Electricity Basics

Voltage

Electrical potential difference between two points that creates the push on electrons

Voltage memory trick

Difference = voltage

Current

Movement or flow of electrons through a circuit

Current memory trick

Movement = current

Resistance

Opposition to current flow

AC

Alternating current; changes direction back and forth

DC

Direct current; flows in one direction

Why transformers need AC

AC creates a changing magnetic field needed for electromagnetic induction

Why the x-ray tube needs DC

Electrons must flow only from cathode to anode

Rectification

Process of converting AC into one-direction current

Diode

One-way electrical gate used for rectification

Half-wave rectification

Uses only one half of the AC cycle and blocks the other half

Full-wave rectification

Uses both halves of the AC cycle by reversing the unwanted half

Half-wave memory trick

Half-wave wastes half

Full-wave memory trick

Full-wave flips and uses both halves