Lesson 0: Electricity Basics

 What is voltage? Voltage(V) is a measure of electrical force-how hard the electrons are being pushed. 

Arduino circuits typically run at 5V; newer devices use 3.3V.

Current is a measure of how many electrons are flowing, and is measured in Amperes or milliamperes(mA =1/1000 of an ampere). For example, LEDs run best at 20 mA; a small motor might draw 200 mA; a string of programmable LEDs might draw 800 mA. An Arduino can supply a maximum of 40 mA on its pins, so we need to use transistors or relays to control larger loads.

Resistance, measured on Ohms or kiloOhms(K), is a measure of how much current flow is resisted. The resistance of a resistor is marked using a color ode.

Ohm's Law: Voltage = Current x Resistance or V=I x R

LED Basics: