GB646253A - Improvements in and relating to cathode ray tube circuits - Google Patents

Abstract

646,253. Cathode - ray oscillographs. GENERAL ELECTRIC CO., Ltd., and KEMP, L. G. July 16, 1948, No. 19146. [Class 37] The width of the trace produced by a marker pulse is rendered narrow and independent of the duration of the pulse, at least over a substantial part of the height of the trace. On the working stroke a, Fig. 5, of the saw-tooth time base is superimposed a triangular wave b producing a resultant wave-form c having a horizontal portion CD indicating zero deflection in the direction of the time-base. The marker pulses are caused to appear during intervals CD and appear as lines of width equal to that of the luminous spot. A time base generator TB, Fig. 6, generating a saw-tooth waveform, is connected to one horizontal deflecting plate D1, while to the other plate D2 is connected a triangular wave generator TW generating a wave-form b, Fig. 5. A marker signal generator MS is connected to one of the vertical deflector plates D4, the other plate D3 being connected to a generator S of pulses to be examined, which may be time-modulated pulses in a pulse signalling system. The mean recurrence frequency of the pulses generated is determined by a master oscillator system SYN, which also synchronizes the time base generator TB, triangular wave generator TW, and marker signal generator MS. The marker pulses themselves may be used to provide a sufficiently close approach to bringing the beam to rest in the direction of the time base instead of using a separate triangular wave-form. A deflecting wave-form for producing a linear time base may be produced by integration of a rectangular wave-form by the procedure illustrated in Fig. 8. A pulse a of triangular form is differentiated, giving the waveform b,which is added to a rectangular waveform c and produces the waveform d. This is integrated to give a time base e of the same form as c, Fig. 5.