Calculator for Regulator IC LM317

Here is an easy Voltage and Resistance calculator tool for IC such as LM117, LM317, LM338, LM350 etc which is a family of 3 terminal programmable regulator. Typically R2 is made Adjustable.

Calculate Output Voltage and Resistance R1, R2 Value

Circuit Diagram of programmable regulated power supply using IC LM317

*Note-> The input voltage to the LM317 must be at least 1.5v greater than the output voltage. Maximum output voltage is 37 V
Three Terminal Regulatore like LM317 are easy to use and require only two external resistors to set the output voltage.

This LM317 IC is commonly used in home UPS to charge battery at required voltage level. This protect over charge of battery.

For Shunt Regulator (Programmable Zener Diode) like TL431 which is commonly used in mobile charger, Laptop charger, SMPS etc. the TL431 output voltage calculator is here. Circuit diagram is also different.