Tutorial: Circuit Basics

These notes are meant to accompany an in-class tutorial presentation, and may not necessarily stand alone. For reference, see also Basic Circuits.

Contents

• Tutorial: Circuit Basics
  • Electricity
  • Schematics
  • Digital Multimeters (DMM)
  • Resistance and Ohm’s Law
  • Breadboards

Electricity

• electrons, currents
• potentials, voltage
• metaphorical traps

Schematics

• Notation, common symbols
• KCL

• KVL

(Images courtesy of wikimedia.)

Digital Multimeters (DMM)

• purpose
• probe locations
• modes: voltage, resistance, current etc.
• later: the oscilloscope

Resistance and Ohm’s Law

• visual guide

• Each resistor follows Ohm’s Law: \(V = i * R\). This idea can be understood in several ways:
  1. a voltage across a resistor will cause a current to flow through it: \(i = V / R\)
  2. a current through a resistor will induce a voltage drop across it: \(V = i * R\)
  3. the resistance is defined by the observed ratio of voltage drop to current flow: \(R = V / i\).
• an empirical property
• an engineered property

Breadboards