US2196845A - Oscillograph circuit - Google Patents

Description

April 9, 1940. ANDR 2,196,845

OSCILLOGRAPH CIRCUIT Filed March 19, 1937 25 I I I I I I I Cathode 1 Tube 'wvyvw|l| 25 25 10 III- T (hf/lode 0 Ray 1: 2 Tube :2 8 Q l I -Ilh- 13 25 INVENTOR ROBERT ANDRIEU ATTORNEY Patented Apr. 9, 1940 UNITED STATES f .Z 96 8 5f 2,196,845 OSCILLOGRAPH clncurr Robert Andrieu, Berlin, Germany, assignor to Telefunken Gesellschaft fiir 'Drahtlose Telegraphic in. b. H., Berlin, Germany, a corporation of Germany Application March 19, 1937,Serial No. 131,875

In Germany March 27', 1936 a 3 Claims. (o 250-46) A sawtooth shaped potential is required for the recording of periodically recurring electrical actions by a Braun oscillograph if Lissajous figures which are generally not evaluable without retracing are to be avoided, and the frequency of the potential must be equal to, or be a multiple of,

the frequency of the action to beinvestigated or analyzed. quency of the potential should be easily adjustable. Moreover, with the use of standard Braun tubes in which the pencil strikes about the middle of the fluorescent screen in the non-deflected or quiescent state of the pencil it is very necessary that the sawtooth voltage wave should be symmetric in shape and trend, in other words, it must be free from D. 0. components.

My invention in general provides a regenerating oscillating tube arrangement having an oscillatory circuit joined to the anodeof said tube, 20 sinusoidal waves generated by the oscillator being fed to a vacuum tube acting as a discharge path for a condenser in which charges are linearly stored and discharged. The condenser resistance combination by means of which the condenser is charged comprises a time constant circuit which is mechanically interlocked with the aforementioned oscillatory circuit so that these two circuits are maintained in a definite relationship each with the other. e

My invention will bestbe understood by reference to the figures in which Fig. 1 shows one embodiment of my invention, and 35 t Fig. 2 shows another embodiment of my invenion.

Referring to Fig. 1 of the accompanying drawing, a vacuum tube III has an oscillation circuit I I connected in the anode thereof, said circuit 40 including the condenser l2 and the'choke coil I3. A regeneration (feedback) coil I5 is 'con nected to a condenser M which is joined with the grid of the tube H). A grid leak acts as a leak path for condenser I4. The plate of tube I0 is 45 connected by way of a coupling condenser H with the control grid of a tube l8. The latter also has a grid leak l9. In parallel connection with the tube i8 is a condenser 20. The plate and the filament of tube l8 are respectively con- 50 nectedby way of two resistances 2|, 22 of like size with the positive and'the, negative pole, respectively, of a source of D. C. voltage, this source being grounded at a suitable point. In parallel relation to the said tube 18 by way of coupling 86 condenser 23 is the deflector plate system of the It is convenient also that the fre earthed by way of resistances 25.

The arrangement shown in Fig. 1 operates'in oscillograph tube 24, the deflector plates being the manner that on the control grid of tube [8,

by way of coupling condenser I1, is impressed a; t

sinusoidal potential to ground. When'the said potential presents a crest value with reference to the filament of tube l8, flow of grid current I will be initiated which sets up the requisite negative grid biasing potential on one side of con- 10 denser l1, the latter being caused to leakaway again gradually by way of the resistance .I9. The condenser 20 is constantly charged by way of resistances 2|, 22, the condenser potential showing 'a rise proportional to time, when start- 'ing from zero potential across condenser or from an initial voltage which is small compared with the source of charge potential. Upon each initiation of discharge inthe tube |8,the condenser 20 is discharged through the said tube, down to. 24! the value at which the plate current as a result of decline of plate potential becomes interrupted or down to the value when the control grid poten-' tial of tube I8 liesagain below the lower bend of the plate current grid voltage characteristic. 25 If tubel8 is a grid-controlled gas or vapor type discharge vessel with an arc-like discharge, it is generally possible to produce lower minimum values of potential at the condenser 20, thanin a case where tube I8 is of the high-vacuum type. 'Ihe sawtooth shaped alternating voltage arising across the condenser 2|] consists of a D. C. com- 'ponent which arises across the blockingcondensers23and a symmetric sawtooth component which in major art is operative at the deflector I plates, of theBraun tube. The resistances 25 moreover have this action that a D. C. voltage possibly set up across the-deflector plates. as a result of creepage or sneak currents is allowed to leak away. e The frequency of the sawtooth voltage may be regulated in a particularly simple manner by I that the setting means for the condensers I2 and 20 aremechanically coupled or interlocked, an end which is attainable inpractice by that the rotor parts of both condensers are seatedu pon, one and the same shaft. In another exemplified embodiment. of the invention as shown in Fig. 2 a coupling by theaid of a transformer ZS-is used in lieu of the capaciexplained by reference to Fig. 1. j Also the chance of coupling the two condensers 20 and I2 is the same as described by reference to Fig. 1.

What I claim is: I

1. An apparatus for producing energizing potentials comprising an oscillator, an electric storage element, means for storing a charge in said storage element, a discharge path for said storage element, means for coupling the oscillator to said discharge path, and means for simultaneously varying the storage rate of said storage element and the natural frequency of said oscillator v 2. An apparatus for producing energizing potentials comprising an oscillator, an electric storage element, means for storing a charge in said storage element, a discharge path for said storage element, a time constant circuit connected to said discharge path, means for coupling said discharge path and said time constant circuit to said oscillator, and means for simultaneously varying the storage rate of said storage element and the natural frequency of said oscillator.

I 3. An apparatus for producing energizing potentials comprising an oscillator having an oscillatory circuit therein, an electric storage element,

ROBERT ANDRIEU.

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