EECS Joint Colloquium Distinguished Lecture Series

Wednesday, April 16, 2003
Hewlett Packard Auditorium, 306 Soda Hall
4:00-5:00 p.m.

Dr. Martin Graham

Professor Emeritus,

Electrical Engineering & Computer Sciences Dept.,

University of California at Berkeley


Evaluating Your Electric Chair




Human health can be affected by low-level electric fields in the frequency range of 10KHz to 100 KHz. Noise voltages of this type are present at the 120V 60Hz outlets in homes and offices. Electric cords plugged into the outlet can bring the electric fields close to humans. Sitting on a chair with your feet close to many such electric cords may be hazardous.

Noise voltages are generated by electrical equipment such as dimmer switches, electronic transformers, and motors with commutators. The voltages at your outlets may be generated by equipment not on your premises.

Measuring and mitigation techniques will be described.


Martin Graham retired from the EECS Department at U.C. Berkeley in 1994. His research includes local area networks, computer systems, and instrumentation; Biomedical signal processing; Grounding, noise, and crosstalk problems. He developed instrumentation for physicists and chemists at Brookhaven National Laboratory, directed a group that built an advanced digital computer at Rice University (1957-1964), and taught biomedical engineering and electronics at U.C. Berkeley (1966-1994). He is the coauthor of "High Speed Digital Design: A Handbook of Black Magic."