What are the main two power supplies and why?

Question

What are the main two power supplies and why?

Answer 1

The two main power supplies are DC current(direct current) and AC current (alternating current). We basically require two power supplies as both these types of electricity are different and both of them are used.For example, the kind of electricity produced by solar energy is AC current and the one which we use in our appliances is DC current. Both are interconvertable and so both of them are used extensively.

Answer 2

Power supply (PSU) is the device that transfers electric power from a source to a load using electronic circuits. A typical application of power supplies is to convert utility's AC input power into regulated DC voltage(s) required for electronic equipment.