Linear Voltage Regulator | Constant DC Voltage
The work of voltage regulator is to provide constant voltage to the load. You can maintain the constant voltage in many ways. But two types of voltage regulator are popular.
- Linear Voltage Regulator or Linear Drop Out Regulator(LDO)
- Switching Regulator (SMPS)
In this tutorial, we will only cover about linear voltage regulator or Linear Drop Our Regulators (LDO)
LDO or Linear Drop Out Voltage Regulators are used to give constant voltage to a load within a certain current limit range. Depending on load, the resistance of regulator varies, maintain the constant voltage.¬† Not only the resistance, but Zener Diode are also used to regulate voltage in a Linear Voltage Regulator.
Where To Use Linear Voltage Regulator?
You can use linear voltage regulator in almost all circuit but , If your electronics device need to be very power efficient , you should avoid using linear regulator, because Linear Voltage Regulator regulates voltage by dropping extra voltage among resistance which converts into heat , which make device very power inefficient.
Where you can use LDO:
- Basic Sensor Circuit
- Development Boards like Arduino
- You can use in Robotics Projects
- Display Circuits
- Simple Microcontroller Projects
Where You Should Avoid Using LDO: (Use Switching Regulator circuit or IC)
- Battery Powered BLE Device
- Battery Power wifi or IOT Projects
- Clock Circuit
- Wearable Application
- Solar Power Devices
Why you need a Voltage Regulator?
As you know most of IC now a days operates in constant voltage like 3.3V , 2.3V, 1.5V, 5V etc. ICs like Microcontrollers (Atmega 328, Atmega 8, PIC, MSP430, CC2541, etc) , LCD circuits like TFT, I2C LCD Display, Microphone, Sensors like GAS sensor or PIR sensors , almost all circuits need constant Voltages.
SO if you have battery or dc power supply of higher voltage say 5V, 9V, 12V or 24V then you need a voltage regulator circuit to give constant voltage to other circuits.
Which Voltage Regulator To Buy?
There are many companies make LDO Voltage Regulators, few famous are listed below.
|Name||Company Who Make||Specification|
|LM7805, LM7809, LM7812, LM7806, LM7815||ST Microelectronics, TI, Local||5V, 9V, 12V, 6V, 15V with current rating of 1.5V|
|LM317||ST, TI||Variable voltage from 1.5V to 37V with current range upto 1.5A|
There are many companies makes almost all voltage range of constant voltage regulator, You can find any range just by doing little GOOGLE search.
Practical Voltage Regulator Circuit:
For Example Purpose, I have taken Popular LM7805 ¬†Voltage Regulator IC to show practical example here. Typical 7805 circuit looks like below. This image below is a through hole type, but SMD type voltage regulators are also available in the market.
Connection diagram of LM7805 Voltage Regulator:
As You can see the input voltage in the above circuit is variable, and ground is common to both input and output, at the output you will get constant 5V. In both input and output side we have added two ceramic capacitor for extra filtration purpose to get smooth ripple free output.
You can use above circuit, any of your electronics circuit, where you need constant 5V, if you want to use any other voltage, you have to check the datasheet of the IC for pin out and connection.
If You have new to electronics world, I will suggest you to have look on our previous tutorial on Full wave rectifier Tutorial.
Hope You like this tutorial, If you have any doubt or suggestion, You can comment down below.
Thanks, Happy Learning ūüôā