VCA/ouput 15V 2,2A. and I have a serious problem because some TOP247YN explodes. This happens intermittently, but as I don´t have very knowledge about smps, I would like that you help me about possible causes.

*In attached is an image of voltage between drain and Ground of TOP247YN.

Ronaldo Lins

Comments

Only for complementary, the exploses happened when the smps is lowest load.

thanks,

Ronaldo Lins

Ronaldo

I need to see more information about your design. COuld you please post your transformer design specifications? your schematic, The device blow up at low load, how much input voltage? any idea?

Dear PI-Worf:

I put attached images showing the behavior of my SMPS. All measurements with 220VAC/60Hz input and the TOP247YN explosion issue occurs from intermittent way, but many times when there is no load at output. I don´t have current probe, so these images are just from the circuit voltages, unfortunately. I also have another question: how can I know about lot identification on this encapsulation?

Thanks in advance.

Ronaldo; where is your schematic? I see an schemtic in the picture laveled as Power Transformer EPS1525A.pdf but this is not a TOP247 power supply, so please provide your actual complete schematic. Also, how did you make the decition when selecting the transformer you are using?

PI-Worf.

I'm sending in attachment the actual schematic of SMPS made with software PI-Expert. About the transformer, I selected according specifications of PI-Expert.

Please, is very important that I learn how know lot identification on this encapsulation.

It is essential to have drain current waveforms. Looks like something wrong with transformer such as phasing or pin-out. Duty cycle is too short.

I am design smps

of rating 24v 4A when i increase the load current above 500mA TOP247yn getting restarted and output voltage is not

building

kindly suggest me to spot the problem in the circuit.

kindly find the attached design file

Attachment	Size
TOPSwitch-GX_24v_4A_new.uds (753 KB)	753 KB

Thanks for Posting your question into forum. At what input voltage you are seeing this Problem?. If you are seeing this at low input voltage, increase the input voltage until you don't see the problem and note the reading of the input voltage where exactly the power supply able to regulate. Please go through the below trouble shooting guide for TOpSwitch Based Power Supplies:

http://ac-dc.power.com/design-support/product-documents/application-notes/an-14-topswitch-tips-techniques/

Regards,

PI-KSAN

I have tested the circuit from 100v to 240v Ac input supply from Auto Transformer.

Iam getting the output voltage 24.5v at No load condition.

on connecting my 50ohms resistive load the output led getting flickers.

i tried by changing the transfomer polarity also. I'm Getting the same issue.

I got my transformer winded my professional transformer maker's in local.

kindly suggest me to spot the correct problem the circuit.

Thanks and Regards.

Dasarathan