LM317 Adjustable Voltage Regulator Module

The LM317 Adjustable Voltage Regulator Module is a compact and versatile solution for powering your DIY electronics and embedded projects. Capable of delivering 1.25V to 37V DC at up to 1.5A, this module uses the reliable LM317 linear regulator IC, complete with a heatsink for stable performance. Unlike switching regulators, it offers a low-ripple output, making it ideal for sensitive analog and audio applications. With built-in thermal shutdown and current limiting, the module ensures safety and long-term durability. The board also includes mounting holes for permanent installations, making it a dependable choice for hobbyists, students, and professionals working with adjustable power requirements. Featured By RoboticsBD.

Product Images are shown for illustrative purposes only and may differ from the actual product.

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Features:

1. Adjustable output voltage range: 1.25V – 37V DC

2. Input voltage supported: 4.5V – 40V DC

3. Output current up to 1.5A with heatsink

4. Built-in thermal protection and current limiting

5. Compact PCB with mounting holes for secure installation

6. Low noise and ripple output compared to DC-DC converters

7. Reliable and widely used LM317 IC for stable regulation

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Applications:

1. Power supply design for DIY electronics and Arduino projects

2. Voltage adjustment in lab testing and prototyping

3. Audio and analog circuits requiring low-ripple regulated voltage

4. Battery-powered device regulation and charging applications

5. Educational and development board projects needing adjustable power

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Please allow 5% measuring deviation due to manual measurement.

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Documentation:

Voltage Adjustment

The on-board multi-turn potentiometer allows for adjustment of the output voltage.

Turning the pot CW decreases the output voltage while turning it  CCW increases it.

The available adjustment range will depend on the input voltage.  The LM317 has a voltage drop of approximately 1.25V, so the typical range is from a minimum of 1.25V up to the input voltage – 1.25V.  If powering the module with 12V for instance, the output range would be approximately 1.25V to 10.75V.

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Module Connections

Inputs and output connections on the module are made via small screw terminals that you can connect to using regular hookup wire or the pin on male jumper wires.

The connections are labeled on the back of the board due to the tight component packing on the top.  The ground is common between the input and output terminals (not isolated).

Input Power

VIN = Input Voltage

GND = Ground for input

Output Power

VOUT = Output Voltage

GND = Ground for output

Note:  Double-check that you have the input and output correctly hooked up before applying power or the module may be damaged.

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OUR EVALUATION RESULTS:

To wire an LM317 circuit on a breadboard takes an LM317 regulator IC, a resistor or two and a potentiometer if you want to be able to adjust the output voltage.  An input/output filter cap is generally a good idea and you may need to add a heat sink to increase the power output capability.  These circuits are easy and fun to create the first time or two, but after a while it is nice to just have the functionality without the fuss of needing to wire it up from scratch each time and that is where these modules come in handy and at a great price to boot!

As with any linear regulator, the power dissipation of the regulator is dependent on the difference between the input voltage and the output voltage along with the amount of current that is being drawn from the regulator.  The larger the difference between the Vin and Vout, the higher the power dissipation which limits how much current can be drawn from the device.

To illustrate this concept, the table below gives some test results with the module using several different input voltages while the regulator output is set for 5V.  As can be seen, with a 9V input the module can handle about 1A of continuous current before power dissipation gets too high without fan cooling.  With a 32V input the module can only handle about 150mA.  If this module was powered off our 7.5V AC Adapter which has a more ideal input/output voltage drop, it would get close to 1.5A with no cooling.

Since the module includes a heat sink, if a modest amount of air movement exists such as from a small fan, that allows the module to safely handle approximately double the amount of current before things get too toasty with all other things being equal.

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Output Current vs Voltage Difference

At 25°C ambient temperature, the regulator can supply up to 1A at 9V input and 5V output (rising to 1.5A+ with fan cooling). With 12V input to 5V output, the maximum current is about 550mA (up to 1.3A with cooling). At higher voltages, such as 32V input to 5V output, the current drops to 150mA (300mA with cooling). This shows how the available output current decreases as the input-to-output voltage difference increases.

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Package Includes:

1 x LM317 Adjustable Voltage Regulator Module

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