Breadboard Power Supply with Adjustable Feature

The project illustrates how an adjustable breadboard power supply can be built entirely from Radioshack parts on a prototyping breadboard where multiple voltages can be provided directly to power rails which will be useful for people with low budget.

The integrated 3-terminal adjustable linear voltage regulator used in this device is the LM317 which supports input voltage of 3V to 40V and 1.25V & 37V of output voltage. Although lower current models are available, it has at least a 1.5A current rating. A potentiometer or a resistor is used to control its output voltage. As a safety feature, the LM317 also has a built-in current limiter and will automatically reduce output current if it gets too hot under load. To extend the power-handling capability of the part, the use of heatsink is recommended.

The PCB used can be made from scrap and be shaped in a 7×8 rectangle. In soldering the resistors, capacitors, diodes, and DIP switch, a Duct tape is used to hold them to the board and will then be removed after soldering. The 8-pin header pins and 2×6 strips are used to connect the power supply to the breadboard.

Rest of the project