Patent GB-446797-A (GB)
Title: Apparatus for regulating the current and/or voltage supplied to an electrical apparatus
IPC: G05D23/275
Filed: 1934-07-27
Abstract: 446,797. Control systems for consumption apparatus; automatic regulation; discharge apparatus. KRAMOLIN, L. L. DE, 53, Nassauischerstrasse, Wilmersdorf, Berlin. July 27, 1934, No. 23990 /35. Divided out of 446,736. [Class 38 (iv)] [See also Group XL] Switching control; thermionic and like control; voltage accommodation.-Current or voltage supplied to a load device is controlled directly, or through relays, by varying the characteristics, (pressure or composition) of the filling in an electric gas or vapour arc discharge tube. The control effect may take place up to the point when the load is switched off, and it may be effected by varying the current or by switching the current on and off periodically directly or through relays. As applied to the automatic temperature regulation of electric heating apparatus such as steam, water or oil baths and boilers, room heating, pressing irons, cooking apparatus, &c., the discharge tube may be in series with the heating resistance or in parallel with a part thereof and is arranged to be heated by the resistance so that its pressure or composition are varied in accordance with the temperature of the heating apparatus. An igniting electrode and an igniting gas may be provided so that starting of the discharge is ensured. The heat conductive connection between the discharge tube and the heated body may be varied so as to adjust the temperature at which the apparatus is to be maintained, e.g. the tube may be immersed or embedded to a greater or lesser extent in a heated liquid or in the heated apparatus, or it may be moved towards or away from the apparatus or by using screening plates or reflectors. The discharge tube itself may provide part of the heat. The luminosity of the tube may be utilized as an indication of the working of the apparatus or as a measure of the current flowing. A pressing iron is provided with two bores one of which contains the heating resistance and the other the discharge tube and is provided with a sight hole. The final temperature may be adjusted by a sleeve varying the thermal contact between the discharge tube and the iron body. The discharge tube may be sensitive to temperature in a refrigerator so as to maintain this constant. Auxiliary heating means may be provided on the tube. An arrangement of a discharge tube in series with a heating resistance for the tube may be connected in series with apparatus, e.g. mains transformers of radio sets, so as to take voltage fluctuations and maintain the voltage across the load constant and permit supply from a source of voltage higher than that for which the apparatus is designed. Where control is effected through relays, controlled discharge tubes such as " Thyratron " (Registered Trade Mark), may be used for amplification. Where the discharge tube controls the circuit directly, high voltage tubes may be used if connected in circuit with the low voltage apparatus through step down transformers. To ensure continuity of control several discharge tubes in parallel may be used so that at least one tube will start at the required time. To ensure easy re-starting of the discharge an auxiliary high voltage source may be connected to auxiliary electrodes so as to maintain a discharge even when the main discharge is blocked. In one arrangement, Fig. 7, auxiliary electrodes h are supplied from the secondary c of a transformer the primary g of which is connected across the main electrodes so as to be operative only when the main discharge is blocked. In a further modification, Fig. 9, a potentiometer i whicn may itself be a heater, is connected across the supply and a discharge tube having electrodes at differing distances from a common electrode is connected across tappings on the potentiometer in series with heating resistances b1, b2, b3 to be controlled. By this means several discharge paths having g graded maximum voltages are arranged to control the resistances so that as the pressure in the tube rises, first resistance b3 and finally resistance b1 is switched out. The discharge tube may have its characteristics varied by varying the pressure or volume or quantity of the filling or by varying the constituents of the filling. Control may be obtained by making the tube of U-shape, Fig. 2, with a barrier fluid such as mercury in the bend and using one end as the discharge space whilst the other end contains a vaporizable substance such as ether, alcohol, benzine or sulphuric ether. The limbs of the tube may be of different lengths and the discharge chamber may contain argon at a pressure of 2-10 mm of mercury. Alternatively the discharge space may contain material such as retort carbon platinum black, phosphorus or other getter, or a palladium sponge which evolves or absorbs gas at high or low temperatures. For example, the filling may consist of argon with which hydrogen is mixed when a palladium sponge is heated. The constitution of the gas may also be varied by mechanical or chemical means. In a further arrangement a vapour former may be used such as mercury, bromium, cadmium, caesium, iodine or phosphorus or compounds such as boron tribromide, mercury bromide or iodide, drisilan (Si3H8), tantalum pentafluoride or uranium hexafluoride. The Provisional Specification discloses an arrangement in which the voltage across an electric device is maintained constant by the series connection of a self-regulating discharge tube which takes voltage variations and permits supply from a source of voltage higher than that for which the device is designed. Specification 427,137 is referred to.