FR2502441A1 - Control for power dissipation in dielectric subject to HF field - by automatic resonance tuning and a reference voltage cycle - Google Patents
Control for power dissipation in dielectric subject to HF field - by automatic resonance tuning and a reference voltage cycle Download PDFInfo
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- FR2502441A1 FR2502441A1 FR8105565A FR8105565A FR2502441A1 FR 2502441 A1 FR2502441 A1 FR 2502441A1 FR 8105565 A FR8105565 A FR 8105565A FR 8105565 A FR8105565 A FR 8105565A FR 2502441 A1 FR2502441 A1 FR 2502441A1
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
- B29C65/04—Dielectric heating, e.g. high-frequency welding, i.e. radio frequency welding of plastic materials having dielectric properties, e.g. PVC
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/46—Dielectric heating
- H05B6/48—Circuits
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/48—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/48—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding
- B29C65/4805—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding characterised by the type of adhesives
- B29C65/483—Reactive adhesives, e.g. chemically curing adhesives
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/70—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material
- B29C66/71—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the composition of the plastics material of the parts to be joined
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/90—Measuring or controlling the joining process
- B29C66/91—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/90—Measuring or controlling the joining process
- B29C66/94—Measuring or controlling the joining process by measuring or controlling the time
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/90—Measuring or controlling the joining process
- B29C66/95—Measuring or controlling the joining process by measuring or controlling specific variables not covered by groups B29C66/91 - B29C66/94
- B29C66/959—Measuring or controlling the joining process by measuring or controlling specific variables not covered by groups B29C66/91 - B29C66/94 characterised by specific values or ranges of said specific variables
- B29C66/9592—Measuring or controlling the joining process by measuring or controlling specific variables not covered by groups B29C66/91 - B29C66/94 characterised by specific values or ranges of said specific variables in explicit relation to another variable, e.g. X-Y diagrams
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
- B29K2995/0003—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds having particular electrical or magnetic properties, e.g. piezoelectric
- B29K2995/0006—Dielectric
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Lining Or Joining Of Plastics Or The Like (AREA)
- Control Of High-Frequency Heating Circuits (AREA)
Abstract
Description
La prbsente invention concerne le secteur des applications industrielles des H. F. On met à profit le fait que la H. F. permet d'apporter par pertes diélectriques des calories au sein des matériaux pour accblérer certains processus industriels comme la soudure des plastiques, la polymérisation des colles, etc. The present invention relates to the sector of industrial HF applications. It takes advantage of the fact that HF makes it possible to bring calories by dielectric losses within the materials to accelerate certain industrial processes such as the welding of plastics, the polymerization of glues, etc. .
L'invention est d'autant plus intéressante qu'elle se rapporte à des matériaux à faibles pertes diélectriques.The invention is all the more interesting as it relates to materials with low dielectric losses.
A l'heure actuelle lorsqu'on désire traiter un matériau par H. F. on le place dans un applicateur alimenté par un générateur H. F. Suivant la forme géométrique du matériau, l'applicaceur est du type condensateur plan, en guirlande, etc. Pour relier l'applicateur C au générateur H. F. (du type piloté a quartz ou auto-oscillateur) on emploie soit un couplage direct : figure 1, soit un couplage indirect par mutuelle induction : figure 2. Actuellement, compte tenu des normes de stabilité en fréquence auxquelles doit répondre le générateur, le montage de la figure 1 est pratiquement abandonné. Pour réaliser un transfert optimal de lté- nergie H.F. du générateur vers le matériau , il est nécessaire que la fréquence f de résonance du circuit applicateur soit égale à celle f du générateur et que
o l'impédance d'entre de l'applicateur vue des points A et B soit la complexe conjugule de celle de sortie vue des points A et B du générateur figure 2. Pour réa- liser ces deux conditions on joue sur le nombre de spires du transformateur de sortie et on place comme le montre la figure 3 des condensateur C1 et C2 en série ou en parallèle avec l'applicateur. On remplace parfois ces condensateurs par des selfs. Par tatonnements successifs on adapte au mieux le transfert d'énergie du générateur H. F.En effet, lorsque l'applicateur n'est pas a la résonance son im pédante est très grande et la consommation du tube oscillateur ou amplificateur est très faible. Dans le cas contraire, celui de l'accord, elle est maximale. On a donc ainsi à sa disposition une indication permettant de contrôler cet accord.At the present time when it is desired to treat a material by HF, it is placed in an applicator supplied by an HF generator. Depending on the geometric shape of the material, the applicator is of the flat capacitor, daisy chain type, etc. To connect the applicator C to the HF generator (of the quartz piloted or self-oscillating type), either a direct coupling is used: Figure 1, or an indirect coupling by mutual induction: Figure 2. Currently, taking into account the stability standards in frequency to which the generator must respond, the assembly of FIG. 1 is practically abandoned. To achieve an optimal transfer of HF energy from the generator to the material, it is necessary that the resonance frequency f of the applicator circuit is equal to that f of the generator and that
o the impedance of input of the applicator seen from points A and B or the complex combines that of output seen from points A and B of the generator figure 2. To realize these two conditions we play on the number of turns of the output transformer and place as shown in Figure 3 capacitors C1 and C2 in series or in parallel with the applicator. These capacitors are sometimes replaced by inductors. By successive trial and error, the energy transfer from the HFE generator is adapted as best as possible, when the applicator is not at resonance, its im pedant is very large and the consumption of the oscillator or amplifier tube is very low. Otherwise, that of the agreement, it is maximum. We therefore have at their disposal an indication enabling this agreement to be checked.
Actuellement, la technologie des applications industrielles de la H.F. se heurte a deux difficultés. La première résulte du fait qu'en cours de traitement le matériau soumis aux ondes s'échauffe ce qui est bien sur le but recherche. Malheureusement cet échauffement entraine une variation de ses proprietes électriques en particulier de ses constantes diélectriques er et er Cela se traduit par un
r désaccord de l'applicateur. n'autre part pour un traitement au d#fil# lorsqu'on passe d'un échantillon à un autre si le suivant n'est pas rigoureusement le même que le prdeédent l'accord de l'applicateur est à nouveau perdu. A ces deux ennuis il faut ajouter les instabilités en fréquence du générateur lui-meme.Ces insta bilités sont provoquees par les fluctuations de la tensions d'alimentation, les dilatations thermiques et surtout la réaction du circuit applicateur sur le circuit oscillant de l'auto-oscillateur. Cette difficulté pourrait être supprimée en utilisant un générateur R. F. piloté par quartz. Compte tenu de tout cela l'utilise teur d'une machine H. F. est alors amené à retoucher des rigolages manuels ce qui est désastreux pour une machine automatique.Pour surmonter ces écueils, certains ont préconisé des dispositifs utilisant un condensateur d'asservissement (placé comme C2 de la figure 3), condensateur entraîne par un moteur de telle façon que le courant débité par le tube du générateur H. F. reste constant. Cette voie semble difficile et n'a pas conduit, à notre connaissance à des applications industrielles.Currently, HF industrial applications technology faces two challenges. The first results from the fact that during treatment the material subjected to the waves heats up which is of course the aim sought. Unfortunately this heating leads to a variation of its electrical properties in particular of its dielectric constants er and er This results in a
r disagreement of the applicator. on the other hand for a wire treatment # when moving from one sample to another if the next is not strictly the same as the previous agreement of the applicator is again lost. To these two troubles must be added the frequency instabilities of the generator itself. These instabilities are caused by fluctuations in the supply voltage, thermal expansions and especially the reaction of the applicator circuit on the oscillating circuit of the car. -oscillator. This difficulty could be eliminated by using an RF generator controlled by quartz. In view of all this, the user of an HF machine is then led to touch up manual jokes which is disastrous for an automatic machine. To overcome these pitfalls, some have recommended devices using a servo capacitor (placed as C2 of Figure 3), capacitor driven by a motor so that the current delivered by the tube of the HF generator remains constant. This path seems difficult and has not, to our knowledge, led to industrial applications.
Le dispositif suivant l'invention permet d'boiter ces inconv#nients. The device according to the invention makes it possible to overcome these drawbacks.
En effets même si les propriétés de l'échantillon du fait de son échauffement viennent à varier en cours de traitement, ou si l'on passe en cours de fabrication en continu d'un échantillon à un autre de dimensions ou de propriétés électriques légèrement différentes le dispositif objet de l'invention permet de dissiper toujours la même puissance dans l'échantillon.In effect even if the properties of the sample due to its heating come to vary during treatment, or if one passes during continuous manufacture from one sample to another of slightly different dimensions or electrical properties the device which is the subject of the invention always allows the same power to be dissipated in the sample.
Le dispositif objet de l'invention comporte un système de balayage en fréquence permettant de moduler la fréquence de résonance série f de l'applicateur de part et d'autre de celle f du générateur. La figure 4 donne le schéma de principe du montage réalisé. Sur cette figure on distingue en parallèle sur l'applicateur C qui peut etre de type quelconque (condensateur, plan, stray field, etc.) un ensemble C pouvant être dans une première version constitué par un con
v densateur papillon dont les lames mobiles sont entraînes d'un mouvement de rotation par un moteur.Les figures Sa, 5b, 5c, 5d donnent respectivement le schéma de principe de ce condensateur, ##n exemple de réalisation, son symbole représenta- tif et la variation de sa capacité C en fonction du temps. Si l'on s'arrange pour qte la résonance du circuit secondaire contenant l'applicateur se produise à f
o (fréquence du générateur) lorsque la lame mobile est à demi engagée entre les lames fixes on comprend que la tension aux bornes de l'applicateur va évoluer comme indiqué sur le graphique 6b.Le graphique 6a identique à 5d est uniquement là pour montrer la liaison temporelle existant entre l'évolution de la valeur de la capacité C et la tension V aux bornes de l'applicateur ainsi que le courant du tube émetteur. Ce courant figure 6c à la même allure, au fond continu près Io, qui subsiste même si le circuit secondaire contenant l'applicateur n est pas accor dé. I varie en sens inverse du coefficient de surtension du circuit oscillant de
o puissance du générateur II. F.On conçoit aisément que si la capacité propre de l'applicateur venait à varier par suite d'une modification des propriétés ou des dimensions du produit à traire #.i fréquence de résonance se produit pour des fréquences légérement supérieures ou inte#rietires à f . Cette variation de capacité n'aura donc aucun rôle tout au moins tant qu'elle reste inférieure à Cmax.- Cmin.The device which is the subject of the invention comprises a frequency sweeping system making it possible to modulate the series resonant frequency f of the applicator on either side of that f of the generator. Figure 4 gives the block diagram of the assembly carried out. In this figure, we distinguish in parallel on the applicator C which can be of any type (capacitor, plane, stray field, etc.) a set C which can be in a first version consisting of a con
v butterfly densifier whose moving blades are rotated by a motor. Figures Sa, 5b, 5c, 5d respectively give the block diagram of this capacitor, ## n example of embodiment, its representative symbol and the variation of its capacity C as a function of time. If we arrange for qte the resonance of the secondary circuit containing the applicator occurs at f
o (generator frequency) when the movable blade is half engaged between the fixed blades, we understand that the voltage across the terminals of the applicator will change as shown in graph 6b. The graph 6a identical to 5d is only there to show the temporal link existing between the evolution of the value of the capacitance C and the voltage V at the terminals of the applicator as well as the current of the emitter tube. This current is shown in figure 6c at the same speed, with the continuous bottom close to Io, which remains even if the secondary circuit containing the applicator is not matched. I varies in opposite direction of the overvoltage coefficient of the oscillating circuit by
o generator power II. F. It is easy to see that if the applicator's own capacity were to vary as a result of a change in the properties or dimensions of the product to be milked. The resonant frequency occurs for frequencies slightly higher or lower than f. This variation in capacity will therefore have no role at least as long as it remains below Cmax.- Cmin.
Pour caler la fréquence de résonance du circuit applicateur au voisinage de f il est nécessaire de prévoir à cet effet un condensateur de tarage Ct disposé en parallèle sur l'applicateur. le dispositif objet de l'invention permet donc de s'afranchir des fluctuations de la fréquence de résonance du circuit applicateur.To set the resonance frequency of the applicator circuit in the vicinity of f it is necessary to provide for this purpose a calibration capacitor Ct arranged in parallel on the applicator. the device which is the subject of the invention therefore makes it possible to overcome fluctuations in the resonance frequency of the applicator circuit.
flans le cas classique on obtient figure 7a aux bornes de l'applicateur une tension dont l'amplitude dépend de l'accord de l'applicateur. Dans le cas où l'on utilise notre dispositif, on obtient des impulsions de tension figure 7b. La puissance moyenne dissipée dans l'échantillon passe donc, si f varie, de quelque chose de très variable pour une installation classique à quelque chose de pratiquement constant lorsque on utilise notre invention ce qui est bien là le but recherché. In the classic case, FIG. 7a is obtained at the terminals of the applicator, a voltage whose amplitude depends on the agreement of the applicator. In the case where we use our device, we obtain voltage pulses figure 7b. The average power dissipated in the sample therefore goes, if f varies, from something very variable for a conventional installation to something practically constant when we use our invention, which is indeed the aim sought.
Il est à noter que pour un générateur H. F. classique sans balayage il n'y a pas de temps mort, l'applicateur étant alimenté en permanence. La présence du balayage conduit à une alimentation impulsionelle donnant un plus faible facteur d'utilisatien. Ce fait pourrait se révéler un inconvénient pour notre invention en pratique il ne conduit à aucune perte de rendement car lorsque le circuit de l'applicateur n'est pas accordé le générateur H. F. consomme une puissance négligeable. Pour compenser ce facteur d'utilisation plus faible il # suffit A'augmenter la puissance instantannée du générateur 11. F. nn peut le faire sans dommage en conservant le même tube que celui d'une installation classique de même puissance puisque seul compte pour le dimensionnement de ce composant la puissance moyenne délivrée. On réalise alors une sorte de générateur à porteuse contrôlée. Il possible de réguler autour d'une valeur de consigne ou même de faire évoluer en fonction du temps suivant un programme prédéterminé la puissance dissipée dans le produit placé dans l'applicateur.En effet, le courant du tube de puissance du générateur (donc la puissance H. F. dissipée dans le produit placé dans l'applicateur) évolue de la même façon que la tension aux bornes de l'applicateur. Il est donc possible en comparant la valeur moyenne de la tension apparaissant aux bornes de la résistance placée dans le circuit de cathode du tube émetteur, figure 8, à une tension de référence d'obtenir un signal d'erreur positif ou négatif. En utilisant pour le générateur H. F. une alimentation controlée (par thyristors ou par inductance saturable) il est possible grâce au signal d'erreur précédemment élaboré de piloter l'alimentation du générateur H. F. dont de réguler la puissance dissipée dans l'échantillon.Si la tension de référence évolue suivant une certaine loi la puissance dissipée dans l'échantillon suit la même loi. Cette possibilité peut être mise à profit pour le soudage de matière plastique permettant ainsi d'utiliser une puissance plus faible en début de soudure lorsque l'échantillon est froid diminuant ainsi les risques de claquage. Notons que l'applicateur travaillant toujours de façon impulsionelle les risques de claquage sont diminués même si l'on augmente un peu la puissance instantannée. C'est le phénomène qui fait qu'à courant égal un interrupteur supporte beaucoup mieux un courant alternatif qu'un courant continu. Notons que dans le cas d'un générateur H. F. piloté le contrôle de puissance ne s'effectuera pas sur l'étage de puissance mais sur l'exciter.La puissance à controler est alors beaucoup plus faible ce qui diminue d'autant le coût de l'asservissement. Remarquons que dans ce dernier cas l'étage de puissance du générateur H. F. devra obligatoirement fonctionner en amplificateur linéaire. La description du système de balayage à condensateur à été simplement esquissée. En pratique, nous utiliserons un condensateur papillon professionnel. Les lames mobiles seront entraînes à vitesse constante par un moteur synchrone de façon à décrire par exemple 50 fois par seconde la courbe de résonance du circuit de l'applicateur. I'ne variante du système pourrait être faite en utilisant une self variable.Il suffit pour cela d'employer une espèce de U en gros fil devant lequel on fait tourner un disque comprenant des secteurs isolants et des secteurs condutcteurs en cuivre, figure 9. T.e passage d'une lame de cuivre parallèlement au plan de l'épingle modifie dans de grandes proportions la self vue des points A et B de l'épingle. Dans ce cas là, le dispositif de balayage n'est pas placé en parallèle sur l'applicateur mais en série.It should be noted that for a conventional HF generator without scanning there is no dead time, the applicator being permanently supplied. The presence of the sweep leads to a pulse supply giving a lower user factor. This fact could prove to be a drawback for our invention in practice, it does not lead to any loss of yield because when the circuit of the applicator is not tuned the HF generator consumes negligible power. To compensate for this lower utilization factor, it suffices to increase the instantaneous power of the generator 11. F. It can be done without damage by keeping the same tube as that of a conventional installation of the same power since only counts for the dimensioning of this component the average power delivered. A kind of generator with controlled carrier is then produced. It is possible to regulate around a setpoint or even to change, as a function of time, according to a predetermined program, the power dissipated in the product placed in the applicator. Indeed, the current of the generator power tube (therefore the HF power dissipated in the product placed in the applicator) changes in the same way as the voltage across the applicator. It is therefore possible by comparing the average value of the voltage appearing at the terminals of the resistor placed in the cathode circuit of the transmitter tube, FIG. 8, with a reference voltage to obtain a positive or negative error signal. By using a controlled supply for the HF generator (by thyristors or by saturable inductance) it is possible, thanks to the error signal previously developed, to control the supply of the HF generator including regulating the power dissipated in the sample. of reference evolves according to a certain law the power dissipated in the sample follows the same law. This possibility can be taken advantage of for welding plastic material, thus making it possible to use a lower power at the start of welding when the sample is cold, thereby reducing the risks of breakdown. Note that the applicator always working in an impulse fashion the risks of breakdown are reduced even if the instantaneous power is slightly increased. It is the phenomenon which makes that with equal current a switch supports an alternating current much better than a direct current. Note that in the case of a controlled HF generator, the power control will not be carried out on the power stage but on the exciter. The power to be controlled is then much lower, which reduces the cost of the enslavement. Note that in the latter case the power stage of the HF generator must necessarily operate as a linear amplifier. The description of the condenser scanning system has been simply sketched. In practice, we will use a professional butterfly capacitor. The moving blades will be driven at constant speed by a synchronous motor so as to describe for example 50 times per second the resonance curve of the applicator circuit. A variant of the system could be made using a variable inductor. To do this, it suffices to use a kind of U in coarse wire in front of which a disk is made up comprising insulating sectors and conductive copper sectors, FIG. 9. The passage of a copper strip parallel to the plane of the pin modifies in great proportions the self view of points A and B of the pin. In this case, the scanning device is not placed in parallel on the applicator but in series.
Le dispositif objet de l'invention peut être utilisé tous les fois où l'on désire chauffer des matériaux par haute fréquence comme pour la soudure des plastiques (mise sous berlingot d'un liquide, fabrication de certains tissus synthétiques, réalisation d'objet de maroquinerie en PVC), le collage de pièces de bois par polymérisation de colle ou toutes autres applications énergétiques des H. F. Son rôle se révèle d'autant plus intéressant que les matériaux a chauffer possèdent de faibles pertes diélectriques. The device which is the subject of the invention can be used whenever it is desired to heat materials by high frequency, such as for welding plastics (placing in a container of a liquid, manufacturing certain synthetic fabrics, carrying out the object of PVC leather goods), gluing wooden pieces by glue polymerization or any other energy application of HF Its role is all the more interesting as the materials to be heated have low dielectric losses.
Claims (8)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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FR8105565A FR2502441A1 (en) | 1981-03-18 | 1981-03-18 | Control for power dissipation in dielectric subject to HF field - by automatic resonance tuning and a reference voltage cycle |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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FR8105565A FR2502441A1 (en) | 1981-03-18 | 1981-03-18 | Control for power dissipation in dielectric subject to HF field - by automatic resonance tuning and a reference voltage cycle |
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FR2502441A1 true FR2502441A1 (en) | 1982-09-24 |
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FR8105565A Withdrawn FR2502441A1 (en) | 1981-03-18 | 1981-03-18 | Control for power dissipation in dielectric subject to HF field - by automatic resonance tuning and a reference voltage cycle |
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FR (1) | FR2502441A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0492789A1 (en) * | 1990-12-24 | 1992-07-01 | Ford Motor Company Limited | A method and apparatus for bonding a non-conductive member to a conductive member |
EP0950608A1 (en) * | 1998-04-15 | 1999-10-20 | Tetra Laval Holdings & Finance SA | Method of monitoring transverse sealing in a packaging unit for continuously forming sealed packages containing pourable food products |
-
1981
- 1981-03-18 FR FR8105565A patent/FR2502441A1/en not_active Withdrawn
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0492789A1 (en) * | 1990-12-24 | 1992-07-01 | Ford Motor Company Limited | A method and apparatus for bonding a non-conductive member to a conductive member |
US5277737A (en) * | 1990-12-24 | 1994-01-11 | Ford Motor Company | Dielectric curing of adhesives |
EP0950608A1 (en) * | 1998-04-15 | 1999-10-20 | Tetra Laval Holdings & Finance SA | Method of monitoring transverse sealing in a packaging unit for continuously forming sealed packages containing pourable food products |
WO1999052776A1 (en) * | 1998-04-15 | 1999-10-21 | Tetra Laval Holdings & Finance S.A. | Method of monitoring transverse sealing in a packaging unit for continuously forming sealed packages containing pourable food products |
US6732496B1 (en) | 1998-04-15 | 2004-05-11 | Tetra Laval Holdings & Finance Sa | Method of monitoring transverse sealing in a packaging unit for continuously forming sealed packages containing pourable food products |
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