Patent GB-190823170-A (GB)
Title: Improvements in and relating to Apparatus for the Production of Continuous Electrical Oscillations.
Inventor: MANDERS HORACE
Filed: 1908-10-30
Granted: 1909-09-23
Abstract: 23,170. Manders, H. Oct. 30. High-frequency oscillatory discharges, producing ; transformers.-Relates to detail improvements in apparatus of the Duddell type for the production of continuous electric oscillations for use in therapeutics and in wireless telegraphy and telephony. The electrodes are formed of metal rods or castings having a central discharge area with the edges bevelled off as shown in Fig. 3, or with the edges cut away and then bevelled off as shown in Fig. 4. For high voltages, the part of the electrodes cut away is filled up with an insulating-material such as the preparation of kaolin known as " Fortafix" or " Cementium," or with steatite, pÔpier machÚ, court-plaster, or superimposed layers of thin silk, as shown in Fig. 3. The electrodes may be immersed in a mass or stream of oil or glycerine ; or the arc may be formed in dried compressed air, nitrogen, or carbon dioxide, the products of combustion being absorbed by soda-lime as described in Specification No. 8172, A.D. 1902. Fig. 6 shows a constructional form of the arc-gap in which the lid of a glass chamber A supports the electrodes I, J, a gas inlet valve D, a manometer M, a stopcock C to permit the escape of the gas, and a micrometer screw S by means of which the upper electrode I is adjusted. In a modification, the electrodes pass through stuffing-boxes in the sides of the chamber, and the sides of the vessel fit in a rubber-lined groove in the lid, which is clamped to the base in a similar manner to that of the Levy mercury-jet interrupter. In a further modification, the body of the chamber may be of metal, and the lower electrode mounted in the centre of the base. Both the electrodes may be of aluminium, iron, or zinc, and an iron anode or cathode may be opposed to a zinc cathode or anode, and these combinations of anode and cathode may consequently be used with an alternating-current supply. An iron or steel anode may be used with a cadmium cathode, or a cobalt anode with a zinc cathode. The two choking-coils in the supply leads are wound on the same iron core so as to form a closed magnetic circuit. The inductances used in the oscillation-circuit are preferably the flat spiral and other inductances described in Specification No. 8172, A.D. 1902, and are constructed of ribbon or tape, of copper, silver, aluminium bronze, phosphor bronze, or silver-plated metals. An inductance of metal ribbon may be wound in the form of a solenoid, the flat part of the ribbon facing the flat parts of contiguous loops, and the edges of all the loops forming the inner and outer walls of the solenoid. The inductance of the flat spirals may be varied (1) by winding up or relaxing the coil so as to vary the distance between adjacent turns ; (2) by using a moving contact-piece connected to a sliding carrying-arm ; (3) by connecting the spiral at intervals to contact studs provided witb a movable band. A "gyrating flat helix," consisting of a spiral divided so that the inner portion can be rotated within the outer, or vice versa, as described in the above-mentioned Specification, can also be used. The coupling between separate spiral inductances can be varied by withdrawing or approaching them in parallel planes, or by connecting them by a hinge so that they can open bookwise. The generating and distributing systems may be simultaneously connected inductively and conductively. The arc may be shunted by a second circuit containing capacity and inductance, the condensers in the two circuits being connected to the positive and negative supply leads respectively. Specifications No. 26,462, A.D. 1903, [Abridgment Class Electricity, Measuring &c.], and Nos. 5164, 4809, 3215, and 1499, A.D. 1907, are also referred to.