GB393865A - Oscillation generator - Google Patents

Abstract

393,865. Converting. SCHLESINGER, K., 39, Friedrichstrasse, Friedrichshagen, Berlin. Nov. 16, 1932, No. 32338. Convention date, Nov. 19, 1931. [Class 38 (ii).] The oscillating potential applied to the deflecting-plates of a cathode-ray tube, and the steady potential, on which the oscillating potential is superimposed, are independently variable. The oscillations are generated by a relaxation-oscillation circuit 1, 2, 3, their amplitude, applied to output terminals 9, 10, is varied by a potentiometer 7, 8 across the condenser 2, and the steady potential is varied by a potentiometer 4, 5. Output terminal 9 is connected to an adjustable tapping on the resistance 7, which is small compared with the load resistance on terminals 9, 10, but is greater than the quotient of the ignition potential of the neon tube 3 and the charging-current of the condenser 2. The impedance of the condenser 8 is small compared with the resistance 7. The time constant of the potentiometer is large compared with the period of the lowest frequency required. Suitable values of resistance and capacity are 0.5 X 10À6 ohms and 0.5 F. respectively. The potential divider 7, 8 may consist of a large fixed condenser of about 1000 cms. in series with a small variable condenser of about 100 cms., Fig. 2 (not shown). The condenser 2 has a capacity of 10<4> cms. to 0.1 F.