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Adjustable linear regulator

LM317 Basic Circuit

Build a basic LM317 circuit with labeled pins, component values and connection guidance.

Package view

LM317 in a circuit

One regulator, two resistors and short bypass connections.

LM317 functional circuit with 9 V to input pin3, output pin2 feeding R1 120 ohms, ADJUST pin1 at the R1 R2 junction, and R2 360 ohms to ground.
Functional wiring layout; use the Pinout view for physical lead placement. VOUT is nominal and depends on reference, resistor and adjustment-current tolerances.

Connect it, step by step

Follow the component values and pin connections

Connect input and return

Feed INPUT from 9 V DC; put 0.1 µF between this rail and the common return.

Connect the divider

R1 = 120 Ω goes from OUTPUT to ADJUST. R2 = 360 Ω goes from ADJUST to GND.

Check the result

The ideal output is 5 V. Account for adjustment current and heating, then check it under the intended load.

Component view