307 Circuits, the eighth in the 300 series of circuit design books, is a compilation of applications, projects, circuits and tips originally published in the July/August and December issues of Elektor Electronics magazine. This book brings the total of published designs in the 300 series to well over 2,300. Books in the 300 series are popular with engineers, students, teachers, hobbyists and other electronics enthusiasts all over the world.

Like its predecessors, 307 Circuits offers a galaxy of designs covering the entire field of modern electronics.
The book is divided into five sections:
- audio & hi-fi
- computers & microprocessors
- general interest
- power supplies and battery chargers
- radio, television & communications
- test & measurement

Many designs and projects are complemented with a printed circuit board (PCB) layout to aid in their construction. Others are complete with control software which may be ordered from the Publishers.