Inventions in Music by Hiton Lisa;

Author:Hiton, Lisa; [Hiton, Lisa]
Language: eng
Format: epub
Publisher: Cavendish Square Publishing LLC

The Telegraphone

Valdemar Poulsen was born in 1869. Before age thirty, this Danish engineer created the world’s first magnetic wire recorder, the telegraphone. The word has three ideas in the roots that make up its name. Tele means “at a distance”; graph means “written” or “writing”; and phone means “sound” or “voice.” From faraway distances and long ago times, people would be able to speak in a format that would become a permanent “text.” Poulsen’s telegraphone was the first machine to use magnetic recording to enhance the quality and scope of inventions like the phonograph and telephone.

Poulsen’s machine recorded sound magnetically onto a steel wire (called “piano wire” by some). Like the phonograph, the steel wire reeled around the cylinder as sound was being captured. By studying the simpler versions of the phonograph and incorporating Smith’s ideas, Poulsen approached magnetic technology with fresh ambition. As a telephone engineer, the primary ideal behind his mission was to record telephone messages—a task that the phonograph could not handle.

In order to record messages from a telephone, the receiving machine would need to be electromagnetic. Since the sound was coming from a distance (as in tele-phone), there needed to be something—a graph—to remember and transcribe what happened over the wires. This feat was far more complex than the phonograph as it would need to both cover great distances and improve upon the distorted quality of Edison’s efforts.

The key to Poulsen’s successful telegraphone was the idea of using an alternating current (AC), an electric current that can periodically reverse direction.

Using AC was first hypothesized by Smith. Yet it was Poulsen’s application that succeeded. The AC came from a telephone microphone signal. Poulsen sent an electromagnet along the steel wire. Electric signals mirrored the sound being recorded and then fed to the recording head, as suggested in Smith’s diagram.

AC and electromagnets work together in the telegraphone.

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