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Last updated: September 20, 2025

12V to 5V Voltage Regulator Circuit Using LM317

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LM317 Voltage Regulator

LM317 Voltage Regulator

Adjustable 3-terminal positive regulator, output 1.25V – 37V, up to 1.5A

1K Fixed Resistor 1/4W

1K Fixed Resistor 1/4W

A 1,000-ohm resistor rated for 0.25 watts

330-ohm Fixed Resistor 1/4W

330R Fixed Resistor 1/4W

A 330-ohm resistor rated for 0.25 watts

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Convert 12v to 5v

Step down 12V to 5V using the LM317 adjustable voltage regulator. Ideal for powering 5V devices safely with a simple resistor setup.

LM317 voltage step-down DIY

Power 5V devices Wallbox Converter Your 12V supply can be used to power 5 V devices by converting to 5 V with LM317. This is adjusted by changing the values of the resistors to establish a stabilized 5V output, overcurrent and thermal protection.

12V to 5V power conversion

With 12V DC available, the 12V to 5V LM317 circuit is a simple, efficient method of powering 5V electronics with 12V DC. LM317 is a variable voltage regulator IC that gives the ability to control the output voltage with two resistors. This is done by linking the resistors into the output, the adjustment pin, and the ground, which will allow you to have a stable 5V output that can already be used to provide power to LEDs, sensors, microcontrollers, or small modules.
LM317 offers current limiting, thermal, and stable output, so it is safer than the old-fashioned voltage dividers based on resistors. An input capacitor and an output capacitor are used to minimize the voltage ripple and improve the smooth operation. It is a cost-effective project, simple to put together, and best suited to a beginner who wants to learn the principles of linear voltage regulation.

Work / Installation (Inputs → Outputs)

  • Power Input → 12V DC supply to LM317 input pin.
  • LM317 IC → Adjustable voltage regulator to step down voltage.
  • Resistors → Set output voltage to 5V using the formula Vout = 1.25 × (1 + R2/R1).
  • Capacitors → Optional 0.1µF input and 1µF output for stability.
  • Output → 5V DC to power microcontrollers, LEDs, or sensors.
  • Installation → Assemble on PCB or breadboard; ensure proper heat sinking if current is high.

Testing & Final Adjustments

Connect the LM317 circuit to a 12V source after assembly. Measured output voltage with a Multimeter. Tune the values of resistors until 5V is obtained. Test load of the test to determine the stability of voltages. Make sure that the LM317 is not overheating, and add a heatsink as needed. Input and output capacitors minimize ripple and improve the performance. Check the polarity of the devices. Check the functionality under various loads to ensure safe and sound functionality. Calibration results in a stable power supply of 5V to different electronics projects.

Frequently Asked Questions - Convert 12v to 5v:

What is LM317 used for?

It is an adjustable voltage regulator for stepping down or regulating voltage.

Can it convert 12V to 5V?

Yes, with appropriate resistor values, LM317 can provide stable 5V output.

Do I need capacitors?

Yes, for input and output to reduce voltage ripple and improve stability.

Can LM317 handle high current?

Typically up to 1.5A with proper heat sinking.

Is it suitable for beginners?

Yes, it’s simple, cost-effective, and educational.

How to set 5V output?

Use the formula Vout = 1.25 × (1 + R2/R1) with suitable resistor values.

Do I need a heatsink?

Yes, for currents above 500mA or prolonged use.

Can it power microcontrollers?

Yes, it is perfect for Arduino, ESP8266, and other 5V devices.

Is it safer than resistor voltage divider?

Yes, LM317 provides stable voltage, current limiting, and thermal protection.

Can it be used in DIY projects?

Yes, ideal for hobby electronics and low-power circuits.

Rojony Khatun

Rojony Khatun

CalculatorToolsProject

Rojony Khatun is the creator of a free online tools website designed to simplify everyday and engineering-related calculations for students, professionals, and hobbyists. The platform offers a wide variety of basic and advanced calculators across key categories, including Electrical Calculators, Electronic Calculators, and Time & Date Calculators, helping users solve problems quickly and accurately.