Improvements in and relating to cathode ray oscillographs

Abstract

Abstract 502,743. Oscillographs ; valve circuits. SCOLES, G. J., and METROPOLITANVICKERS ELECTRICAL CO., Ltd. Sept. 23, 1937, No. 25866. [Class 37] [Also in Group XL] A cathode-ray oscillograph and impulse generator for producing and indicating or recording transients has a voltage across the time-sweep condenser applied to a tripping circuit including a discharge tube and series resistor, the discharge tube igniting at an adjustable interval after the termination of the time-sweep and producing a change of potential at the junction of the resistor and tube which is caused to initiate the charging of the impulse generator and also to discharge the time-sweep condenser. The time-sweep circuit 2 has the condenser 8 charged through a resistor 7 on which a tripping circuit 30 .. 32 is tapped at 33 and connected across the circuit 2. A spot-suppressing circuit 10 .. 12 is provided and when the tube 10 ignites, the resistor 11 permits the voltage across condenser 8 to increase at a slower rate. The potential at 33 thus increases until tubes 30, 31 ignite, and the potential produced at the junction point 34 is applied through condenser 35 to the grid of tube 5 to discharge the time-sweep condenser 8. The junction point 34 is also connected through condenser 36 to a gridcontrolled tube 14 to permit charging of the surge condenser 16, the periodical discharge occurring through tube 17 into the network 18. The bias resistor 20 of tube 17 includes a parallel connection 21 .. 23 to which is connected a synchronizing condenser 24. During successive time-sweeps, surges and zero lines are traced alternately upon the screen since, while charging current flows in resistor 15 a negative bias is applied to the grid of tube 17 and the sweep condenser impulse is ineffective to trip, whereas when the surge condenser is charged no current flows in resistor 15 and the sweep condenser impulse is effective. The time elapsing between striking of tubes 10 and 30, 31 is varied for different surge durations by altering the tapping position 33, varying resistor 11, employing a biassing battery in a single-tube tripping circuit or by varying the bias of a grid-controlled tube used in place of the discharge tubes 30, 31. Specifications 482,956; 482,957, [Group XXXV], and 482,994 are referred to.

Inventors

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