Vol. EE Reference
Chapter 9 Circuit Schematic Symbols

Power Sources

There are many different types of power sources, and here some of the most common types that are mainly used in electronics. These can be classified into two main types , AC and DC. DC have its subtypes, DC voltage and DC current, same goes for AC. 

DC voltage can be supplied by using a battery or  by a power supply circuit; power supply circuit is also a variable type supply depending on its design construction.

AC on the other hand is be supplied by the “power sockets” that are readily available at homes, or a generator that generates power using fuel. There are also variable types of AC power but it still depends on its design construction.