Thomas Petruzzellis is an electronics engineer currently working with the geophysical field equipment in the geology department at the State University of New York, Binghamton. Tom has over 30 years' experience in electronics and he is a veteran author who has written extensively for industry publications, including Electronics Now, Modern Electronics, QST, Microcomputer Journal, Circuit Cellar and Nuts & Volts. The author of three earlier books: STAMP 2 Communications and Control Projects; Optoelectronics, Fiber Optics, and Laser Cookbook; Alarm, Sensor, and Security Circuit Cookbook, all from McGraw-Hill, he lives in Vestal, New York.