Basic Electronics
This page will explain some basic electronics concepts. It is not the intention of this page to teach in-depth electronic engineering but merely to cover the concepts necessary or relevant for embedded projects.
One of the challenges of understanding basic electronic principles is the fact that we can not "see" electrical current. We can observe some of the consequences of electrical current (heat, magnetism) but we can not observe the current itself. Because of this fact, the water analogy is often initially used.
In this analogy, voltage is explained by water pressure, current is explained by the amount of water flowing, and resistance as restrictions to the flow. It is clear to understand that if a bucket of water is flipped over at some height, there is very little restrictions on it flowing (small resistance, high current), whereas if it have to pass through a narrow pipe or hose, more restrictions are in place (high resistance, low current). It is also quite intuitive to understand that given a fixed resistance, higher voltage will result in higher current.
Basic Concepts
Voltage
Voltage, also known as (electrical) potential difference, electric pressure, or electric tension is the difference in electric potential between two points.
Voltage is measured in Volt (V).
Current
Current can be described as an amount of charged particles (electrons) passing through a conductor of some kind.
Currents are measured in Ampere (A - aka. amps).
Resistance
Resistance described the quality of a conductor. A good conductor will have a low resistance, a "poor" conductor will have a high resistance.
Resistance is measured in Ohm (Ω).
Circuits
A battery on it's own is a voltage source, however, if nothing is connected between the + and -, no current will flow.