TNY 289 OUTPUTS FLUCTUATIONS AND OUTPUT DROPS WHEN I DRAW THE CURRENT

Posted by: Tarun on 07/30/2018

Hi PI Team,

Here I have designed a SMPS for the output of +18 and -18V with a current rating of 0.5A.
The output of the +18V varies from +22V to +25V and where as negetive output remains +25V stable.
When I connect the Load to the output the output suddenly goes to zero and keep variying.

Kindly suggest the solution. Here I have attached the schematic

Files

18 - 0 - 18 /0.5A (2.85 MB)

Comments

Hi Tarun,
You're schematic won't run. One of your output is in flyback condition while the other is in forward.
Regards,
Jedidiah

Hi PI team

This schematic & transformer is designed using PI Expert suite.
Kindly tell me what are the corrections to be made in the schematic to make it work.

Hi Tarun,
Let's try changing the regulator circuit. Attached here is the schematic for TL431 for the modified secondary circuit.
Regards,
Jedidiah

Attachment	Size
18V_-18V_dual_output.png (51.87 KB)	51.87 KB