DEP0009682MA - - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

Registration date: April 29, 1953 Announced on March 29, 1956

GERMAN PATENT OFFICE

PATENT APPLICATION

CLASS 21a ⁴ GROUP 74 P 9682VlUaI 21a "

Dr. Hans-Heinrich Meinke, Pöcking near Starnberg

has been named as the inventor

Pintsch-Electro G.m.b.H., Konstanz (Lake Constance)

Hollow tube voltage divider

Capacitive hollow pipe dividers have so far been built in the form of Fig. I. The properties of such dividers are in the book: Meinke, "Fields and waves in waveguides", Munich, 1949, explained in more detail. There the main law is derived, which for not too small plate distances χ an increase Δ χ in the plate distance an increase of attenuation of

Ax
4.8 - Neper (D - diameter of the hollow tube) results. On logarithmic paper, the damping curve for larger χ is a straight line (Fig. 2, curve I). For smaller χ there are deviations from the straight line due to the effectiveness of so-called hollow tube fields of a higher order. This has the disadvantage that a separate calibration has to be carried out in this area, which is not necessary in the straight part. For very small χ the attenuation curve becomes very steep, so that an exact setting is no longer possible and the divider cannot be used there.

509 699/365

P 9682 VIIIal21 α ⁴

The problem arose of creating small adjustable attenuations. This was generally resolved by constructing different types of voltage dividers, which in turn are not large ones Allow attenuations' to be set. There were z. B. so-called ohmic divider common. the The calibration of these dividers is highly dependent on the frequency, and their adaptation is not good. The invention expanded the linear area of the original

ίο capacitive divider up to very small attenuations, thus also replaces the ohmic divider. Curve II of Fig. 2 showing this effect is measured on a sample. ,

Although a voltage divider is known that has a pot electrode. a piston-shaped Has counter electrode. This results in an approximately logarithmic output voltage of the Divisor, but the course of the curve can only be determined by trial and error, and such a Divider must always be specially calibrated. Detn, opposite has the arrangement according to the invention a course that can be calculated up to the stop, which is essentially due to the excitation only one field type is effected.

The errors of the earlier divisors arise from the fact that the plate used for excitation or similarly shaped objects, in addition to the desired aperiodic £ ₀₁ wave, also excite E "" fields of a higher order, which decrease rapidly, but are effective when the plates come closer together will. If one now uses stimulating body _{shapes that are equipotential surfaces of the £ 01} field, a pure ii _ol field is created. Such an equipotential surface is also used as a counter body. Then the E ₀₁ field is preserved even with the smallest distances. So you get a divider according to Fig. 3. The intersection curve of the surfaces can be calculated relatively easily. Fig. 4 shows the equivalent image of the divider. The important capacitance C ₂ can be regulated by the variable distance, and the fixed capacitance C ₃ can be brought to a suitable value by shaping the body. An example of the shape of the movable body with a larger C ₃ is given

Fig. 3-.

So far, the shape of Fig. 5 (equivalent image in Fig. 6), two loops with variable spacing, has often been used as an inductive divider. These result in the same defects in the curves as in Fig. 2, curve I. They can be avoided if the coupling conductors are given the appropriate shapes that only stimulate a single type of field. With ladders, as shown in Fig. 7, you can z. B. stimulate the H ₁₀ field in rectangular tubes. As can be seen from the cross section (Fig. 7 "), the upper surface α of the conductor forms the supply line. In Fig. 7 the course of the streamlines is indicated by arrows. The course of the magnetic field lines seen from above is shown in Fig. J _b . Formulas for calculating such equipotential surfaces are given in Meinke's book mentioned at the beginning. _{In a pipe with a circular cross-section, a / Z 11} field can be excited by surfaces that are similar to those in Fig. 7, but slightly differently curved. These surfaces can only be constructed graphically.

At very high frequencies, the output resistance must have a desired ohmic resistance Z in order to be able to measure over a connecting cable of any length. This can be done in such a way that the drawn surfaces do not need to be made of metal, but can also consist of a resistive layer W on an insulating support, both in the capacitive and in the inductive divider. In the case of the capacitive divider, however, this resistance layer must form a complete connection between the inner conductor and the outer conductor (Fig. 8). If you want an extremely linear division, you have to make the curvature of the surfaces a little smaller than in Fig. 3, because there is a voltage drop along the resistance layer and the relevant parts of the surface must correspond to the equipotential lines belonging to this low voltage. A practically reflection-free closure of both sides of the divider can be achieved by appropriate distribution of the surface resistance of the layer.

Claims (7)

PATENT CLAIMS: 1. Adjustable capacitive or inductive hollow tube voltage divider for high frequency a pipe with conductive walls and with one coupling-in and one coupling-out Structure, characterized in that the stimulating coupling organ has such a curved surface has that only a single one in the tube. Field type is stimulated and the one facing it Counter surface receives such a counter curvature that both surfaces fit exactly into one another. 2. Hollow tube voltage divider according to claim 1, characterized in that the surface of the exciting coupling organ represents approximately an equipotential surface of the field to be excited. 3. Hollow tube voltage divider according to claim 1 or 2, characterized in that the curvature the area of the exciting coupling organ corresponds approximately to the course of the magnetic field lines of the field to be excited. 4. Voltage divider according to claim ι or the following, characterized in that at very high frequencies an ohmic resistor assembled with the voltage divider in this way becomes that the initial resistance has a desired value. 5. Voltage divider according to claim 4, characterized in that the curved Surfaces consist of a resistive layer on an insulating carrier. 699/365 P 9682 VIIIal21 α ⁴ 6. Voltage divider according to claim 5, characterized in that the resistance layer is a forms a complete connection between the inner and outer conductors (Fig. 8). 7. Voltage divider according to claim 4 and following, characterized in that the The curvature of the surfaces is chosen to be somewhat smaller than what corresponds to the theoretical values. Referred publications:
Otto Simann, Prüffeldmeßtechnik, 1947, Funkschauverlag, p. 79. For this purpose 2 sheets of drawings