A power supply receives 120 volts of AC power from a wall outlet and converts it to 3.3, 5, and 12 volts of DC power.
Usually 110 volts
Usually 110 volts
120 volt one phase means that the electrical system operates at a voltage of 120 volts and is supplied by a single phase of alternating current. This type of power supply is commonly used in residential settings and for smaller electrical devices.
220V50Hz
Within 220~240 Volts (AC) Mostly 230Volts
A dedicated wall outlet is the only one on the circuit.
In Canada and the United States, wall outlet voltage is standardized at 110 to 120 volts (anywhere in that range is considered "OK"). In Europe - most of the rest of the world, actually - it is standardized at 220 volts.
We know that Voltage = Current x Resistance, so if E = I x R, then E = 20 x 12 = 240 volts, and the dryer must be plugged into a 240 volt outlet.
A charger (like cable - plugs into an outlet) and charges from an outlet on the wall...?
Different plugs are designed so that you can't plug an appliance into the wrong voltage. A dryer is usually 220-240 Volts and your standard outlet is 110-120 Volts. You can't do what you suggest.
Change the wall outlets