A simple tool that fits in your pocket. Built with a 7400 quad NAND gate (or a 555), this probe uses two LEDs to indicate High, Low, or Pulse. Every digital electronics student in the 80s built this in their first semester. It is still a valid diagnostic tool for 5V TTL logic today.
Unlike today's 0402 SMD components that require a microscope, the Elektor 305 circuits use DIP chips, resistors with color bands, and capacitors you can actually see. They are perfect for breadboarding, stripboard (Veroboard), or custom PCBs made with a laser printer (toner transfer).
The Elektor 305 Circuits book is a comprehensive collection of electronic circuits designed by the renowned electronics magazine Elektor. Published in the 1980s, this book contains 305 practical and innovative circuits that cater to a wide range of applications, from simple audio and radio circuits to complex digital and microprocessor-based designs.
