Automatic curb sender
Encyclopedia
The automatic curb sender was a kind of telegraph key
, invented by William Thomson, 1st Baron Kelvin
for sending messages on a submarine cable
, as the well-known Wheatstone transmitter sends them on a land line.
In both instruments
the signals are sent by means of a perforated ribbon of paper
but the cable sender was the more complicated, because the cable signals are formed by both positive and negative currents, and not merely by a single current, whether positive or negative. Moreover, to curb the prolongation of the signals due to induction
, each signal was made by two opposite currents in succession: a positive followed by a negative, or a negative followed by a positive. The aftercurrent had the effect of "curbing" its precursor.
This self-acting cable key was brought out in 1876, and tried on the lines of the Eastern Telegraph Company.
Telegraph key
Telegraph key is a general term for any switching device used primarily to send Morse code. Similar keys are used for all forms of manual telegraphy, such as in electrical telegraph and radio telegraphy.- Types of keys :...
, invented by William Thomson, 1st Baron Kelvin
William Thomson, 1st Baron Kelvin
William Thomson, 1st Baron Kelvin OM, GCVO, PC, PRS, PRSE, was a mathematical physicist and engineer. At the University of Glasgow he did important work in the mathematical analysis of electricity and formulation of the first and second laws of thermodynamics, and did much to unify the emerging...
for sending messages on a submarine cable
Submarine communications cable
A submarine communications cable is a cable laid on the sea bed between land-based stations to carry telecommunication signals across stretches of ocean....
, as the well-known Wheatstone transmitter sends them on a land line.
In both instruments
Tool
A tool is a device that can be used to produce an item or achieve a task, but that is not consumed in the process. Informally the word is also used to describe a procedure or process with a specific purpose. Tools that are used in particular fields or activities may have different designations such...
the signals are sent by means of a perforated ribbon of paper
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
but the cable sender was the more complicated, because the cable signals are formed by both positive and negative currents, and not merely by a single current, whether positive or negative. Moreover, to curb the prolongation of the signals due to induction
Electromagnetic induction
Electromagnetic induction is the production of an electric current across a conductor moving through a magnetic field. It underlies the operation of generators, transformers, induction motors, electric motors, synchronous motors, and solenoids....
, each signal was made by two opposite currents in succession: a positive followed by a negative, or a negative followed by a positive. The aftercurrent had the effect of "curbing" its precursor.
This self-acting cable key was brought out in 1876, and tried on the lines of the Eastern Telegraph Company.