At first it was usual to join the microphone transmitter in the direct circuit.
He wore headphones and spoke into a microphone, simultaneously responding to half a dozen chat windows open on this computer.
Hughes invented the microphone, but did not apply for letters patent.
- Edison's Microphone Transmitter.
Another type of microphone which was used in Europe much more than in the United States was the multiple-contact instrument.
The resistance of the microphone can thus be made a large fraction of the total resistance of the circuit in which it is placed; hence by using considerable currents, small variations in its resistance can be made to induce somewhat powerful currents in the line wire.
He employed as a detector of this wave a simple, nearly closed circuit of wire called a Hertz resonator, but it was subsequently discovered that the metallic microphone of D.
7, the microphone, a battery and the primary of an induction coil in a local circuit, and putting the line in circuit with the secondary of the induction coil, which acted as the transmitter.
In circuit with this battery was placed the secondary circuit of an induction coil, the primary circuit of which contained a telephone transmitter or microphone interrupter.
Acting upon this discovery, he constructed an instrument which he called a " microphone," 6 and which consisted essentially of two hard carbon electrodes placed in contact, with a current passing through the point of contact and a telephone included in the same circuit.