# Patents and Inventions

Wattenburg holds patents on ideas as diverse as computer design, medical diagnostic instruments, power line communication systems, tennis training devices for handicapped people, movable traffic barriers for multi-lane highways, and home alarm systems. Asked which one he was most proud of, he singled out the home alarm systems he invented in 1964 when he was a young professor at U.C. Berkeley. This invention (patent 3,460,121, Signaling and Communication System, 1965) has saved thousands of lives over the last twenty years. Hundreds of thousands of home fire and smoke alarm systems based on his patent were installed in homes in the U.S., Canada, and Europe.

He holds the original patent on the use of existing electrical house wiring as a means for communicating alarm signals from sensors, such as smoke detectors, to receivers placed elsewhere in the building. His inexpensive design was the first that eliminated the need for separate wiring to connect multiple alarm devices to remote receivers far away in the same building or even outside the building on the same power line.

His home and building alarm systems were originally marketed by the Heath Company (Heathkit) in Benton Harbor, Michigan. They were able to sell smoke and fire alarm systems to protect all areas of a home for less than $100. The technology in his original patent is now used by many companies all over the world for a wide variety or electronic and alarm devices that plug into power receptacles and use the power lines to communicate electrical signals. He also invented one of the first inexpensive smoke alarms for homes which was installed in hundreds of thousands of homes throughout the U.S. beginning in 1967. His two inventions allowed several hundred thousand homeowners to have reliable fire and smoke alarm systems that would otherwise have been too expensive by the old procedure of installing special wiring for an alarm system.

Since this was his first patent, we asked him what it was like and how did he come up with the idea. He said that a friend of his was going to have to pay over twenty thousand dollars to have a standard fire alarm system put in a warehouse that he owned. Wattenburg said that he asked his friend if he could have half that much if he could find a cheaper way than having to put special wiring in the whole building. He shrugged his shoulders and told us: “Well anyway, I needed some money for more important experiments that I wanted to do about that time. I had no choice.”

We asked him if it made a lot of money. He answered: “Oh yes, about twenty times what I needed in those days. It carried me over until I got some really expensive ideas.”