US2083202A

US2083202A - Arrangement for generating tilting oscillations

Info

Publication number: US2083202A
Application number: US668940A
Authority: US
Inventors: Schlesinger Kurt
Original assignee: Individual
Current assignee: Individual
Priority date: 1932-05-02
Filing date: 1933-05-02
Publication date: 1937-06-08
Anticipated expiration: 1954-06-08
Also published as: FR46450E; US2188288A; GB423583A; GB423394A; FR755061A; GB453011A; US2113163A

Description

June 8, 1937. K. SCHLESINGER ARRANGEMENT FOR GENERATING TILTING OSCILLATIONS Filed May 2,- 1933 Patented June 8, 1937 'UNlTED STATES ARRANGEMENT FOR GENERATING TILTING OSCILLATIONS Kurt Schlesinger, Berlin, Germany Application May 2, 1933, Serial No. 668,940

Germany May 2, 1932 11 Claims.

Discharge tubes are already known having a hot cathode, a grid and a gas filling of relatively high pressure (for example V atmosphere). these discharge tubes the grid does not act as a 5 control element but as blocking element. As

long as the control grid possesses a corresponding negative potential a discharge does not take place, however high the potential may be between the anode and thecathode. Immediately,

10 however, the discharge-by shifting of thegrid potential-hasonce commenced, the same-irrespective of any variation in the grid potentialcontlnues as long as a potential exists between the cathode and the anode.

The subject matter of the invention is an improved arrangement making use of these discharge tubes of the kind known per se, for generating self-controlled (so-called free relaxation oscillations) or foreign-controlled (induced) reso laxation oscillations. v

The invention comprises means to decrease, in a connection system of the mentioned type, the

' rate of discharge to such extent as to allow the occurrences concerned accurately to be govu erned.

The invention also comprises improved charging means.

Furthermore, the invention comprises means to prevent currents from flowing in the grid cir- 30 cults of the above mentioned discharge tube, as to increase ,the steadiness of the occurrences concerned.

For the generation of foreign-controlled relaxation oscillations the potential of the charg- 35 lng condenser, which is charged in chronologically linear fashion, possibly with the assistance of a screen grid tube, in the manner known per se, is, in accordance with the invention, applied between the cathode and the anode, and the control potential to the correspondingly negativeblassed grid. For producing self-controlled relaxation oscillations the control potential in accordance with the invention is derived from the relaxation oscillation potential, for example by 45 means of a potential divider connection system.

Capacitative dividing of the potential is particularly suitable for the purpose of the invention, as leakage currents do not take place in connection therewith. Naturally. however, it is also 50 possible to employ highly ohmic division of the potential, and if necessary also an inductive division of the potential.

Preferably, foreign control and self-control may be comblnedwith each other-in the arrange-- tion of this character possesses the advantage that the relaxation oscillation does not cease upon momentary failure on the part of the foreign control potential. This arrangement possesses particular advantages in connection with 5 television receiving arrangements.

The arrangement according to the invention permits of the use of ignition potentials as desired, as the ignition potential in the case of a given frequency depends solely on the extent of the charging current. The quenching potential is equal to zero". The charging condenser is completely discharged. The arrangement permits of very exact control at the merely weakly negative-biased grid. A further appreciable advantage of the arrangement resides in the fact that the same also enables relatively small ignition potentials-approximately 150-200 voltsto be employed. I

Other objects and embodiments of the invention will be more fully understood from the appended drawing, whereof Fig. 1 shows an arrangement for generating foreign-controlled relaxation oscillations, whilst in Fig. 2 there is shown an embodiment of the present invention.

Fig. 3 shows a. special feature of the invention.

In the drawing i is the, discharge tube, which is filled with gas of approximately mm.-1 mm. atmosphere, (thegas pressure depends on the peculiar gas the tube is to be filled with) having the hot cathode 4, the grid 3 and the anode 2. 8 is the grid bias battery. The control potential is represented in symbollcal fashion by 9. 5 is the charging condenser. At 6 and 'I there is fed the charging current, which serves for chronologicallinear charging of the charging condenser 5, and may beproduced by means of a screen d tube. v 4

Thearrangement operates in the following manner: At first the condenser 5 is charged to the ignition potential, which may be selected as desired, and in the case of a given frequency depends only on the extent of the charging current. A discharge cannot take place so long as the grid 3 receives the requisite negative bias (for example, approximately 1, 10 or -20 volts) through the medium of the battery 8. At the moment when the negatlve-biassed grid has been raised by the control potential to a sufficiently high potential the discharge commences. The discharge continues until the condenser 5 has been completely discharged. The quenching potential is accordingly equal to zero. The re- According to the invention, the anode is furnished with a constant positive potential, whilst the grid is furnished with alikewise constant negative bias. The potential of the cathode is shifted during the charging operation into negative until the potential of the-negative-biassed grid has become to such extent positive in relation .to the cathode that the tube is able to ignite.

(The difference in potential between grid and cathode necessary for ignition is dependent on the nature of the filling gas.)

For charging purposes there is employed a screen-grid charging tube having a reciprocal of the amplification factor of less than Aoo%, the grid situated next to the anode *serving forcontrol, whilst the grid situated in the vicinity of the cathode is preferably raised to cathode potential.

The frequency of the relaxation oscillation may be regulated by variation of the charging current and/or by variation of the charging condenser, .According to the invention, the control potential of the screen grid charging tube is taken at a potentiometer, and at the same time there are provided a number of charging condensers, which are capable of being connected as desired and which determine the frequency range.

The relaxation oscillation potential to be conducted to the consumer is also taken via a potentiometer. By varying the adjustment of the potentiometer the amplitude of the relaxation oscillations may be changed within wide limits. Further, there is provided in the receiving circuit a counter-potential battery (which may also be replaced by a potentiometer), by the variation of which the position of the image in the Braun tube may be adjusted in simple fashion.

The synchronization potential necessary for the generation of controlled relaxation oscillations may, in accordance with the invention, be applied to the grid of the hot glow tube through the medium of a high resistance. It has been found that the synchronization potential, in the same manner as the negative bias, requires to be fed in such fashion that a load on the grid is avoided to all possible extent, so that the grid during the ignition process is able to assume instantaneously the potential corresponding with the run of the field.

Furthermore it was ascertained that the tilting potentials (more particularly the extremely rapid return) cause considerable electrical disturbances in thevicinity of the tilting oscillation generator. According, therefore, to the inv ntion, all lines leading fluttering potentials, and also the hot glow tube itself, are completely screened ofi. The tube is arranged together with the said lines in a special screening casing, and the lines within the casing are again furnished with special screening means.

In Fig. 2 there is shown a form of embodiment of the arrangement according to the invention, by Way of example. In the same I is the hot glow tube with the grid 2, to which there is conducted over the resistance 2| the negative bias,

and over the resistance 20 and the condenser 4| the synchronizing potential from the terminals 3|, 32. 3 is the cathode of the hot glow tube. According to the invention a low ohmic resistance 28 is arranged in the discharge circuit of the tube l, which serves for delaying the rate of the return. This resistance may have, for example, a value of about 1 ohm. In the anode circuit of the screen grid charging tube with the anode 26 and the screen grid 38 acting as control grid there are situated the charging condensers l1. l8 and I9 capable of being connected as desired, which condensers may be selected at, say, .5 mf., .05 mi. and 5000 cm. Naturally, it is possible to provide a larger number of condensers. or to select condensers of other sizes. The adjustment of the frequency of the relaxation oscillation is performed by regulation of the bias of the grid 38 of the screening grid tube by means of the potentiometer 25 and by selection of the corresponding tilting condenser. The operating potential, which is conducted by means of the coupling resistances l5 and Hi to the terminals 29 and 30 of the consuming apparatus, for example a Braun tube, is taken at the potentiometer 2 3. By varying the potentiometer adjustment the amplitude of the relaxation oscillations is changed within the practically desired limits. The counter-potential battery, as shown in the drawing, may conveniently be replaced by the potentiometer 23. By adjustment of this potentiometer there is determined the position of the image in the Braun tube. The hot glow lamp i, the condensers l1, I8 and I9, and also all leads are arranged within a screening casing 33. The leads may preferably again be screened off within the casing which screening is shown in Fig. 2 by the chain-dotted line. Furthermore, additional disturbance-ridding measures, such as a wave filter 20, 50, chokes 5 and 6 and condensers l and 8, etc., may also be provided. The heating elements 4 and I0 of the indirectly heated cathodes 3 and 9 may be heated for example in direct fashion by the mains in parallel connection. The remaining working current is if necessary also supplied ,from the mains through the medium of the steadying device 21. It has been found convenient to select the resistance 20 at approximately 10 ohms, the resistance 2| at approximately 3-10 ohms, the

resistance 15 and 16 at approximately 5000 and 10000 ohms, and the potentiometers 23, 24 and 25 at approximately 10 ohms, 0.5-10 ohms and 25000 ohms. The condenser M may conveniently be selected at 10 cm., the condensers l and 8- each at 5000 cm.

Naturally the invention is in no way limited to the form of embodiment as described. Thus, for example, it is quite readily possible to provide the total arrangement in a screening casing, and to employ also other known disturbance-ridding means beyond those stated by way of example.

There may be essential as regards this embodiment of the invention that the c ontrolupon the generation of free tilting oscillationstakes place into negative by shifting ofi the cathode potential, that the negative bias and also the synchronizing potential are conducted to the grid over high ohmic resistances for the purpose of producing induced relaxation potentials, that a plurality of tilting condensers are provided, which are capable of being selected or varied as desired, and bymeans of which there is determined the frequency range of the tilting oscilla ter-potential, which permits of adjustment of the 4 position of the image, and that the hot-cathode glow' tube itself together with all lines leading fluttering potential is screened oif in such fashion that electrical disturbances are avoided in the vicinity of the tilting condenser.

Though each kind of gas-filled, hot-cathode, three-electrode tubes may be employed for the arrangements according to the invention, preferably tubes may be employed, which are constructed in such fashion that the cold glow discharge only takes place at potentials which are as high as possible. 4

In Fig. 3, l-9 designate the same parts as in Fig. 1. Ill is a limiting resistance, which prevents the occurrence of a grid current upon the discharge, l2 the second condenser of the capacitative potential divider, which is made considerably, for example 100 times, larger than the main condenser 5, and in accordance with the invention may conveniently be constructed in the form of a rotary plate condenser. II is a counter-potential battery of preferably very few volts, which has the object of eliminating any remaining potential, and accordingly ensures proper quenching.

In the case of pure self-control the grid 3, which is biassed negatively by the battery 8, is charged by the charging current in the same manner as the main condenser, but considerably more slowly than the main condenser in accordance with the ratio given by the potential divider. The relaxation frequency, therefore, may be adjusted as desired by suitable adjustment of the potential. divider. When combining foreign-control and self-control, the foreign-control potential may be supplied at 9.

' The use of the connection systems according to the invention enables completely even synchronization to be obtained and to reduce the return period to such extent that the return line is almost entirely invisible.

I claim:

1. An arrangement for producing relaxation oscillations comprising a gaseous discharge device including a cathode, a control electrodeand an anode, means for producing the charging current, said charging means being connected with said anode on the one hand and with said cathode on the other hand; an auxiliary condenser being connected to said cathode on the one hand and to said control electrode on the other hand; a main charging condenser being connected to said control electrode on the one hand and to the anode on the other hand, said main charging condenser being smaller than said auxiliary condenser for producing a voltage-division; means for supplying said control electrode with a negative bias; means to supply said control electrode with a synchronizing voltage and a resistance being arranged'in the lead connection of said negative bias to said control electrode and a resistance arranged in the lead connection of said synchronizing control voltage to said control electrode.

2. An arrangement for producing relaxation oscillations comprising a gaseous discharge device including a cathode, a control electrode and an anode, meansfor producing the charging ourrent, said charging means beingconnected with said anode on the one hand and with said cathode on the other hand; an auxiliary condenser being connected to said cathode on the one hand and to said control electrode on the other hand; a main charging condenser being connected to said control electrode on the one hand and to said anode on the other hand, said main charging the lead connection of said synchronizing control voltage to said control electrode.

. 3. An arrangement for producing relaxation oscillations for television purposes comprising a gaseous discharge device including a hot cathode, a grid, and an anode; a condenser, a resistance of low value, means for charging said condenser, means to connect said discharge device, said condenser, and said resistance to form a discharge circuit, and means to apply a bias to said grid.

4. An arrangement for producing relaxation oscillations for television purposes comprising a gaseous discharge device including a hot cath- .ode, a grid, and an anode; a condenser, a resistance of low value, means 'for charging said condenser, means to connect said discharge device, said condenser, and said resistance to form a discharge circuit, means to apply a bias to said grid, and means to apply a synchronizing potential to said grid.

5. An arrangement for producing relaxation oscillations for television purposes comprising a gaseous discharge device including a hot cathode, a grid, and an anode; a condenser. a resistance of the order of 1 ohm, means for charging said condenser, means to connect said discharge device, said condenser, and said resistance to form a discharge circuit, means to apply a bias to said grid, and means to apply a synchronizing potential to said grid.

6. An arrangement for producing relaxation oscillations for television purposes comprising a gaseous discharge device including a hot cathode, a grid, and an anode; a condenser, a resistance of -low value, means for charging said condenser, said means including a charging tube having an auxiliary grid of the screen grid type, means to connect said discharge device, said condenser and said resistance to form a discharge circuit, means to apply a bias to said grid, and

means to apply a synchronizing potential to the grid of said discharge device.

'7. An arrangement for producing relaxation oscillations for television purposes comprising a gaseous discharge device including a hot catha grid, and an anode, means for producing thev charging current, said charging means being connected with said anode on the one hand and with said cathode on the other hand; a main charging condenser, an auxiliary condenser, and a resistance of low value being connected in series, said series connection being connected across the discharge space between said anode and said cathode, said auxiliary condenser being connected between said cathode and said grid, said main charging condenser being smaller than said auxiliary condenser for producing a voltage-division, means for supplying said grid with a negative bias, means to supply said grid with a synchronizing voltage and a high value resistance being arranged in the lead connection of said negative bias to said grid and a high value resistance arranged in the lead connection of said synchronizing voltage to said grid.

9. An arrangement for producing relaxation oscillations for television purposes comprising a gaseous discharge device, including a hot cathode, a grid, and an anode, means for producing the charging current, said charging means being connected with said anode on the one hand and with said cathode on the other hand; a main charging condenser, an auxiliary condenser, a resistance of low value, and an auxiliary voltage source being connected in series, said series connection being connected across the discharge space between said anode and said cathode, said auxiliary voltage source being arranged in the anode line to supply said anode with a weak negative bias, said auxiliary condenser being connected between said cathode and said grid, said main charging condenser being smaller than said auxiliary condenser for producing a vo1tage-division, means for supplying said grid with a negative bias, means to supply said grid with a synchronizing voltage, a high value resistance being arranged in the lead connection of said negative bias to said grid, and a high value resistance arranged in the lead connection of said synchronizing voltage to said grid.

10. An arrangement for producing relaxation oscillations for television purposes comprising a gaseous discharge device including a hot cathode, a grid, and an anode; a condenser, a resistance of low value, means for charging said condenser, means to connect said discharge device, said condenser, and said resistance to form a discharge circuit, means to apply a bias to said grid,

and an encasing to screen ofi said discharge device, said charging condenser and all leads conducting the relaxation oscillation potential.

11. An arrangement for producing relaxation oscillations for television purposes comprising a gaseous discharge device including a hot cathode, a grid, and an anode; a condenser, a resistance of the order of 1 ohm, means for charging said condenser, means to connect said discharge device, said condenser, and said resistance to form a discharge circuit, and means to apply'a bias to said grid, and an encasing to screen off said discharge device, said charging condenser and all leads conducting the relaxation oscillation potential.

KURT SCHLESINGER.