GB637296A - Improvements in circuits for supplying the deflecting systems of cathode ray oscillographs - Google Patents

Abstract

637,296. Cathode-ray oscillographs. SOC FRANCAISE RADIO-ELECTRIQUE. May 22, 1946, No. 15502. Convention date, June 11, 1942. [Class 37] [Also in Groups XXXVIII and XL (c)] A normal depth sounding system, in which supersonic pulses 47 are emitted at 45, Fig. 3, reflected from the ocean bed 48, received at 46 and displayed on a cathode-ray tube 37, has an additional cathode-ray tube 51 on which the forms of the successive echoes due, e.g. to shoals of fish 62 and the ocean bed 48 are superposed and displayed. The cathode-ray tube 37 is controlled to trace a series of parallel lines, each corresponding to a depth of e.g. 100 metres, the echoes appearing as vertical excursions from these lines. The cathode-ray tube 51 is fed with a time base initiated by the echo and having a duration and amplitude dependent on the duration of the echo ; as shown in Fig. 1, the echo is applied at 28 to produce a negative signal 15 on the grid of valve 14 to block it, while a positive signal 12 is applied over resistance 10 to the grid of the cathode-ray tube to switch on the cathode-ray beam ; the blocking of valve 14 allows condenser 19 to charge over pentode 26 to provide the time base for the horizontal deflecting plates of the cathode-ray tube, this time base terminating at the end of the echo signal when valve 14 becomes conductive ; the echo is also applied at 9 to the vertical deflecting plates of the cathode-ray tube so that the various echoes are superposed as shown at 51 in Fig. 3