Patent GB-190607565-A (GB)
Title: Improved Method of and Means for Signalling or Effecting Operations in Local Electric Circuits by Means of Sound or other Vibrations.
Inventor: GARDNER JOHN
Filed: 1906-03-29
Granted: 1907-03-21
Abstract: 7565. Gardner, J. March 29. Sound, controlling and actuating apparatus by; signals, audible; electric, and submerged ; signals, receiving apparatus forÀ-Relates to means for giving a signal, or for controlling apparatus, by means of sound or other vibrations acting on a microphone, included in the primary circuit of an induction coil, the secondary circuit of which controls the signalling or relay circuits. The apparatus may be used in connexion with submarine sound-signalling, for indicating tremors of the earth, or for controlling an electric switch. In one form, the receiving microphone A, Fig. 1, is directly in series with the primary B of the induction coil, the secondary D of which is in series with a coherer E controlling a relay G, which in turn controls the signalling or controlling magnet K and the tapper L. When the microphone A is vibrated, a high-tension current is set up in the secondary circuit and breaks down the resistance of the coherer. In a modified arrangement, the coherer may contain peroxide of lead, the resistance of which is increased by high-tension currents. The microphone A may be attached to the diaphragm of a telephone receiver N in circuit with a second microphone A' by which the sounds are received, as shown in Fig. 2. This receiver may be tuned to respond only to a certain note or period of vibration. Fig. 3 shows such a receiver in which the usual diaphragm is replaced by a spring strip P, carrying one electrode of the microphone A, and tuned to respond to the desired note. In order to magnify the vibration given to the microphone, the movable electrode may be mounted on a lever, connected also to the strip P, and to the receiver framing. A simple magnetic reed may replace the strip P. Two or more receivers may be in circuit with each other, and each diaphragm may carry one of the electrodes of the microphone. Three or more microphones may be arranged in combination with the necessary receivers in the manner indicated in Fig. 2. The magnet K, Fig. 1, may be replaced by means for controlling an electric switch such as is described in Specification No. 20,496, A.D. 1904, [Abridgment Class Electricity, Regulating.&c.], the moving part passing over successive contacts according to the length of time during which the circuit is influenced by the sound vibrations. According to the Provisional Specification, instead of controlling a coherer, the current produced in the secondary coil may act directly upon a suitable relay, or upon the diaphragm of a telephone receiver, having one end of a lightly balanced lever resting upon it. When the diaphragm vibrates, the lever may engage a yielding contact, and intermittently close a local circuit in which the signalling device is included. The Provisional Specification also states that a number of local circuits may be employed, each with its own microphone, and each responding only to its own note, or a number of the circuit-closing devices may be arranged in series in one local circuit, and each be thrown into operation by its own note. To close the circuit, the notes of all the devices would be simultaneously souuded.