GB620851A - Improvements in or relating to circuits for cathode-ray oscilloscopes - Google Patents

Abstract

620,851. Cathode-ray oscillographs. PHILIPS LAMPS, Ltd. Oct. 5, 1946, No. 29748. Convention date, March 16, 1943. [Class 37] The amplitude of a cathode-ray tube trace is measured by producing a cursor or datum trace whose position is adjustable to coincide with a peak of the trace to be measured, a calibrating voltage then being substituted for that producing the trace to be measured and being adjusted to be coincident with the datum trace. In one embodiment, the signal to be measured is applied at 3, Fig. 1, over switch 13 and amplifier 2 to an electronic switch 9 controlled by pulse generator 10; an adjustable direct potential 7 is applied to the switch 9, so that the signal 4 is displayed on the cathode-ray tube alternately with a datum dot or line 6 which is adjusted to the peak of signal 4; switch 13 is then changed and the signal replaced by an oscillation from 14 adjusted to be of approximately the same frequency and to have its peak at the datum 6; the signal at 3 then has a peak voltage equal to that developed at 4. In a further modification, the amplifier 2 is applied to one deflecting system and the datum signal from 7 is applied to another deflecting system of a tube having two complete deflecting systems, Fig. 2, not shown. The voltage from 7 may be alternating with a frequency ten times greater or ten times less than the time-base frequency. The Specification as open to inspection under Sect. 91 includes the case where the source 14 is used in place of source 7, Fig. 2 (Cancelled). This subject-matter does not appear in the Specification as accepted.