Need help from an expert in electronics and electricity

I think that i made a mistake, this should be in the prop building workshop... i dont know how it ended up here... sorry. Please admin move it to the right place.

thanks

Alfredo

Going from 220 to 9V is definitely a transformer requirement. No to mention, I am assuming that you are converting AC to DC in the process. Going from 9VDC to 3VDC is no big deal. That can be handled through a very small circuit board. If you were in the US I would suggest checking with Radio Shack, but I am sure you can find a solution on the web. Also, many DC items have an operating range. IN other words it may operate on anything between 6-12V, but it depends on the circuit. You may also need to know the current, but probably for the size application you are talking about, it will be insignificant.

Here is a link to a simple circuit that can be built to do what you are looking for.

http://www.elecfree.com/electronic/9...ter-by-lt1073/

You find pre-made circuits, but you can build this for next to nothing.

Thanks Astro Builder for your help. I do have a transformae that can change 220v to 3, 4.5, 6 , 9 or 12 volts. But if i use it with 9 volts, then i can not feed with the same one the 3 volt item. So i guess that what i need is something between the 9 volts and the device, to reduce the voltage to 3.....

Thanks

Alfredo

If you use a parallel circuit, with both loops at 9V, you can put a resistance into one loop at twice the resistance of the 3V load - that way the load would only receive 3V, while the other loop would get 9V.

Simples ......

Thanks again !!!