This voltage regulator circuit is very simple. Working of LM317 Voltage Regulator Circuit You can check the live demonstration Video below. Let’s take an example, the value of R1 will be the recommended value 240ohm and R2 we are taking of 300ohms, so what will be the output voltage: You can directly use LM317 Calculator for fast calculation of resistor R2 and output voltage.

You can directly find the value of the output voltage or resistor R2 by using the formula below: Vout = 1.25 Generally the recommended value of resistor R1 is 240ohms (but not fixed you can change it too as per your requirement), we can vary the resistor R2. “Output will depend on the external resistor only, but the input voltage should always be greater than (minimum of 3v) the needed output voltage”. If we talk about the input voltage it can be in range of 3 to 40v DC. We can adjust the output voltage by two external resistor connected through the adjustable pin of the IC. As the LM317 having an output voltage range of 1.25v to 37v DC. We can adjust the Vout through this pin, by connecting to resistor divider circuit.įirstly, you have to decide what output you want. Check here the 12v Battery Charger Circuit using LM317 These two resistors works as voltage divider circuit used to increase or decrease the output voltage.

We can provide input voltage in the range of 3v-40v DC and i t can give output voltage of 1.25 v to 37v which we can vary according to the need by using two external resistors on adjustable PIN of LM317. Its operating and storage temperature is in range of -55 to 150 ☌, and provide a maximum output current of 2.2A. It’s having a typical line and load regulation of 0.1%. If we disconnect the adjustable terminal still LM317 will helpful in Overload protection. It can also provide float operation for High voltage application. The LM317 IC helps in current limiting, thermal overload protection and safe operating area protection. It’s an adjustable three-terminal voltage regulator IC, with a high output current value of 1.5A. The output voltage is varied by varying the resistor connected to LM317’s adjustable pin. With a small circuitry attached with LM317 we can get variable voltage up to 37v with 1.5A max current. In this tutorial we will show you how to get the variable regulated Voltage from the LM317 IC. But what if need to vary the power supply voltage, so here we have Variable Voltage Regulator IC LM317.

We have 78XX (7805, 7806, 7812 etc) series voltage regulators for positive power supply and 79XX for negative power supply. They provide a fixed regulated power supply. Whenever we need a constant and specific value of voltage without fluctuation we use voltage regulator IC.

Persamaan ic lm317