---
tags: [electricity, circuits]
---

# LEDs

LED' stands for **Light Emitting Diode**, a [circuit]() component that emits
light. The symbol for an LED is displayed below:

![](/img/diode-led.png)

A **diode** is a special kind of component that only permits current to flow
through it in one direction. To achieve this it has very low resistance in one
direction to allow current flow and high resistance in the other direction to
impede current flow. This feature of diodes is clearly represented in the
generic diode circuit symbol:

![](/img/diode.png)

An LED diode lights up when the right amount of current flows through it. A
standard LED has a maximum current of 20mA. An appropriate
[resistor](Resistance.md#resistors)
must therefore be added to the circuit to ensure the current doesn't exeedd this
amount.
