November 15, 1965 Electronics
[Table of Contents]
Wax nostalgic about and learn from the history of early electronics.
See articles from
published 1930 - 1988. All copyrights hereby acknowledged.
It is easy to not notice the ingenuity
that has gone into making even seemingly simple components designed and perfected by
supplier companies' employees. That fact that we tend to take them for granted
and assume that they "just work" when incorporated into our own higher level designs is
a powerful passive endorsement. Potentiometers (pots) are a prime example - particularly high-end
models like these three Bourns Trimpot® examples. I installed hundreds of the leadscrew-actuated
and worm gear-actuated pots on military grade circuit boards during my time in the 1980s
at Westinghouse Electric's Oceanic Division in Annapolis, Maryland. An inspection of
the cut-away drawings reveals the thought that went into making the devices robust, reliable,
and even fool-proof (lots of fools handle these things). Particularly clever is the "no
backlash idling spring" mechanism that not only minimizes the amount of adjustment screw
rotation that occurs without a change in resistance when reversing direction, but also
prevents damage when the wiper carriage is run to the end extremes and the user keeps
turning the screw.
Bourns Quality Design insures Built-in reliability and performance.
Trimpot® Leadscrew Actuated Potentiometers
were introduced by Bourns, Inc., in 1952 to meet the need of the aerospace industry for
a rugged, high performance miniature adjustment potentiometer. These units pioneered
such potentiometer qualities as small size, accuracy, multi-turn adjustment and stable
settings, as well as rugged, sealed construction for reliable performance in severe environments.
Bourns Worm Gear Actuated Potentiometers, in
the popular square configuration, were developed to add packaging versatility yet assure
the same high performance and reliability as the Trimpot Leadscrew Actuated Potentiometer
line. These units, in 1/2" and 3/8" sizes, available with stranded insulated leads or
printed circuit pins, feature all-sealed construction, excellent resolution, and an exclusive
clutch-action wiper which prevents damage from forced adjustment.
Bourns Single-Turn Rotary Potentiometers combine
many of the leadscrew actuated and wormgear actuated potentiometer features in micro-miniature
and subminiature circular configurations. Available with solder lugs and printed circuit
pins, these units operate up to 175°C, are encased in a lightweight, all plastic
case, and have excellent shock and vibration stability. Micro-miniature types smaller
than a transistor - are available; while sub-miniature types combine high performance
with nominal cost.
Posted September 3, 2018