# What is the 7-segment display?

The 7-segment display is an electronic device that is used to visually represent numbers and some characters. This display is very popular due to its great effectiveness and simplicity when using it.

## Parts of a 7-segment display

It is known as 7 segments because it has seven main LED diodes and an extra one to represent a point. It also has housing to cover them and 10 terminals: 2 are for power supply (2 for Vcd or 2 for Gnd), 1 is for displaying a point and 7 are for representing each of the numbers according to the combination you put on them, these they are represented by a letter of the alphabet from «A» to letter «G».

## How does a display work?

To be able to represent the numbers or characters with this device, it is only enough to know the configuration of each one of its LEDs and combine them.

Examples:To represent the number 3 we must light the letters A, B, G, C and D, to represent the number 6 we have to combine the letters A, F, E, D, C and G.

When we need to indicate numbers with two digits we only need to integrate 2 displays and make the combinations in the same way, for example, for the number 20 we need to combine A, B, G, E, D + A, B, C, D, E, F .

## 7-segment display types

Being a very simple device there is not much variety, we can only find:

• common anode
• common cathode
• Dual display
• By size

### Common anode

It is called like this because all the LEDs are connected to its positive terminal (anode), to light them we have to put earth on the terminal of the letter that we want.

### Common cathode

This display is the opposite of the common anode since the LEDs are connected to the negative terminal (cathode). To turn on the LEDs we have to put voltage on the letter terminals.

### Multiple displays

Within this type we can find a common anode or cathode, the only difference is that they are 2, 4 and up to 6 united displays. These are ideal for when figures of more than one digit need to be represented.

### By size

In this type we can also find a common anode or cathode, the only variation is the size of the display since we can find them 2.3 and 4 inches.