From VACUUM TUBE to TRANSISTOR to (IC) CHIPS -
The EVOLUTION of ELECTRONICS - My Collection
|Vacuum Tube, also called a Vacuum Valve, a plug-in vacuum sealed
glass tube, in the simplest diode form, it contained a cathode and/or
cathode heating filament and a plate electrode. Advanced tubes called
triodes, tetrodes and pentodes, named so in accordance with the
number of electrodes 3, 4, or 5 within, were used for amplification,
oscillation and switching. These added electrodes were called grids, up
to three grids were used, with the control grid being the most important,
since voltages applied to it could turn tubes off/on or help make them
oscillate. When a weak signal voltage was input on the control grid, a
replica of that input signal would in turn be created in amplified form by
the plate circuit. Tubes were formerly used in the early age of Radio
and TV / electronics. In 1948 Bell Labs invented a semiconductor device
called a transistor which performed the same functions as the vacuum
tube, but it had the advantage of being much smaller in size and it did
not require a cathode heating filament. Transistors were more efficient,
operated cooler, faster, and at much lower power levels, also, most
transistorized circuitry was safer to work on because of its low voltage
requirements. They were considerably more rugged then tubes, able to
sustain high impact loads and still continue to function. Because of the
transistor, vacuum tubes died hard and finally became obsolete.
Needless to say, electronics is the silent servant that touches every
aspect of day to day life, without it, the modern world would grind to a
halt. The advent of modern electronics came into being at just the right
time, because the Space Age would never have blossomed forth
without miniature transistorized circuits and the later more compact
Integrated Circuits (IC). Satellite design constraints of weight and size
have necessitated even more compact electronic chips. Space systems
and modern electronics go hand in hand as they promote each other.
Electronics complements modern life, and is master over every
technical and scientific and commercial endeavor.
|Old Radio Tube Boxes are
collector items now.
|Above- Actual size of a plug-in vacuum tube switch and supporting components in a 1950s IBM computer.
By comparison, see the paperweight below and the early computer chip which contains 30,000 components.