need to convert this into Universal Input SMPS
Hello there,
We have been manufacturing this 24V/5A SMPS for a very long time having an input voltage of 195-285 VAC but one of our clients needs the same in 85-265 VAC please suggest ways to convert this into a universal Input SMPS. We are ok with the new transformer of same core type having minimum components changes
评论
thank you so much for the suggestion, it actually worked
but we are facing a new problem which is as follows:
we tuned it to 24V at no load but at 4apm load the voltage drops to 21v hoe to minimise this gap
Hi Oki,
There are major changes needed when changing input range from high line (195-285V) to universal line (85-265V) for the TopSwitch.
In your current design, you are using TOP267EG for high line. However, for universal line, you need to upgrade the IC to higher variant since you will need higher input current to deliver the needed output for low input voltage. For 120W, you may need to use TOP269 or higher to have optimal operation. With the change of the IC, a transformer construction change is also needed.
Regarding the schematic, some of the component values will change such as V pin line resistors, and input capacitor. I created a sample design, please see attached file.
Regards,
PI-Nanoe
| Attachment | 大小 |
|---|---|
| TOPSwitch-JX_PIDesign2_0.pdf (2.38 MB) | 2.38 MB |
change R9/R10 to total resistance of 4Mohm