Description:A compilation of 103 electronic circuits grouped in nine categories with ready to use printed circuit board designs, parts layouts, circuit design explanation and installation guides. About the Author This volume is the fourth in a series. It is the result of over 14 years of collection work of the authors who are hobbyists, technicians, electricians, engineers, computer programmers and designers. These people decided to compile all the circuits with related documentation and release it in organized manner.