Glossary
Phonograph
Carbon button Transmitter Direct Current (DC) Multiplex telegraph system. Alternating Current (AC) |
Record Player (music).
(Microphone) improved the telephone. A flow of current that flows in one direction only. Low Voltage. A Telegraph that could send 4 messages on a single wire at once. An electrical current that reverses its direction at regular intervals. More efficient than direct current, but has a higher voltage. |