SparkFun Breadboard Power Supply 5V/3.3V

A through-hole soldering kit that builds into a compact breadboard power supply. It accepts a DC barrel jack input and outputs a selectable 5 V or 3.3 V regulated supply via 0.1" (2.54 mm) header pins that plug directly into breadboard power rails.

The board features an on/off switch, a 3.3 V / 5 V selector switch, reverse polarity protection, a PTC resettable fuse, and a power LED indicator. Stripped wire can also be connected directly through pads within the barrel jack footprint as an alternative to using a DC adapter.

Key Features

• Selectable Output – Switch between 5 V and 3.3 V regulated output
• LM317 Regulator – Up to 1.5 A maximum current
• Breadboard Mounting – 0.1" header pins on the underside for direct insertion
• On/Off Switch – Convenient power control
• Protection – Reverse polarity diode and PTC resettable fuse
• Soldering Kit – Comes as a bag of parts with silkscreen-guided assembly

Specifications

• Input – DC barrel jack (2.1 mm centre positive)
• Output – 5 V or 3.3 V (selectable)
• Regulator – LM317 (1.5 A max)
• Dimensions – 32 × 32 mm

Package Contents

• 1× Bare PCB with silkscreen indicators
• 1× DC barrel connector (2.1 mm centre positive)
• 1× LM317 voltage regulator (TO-220)
• 1× 1N4004 reverse protection diode
• 1× PTC resettable fuse
• 1× 100 µF 25 V capacitor
• 1× 10 µF 25 V capacitor
• 1× 0.1 µF 50 V capacitor
• 1× Red power LED
• 2× SPDT slide switches
• 4× 0.1" header pins
• 2× 330 Ω resistors (⅙ W)
• 1× 390 Ω resistor (⅙ W)
• 1× 240 Ω resistor (⅙ W)

Resources

• Schematic (PDF)
• GitHub – Design Files