Adjustable breadboard power supply kit [v1.0]

Build your own breadboard-friendly adjustable power supply with this soldering kit. Based on the MIC2941 low-dropout regulator, it provides a guaranteed 1.25A output with only 40–400 mV dropout — far better than the LM317's typical 1.25–2.0V. This means you can generate 3.3V from as low as 3.7V input (three AAs or a lithium-ion battery).

The kit includes all components and a PCB, ready to assemble in about 30–45 minutes with basic soldering skills. An output selection switch lets you quickly choose between 3.3V, 5V, or a continuously adjustable voltage via the onboard potentiometer.

Key Features

• MIC2941 Low-Dropout Regulator – 1.25A guaranteed output with only 40–400 mV dropout
• 3 Output Modes – Switch between 3.3V, 5V, or adjustable (1.25V to input voltage minus 0.5V, 20V max)
• Onboard Potentiometer – Fine-tune the adjustable output voltage
• Short Circuit & Overheating Protection – Built-in safety features
• Input Protection Diode – Guards against negative voltages or AC power supplies
• Dual Input Options – 2.1 mm DC jack and screw terminal connector
• Dual Indicator LEDs – Visual feedback for high and low voltages
• On/Off Switch – Power control for the entire board
• Heat Sink Included – Keeps the regulator cool under load

Ideal For

• Powering breadboard circuits at 3.3V or 5V
• Projects requiring adjustable voltage from battery or DC supply
• Beginner-friendly soldering practice
• Workbench power supply for prototyping

Package Contents

• 1× PCB and all components (unassembled soldering kit)
• 1× Heat sink

Resources

• Assembly Guide & Project Page (Adafruit Learn)