Sources

An AC source provides alternating current voltage. The symbol is a circle with a sine wave inside, indicating the oscillating nature of the output. AC sources are the standard for household power distribution.

A battery provides a steady DC voltage source. The symbol shows alternating long and short parallel lines, where the long line represents the positive terminal and the short line represents the negative terminal. Multiple cells may be shown for higher voltages.

A DC source provides constant-polarity voltage. The symbol is a circle with plus and minus signs, distinguishing it from AC sources. DC sources include batteries, solar cells, and rectified power supplies.

A generator converts mechanical energy into electrical energy. The symbol is a circle with the letter G inside. Generators are used in power plants, backup systems, and portable power applications.