Word: filaments
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Dates: during 1950-1959
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...chief advantage of transistors-besides their smallness-is that they have no glowing filament and therefore need no "A current" to keep the filament hot. All they need is the "B current," and very little of that. According to Edward C. Tudor, president of I.D.E.A., the 22½ volt B battery (cost: $1.15) lasts 20 to 30 hours if used continuously, longer when played intermittently...
More important in this case than the transistor's small size is its saving on electric current. It has no hot filament, and so needs no filament-heating A-battery. It is also much easier on expensive, high-voltage B-batteries. According to Sonotone, the semi-transistorized instrument gets twice the normal service out of an A-battery and makes a standard B-battery last six months instead of the usual three or four weeks...
Between the Atoms. In an ordinary electron tube, electrons "boil" off a heated filament into a high vacuum. There, unhampered by clogging air, they dance around obediently in response to electrical forces provided to act upon them. A transistor has no filament or vacuum, only a speck of hard germanium cut from a silvery crystal. But the mobile electrons are there, flashing through the empty channels between the ordered atoms of the crystal fragment...
...transistor's greatest advantage is its lack of a heated filament. Most of the currents that pulse through electronic apparatus are extremely small, but when they are amplified or relayed by a conventional vacuum tube, its filament consumes a full watt. It is the same, says Dr. Ralph Bown, vice president in charge of research at Bell Laboratories, as "sending a twelve-car freight train, locomotive and all, to carry a pound of butter." A transistor gets along with a millionth of a watt, not enough in most cases to make it faintly warm. The Bell men take...
...method has been tried only in the laboratory. Among their test shots, the inventors have two pictures of a glowing filament covered by a dense filter that made it invisible to the naked eye. One picture, taken directly on a photographic plate, showed only a dim trace of the filament after a six-hour exposure. The other, taken with speeded-up electrons, showed the whole filament clearly after only four minutes...