[earthflyer]

Anyone has any good website in showing building a 5Vdc Psu using 230V AC transformer.

 

[FallenAngel]

Uhm... with a question like that, don't. Line voltages can kill, but mostly, they just hurt.

I'm assuming your transformer is 230V input with 5VAC output?

 

[earthflyer]

230V AV input with 12V AC output. Just like to know what type of circuit will step down the 12V AC to 5V DC 2A. Wish to build one 5V dc for my squeezebox3

 

[FallenAngel]

That size drop is fairly hard for a regulator. You can build a TREAD, but use LM338 with a BIG heatsink. Maybe add a power resistor after the diode bridge to drop it lower.

 

[Uncle Erik]

I don't know of a specific website, but run searches about building a DC power supply. There are more considerations than just voltage. How many amp's do you need to draw? How are you going to rectify AC into DC? Do you need regulated power? How much filtering do you want? There are other considerations, too. Since you already know the voltage requirement, look into how many amps you need. Then read up on the other design considerations.

 

[earthflyer]

I will be drawing a max of 2A. Yah..i will be needing linear regulated power. Think of using a full wave rectify. For filtering part, I really have no idea. Was hoping someone can help me with that.

 

[rds]

Filtering is just done with capacitors.
The ripple voltage is inversely proportional to the filter capacitance. So big is good. 2000 uF is probably a good number. Those will be electrolytic. Then you want a least one film cap with low esr to filter out the high frequency portion of the ripple. 2 uF film would be good. Just to go the extra mile you can add a 0.02 uF film or ceramic as well. That should give very good filtering.

 

[Fixz8]

Is there any reason you couldn't use a DC-DC buck converter?

 

[BrianDonegan]

Although the Sueezebox is rated for a 2A supply, it will never actually draw that much. A 1.5A supply will do just fine, meaning a simple LM317 regulator will fit the bill. Check it's datasheet for 99% of what you need to know.