What is a 7 segment LED display
7 Segment Display is an LED based display screen that can display information in the form of decimal numbers. The seven segment display is a used in place of the more complex dot matrix displays. It is called so because it consists of seven segments of light emitting diodes (LEDs) that are assembled like decimal 8 as shown in the following figure.
7 segments LED display can be used in applications where an electronic display device is required for showing decimal numbers from 0 to 9, sometimes, basic characters as well. Since, it uses LEDs, therefore it is an energy efficient display device. Therefore, it is most widely used in those devices that are powered by a small battery or a cell.
Working of 7 Segment LED Display
7 segment LED display is a type of display device composed of 7 individual LEDs (light emitting diodes). A 7 segment display can often be used to display the characters numeric digits and some letters. It is widely used in digital clocks, electronic meters, and other electronic devices.
The device is designed to display numbers and make calculations when used in combination with additional electronic components. It is composed of two different types of LEDs, namely common anode or common cathode. A common anode display consists of seven LEDs connected in series, with the anode connection of all the LEDs connected together and the cathode of each LED connected to a different terminal. Common cathode displays, on the other hand, consist of seven LEDs connected in parallel with the cathode of each LED connected to a different terminal and the anode connection of all the LEDs connected together.
By turning on one LED, you can display a number or character. The individual LED segments are usually labeled as A, B, C, D, E, F, and G. The different segment labels indicate the patterns in which the LEDs should be connected to display a particular character or number. With the LEDs connected in this manner, a display can show a number or letter if all of the appropriate segments are lit up.
A 7 segment LED display can be used in various applications such as tally counters, digital clocks, electronic calculators, portable gaming systems, and measurement instruments. They are also used in automotive instruments and warning lights. In addition, these types of displays are commonly used in medical devices such as those used in hospitals to display various types of patient information.
In addition to displaying a number or character, a 7 segment LED display can be used to create graphical patterns, such as bar graphs. These patterns can be displayed in a single color or with alternating colored LEDs to create a color wheel effect.
The working of a 7 segment LED display is relatively simple. The electrical current is applied to the appropriate pins or terminals connected to the display. Depending on the type of 7 segment display, the appropriate pins or terminals will either be common anode or common cathode. When the current is applied, the LEDs will light up, forming the desired character or number depending on the current setting.
The brightness of the display can be controlled by varying the input current, either by using a potentiometer or variable resistor. One advantage of these types of displays is that they are relatively inexpensive when compared to other types of displays, such as liquid crystal displays. The more complex a display is, the more costly it can become.
A 7 segment LED display is an efficient and effective way to display numbers, characters, and other simple graphical representations. As the components of a 7 segment LED display are relatively simple, it is a cost effective way to display data and information in difficult to read environments.
Types of 7 Segment LED Displays
There are two types of seven segment displays available −
Common Cathode Seven Segment Display − In this type of seven segment display, the cathode terminal of all LED segments are connected together to logic 0 (lower voltage level). The logic 1 (higher voltage level) is applied through a current limiting resistor to forward bias the individual LED segments at their anode terminals.
Common Anode Seven Segment Display − In this type of seven segment LED display, the anode terminals of all the LED segments are connected together to the logic 1 (higher voltage level), and the logic 0 (lower voltage level) is used through a current limiting resistor to the individual cathode terminals of LED segments.
Note − Common Anode Seven Segment LED Displays are more popular than Common Cathode Seven Segment Display because logic circuit can sink higher current as compared to they can source.
Applications of 7 Segment LED Displays
Seven segment LED displays have a variety of applications across various industries. It is widely used for displaying numeric values in digital clocks, calculators, and digital displays. It is also used for displaying letters and characters in devices like televisions, microwaves, and some appliances. Seven segment LED displays are also used in medical devices, industrial controllers, and various consumer electronic products.
First, seven segment LED displays are extensively used for displaying numeric values in digital clocks, calculators and digital displays. For example, when the time is 10:40 a.m., a seven segment display can show the numbers ‘1’, ‘0’, ‘4’ and ‘0’ clearly and accurately. Specifically, four seven segment LED displays can be used to represent the time in a digital clock. These numbers can be displayed anywhere on the seven segment LED display. This type of LED display is also used in sophisticated calculators like advanced scientific and graphing calculators.
Second, seven segment LED displays are used for displaying letters and characters in devices like televisions, microwaves, and other appliances. When turning on a TV, it is possible to view channel name, menu selections, time and other information on a seven segment LED display. Seven segment displays are also used to display information such as current time and temperature on some microwave ovens. In addition, some appliances also have seven segment displays that are used to indicate temperature and other information.
Third, seven segment LED displays have many applications in the medical field. Medical devices such as blood pressure and temperature monitoring devices use seven segment LED displays to display the measured values. Heart rate monitors also use seven segment displays to show the heart rate of a user. Additionally, seven segment displays are also used in medical imaging devices to display various diagnostic information.
Fourth, seven segment displays are also used in industrial controllers and devices. These displays can be used to display the diagnostic information of the machine such as motor speed, pressure level, or temperature. Seven segment LED displays are also used in some types of flow meters and other measuring instruments.
Finally, seven segment displays are widely used in various consumer electronic products such as radios, CD players, and DVD players. These displays are also used in some remote controlled devices to indicate the devices channel and volume.
Overall, seven segment LED displays are increasingly used for many applications across various industries. This type of display has many advantages such as low power consumption, long life, and excellent viewing angle. Due to its unique advantages, it is increasingly being used in a growing variety of products and applications.