R.F. Energy Powers Incandescent Lamp
April 1956 Popular Electronics
Wax nostalgic about and learn from the history of early electronics. See articles from Popular Electronics, published October 1954 - April 1985. All copyrights are hereby acknowledged.
Wireless power distribution has been in the news a lot for the last couple years. It began with a goal of just wirelessly charging mobile devices like cellphones, smart watches, and tablet computers. Next came articles about charging electric cars wirelessly while sitting in a parking lot or garage, or even at a stop light. In each instance, the item being charged needed to sit in close proximity to an electric induction coil to be effective. Just a couple days ago, however, a new item appeared where Disney Research has come up with a 'quasistatic cavity resonance' system that covers an entire room. This story from a 1956 edition of Popular Electronics reports on an incandescent lamp powered wirelessly by an RF energy source. It's not quite the same thing, but is the same basic principle.
Powered by radio-frequency energy, an incandescent lamp developed by Sylvania is said to be the world's brightest. Its strong, uniform light is especially useful in movie-making. Other uses include color television tube processing, medical research, radar and air traffic control, and computers. The lamp is not connected by wires to the source of its activating energy. It is heated by induction - the r.f. is carried to the outside of the lamp via a copper coil wrapped around it. A d.c. voltage energizes the oscillator; varying the d.c. controls the brightness of the lamp. 'In addition, a water line can be connected to the oscillator to cool both lamp and coil. The lamp uses a disc of special material, instead of tungsten filaments, for its light element.