Hello Guys,

I just need everyones BIG help, I need to construct a 12VDC 6A rating power supply with 220VAC input, can someone help me with the circuit? I dont want to use big transformers, maybe can someone help me with a circuit having only small trasformer but have amplifier transistor, its value and how to do it.
Tahnk you very much.

 

Hi,

If it's a linear supply you want to make, there is really no practical way to get atound a stepdown transformer that can supply the current. You can look at the spec sheet for a 7812 regulator with an external transistor current booster.

A switcher will let you use a small transformer, but at the expense of a more elaborate circuit. Linear Technologies makes a line of SMPS controllers, and offers a free Switcher CAD program to help with the design.

 

And be careful with designing and assembling off-line switcher. I can only say it is not a recommended project for a beginner.

 

So what would power your "Amplifier Transistor"..??

Really, there is no way around a big transformer, unless you go with the very elaborate, tricky, and quite lethal Switch mode designs.