transformer connections

working on a power supply for my arduino, it is a slightly older transformer that goes from 120 vac to 12v, the transformer itself is alot of copper wires wrapped in a circle with a big silver colored block of metal surrounding part of it, similar to this:

excpet take is not wrapped around the copper wires, the wires are exposed.

simply put i tore off the two wall socket connectors ( the two prongs ) and i see that directly connected to the two prongs is a TINY TINY TINY wire. Im woundering if this little tiny wire is what takes the full 120 vac to the transformer, or if somewhere deeper where the prongs were located there was another connection. im asking only because i never thought you chould run 120 vac through such a tiny wire without the wire heating up and melting/burning/ or something else. just wanted to make sure before i hook anything up so i don't go on getting myself electrocuted :)

Wire size is determined by the current designed to flow through it. On a step down transformer the primary is higher voltage but lower current then the secondary winding which will have lower voltage and higher current due to the turns ratio of the primary/secondary windings. The total power (voltage X current) that the transformer is designed to handle will determine the wire size for both windings.

Lefty

does that mean the tiny wires connected to the prongs are infact all that the prongs are connected to?

nope

there is 2 coils of wire in there

http://en.wikipedia.org/wiki/Transformer#Basic_principles

does that mean the tiny wires connected to the prongs are infact all that the prongs are connected to?

Most likely. I would have to see a picture of what you are trying to explain by prongs.

Lefty

Mr Big:

Is your insurance paid up?

Don

lol don i play it safe man don't worry, i always hook up heavy electricity to a power strip with an on and off button, and i haven't had an accident yet dealing with all of my electronics ( both high voltage and current, and low ). And lefty, when i say prongs, i simply mean the two metal pieces that stick right into the wall. for example every electrical appliance like a blender, or toaster has a cable, and u connect it into the wll using the two prongs on the end of the cable, those are the prongs i am referring to. I opened the transformer case, and when i tore out the prongs they were simply connected to little tiny wires ( one for each ).

I opened the transformer case, and when i tore out the prongs they were simply connected to little tiny wires ( one for each ).

Depending on the volts/amps rating of the transformer the primary AC wiring can be very small. To you have a rating for the transformer you are talking about?

Lefty

i did i think, but i threw out the casing :( .

Im very sure that the prongs were connected to those small wires. Looking into the groves of where the prongs were insterted, there is no otherp lace for connections, and theres only one solder place on the metal prong itsle,f and that is where i tore off the little wire. The only real info i can tell you is that the transformer is very similar to the one in the picture i posted above, and it changes electricity from 120 vac ( outlet power ) to 12v. I will just have to test this. ill just carefully hook all this up to an outlet, and make sure everything is nice and safe!

ill post back if i it works! ( don't be scared if i don't haha i forget sometimes! )

remember, tho its output is 12v its 12 volts AC