Switching supply 12 V DC 3A

[zeeekay]

Hi.. I need to design a switching power supply with 220 V AC (50 Hz) input and 12 V DC 3A output. The design must not use a transformer (need to be embedded in small 2.5'' by 2.5'' assembly). I will be thankful if along schematic solutions, some one may contribute with reading material regarding switching supply designs.
Thanks.

 

[alexan_e]

You probably mean something like
Google Translate http://radio-konst.narod.ru/moi_konstrukcii/polumostov_preobr/polumostov_preobr.html
which has a small output transformer

Also check
Google Translate http://www.classd.fromru.com/circuits/ir2153converter.html

Read some theory
SMPS (Switching Power Supply)- Design Tutorials, Circuit Diagrams

If you design a psu like that then you need to be careful and design a safe circuit because this is a high voltage design.
I also find difficult the part of building/finding the appropriate inductor/transformer.

My suggestion would be to buy a ready 12V pulse psu which are available for computers and especially since you want a very common output voltage.
You can find ready psu like the one in the picture (12v/5A) in prices starting from $8 including shipping in ebay (from HK sellers)



Alex

 

[zeeekay]

Thanks Alex .. Thank you very much for such helpful reply....

 

[alexan_e]

This is also a nise web page with online calculator for different switching topologies and explanation of the operation.


and another tutorial
**broken link removed**

Alex