AC is always reversing succinctly so there for the power grid turns direct current in the H form so direct currnet is produced to a more usable amount like 12volts.
Think of AC as a wave that undulates between a peak positive and negative value. Now if you flip the negative half of the wave above zero line you have all the peaks positive. This is done with what...
Depending on the device to be powered, a.c. current may be used directly, or converted to d.c. Electric lighting, motors, and heating appliances, typicaly use a.c. power directly. Electronic...
By using a half wave or a FULL wave rectifier. The full wave rectifier achieves a smoother DC signal than the half-wave. Using filters to smooth the signal, pure DC can be achieved.