Method of and arrangement for producing relaxation oscillations of constant frequency

摘要

426,055. Valve generating circuits. RADIOAKT.-GES. D. S. LOEWE, 10, Wiesenweg, Steglitz, and SCHLESINGER, K., 39, Friedrichstrasse, Friedrichshagen, both in Berlin. Sept. 27, 1933, No. 26536. Convention date, Oct. 1, 1932. [Class 40 (v)] In order to maintain constant frequency in a relaxation oscillator despite changes in supply voltage, the breakdown voltage of the discharge valve is arranged to vary automatically with the supply changes. The supply may be taken from house mains 11 through a transformer 10, rectifier 7, and smoothing condenser 6. The relaxation condenser 2 is charged through a resistance 1, until the voltage on the condenser 2 reaches the breakdown voltage of the discharge valve 4, whereupon the' condenser is discharged. A resistance 12 is placed in the charging circuit, and the voltage across it is conveyed to the grid 5 of the valve 4 through a resistance 13. If supply voltage rises, the condenser 2 charges more rapidly, and the voltage applied to the grid 5 becomes more negative so that the breakdown voltage of the valve 4 is increased. The valve may have a heated or unheated cathode, and preferably contains mercury vapour or neon at low pressure. The oscillations may be synchronized for television &c. by applying synchronizing voltages at 14.