Inverter type

As follows, a method in which the input is converted 4(3) times before output

1. Convert commercial power supply or other AC input to DC
   (or DC from the beginning)
2. Convert to high-frequency AC using an inverter
3. Convert the voltage with a transformer
4. Convert to DC with a rectifier circuit

Since a transformer is used in step 3, the input and output can be isolated, and there is also the advantage that the voltage level can be changed arbitrarily.