Every Page in This Book Is a Functional PCB

When you think of an e-book, your mind likely drifts to the soft appearance of E Ink and the quiet focus of a distraction-free screen. However, that is not the type of electronic book that Bolt Industries has created. It has created a book called Reference Circuits, in which each page is a printed circuit board (PCB) populated with electronic components. These functional circuits can be experimented with to aid readers in understanding the principles behind their operation.

Reference Circuits, Volume 0 is a 12-page introduction to fundamental electronic components, but it approaches education in a way that is distinctly hands-on. Rather than relying on dense explanations and static diagrams, each “page” is fabricated from FR-4 PCB material and contains real components soldered directly in place. Readers can power the book on, press buttons, probe test points with a multimeter, and observe exactly how each part behaves in a working circuit. There is no paper involved — this is a book meant to be plugged in.

The focus of Volume 0 is the core building blocks of electronics. It begins with resistors, explaining how they work and how to decode both traditional color bands and surface-mount markings. From there, it moves on to specialty resistors and switches, including photoresistors and thermistors. These components are not just described; they are demonstrated. Covering a photocell with a finger directly changes the behavior of an LED, making abstract concepts immediately tangible.

Capacitors receive extensive coverage across multiple pages. One page explains capacitor theory and typical circuit usage, while another shows several real capacitor types — ceramic, electrolytic, tantalum, and variable — mounted on the board. By pressing a button, readers can watch an LED slowly brighten and fade as a capacitor charges and discharges, offering a visual representation of energy storage that textbooks can only describe.

Later pages introduce protective and electromechanical components such as fuses, resettable fuses, inductors, transformers, optocouplers, and relays. A live circuit demonstrates how an optocoupler can safely isolate parts of a system while still controlling a relay, reinforcing key concepts about isolation and switching. Diodes, Zener diodes, LEDs, transistors, and op-amps follow, each accompanied by interactive circuits that reveal how voltage, current, and control signals influence real-world behavior.

The final pages step into power electronics, explaining DC-DC converter theory before demonstrating both boost and buck converters alongside a linear voltage regulator. LEDs indicate the presence of different voltages, and test points allow direct measurement.

Reference Circuits began as a way to bridge the gap between theory and experimentation, and earlier volumes proved the idea’s appeal, with over 1,000 copies sold through Kickstarter. Volume 0 builds on that success as an accessible starting point, and Bolt Industries is again turning to crowdfunding to make production affordable. For anyone learning or revisiting electronics, the book can be purchased for $43.