SU610197A1 - Variable capacitor - Google Patents

Description

(54) CAPACITOR OF A VARIABLE CAPACITY

The invention relates to semi-advanced devices that change their electrical parameters when exposed to a control signal, in particular, to electric capacitors of variable capacitance, which change their capacity when exposed to an external signal. A variable capacitor is known, for changing the capacitance of which an electric heating of one of the plates is necessary. The dielectric between the plates, when heated, changes the dielectric constant jlj. An insignificant change in the capacitance should be attributed to the deficiency of this capacitor. When the ambient temperature is close to the maximum allowable temperature of the dielectric, the control plate can be heated to a small value relative to the environment, which, in turn, entails an insignificant change in capacitance condat; satbra. The change in temperature of the dielectric, tric in the non-switched on state is the rise of the initial value of the capacitance. Since the temperature of the dielectric depends on the ambient temperature, the oscillations of the latter during operation also cause capacitance capacitance to fluctuate. The purpose of the invention is to expand the range of capacitance variation and reduce the effect of temperature fluctuations -o by the fact that a Peltier element is inserted into a variable capacitor, between the flat sides of which has a thermo-sensitive dielectric, one side of which is a capacitor plate, the Peltier element and the capacitor plate is a beryllium oxide gasket, metallized on one side and the non-metallized side adjacent to the side of the Peltier element. FIG. 1. shows a variable capacitor, having at least two i plates 1 and 2, between which dielectric 3 is placed, the dielectric constant of which depends on temperature, and plate 1, on which the dielectric is applied, is simultaneously one of the article; oron Peltier element - thermopile .4. Each of the capacitor plates has pins 5 and b in the form of a mounted installation. In FIG. 2 shows a variable capacitor, in which, to expand the operating values of the containers obtained, both plates 1 and 7 of thermal bath 4 are simultaneously plates of two sections of a capacitor, and dielectric 3 deposited on the cold plate of 1 thermopile has a positive on the hot side of the plate 7 has a negative temperature dependence of the dielectric constant; Each capacitor plate has a separate external output. (5, b, 9 and 10) in the form of mounted installation. In order for the fluctuations in ambient temperature to have less effect on the operation of the device, as well as to provide resistance to shock and vibration loads, the capacitor is placed in a housing 11 of rigid thermally insulating material, such as polyurethane foam. . FIG. 3 shows a variant of galvanic uncoupling of the coupling plates of the semiconductor elements 12 of the element 4 and capacitor plates, for example, the plates 1, by installing an electrical insulation strip 13 of high heat conductivity between them, for example, from oxide b., To which a metal layer is applied. 14. In FIG. Figure 4 shows an embodiment of a multi-section variable capacitor. He has at least two thermopile semiconductor elements 15 around the perimeter. A heat-sensitive dielectric 16, which is formed by a capacitor plate 17, for example, by a metallization method, is unprofitable for a length not having a temperature equal to the temperature of the switching plates 12 of the thermal battery and adjacent to the corresponding end of the semiconductor element. The second plate of the capacitor serves as the surface of the semiconductor element 15, and the electrical leads of the device are made in the form of a printed wiring 18 between the lmutation plates 12.. The device operates as follows (Fig. 1). When a supply voltage of the appropriate size and floor is applied to the thermopile 4, the last side, which is simultaneously one of the capacitor plates 1, cools and cools the dielectric 3 applied to it, which, depending on from ste-j cooling rate changes its dielectric permeability, which leads to a change in the capacitance of the capacitor. The electrical signal from the condenser is lowered: it is ignited using pins 5 and 6. For a capacitor with an extended operating range of the capacitances obtained when the thermal battery 4 is operated, the dielectric 3 deposited on the cold side of the thermopile is cooled, and the dielectric 8 applied to the hot The side of the thermopile is heated, but since the insulators 3 and 8 have, depending on the signs, the dependence of the capacitance on temperature, the capacitance of both sections is condensed. the sator changes its value in one direction (it increases or decreases, depending on the polarity of the voltage supplying the thermopile). In order to provide a rough and precise adjustment of the capacitance of the capacitor, the thermoelectric battery, which is the control element of the device, is filled in the form of sections with separate electrical leads. To switch sections of the thermopile, corresponding to the achievement of the required cooling depth of the cold side of the thermopile (or hot side), i.e. changing the capacitance of the capacitor, use the switching power, for example, the electronic key with the number of outputs corresponding to the number of sections. The corresponding sections of the thermopile are connected to the power source using an electronic key when the last control is fed to the input. tension When the thermopile works, a constant electric field arises along the semiconductor elements and switching plates. To reduce the effect of this field on the accuracy of the operation of the capacitor of the thermopile, they are turned on bifilically, i.e. parallel sections in the battery are switched so that the direction of the supply current of these sections is in the opposite direction. The resulting electric fields have opposite directions and are mutually destroyed. Multi-section capacitor (figure 4) works as follows. j When power is supplied to the thermopile 4, the Peltier heat is absorbed (released) by the corresponding pn junctions of the semiconductor elements of the battery 15, which causes cooling (heating) of the part of the semiconductor elements; and the switching plates 12. As a result, the dielectric 16 element 15 is cooled (heated), which causes a change in its dielectric constant and capacitor capacitance. | Sections of a multisection variable capacitor capacitor commute 4epe3 conductors, made by the method of printed wiring, using communi- cation:

devices such as electromagnetic relays.

The use of the invention allows, while maintaining the dimensions of the device, to several times expand the range of operating values of the capacitor capacitance, increase its resistance to shock and vibration loads, expand the range of operating ambient temperatures, as well as improve the tuning accuracy. In addition, the proposed capacitor has the ability to vary the capacitance according to the required law, both in time and in magnitude.

This design of a variable capacitor is viable, allows for maximum mechanization of production and reduces the cost of production approximately by half.

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Claims (2)

1. A variable capacitor, between the flat sides of the plates of which a thermosensitive dielectric is located, characterized in that, in order to expand the range of capacitance changes and reduce the effect of temperature fluctuations, a Peltier element is introduced into it, one of the sides of which is a capacitor plate. 2. A capacitor in accordance with claim 1, 6 tons of liquid with the fact that between the Peltier element and the capacitor plate there is a gasket of beryllium oxide, metallized on one side and the non-metallized side adjacent to the side of the Peltier element. Sources of information taken into account in the examination: 1. Patent S1T1A 3257607, cl. 32393, 1968. thirty ipui.-Z 35 1t " Fig.Z fui. #