I wanna use a transformer to convert AC voltage. 220V AC ------ for example, 5V 30mA AC. Many people told me, this transformer will be huge big. because the main frequency is huge low But, I check something about the transformer design, still have no idea, how big it will be. (BTW, 50Hz main Fre is so low, I am not sure if the transformer could magnetize..., maybe need big Fe core....)

For my converting requirement, and take Piezo transformer or any other high-advanced transformer design (like pcb stack twisting transformer) for example (smaller, better). How large it will be  ? Suprise me.

(I have no idea about the transformer design, I mean, how thick the conventional coil wire, etc. I just know the basic equations Vin x Iin = Vout x I out...some text book stuff, no experimental experience.)

I want to use a transformer to convert AC voltage. Input is 220V AC at 50 Hz and output is, for example, 5V 30mA AC.

Many people told me, this transformer will be huge because the mains frequency is low. But, I still have no idea, how big it will be. (BTW, 50Hz main Frequency is so low, I am not sure if the transformer could magnetize..., maybe need big Fe core...)

For my converting requirement, and take Piezo transformer or any other high-advanced transformer design (like pcb stack twisting transformer) for example (smaller, better). How large it will be? Suprise me.

(I have no idea about the transformer design, I mean, how thick the conventional coil wire, etc. I just know the basic equations Vin x Iin = Vout x I out... some text book stuff, no experimental experience.)

How do I determine which core size is appropriate and how many windings of what type of wire I am supposed to use for primary and secondary?

I wanna use a transformer to convert AC voltage. 220V AC ------ for example, 5V 30mA AC. Many people told me, this transformer will be huge big. because the main frequency is huge low But, I check something about the transformer design, still have no idea, how big it will be. (BTW, 50Hz main Fre is so low, I am not sure if the transformer could magnetize..., maybe need big Fe core....)

For my converting requirement, and take Piezo transformer or any other high-advanced transformer design (like pcb stack twisting transformer) for example (smaller, better). How large it will be ? Suprise me.

(I have no idea about the transformer design, I mean, how thick the conventional coil wire, etc. I just know the basic equations Vin x Iin = Vout x I out...some text book stuff, no experimental experience.)

I know this question sounds a little stupid...

I wanna use a transformer to convert AC voltage. 220V AC ------ for example, 5V 30mA AC. Many people told me, this transformer will be huge big. because the main frequency is huge low But, I check something about the transformer design, still have no idea, how big it will be. (BTW, 50Hz main Fre is so low, I am not sure if the transformer could magnetize..., maybe need big Fe core....)

For my converting requirement, and take Piezo transformer or any other high-advanced transformer design (like pcb stack twisting transformer) for example (smaller, better). How large it will be ? Suprise me.

(I have no idea about the transformer design, I mean, how thick the conventional coil wire, etc. I just know the basic equations Vin x Iin = Vout x I out...some text book stuff, no experimental experience.)