Power supplier 220VAC to 3VAC

[Neeeeeeeeeel]

Hello, I joined here because I need help making a power supplier.

I know how to made 220VAC to 12VDC, but I didn't found information about what I need. The thing is that I bought something outside my country and the power supplier was 110VAC to 3VAC so you can imagine what happend when I connected to 220VAC xD
Here in my country I cant get something like this so I decided to make one, i know it's not too difficult. I need at least 100mA...

any information that you have will be useful to me since electronics it's not my area xD i'm studing computer enginnering...

Thanks in advance for your help

 

[(*steve*)]

I would recommend you go out and purchase a cheap plugpack rated for 12V output and at least 100mA.

 

[Neeeeeeeeeel]

I would recommend you go out and purchase a cheap plugpack rated for 12V output and at least 100mA.

Ones I found here have DC output... I need AC.

 

[(*steve*)]

Sorry, I misread that you wanted 220VAC -> 12VDC.

3VAC is an unusual output. Perhaps the easiest option would be to look for an old* switchable DC plugpack.

I have several that have a switch allowing you to select 6C, 7.5V, 9V, and 12V (as examples). Whilst these produce DC, the transformer inside them has various taps. You might be able to find a combination of taps giving you close to 3V AC.

The same thing can be done with any other transformer where there are multiple taps. If two of these taps differ by 3V, connect across them.

Be aware that by doing this you will be getting close to mains voltages and it has a nasty habit of killing people.

* It must be an old one with a transformer inside, not a newer switchmode plugpack.

 

[Neeeeeeeeeel]

Do you have any circuit diagram on how to make it (or a place where I can found one)? I mean, I would prefer to make it all instead of modifying one of them.

 

[(*steve*)]

Sure. Here is the circuit diagram

You might want to add a mains switch and a fuse (I'd certainly recommend the latter).

 

[Neeeeeeeeeel]

Sure. Here is the circuit diagram

You might want to add a mains switch and a fuse (I'd certainly recommend the latter).

As simple as that?

 

[(*steve*)]

Yep. A transformer does what you need.

However that's not the whole story.

Not shown on schematics are things like plugs, enclosures, mounting hardware, etc. Also it assumes you can get the right transformer (in this case a 220V to 2V transformer).

The hard part is getting the transformer, mounting it, making it safe, etc. And that's why I suggested basing the design on an existing plugpack where you can essentially remove everything but the transformer.