why are cellphone chargers so small?
is it possible to use audio transformers to step down mains AC? if yes, is it safe?
my professor gave us a very simple project - to make a power supply. of course i will use a transformer. when i pass my project she told me that i used a audio transformer. i don't know that the transformer was an audio transformer because it was labeled 220v 50Hz to 9v 200mA
i searched my area for transformers i found several with identical ratings but they are significantly larger. my conclusion is my transformer was small due to the fact that it is an audio transformer. when i searched for audio transformer i found a lot of very small transformer. now, is it safe to use those very small transformers to step down 220VAC mains?