Direct Current (DC) is just that -- direct or constant in time.

The voltage V and current I in a direct current (DC) circuit are constant over time.

The voltage V and current I in a direct current (DC) circuit are constant over time.

It is customary to indicate these constant values with capital letters; the current, as I, and the voltage, as V. This is nothing new; it is the same convention we have used until now.

Alternating Current (AC)	Return to Ch 22 Home Page (ToC)		Resistance

(c) Doug Davis, 2002; all rights reserved