CH272932A - Method for driving an electron tube and device for implementing this method. - Google Patents

Description

Procede pour piloter un tube electronique et dispositif pour la mise en Oeuvre de ce procede. Les montages de la elasse C, realises au moyen de tubes-relais electroniques montes en oscillateurs ou bien en amplificateurs, out ceci de particulier que 1e courant anodique appa- rait seulement Pendant une fraction phis ou moins Brande de 1'alternance positive de la tension de grille de commande; et que pour 1e reste du temps 1e tube ne debite aucun cou- rant anodique. Process for driving an electron tube and device for implementing this process. The assemblies of class C, made by means of electronic relay tubes mounted as oscillators or as amplifiers, have the particular feature that the anode current only appears during a phis or less fraction of the positive alternation of the voltage. control grid; and that for the rest of the time the tube does not deliver any anode current.

Ce resultat est atteint generalement quand an applique ä la grille une Polarisation ne gative continue relativement tres forte et qu'on donne une Brande amplitude aax oscil- lations de la tension d'entree appliquees ä cette grille. A chaque alternance positive de cette tension, la grille acquiert une tension resultante positive par rapport ä la cathode, ee qui donne lieu ä un courant de grille dont 1e Passage correspond generalement ä celui du courant anodique. This result is generally achieved when a relatively very strong continuous negative bias is applied to the grid and an amplitude band is given to the oscillations of the input voltage applied to this grid. At each positive alternation of this voltage, the gate acquires a positive resultant voltage with respect to the cathode, which gives rise to a gate current whose passage generally corresponds to that of the anode current.

La tension de commande a generalement la forme sinusoidale, et elle est prelevee sur un eireuit oscillant sur une frequence d6ter- minee. Cette tension est appliquee au eireuit de grille, en serie avec sa source de Polarisa tion. L'anode est reliee generalement ä un cir- cuit oscillant de charge, resonnant ä la meme frequenee. La tension alternative apparais- sant ä ses Bornes offre une Phase opposee ä celle de la grille, et olle se superpose ä la tension continue d'alimentation anodique, de manPre telle que, Pendant 1e Passage du cou- rant anodique, la tension sur 1e tube passe par son miniinum. Le tube travaille dans ces condit.ions avec un assez bori rendeinent et permet de prelever sur 1e eireuit de charge une puissance notable. The control voltage generally has a sinusoidal form, and it is taken from a circuit oscillating at a determined frequency. This voltage is applied to the gate circuit, in series with its bias source. The anode is generally connected to an oscillating load circuit, resonating at the same frequency. The alternating voltage appearing at its terminals offers a phase opposite to that of the grid, and it is superimposed on the direct voltage of the anode supply, in such a way that, during the passage of the anode current, the voltage on the tube passes through its miniinum. The tube works under these conditions with a fairly high yield and allows a notable power to be taken from the load circuit.

La presente Invention a pour objet un procede pour piloter un tube eleetronique de- vant fonctionner ä une frequence fondamen- tale determinee et dont lec ourant anodique est interrompu Pendant une importgute fraction de chaque Periode de ladite frequence, dans lequel an applique ä la grille de commande dudit tube une tension periodique eomplexe obtenue en superposant ä une tension sinusoi- dale ayant ladite frequence fondamentale une tension de frequence harmonique de la Pre miere. The subject of the present invention is a method for driving an electronic tube which must operate at a determined fundamental frequency and whose anode current is interrupted during a large fraction of each period of said frequency, in which an application to the grid of driving said tube a complex periodic voltage obtained by superimposing on a sinusoidal voltage having said fundamental frequency a voltage having a harmonic frequency of the first.

Ce procede est caracterise en ce qu'on Fait coineider au moins approximativement les maximums de la tension de frequence fonda- mentale chacun avec un des minimums de la tension de frequence barmonique. This method is characterized in that the maximums of the fundamental frequency tension are each made to coincide at least approximately with one of the minimums of the barmonic frequency tension.

D'urie fagon generale, dans les montages connus, deux facteurs s'opposent ä ce qu'on augmente 1e rendement du tube, et, par suite, la puissance disponible. Le courant dann 1e eireuit de grille produit une perte de 1'energie d'entree; d'autre Part, la difference tres im portante de tension entre 1'anode et la grille au moment oü cette derniere passe par son maximum negatif et la Premiere par son maxiinum positif risque de provoquer des cla- quages. Ces faeteurs s'opposent ainsi ä ce qu'on augmente 1'amplitude et la duree du courant anodique en augmentant l.'amplitude de la tension de grille. Enfin, aux Moments de passalte de la tension anodique par son Mi nimum et de la tension <B>-</B>de grille par son Maximum positif; du Fait de 1'emission secon- daire, 1e tube tend ä osciller ä des frequenees ultra-elevees. Le procede enonce ei-dessus permet, Jans certains cas, d'ameliorer sensibleinent 1e ren- dement de Ces Montages, tout en augmentant la securite de leer fonctionnement. Par exem- ple, pour une piiissance disponible Sur 1e cir- cuit de Charge, maintenue pratiquement la meme, ou meme aiigmentee, 1e procede per- met, lorsqu'on Bonne ä la tension complexe et ä la Polarisation negative de grille des va- leurs determinees, de reduire largement 1e courant de grille, ce qui a pour effet, dune Part, ün rendement phis eleve, et pour 1e mAme courant Maximum anodique, une puis- sance disponible accrue et, d'autre Part, de reduire la difference de tension entre anode et grille aux Moments critiques indiques ci- dessus. Generally speaking, in the known assemblies, two factors are opposed to increasing the efficiency of the tube, and, consequently, the power available. The current in the gate circuit produces a loss of input power; on the other hand, the very large difference in voltage between the anode and the grid at the moment when the latter passes through its negative maximum and the former through its positive maximum risks causing breakdowns. These factors thus prevent the amplitude and duration of the anode current from being increased by increasing the amplitude of the gate voltage. Finally, at the Moments of passalte of the anode voltage by its Minimum and of the <B>-</B>gate voltage by its positive Maximum; Due to the secondary emission, the tube tends to oscillate at ultra-high frequencies. The process set out above makes it possible, in certain cases, to significantly improve the performance of these assemblies, while increasing the safety of their operation. For example, for a power available on the load circuit, maintained practically the same, or even increased, the method allows, when good at the complex voltage and at the determined, to greatly reduce the grid current, which has the effect, on the one hand, of a higher efficiency, and for the same Maximum anode current, an increased available power and, on the other hand, of reducing the difference voltage between anode and grid at the Critical Moments indicated above.

L'invention a egalement pour objet un dispositif pour la mise en oeuvre de ce pro c6de, qui est earacterise en ce que 1e eirciüt .de grille dudit tube comprend, en Serie, des moyens pour introdiüre la frequence fonda- mentale, des moy ens pour intr oduir e avec ime Phase et iuie amplitude determinees la tension de frequence harinonique, et des moyens pour introduire .n ie tension continue de Polarisation de Faible amplitude. The invention also relates to a device for the implementation of this process, which is characterized in that the first grid eirciüt of said tube comprises, in series, means for introducing the fundamental frequency, means ens for introducing with a determined Phase and amplitude the Harinonic frequency voltage, and means for introducing a Low Amplitude Bias DC voltage.

Le proc6de siüvant 1'invention peut s'ap- pliquer aux dispositiis amplifieateurs aussi bien qu'aux oscillateurs, 1e circuit de grille etant, dans ce dernier cas, retrocoilple au cir- ciüt anodiqüe de maniere ä entretenir les oscillations. 0n a interet ä appliquer ce pro ced6 ä toute installation, de basse et de haute freqiience, dans laquelle an veut disposer d'ime forte puissance ä la sortie et dun bon rendement, saus se preoccuper de la forme des oscillations. Elle s'applique plus particu- lierement aux generateurs d'oscillations de haute frequence destines aux traitements ther- iniques, soumis ä un long regime de travail, et consommant beaucoup d'energie. The method according to the invention can be applied to amplifying devices as well as to oscillators, the gate circuit being, in the latter case, retrocoupled to the anode circuit so as to sustain the oscillations. It is in our interest to apply this process to any installation, low or high frequency, in which we want to have high output power and good efficiency, without worrying about the shape of the oscillations. It applies more particularly to high frequency oscillation generators intended for thermal treatments, subjected to a long working regime, and consuming a lot of energy.

La description qui suit et qui est faite en regard du dessin annexe se rapporte ä des exemples d'application du procede objet de 1'invention et ä des forines d'exeeution du dispositif objet de 1'invention, Ces formes d'execution etant donnees ä titre d'exemple. The description which follows and which is given with regard to the appended drawing relates to examples of application of the method which is the subject of the invention and to forms of execution of the device which is the subject of the invention, these embodiments being given for exemple.

La fig. 1 represente un sehema de Mon tage oscillateur, dans lequel 1'harmonique est engendre au moyen dune valve. fig. 1 shows an oscillator circuit diagram, in which the harmonic is generated by means of a valve.

La fig. 2 represente, en fonction du teinps, les tensions et courants anodiques apparais- sant Jans un oseillateur Blasse C du type nor mal. fig. 2 represents, depending on the type, the anode voltages and currents appearing in a Blasse C oscillator of the normal type.

La fig. 3 represente ]es tensions et cou- RTI ID="0002.0269" WI="8" HE="4" LX="1139" LY="974"> rants dans 1e cas du Montage de la fig. 1. Sur la fig. 1, an a ,clesigne par 1 une triode d'emission de Brande puissance. 0n a repre- sent6 en 2 iln eircuit oscillant de Charge Sur lequel im dispositif, non represente Sur 1e 'Schema, permettra de prelever 1'energie en- gendree, et 1'appliquera aux appareils d'uti- lisation. L'anode du tube 1 est cöuplee ä ee cireuit oscillant au moyen d'ilne capacite, et elle est alimentee ä, partir dune source de courant ä haute tension, ä travers une bobine de choc 4. Comme il est d'usage, an installe, en Serie avee la cathode, im. eondensateur shimte 5, permettant de realiser la Polarisa tion negative continue (de Base) de la grille (reglable par variation de la resistance en de- rivation). 0n couple au cireuit oseillant de eharge un autre circuit oscillant, Monte dann 1e cireuit de grille, comprenant wie capacite 7 et üne self-inductance B. En reglant la va- leur de la capacite, an parizent ä, regler 1a. Phase de la tension alternative qui alimente la grille, et en medifiant 1e nombre de spires de la bobine intercalees dans 1e circuit de gmille, an parvient ä modifier 1'amplitude de Bette tension. fig. 3 represents] the voltages and currents in the case of the assembly of FIG. 1. In fig. 1, year a ,signed by 1 a transmitting triode of Brande power. 0n has represented in 2 an oscillating load circuit on which a device, not represented on the 1st diagram, will make it possible to take the generated energy, and will apply it to the appliances of use. The anode of the tube 1 is coupled to this oscillating circuit by means of a capacitor, and it is supplied from a high voltage current source through a shock coil 4. As is customary, an installs, in series with the cathode, im. shimte capacitor 5, making it possible to carry out the continuous negative polarization (Basic) of the grid (adjustable by variation of the resistor in derivation). 0n couples to the charging circuit osaillant another oscillating circuit, Mounted in the 1st gate circuit, comprising a capacitor 7 and an inductance B. By adjusting the value of the capacitor, in parizent ä, adjust 1a. Phase of the alternating voltage which feeds the grid, and by modifying the number of turns of the coil interposed in the grid circuit, one manages to modify the amplitude of this voltage.

0n se sert d'itne valve 9, ä autopolarisa- tion tres fortement negative (realisee ä 1'aide du condensateur 6 shunte par une resistanee 5' pour engendrer, dans une resistance 10, une impulsion de courte duree, ä ehaque Pe riode du courant alternatif. Cette impulsion est amplifiee par 1e tube 11, autopolarise par 1e condensateur shunte 12. La Plaque de ce tobe est aliinentee positivement, ä travers une bobine de choc 14, et couplge par capacite ä un cireüit oseillant 13, accorde sur 1e ein- quieme harmonique du circuit oscillant 2. Les tops qui apparaissent sur la resistance 10, ä la frequence F, excitent, dang ce circuit 13, une tension sinusoidale ayant sa frgquence propre, donc 5F. Ce eircuit oscillant 13 est couple ä son tour. ä un circuit 16 comprenant une capacite 17 et une seif 15. En agissant sur la capaeite 17, an peut regier la Phase, et en choisissant 1e nombre de spires de cette inductance, an peiit regier 1'amplitude de la tension ä la frequence 5F. En disposant 1e cir- euit oscillant 16 en sgrie dang 1e circuit de grille de la lampe 1, an Superpose Bette ten- sion ä Gelle de la freqiience F prglevee Sur 1e circuit 7-8. Use is made of a valve 9, with very strongly negative self-biasing (made with the help of capacitor 6 shunted by a resistor 5' to generate, in a resistor 10, a pulse of short duration, at each period of the This pulse is amplified by tube 11, self-biased by shunt capacitor 12. The plate of this tube is positively powered, through a choke coil 14, and capacitively coupled to a circuit breaker 13, tuned to the - fifth harmonic of the oscillating circuit 2. The tops which appear on the resistor 10, at the frequency F, excite, in this circuit 13, a sinusoidal voltage having its own frequency, therefore 5 F. This oscillating circuit 13 is in turn coupled. to a circuit 16 comprising a capacitor 17 and a capacitor 15. By acting on the capacitor 17, an can regulate the Phase, and by choosing the number of turns of this inductance, an can regulate the amplitude of the voltage at the frequency 5F . By arranging the oscillating circuit 16 in series with the grid circuit of the lamp 1, an superimposes this voltage on the frequency F taken from the circuit 7-8.

0n se represente tres facilement 1e Tone t.ionnement dun dispositif connu si an se re- porte aux fig. 2a, 2b, <I>2c</I> et 2d qui repre- sentent, en fonction du temps, la tension dang 1es differentes Parties d'un tel dispositif. 0n concloit tres facilement 1e fonctionnement du dispositif represente ä la fig. 1 en se repor- tant ä la fig. 3 qui represente, en fonction du temps, la tension et 1'intensite dang leg dif ferentes Parties du Schema de la fig. 1. La fig. 2 se rapporte ä im oscillateur normal, du type Blasse C, et la comparaison des courbes des fig. 2 et 3 permet de mieux apprgcier leg avantages du montage reprgsente ä la fig. 1. The Tone t.ionnement of a known device is very easily represented if one refers to FIGS. 2a, 2b, <I>2c</I> and 2d which represent, as a function of time, the voltage in the various Parts of such a device. 0n concludes very easily the first operation of the device shown in FIG. 1 with reference to fig. 3 which represents, as a function of time, the voltage and the intensity dang leg different parts of the diagram of fig. 1. Fig. 2 relates to a normal oscillator, of the Blasse C type, and the comparison of the curves of FIGS. 2 and 3 makes it possible to better appreciate the advantages of the assembly shown in FIG. 1.

La courbe superieure 2a de la fig. 2 re- presente, en fonction du temps, la tension entre anode et eathode du tube d'un oscilla- teur normal, c'est-ä-dire d'un oscillateur tel que celiii de la fig. 1, mais qui ne pr6sente- rait pas leg organes ayant leg chiffres de rgfe- renee 5', 6, 9 ä 17. Elle resulte de la Super position de la tension continue 19 provenant de la Batterie 3 ä la tension alternative 20 fournie par 1e circuit oscillant 2. La seconde courbe 2b de cette fig. 2 represente, aux memes instants, la tension entre grille et ca- thocle dang un oseillateur normal du type classe C, c'est-ä-dire un oscillateur comportant seule- ment, comme il est d'usage, un circuit oscil- lant 7-8 ä la frequence F (mais pas de cir- cuit oscillant ä la frequence harmonique 5F) 1e circuit 16-17 n'existe pas. Sur la courbe 2b, an a represente par la ligne 00', en traft mixte, la valeur ä partir de laquelle 1e courant anodique apparait. The upper curve 2a of FIG. 2 represents, as a function of time, the voltage between anode and ethode of the tube of a normal oscillator, that is to say of an oscillator such as that of FIG. 1, but which would not present the organs having the reference numbers 5', 6, 9 to 17. 1st oscillating circuit 2. The second curve 2b of this fig. 2 represents, at the same instants, the voltage between gate and cathocle in a normal oscillator of the class C type, that is to say an oscillator comprising only, as is customary, an oscillating circuit 7-8 at frequency F (but no circuit oscillating at harmonic frequency 5F) 1st circuit 16-17 does not exist. On curve 2b, an a represents by line 00', in mixed line, the value from which the anode current appears.

Comme il est d'usage, an applique ä la grille du tube une tres forte Polarisation de Base 21 (ai.x Bornes du dispositif autopolari- sant 5), et an y ajoute ime tension alternative de grande amplitude 22. Le tube West d6blo- que que Pendant im tres Court intervalle de temps 24, 25, 26. La troisieme coLlrbe 2c de la fig. 2 represente, aux memes instants, 1e courant Plaque, et la quatrieme courbe 2d, 1e courant grille. La forme courbe de tension de la grille<B>(2b)</B> presente de graves inconvenients : eile a, en eilet, une Pointe negative 27 tres accentuge, qui risque de provoquer des claquages entre electrodes. 0n ne peut eviter que la Periode de Passage 24, Y et Y'26 de la condiictibilitg presque nulle du tube ä sa conductibilite maximum soit relativement longue, mais cela est prejudiciable ä 1'obtention d'un Bon ren- dement et provoque ime perte considerable dang 1e tube, obligeant ä evacuer leg calories correspondantes par des systemes de refroi- dissement coilteux, et limitant la puissance disponible du tübe. D'autre Part, la grille prend une valeur positive notable en 25, au moment oü, precisgment, 1'anode est ä une tension relativement Faible, et cela occasionne un courant grille extremement important (courbe 2d) qui risque de deteriorer la grille et qui contribue ä reduire la puissance four- nie en augmentant considerablement leg pertes dann 1e circuit d'entretien 7-8. A ce moment, 1'anode du tube Bonne une tres forte gmission secondaire, et 1e tube risque d'osciller Sur des frgquences ultra-hautes, Ces oscillations etant sitsceptibles encore d'augmenter leg pertes et de diminuer 1e rendement. Le courant instan- tane debite par 1'anode prend des valeurs excessives, dangereuses et compromettant la duree de vie de la cathode. Les avantages du montage represente ä la fig. 1 apparaissent clairement ä 1'examen de la fig. 3: 1a couibe 3a, qui represente, en fone- tion du temps, la tension anode-cathode, est sensiblement la meme que la courbe 2a, p-Lüs- que la tension d'alimentation (Batterie 3) n'a pas varie et que la tension d'utilisation (eir- cuit 2) s'est seulement accrue legerement. La courbe 3b represente, aux memes moments, la tension prelevee, ä la frequence F, dans la bobine 8 du cireuit oscillant 7-8. Son ampli- tude est choisie ä une väleur bien inferieure ä celle de la courbe 2b de la fig. 2. La courbe 3c represente, aux memes moments, la ten- sion ä la frequente 5F, prelevee sur la bobine 15, Jans 1e circuit oseillant 16. 0n a choisi la Phase de cette nouvelle frequente de telle fa@on qu'un minimum ä la frequente 5F' coin- cide avec 1e maximiim de la frequente F. La courbe 3d represente la superposition de la Polarisation 23 (choisie beaucoup plus Faible que dans 1e cas normal 21), ainsi que des courbes 3b et 3c. C'est la tension entre grille et cathode du tube, resiidtant de l'addi- tion de la tension d'autopolarisation 5, -de la tension prelevee sar la bobine 8 (freqLience F) et .de la tension prelevee siir la bobine 15 (fre quente 5F). La courbe 3e represente, aux memes mo- ments, 1e courant anodique, et la cotirbe 3f, 1e coiirant de grille. La courbe 3h represente, aux memes moments, 1'impulsion de tension (Partie hachuree) fournie par la valve 9 Jans la resistance 5'. Cette impulsion est LZtilisee, apres amplification, poiir synehroniser 1e cir- cuit 13 (ä la freqiience 5F). Comme an peut 1e voir sur la fig. 3, les minima 28 de la ten- sion de grille ont une amplitude beaLlcoLip plus Faible que dans 1e cas de la fig. 2 (mini- inLun <B>27).</B> De meme, les maxima de tension ont une valeur plus Faible que 1e maximum 25 de la fig. 2. Les risques de to-Lite nature, tels que elaquages des isolants, debit en sens in verse de la grille, emission secondaire, ete., se trouvent ainsi reduits. Et cependant, an voit qii'on a considerablement atteniie la variation de tension qui survient au moxnent oü 1e tube passe dune conductibilite pratiquement nulle ä une conductibilite presque totale. As is customary, an applies to the grid of the tube a very strong Base Bias 21 (ai.x Terminals of the self-biasing device 5), and an adds a large amplitude alternating voltage 22 to it. - That that during im very short time interval 24, 25, 26. The third coLlrbe 2c of FIG. 2 represents, at the same instants, the first plate current, and the fourth curve 2d, the first grid current. The curved voltage form of the grid<B>(2b)</B> has serious drawbacks: it has, in the eyelet, a very accentuated negative tip 27, which risks causing breakdowns between electrodes. It is unavoidable that the Passage Period 24, Y and Y'26 from the almost zero condition of the tube to its maximum conductivity is relatively long, but this is detrimental to obtaining a good yield and causes a loss. considerable dang the tube, forcing the corresponding calories to be evacuated by costly cooling systems, and limiting the power available from the tube. On the other hand, the grid takes on a notable positive value at 25, precisely when the anode is at a relatively low voltage, and this causes an extremely high grid current (curve 2d) which risks damaging the grid and which contributes to reducing the power supplied by considerably increasing the losses in the sustain circuit 7-8. At this time, the anode of the tube has a very strong secondary emission, and the tube runs the risk of oscillating at ultra-high frequencies, these oscillations being still likely to increase the losses and reduce the efficiency. The instantaneous current drawn by the anode takes on excessive values which are dangerous and compromise the lifetime of the cathode. The advantages of the assembly shown in fig. 1 appear clearly on examination of FIG. 3: curve 3a, which represents the anode-cathode voltage as a function of time, is substantially the same as curve 2a, provided that the supply voltage (battery 3) has not varied and that the operating voltage (circuit 2) has only increased slightly. Curve 3b represents, at the same times, the voltage taken, at frequency F, from coil 8 of oscillating circuit 7-8. Its amplitude is chosen at a value well below that of curve 2b of FIG. 2. Curve 3c represents, at the same times, the voltage at frequency 5F, taken from coil 15, in the oscillating circuit 16. The Phase of this new frequency has been chosen so that a minimum at the frequency 5F' coincides with the maximum of the frequency F. Curve 3d represents the superposition of the Polarization 23 (chosen much weaker than in the normal case 21), as well as curves 3b and 3c. It is the voltage between grid and cathode of the tube, resulting from the addition of the self-bias voltage 5, - of the voltage taken from coil 8 (freqLience F) and .from the voltage taken from coil 15 (fre quente 5F). Curve 3e represents, at the same times, the anode current, and curve 3f, the grid current. Curve 3h represents, at the same times, the voltage pulse (shaded part) supplied by valve 9 Jans resistor 5'. This pulse is used, after amplification, to synchronize circuit 13 (at frequency 5F). As can be seen in fig. 3, the minima 28 of the grid voltage have a much lower amplitude than in the case of FIG. 2 (mini-inLun <B>27).</B> Likewise, the voltage maxima have a lower value than the maximum 25 of FIG. 2. The risks of to-Lite nature, such as insulation breakdown, flow in the opposite direction to the grid, secondary emission, summer, are thus reduced. And yet, it is seen that the voltage variation which occurs at the moment when the tube changes from practically zero conductivity to almost total conductivity has been considerably attenuated.

Le courant ia (courbe 3e) a une forme sensiblement rectangulaire au lieu dune forme en- Pointe (courbe 2c); les pertes dann 1e tube en sont considerablement rediiites, et la deterioration de la cathode est evitee. Comme, d'autre Part, 1e courant de grille ig (3f) Teste negligeable, aucun eehauffement de la grille n'est plus ä craindre et 1'emission secondaire est evitee. Enfin, la perte de puis- sance RTI ID="0004.0270" WI="14" HE="4" LX="1243" LY="734"> absorbee par 1e circuit pour la com- mande de grille devient tout ä Fait n6gli- geable. Le montage decrit en regard de la fig. 1 ne presente pas les desavantages des montages connus an extrait dudit montage 1e maximum de puissance du tube et an reduit 1'usure de la cathode; an reduit au minimum les pertes dann 1e tube; on diminLte 1'emission secondaire et les ris- ques de claquage; an reduit la tension entre les eleetrodes, et specialement entre la grille et la cathode qui sont situees tres pres l'une de 1'autre; an rend la tension positive de la grille re- lativement tres Faible quand la tension ano- dique passe par son minimum, de fagon ä evi- ter tobt dangen; an reduit la puissance consommee par 1e circuit d'entretien. Current ia (curve 3e) has a substantially rectangular shape instead of a pointed shape (curve 2c); the losses in the tube are reduced considerably, and the deterioration of the cathode is avoided. Since, on the other hand, the gate current ig (3f) is negligible, no heating of the gate is to be feared and secondary emission is avoided. Finally, the power loss RTI ID="0004.0270" WI="14" HE="4" LX="1243" LY="734"> absorbed by the circuit for the gate drive becomes quite negligible. The assembly described with reference to FIG. 1 does not present the disadvantages of the known assemblies an extracts from said assembly the maximum power of the tube and an reduces the wear of the cathode; an minimizes losses in the tube; the secondary emission and the risks of breakdown are reduced; an reduces the voltage between the electrodes, and especially between the grid and the cathode which are located very close to each other; an makes the positive grid voltage relatively very low when the anode voltage passes through its minimum, so as to avoid any danger; an reduces the power consumed by the sustain circuit.

La courbe 3h represente les pointes de courant (Partie hachiiree 31) realisees ä 1'aide de la tension 32 prelevee sur la bobine 2 d'oii an retranche la Polarisation 30 (pre- levee aux Bornes du condensateur 6). Curve 3h represents the current peaks (hachiiree part 31) produced using voltage 32 taken from coil 2 from which Polarization 30 (taken from the terminals of capacitor 6) is subtracted.

En variante, au lieu de la valve 8 (fig. 1), an peut avantageusement se servir dune triode : an applique ä la grille une tres forte Polarisation negative ä laquelle an Superpose une tension alternative ä la freq-Lience fonda- mentale. Le courant Plaque n'apparait qu'au moment oü. la tension grille resultante est au-dessLls de zero, et 1'on reeueille dans 1e cir- cuit Plaque les courtes impulsions de courant desirees. Mais ä cause de la courbure du pied de la earaeteristique des triodes, la forme de l'impulsion de courant engendree est plus avant.ageuse et offre une forme en Pointe plus accentuee (figuree en traft ponctue sur la courbe 3h.). Alternatively, instead of valve 8 (fig. 1), an can advantageously use a triode: an applies a very strong negative bias to the grid, on which an alternating voltage is superimposed on the fundamental frequency. The current Plate only appears when. the resulting gate voltage is above zero, and the desired short current pulses are collected in the Plate circuit. But because of the curvature of the base of the triodes' heterodistics, the shape of the generated current pulse is more advantageous and offers a more accentuated peak shape (shown as a punctuated traft on the curve 3h.).

Dans une autre forme d'execirtion, an se servira dun montage relaxateur, fournissant une tension en dents de scie, comprenant un condensateur Charge progressivement ä tra vers une resistance et decharge brusquement par une lampe electronique, Pax exemple an thy ratron, dont la grille re@oit la tension alternative, ä la frequence F, prelevee sur 1e eireuit de Charge. Cela Bonne lieu ä une de- eharge brusque ä la cadence F. 0n introduit, en serie avec 1e thyratron, 1e Primaire d'un transformateur dont 1e secondaire Fait Partie d'un eireuit oseillant ä la frequence 5I'. In another form of execution, an will use a relaxator assembly, supplying a sawtooth voltage, comprising a capacitor Charged progressively through a resistor and discharged abruptly by an electronic lamp, Pax example an thy ratron, whose grid receives the alternating voltage, at the frequency F, taken from the Load circuit. This gives rise to a sudden discharge at the rate F. We introduce, in series with the thyratron, the primary of a transformer, the secondary of which is part of a oscillating circuit at the frequency 5I'.

Au lieu de se servir dune Impulsion de Courte duree pour produire les oscillations du eireuit oscillant, ä la frequence 5F, an peut aussi engendrer 1'harmonique desiree en creant, ä partir de la frequence fondamen- tale, une distribiition polyphasee ä cinq phases. On redresse, au moyen de cinq anodes, 1e cou- rant palyphase, et dans 1e eireuit de la ca- thode, an recueille, outre un courant continu, une ondulation dont la frequence de Base Correspond ä 1'harmonique cherchee. Instead of using a Short Duration Pulse to produce the oscillations of the oscillating circuit, at the frequency 5F, one can also generate the desired harmonic by creating, from the fundamental frequency, a five-phase polyphase distribution. The palyphase current is rectified by means of five anodes, and in the circuit of the cathode, an undulation is collected, in addition to a direct current, the Base frequency of which corresponds to the harmonic sought.

Dans une autre variante du procede selon l.'invention, an superpose, ä la tension siniLsoi- dale ä, frequence fondamentale, plusieurs ten- sions ä. des freqliences differentes, harmoniques de la fondamentale, qiü sont obtenues en par- tant de 1'un des circuits resonnants du mon tane, notamment du eireuit d'entree, ou encore du cireuit de Charge, s'il s'agit d'un oscilla- teur. 0n multiplie la frequence de ce eireuit en se servant de moyens appropries, par exemple an engendre ä la frequence princi- pale du eireuit d'entree des pointes de ten- sion de tres courte duree au moyen dune v alve ou d'une triode. L'une des electrodes de la valve ou de la grille de la triode a une forte Polarisation negative, de telle fa#ton que 1e courant West debite que Pendant rme fraction tres faible de la duree de 1a fre- quence fondamentale. Avec Ces pointes de ten- sinn, an produit des oscillations ä des fre- quences multiples de la frequence du eireuit d'entree, en les faisant agir sur des circuits oscillants, respectivement aecordes sur les dif ferentes frequenees harmoniques. 0n preleve sur Ces circuits oscillants des tensions harmo- niques dont an regle la Phase et 1'amplitude. 0n additionne les tensions ä freqitences äiffe- rentes ainsi obtenues, et la tension.ä la fre- quence fondamentale, et an applique la somme de Ces tensions ä la grille de contröle du tube, en serie avec la Polarisation continue conve- nablement reglee. In another variant of the method according to the invention, an superimposes, on the siniLsoidal voltage ä, fundamental frequency, several voltages ä. different frequencies, harmonics of the fundamental, which are obtained starting from one of the resonant circuits of the mon tane, in particular from the input circuit, or even from the Load circuit, if it is a circuit oscillator. The frequency of this circuit is multiplied by using appropriate means, for example by generating voltage spikes of very short duration at the main frequency of the input circuit by means of a valve or a triode. One of the valve or grid electrodes of the triode has a strong negative bias, so that the West current flows for only a very small fraction of the duration of the fundamental frequency. With these voltage spikes, an produces oscillations at multiple frequencies of the frequency of the input circuit, by causing them to act on oscillating circuits, respectively tuned to the different harmonic frequencies. Harmonic voltages are taken from these oscillating circuits, the phase and amplitude of which are regulated. The voltages at different frequencies thus obtained are added to the voltage at the fundamental frequency, and the sum of these voltages is applied to the control grid of the tube, in series with the suitably set dc bias.

En variante encore, pour regler la Phase des tensions composantes, an peut faire va- rier la self ou la capacite des circuits oscil- lants dans lesquels Ces tensions sont induites, de telle fagon que la frequence propre d'ac- Cord de Ces circuits soit egale, ou legerement superieure ou inferieure, ä la frequence d'excitation. Pour faire varier 1'amplitude de Ces tensions, an peut les prelever, au moy en de contacts mobiles, sur les self-inductances de Ces cireuits oscillants. 0n peut utiliser pour prelever la tension une bobine, dont an Fait varier 1e couplage, ou an peut regler 1'amplitude de Ces tensions par im couplage inductif variable. Enfin, an peut aussi se ser- vir, dans 1e meme but, d'un potentiometre diviseur de tension, place aux Bornes du cir- cuit oscillant. As a further variant, to adjust the phase of the component voltages, one can vary the inductance or the capacitance of the oscillating circuits in which these voltages are induced, in such a way that the natural tuning frequency of these circuits either equal to, or slightly above or below, the excitation frequency. To vary the amplitude of these voltages, they can be taken, by means of movable contacts, from the self-inductors of these oscillating circuits. It is possible to use a coil to take the voltage, the coupling of which can be varied, or the amplitude of these voltages can be regulated by a variable inductive coupling. Finally, you can also use, for the same purpose, a voltage divider potentiometer, placed at the terminals of the oscillating circuit.

Claims (7)

REVENDICATIONS I. Procede pour piloter im tube eleetro- nique devant fonctionner ä une frequence fondamentale determinee et dont 1e courant anodiqrle est interrompu Pendant uze impor- tante fraction de chaque perio-de de ladite frequence, dans lequel. an applique ä la grille de commande dudit tube une tension p6riodi- que complexe obtenue en superposant ä une tension sinusdidale ayant.ladite frequence fondamentale une tension de frequence har- monique de la Premiere, caracterise en ce qu'on fait concider au moins approximative- ment les maximums de la tension de frequence fondamentale chacun avec un des minimums de la tension de frequence harmonique. II. Dispositif pour la mse en ce@lvre du procede selon la revendication I, earacterise en ce que 1e eireuit de grille dudit tube com- prend en serie des moyens pour introduire la frequence fondamentale, des moyens pour introduire avec une Phase et une amplitüde determinees la tension de frequence harmo- nique, et des moyens pour introduire une tension continue de pölarisation de faible am- plitude. SOUS-REVENDICATIONS 1. Procede suivant la revendication I, ca- racterise en ce qu'on derive la tension de fre- quence harmonique dun cireuit oscillant ä la frequence fondamentale, ce eireuit etant con- nect6 audit tube. CLAIMS I. Process for controlling an electronic tube having to operate at a determined fundamental frequency and of which the anodiqrle current is interrupted for a large fraction of each period of said frequency, in which. an applies to the control grid of said tube a complex periodic voltage obtained by superimposing on a sine wave voltage having said fundamental frequency a voltage of harmonic frequency of the First, characterized in that it is made to coincide at least approximately ment the maximums of the fundamental frequency voltage each with one of the minimums of the harmonic frequency voltage. II. Device for carrying out the process according to claim I, characterized in that the gate circuit of said tube comprises in series means for introducing the fundamental frequency, means for introducing with a determined phase and amplitude the harmonic frequency voltage, and means for introducing a low amplitude bias DC voltage. SUB-CLAIMS 1. Process according to claim 1, characterized in that the harmonic frequency voltage of a circuit oscillating at the fundamental frequency is derived, this circuit being connected to said tube. 2. Procede suivant la revendication I et la sous-revendication 1, dann lequel an produit plusieurs tensions de frequences harmoniques differentes, caracterise en ce qLi'on derive ces dernieres tensions dudit circuit oscillant ä la frequence fondamentale, ce eireuit etant 1e eireuit anodique dudit tube, au moyen de cir- cuits oscillant sur lesdites frequences harmo- niques. 2. Process according to claim 1 and sub-claim 1, in which an produces several voltages of different harmonic frequencies, characterized in that the latter voltages are derived from said oscillating circuit at the fundamental frequency, this circuit being the first anode circuit of said tube, by means of circuits oscillating on said harmonic frequencies. 3. Procede saivant la revendieation I et les soLis-revendications 1 et 2, caracterise en ce qu'on produit chaque tension de freqLience harmonique au moyen d'impulsions breves ayant la frequence fondamentale et excitant, apres amplification, Lm desdits circuits oseil- lant sur lesdites frequenees harmoniques. 3. Process according to Claim I and Solis-Claims 1 and 2, characterized in that each harmonic frequency voltage is produced by means of short pulses having the fundamental frequency and exciting, after amplification, Lm of said osilating circuits. on said harmonic frequenees. 4. Proeede siüvant la revendieation 1 et les soL1s-revendications 1 et 2, caracterise en ee qu'on regle la Phase de la, tension de fre- quence fondamentale et des tensions de Ire quences harmoniques en desaccordant ees cir- euits oscillants et en ce qu'on regle 1'ampli- tude de chacLUie desdites tensions. 4. A method according to claim 1 and sole claims 1 and 2, characterized in that the phase of the fundamental frequency voltage and the voltages of the first harmonic frequencies are adjusted by detuning these oscillating circuits and by whereby the amplitude of each of said voltages is adjusted. 5. Dispositif stüvant la revendication II, caracterise en ce que lesdits moyens pour in- trodLüre la frequence fondamentale com- prennent un eireuit oscillant sur cette fre- quence et en ce que lesdits moyens pour intro- duire la tension de frequenee harmonique coinprennent ui aLitre eireuit oscillant sur la- dite frequence harmonique. 5. Device according to claim II, characterized in that said means for introducing the fundamental frequency comprise a circuit oscillating on this frequency and in that said means for introducing the harmonic frequency voltage comprise a eireuit oscillating on said harmonic frequency. 6. Dispositif suivant la revendieation II, caracterise en ce que lesdits moyens pour introduire la tension de frequence harmoni- que comprennent un redresseur auquel est appliquee la tension de frequence fondainen- tale qui est prelevee sur 1e circuit d'anode du- dit tube, ce redresseur etant polarise n6gati- veinent, la sortie de ce redresseur etant reliee par 1'intermediaire d'un amplificateur ä Lui eireuit oscillant sur ladite frequence harmo- nique, ce dernier eircuit oscillant etant cou- ple ä un RTI ID="0006.0274" WI="10" HE="4" LX="1280" LY="1273"> eireuit oscillant insere dann 1e cir- cuit de grille dudit tube en serie avec un autre eireuit oscillant ä la frequence fonda- mentale, ce dernier circuit etant couple direc- tement audit eircuit d'anode. 6. Device according to Claim II, characterized in that the said means for introducing the harmonic frequency voltage comprise a rectifier to which is applied the fundamental frequency voltage which is taken from the anode circuit of the said tube, this rectifier being negatively biased, the output of this rectifier being connected via an amplifier to it oscillating on said harmonic frequency, the latter oscillating circuit being coupled to an RTI ID="0006.0274" WI="10" HE="4" LX="1280" LY="1273"> oscillating circuit inserted in the grid circuit of said tube in series with another circuit oscillating at the fundamental frequency, this latter circuit being coupled directly to said anode circuit. 7. Dispositif suivant la revendication II, caracterise en ce qu'il eomporte un g6n6ra- teur d'öscillations de relaxation, une lampe de ee generateur etant commandee par 1e eir- cuit d'anode dudit tube, 1e circuit de sortie de ce generateLlr etant refie ä un eircuit oseil- lant sur ladite frequenee harmonique. 7. Device according to claim II, characterized in that it comprises a generator of relaxation oscillations, a lamp of the generator being controlled by the first anode circuit of the said tube, the first output circuit of this generator. being referred to a circuit which oscillates on said harmonic frequency.