Electronics
47 sites
https://electronics2000.co.uk/
Electronics 2000, created by Simon Carter, is a comprehensive hobby electronics reference packed with online calculators for resistors, capacitors, inductors, Ohm's Law, and more, plus technical data articles, pin-outs, and a beginner's guide. The site also offers downloadable Windows software like Electronics Assistant and an EPE Index, making it a genuinely useful toolkit for hobbyists, students, and engineers alike.
http://redcircuits.com/
RED Free Circuit Designs is a hobbyist electronics resource offering dozens of free audio amplifier schematics, preamplifier modules, headphone amplifiers, and miscellaneous electronic circuit designs. Visitors can browse Class-A and Class-B amplifier projects, phono preamps, intercom circuits, and many more practical designs, all available at no cost.
https://solorb.com/elect
FC's Electronic Circuits is a sprawling hobbyist archive packed with schematics and project descriptions covering everything from solar charge controllers and LED circuits to tube amplifiers, Geiger counters, and amateur radio gear. With dozens of original circuit designs, Arduino projects, and links to related ham radio and electronics builders, this site is a goldmine for DIY electronics enthusiasts.
http://williamson-labs.com/
Williamson Labs is a comprehensive electronics tutorial site covering foundational topics like transistors, op-amps, 555 timers, and circuit design for learners at various levels. It serves as a structured educational reference for anyone looking to understand basic and intermediate electronics concepts through instructional content.
http://donklipstein.com/
Don Klipstein's sprawling technical resource covers everything from LEDs and fluorescent lamps to Tesla coils, xenon strobes, lasers, and high voltage experiments. With decades of accumulated hobbyist knowledge, detailed guides, and regularly updated content, it's an indispensable reference for electronics enthusiasts interested in lighting and discharge lamp technology.
https://aaroncake.net/circuits/index.asp
Aaron Cake's extensive collection of electronic circuit schematics covers categories from power supplies and light/laser projects to telephone circuits and sound/radio designs. Each circuit includes printable PCB patterns, community rankings, and user comments, making it a hands-on resource for hobbyist electronics builders.
http://nmia.com/~roberts/robert.html
Robert Smathers maintains this personal hub dedicated to TVRO (Television Receive Only) satellite reception, featuring links, schedules, mail lists, newsgroups, and dealer resources for satellite hobbyists. The site also touches on visual satellite observing and space topics, making it a useful reference point for backyard dish enthusiasts.
http://jap.hu/electronic
Peter's DIY electronics hub showcases a range of original hardware projects including relay modules for Raspberry Pi and Arduino, PIC microcontroller circuits, remote control encoders, and an LCD thermometer. Each project comes with schematics and build guides, making this a great resource for hobbyist engineers looking for practical, hands-on circuit designs.
http://discovercircuits.com/
DiscoverCircuits.com, run by engineer Dave Johnson P.E., is a massive repository of over 45,000 free electronic circuits and schematics cross-referenced across 500+ categories for engineers, hobbyists, inventors, and students. Online since 2002, it serves as a go-to reference for quick design ideas, circuit solutions, and component resources covering an enormous breadth of electronic applications.
https://solarpower.guide/
Bob Robertson's hobby site is a sprawling reference on solar power, covering everything from basic definitions and how solar panels work to educational guides for kids and van-life solar setups. With dozens of articles on renewable energy topics, it reads like a one-man encyclopedia built by a retiree passionate about the subject.