Tom Thoen's 31 Fun Experiments Board Revives a Classic Electronics Teaching Tool

The 1970s Radio Shack "65 in 1 Electronics Project Kit" was Tom Thoen's first exposure to electronic circuits, sparking a career that led from hobbyist to engineer to educator. As a DesignLab Residency project, Thoen set out to create a modern version with a strong educational focus. The result is a valuable resource for teaching electronics called the Circuit Scholars 31 Fun Experiments board.

When Thoen began the project, the intent was to make a training kit with 25 circuits in 2024. The clever engineer named the project 25in24. However, now that the multi-week project is coming to a close, the result is a kit that offers not just 25, but 31 experiments (along with a new name)!

The kit has multiple printed circuit boards (PCBs), each containing components like resistors, capacitors, and transistors. Another PCB houses the battery options, LEDs, a speaker, and an analog meter. A slide switch allows users to easily choose between measuring current or voltage. Components quickly connect to each other with Dupont-style connectors. To increase robustness and friendliness, Thoen chose header pins with a shroud. The shroud prevents the pins from bending (and breaking off.)

Thoen paid homage to the 1970s kits in several ways. First, the PCBs use three different solder mask colors, resembling the original kit's different-colored rectangles. Another callback is developing the experiments from the 65 in 1's guidebook.

Artist Tiffany Tang illustrated a playful guide showing how to use the 31 Fun Experiments. Each one-page guide contains a project description, instructions on connecting it, wiring guides, and an explanation of how the circuit works. In addition to the cartoon graphics, there is also a schematic.

Thoen is still considering making the 31 Fun Experiments a purchasable kit. Until then, you can download the PCB files, bill of materials (BOM), and instruction booklet from the 25n24 project page. Tang's project guide is also available as a print-ready PDF.