AC Adaptor / Wall-wart

Model Name
Input: AC100-240V ~ 50/60Hz 0.3A
Output: 12V ______1A
-------
And a symbol with thats Something like this (-)----- (.----(+)

What Does ' 0.3A ' in Input Signify , 1A in Output Signify and the Symbol Signify ?
I Guess, According to Ohms Law Current Is proportional to voltage, then what does those Ampere's Tell us,
(Voltages and Hz are operating Points suitable right?)

1) The wide range of input voltage signifies that it is a high frequency switching power supply, not just a transformer, rectifier and filter capacitor.
2) (-) and (+) signify that the output is DC, not AC.
3) 0.3A input current occurs probably when the input voltage is 100VAC.
4) The max allowed output current is 1A.

Ohm's law applies to the load, not to this power supply.

r.vittalkiran said:

...And a symbol with thats Something like this (-)----- (.----(+)....

Click to expand...

This also indicates the polarity of the output plug...the outer ring is the negative connection and the inner tube is the positive.

Ken

audioguru said:

1) The wide range of input voltage signifies that it is a high frequency switching power supply, not just a transformer, rectifier and filter capacitor.
.............>The max allowed output current is 1A.

Ohm's law applies to the load, not to this power supply.

Click to expand...

Thanks, but.....Whats Used to rectify and regulate and give a constant DC voltage when the AC voltage have a Wide Range? Because Step-down transformers decrease the voltage proportionally?
Max 1A current when when the external load is negligible right?

It is not just a transformer. It is a switching power supply circuit. it probably uses pulse-width-modulation at a high frequency. Its 12V output is probably regulated.

Look-up switching Power Supply circuit in Google.

thanks for the info...