# Three Basics of Electronics

Created | Updated Mar 29, 2009

Electronics is a difficult field. You can get your machine to work perfectly once or for 20 years. Alternatively, you can make a prototype that works perfectly, twiddle with it and it will never function at full capacity again. Below are three basics of electronics that will help you start to understand the broader topic.

### Three Basics

It must be stated first that current *flows* and voltage is a measure of electrical *pressure*.

The behaviour of electronics can be described with some basic rules which are sometimes called first principles. The three most used are:

**Kirchhoff's**- This law states that the sum of all the currents coming out of a node, like at a junction, is equal to the sum of the currents going into the node.^{1}current law (KCL)**Kirchhoff's voltage law (KVL)**- This law states that the sum of the voltages across all the components in any closed loop in a circuit equals zero. Components can be resistors, batteries and so on.**Ohm's law**- This law states that the voltage across a resistor is equal to the resistance multiplied by the current through the resistor.

^{1}Also spelled Kirchoff.