how can i get 12v100ma from 220vAC

[nuyi]

without using step down transfomer can anyone teach me to details on how i can get 12vDC from 220vAC like such i use to see in modern day charger or power supply pls eager to know this . thanks

 

[Leftyretro]

without using step down transfomer can anyone teach me to details on how i can get 12vDC from 220vAC like such i use to see in modern day charger or power supply pls eager to know this . thanks

A step down transformer is an important safety isolation component is such an application so I would not give specific information on how to do it without utilizing a transformer.

That aside, it is possible, with a properly sized capacitor, to capacitively couple AC voltage to a rectifier/filter/regulator circuit, but again not recommended for safety reasons.

Lefty

 

[ecerfoglio]

without using step down transfomer can anyone teach me to details on how i can get 12vDC from 220vAC like such i use to see in modern day charger or power supply pls eager to know this . thanks

A step down transformer is an important safety isolation component is such an application so I would not give specific information on how to do it without utilizing a transformer.

Lefty

I agree with Lefty's advice: you need isolation from the 220vAC line.

A "modern day charger or power supply" may be one of two types:
>>> A "traditional" transformer, that is one operating at 50 or 60 Hz, or
>>> A SMPS (Switch Mode Power Supply), like the power supply in a PC, only smaller.

A SMPS may also provide isolation (and both the "wall wart" ones and the PC ones do that).

You may use a "recycled" one from a discarded cell phone or similar (or even buy one new), but it is not easy to design, build or ever repair one without taking safety measures. (If you don't know how to work inside line powered equipment stay away from the supply's innards)

That said, if you have an isolating supply (like a cell phone's) you can use it's output without danger.

That aside, it is possible, with a properly sized capacitor, to capacitively couple AC voltage to a rectifier/filter/regulator circuit, but again not recommended for safety reasons.
Lefty

This capacitively coupled supplies should be used only inside an enclosure, and you should treat the supply's output as a "hot" circuit like the 220 V line it is connected to.