Understanding Electricity, Basics and Common Components

Explain how electricity is made from direct current and alternating current. Describe battery chemistry with cathode, anode, and electrolyte, and how loads, switches, and series/parallel connections shape current.

Explore how frequency shapes alternating current and its waveform, contrast with direct current, and show how transformers and three-phase systems enable power distribution from generation to homes.

Master essential multimeter and amp probe settings, including ac and dc voltage, ohms, continuity, and diode tests. Emphasize rms measurements, auto ranging, and non-contact voltage checks for safe, accurate readings.

Learn electrical math terminology: voltage as potential difference, amps as current, resistance in ohms, and watts as total power. Note that infinite total resistance means no current and no continuity.

Understand the separation of control and load circuits, how relays and contactors use coils in the control circuit and contacts in the load circuit to drive loads in parallel.

Explore common electrical switches and mechanical thermostats. Learn how switches close circuits to allow current flow, test continuity, and identify configurations like single pole, double throw, normally open and normally closed.

Explore capacitors in DC and AC circuits, their polarization, voltage and microfarad ratings, and how they smooth voltage, boost start motor voltage, test, and diagnose swelling or leakage.

Explore how transformers step voltage using primary and secondary windings, taps, and impedance in ac circuits, and learn isolation transformer basics, testing, fault diagnosis, and fuse sizing using va ratings.

Identify relay switches as coil-driven devices with normally open and normally closed contacts that control circuits. Test coil continuity, check contact ratings, and replace faulty relays.

Explore contactors, high‑current relays that use a coil and armature to pull normally open contacts closed. Learn about voltage and amp ratings, and the importance of matching like-for-like replacements.

Explore how DC motors use brushes, commutators, and permanent magnets with windings, and how speed is controlled by a DC control board and potentiometer.