magnetic recorder वाक्य

The first crude magnetic recorder was invented in 1898 by Valdemar Poulsen.
They had been invented in 1898 when a Danish engineer named Valdemar Poulsen patented the first magnetic recorder which he called the " telegraphone ."
This was because the film was shot on 16mm, using an Auricon sound-on-film camera which recorded the sound on the 16mm film optically, unlike in the case of where the sound was recorded on a Kinevox 35mm magnetic recorder.
In addition to the patent on the telephone answering machine ( 1948 ), Zimmermann held dozens of other patents, including a security device that automatically dials a phone number and conveys information in case of an emergency; a magnetic recorder used to monitor heart patients; a system for accessing prerecorded lectures to earn college credit; an airport system to send out landing information to planes 24 hours a day.