DE2207766A1 - CIRCUIT ARRANGEMENT FOR ADJUSTMENT OF ELECTRONICALLY TUNED VIBRANT CIRCUITS - Google Patents

Description

Standard electrical system Lorenz Aß,

W, Miller-6

Circuit arrangement for balancing electronically tuned oscillating circuits

The invention relates to a circuit arrangement for electronic Tuning of resonant circuits by means of varactor diodes operated in the restricted area, the tuning voltage of which is from Wiper of a tuning potentiometer is removed, and the adjustment by switching on one or more, with the Tuning potentiometer in series of resistors or range balancing (Base point and hot point) controller takes place.

With electronic tuning, the variable capacitance of the oscillating circuits is not achieved by means of variable capacitors, but rather formed by capacitance (variation) diodes. she are operated for this purpose in the blocking range and change their capacity according to the applied blocking voltage, in such a way, that the smallest capacitance occurs at the highest reverse voltage.

The comparison itself has two goals. On the one hand synchronous or parallel running should be achieved, on the other hand one should if possible good match with the scale can be established. While preferably on VHF the synchronous or parallel operation largely given by the sorting of the capacitance diodes (pairs, terzets and quartets) and the circuit dimensioning is, the main task of the balancing controller is to adjust the frequency to the scale by adding the Tolerances in the capacitance curve of the capacitance diodes and the tolerances in the tuning potentiometer curve are compensated.

For the production of synchronous or parallel running of oscillating circuits the following three processes are known, among others: the

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One-point adjustment, two-point adjustment and three-point adjustment. The one-point adjustment requires the shortest adjustment time, as it is only carried out once in each area. However, it can only lead to optimal values in special cases.

The two-point adjustment is the most common. At the Two-point adjustment, one adjustment element causes a relatively equal change over the entire range, while the other adjustment element at one end of the range causes a change results in a relatively larger change. Since the Ablgiech must always take place by means of this second adjustment element, where the The relatively largest change occurs, the other end of the range results for the adjustment using the adjustment element.

With electronic tuning, for example, one tuning element can be the coil and the second one with the tuning controller in Series of horizontal trim resistance. Since in this case the If the trim resistance causes the largest change at lower frequencies, the coil is trimmed at higher frequencies.

With three-point adjustment, three points are adjusted so that three adjustment elements are required. This comparison will Used in cases where very good synchronization and good scale accuracy are required, or where the tolerances of the tuning elements are otherwise too large high calibration and synchronization errors. Since in the three-point adjustment, the others are adjusted at one point Both points are influenced, the result is a much longer repetition or lengthening of the adjustment processes and thus the adjustment time than with two-point adjustment.

The invention is therefore based on the object of improving and shortening the adjustment process, in particular for electronic voting.

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For circuit arrangements for the electronic coordination of several oscillating circuits in synchronism or parallel operation of the input mentioned type it is known for each of the oscillating circuits to be tuned in series with the tuning potentiometer lying first adjustment potentiometer and one lying with the outer connections on the wiper of the tuning potentiometer Provide a second adjustment potentiometer, and the taps of the adjustment potentiometer via decoupling elements known per se to be connected to the respective capacitance diode (see e.g. German patent specification 1 269 689, W. Dollries-3, SEL-Reg. 11 of the applicant). With this arrangement, however, another object is achieved: namely, synchronous and parallel operation even then to produce electronically tunable receivers if the inductance or the initial capacitance are not changed can.

It is also known per se, e.g. to stabilize the frequency of an oscillator, capacitance diodes in connection with to provide a bridge circuit (see e.g. German Auslegeschrift 1 176 725, Th. Ohlhauser-4, SEL-Reg. 9711 of the applicant) .

Another known circuit arrangement for the electronic coordination of several oscillating circuits in synchronism or parallel operation consists in that the adjustable resistors, designed as voltage dividers and connected in parallel, have one connection line at the pole of the control voltage source carrying the blocking potential and the other connection line at the tap of the common controller lie that the capacitance diodes are connected to the taps of the voltage divider via decoupling resistors and that the tuning of the resonant circuits is carried out at the upper end of the frequency range by changing the inductances of the resonant circuits and at the lower end of the range with the aid of the voltage divider. (See BB Deutsche Auslegeschrift 1 277 95 ¹ J, H. Forsthuber-2,

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SEL reg. 9691 of the applicant). However, this solution is based on the object of creating a circuit arrangement for tuning several resonant circuits in which an independent setting of the range position and the variation is possible and the tuning range is not restricted by an additional trimmer capacitor.

It should also be noted that it is known per se to use a potentiometer twice by adding that formed by the grinder both sections of a potentiometer can be used simultaneously to control two different circuits (cf. e.g. German Patent 1 021 020, Fig. 5, A. Rappold-10, SEL reg. 9566 of the applicant, German patent specification 1 072 652, Fig. Ί, A. Rappold-17, SEL-Reg. 9605 of the applicant or the German Patent 1,269,689 already mentioned). However, these known arrangements serve to solve other problems.

In contrast to all these circuit arrangements mentioned, the object of improving and shortening the adjustment process is achieved by the invention in such a way that the base point controller is used on both sides in such a way that an additional resistor is connected from the free controller end to the hot point controller, and the resistor (s) is (are) dimensioned in such a way that the adjustment curve A,? = £ (f) for the adjustment with the base point controller at the high-frequency range end (or at the adjustment point near this range end) runs through zero and / or that the hot point controller is used on both sides in such a way that an additional one from the free controller end to the base point controller Resistance is connected, and the resistor (s) is (are) dimensioned such that the adjustment curve Af ^s f (f) for the adjustment with the hot spot controller at the low-frequency range end (or at the adjustment point near this end of the range) passes through zero runs, where f is the loop or receiving frequency and Af is the controller

conditional frequency change means.

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This means that the adjustment of the foot point regulator at the high-frequency range end (or in its vicinity) at this Digit brings no change, while adjusting the hot spot regulator at the end of the low-frequency range (or in its proximity) does not cause any change at this point.

Another embodiment of the invention consists in that, in addition to the appropriately dimensioned resistors between the free ends of the foot and hot point regulators, two diagonally positioned resistors are also connected, and the resistors are dimensioned in such a way that both the adjustment of the foot point regulator at the high-frequency range end (or . at the adjustment point near this end of the range) and the adjustment of the hot spot regulator at the low-frequency end of the range (or at the adjustment point near this range) have no influence at this point .

The invention has the particular advantages that the adjustment processes are shortened and improved and that the mutual influence of the two adjustment elements (foot and hot point regulator) is eliminated.

Embodiments of the invention are shown in the drawings and described in more detail below. Show it

Figure la and Figure Ic the basic principle of known designs

Figure Ib and Figure Id the associated diagrams for explanation

the operation of the arrangements shown in Figure la and Ic compared to which the basic mode of operation of the invention in

Figure 2 da diagram

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Figure 3a and 3d further embodiments of the "invention with

the in

Figures 3b, 3c and 3e shown, associated diagrams

Figure Ma shows another embodiment of the invention with the in

Figure ¹ Ib shown associated diagrams.

Based on the figures la and Ib are for a better understanding of Invention first briefly the adjustment processes in known electronic Voting with two-point adjustment explained. The adjustable diode bias or tuning blocking voltage for the Capacitance or tuning diode D is taken from a voltage source UR, which can be regulated via the tuning regulator R2. That one balancing element is connected by the parallel-connected coil L and the other by one in series with the tuning regulator lying trimmer resistor or base point controller Rl formed. As at low frequencies when setting a corresponding If only a relatively small part of the tuning regulator R2 is effective, the trimmer resistance has in this case Rl has a relatively large influence, which decreases relatively steadily after higher frequencies.

This relationship can be seen from the diagram in FIG. 1b, in which the abscissa shows the reception frequency f and the ordinate shows the frequency change in relation to the reception frequency f, ie Δι . In this case it is assumed that a small area (e.g. VHF) is swept over with the electronic voting. If the change is small, the curve for Rl shows the relative influence of the diode bias voltage and the curve L shows the relative influence of the coil (with coil L connected in parallel). Since the trimmer resistor Rl has the greatest influence at lower frequencies, the coil L is at higher frequencies

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Frequencies matched. In the case of two-point adjustment, the adjustment process must then be repeated until there is no change more is done.

The circuit shown in Figure Ic or Id differs essentially from the one shown in Figure la that with the tuning controller R2 not only a base controller, but also a further setting controller, which is connected as a hot spot controller, in series with the resistors Rl and R2 is provided with which the initial and final voltage (stroke) can be set over the range. The diagram in Figure 'Id shows the influence of the two regulators. It gives the frequency deviation i \ f as a function of the receiving frequency f / ^ fM- (f) in relation to the base point controller Rl and the hot point controller R3. Neither for Rl nor for R3 does the frequency deviation become zero at any point.

For the adjustment, however, it is advantageous if one of the two curves, in each case at the opposite adjustment point, runs through zero, e.g. as shown in Figure 2, in which the first adjustment point with a and the second Adjustment point is denoted by b.

The most efficient range adjustment is given when a curve at one adjustment point and at the Three-point adjustment, two of the curves mentioned go through zero at a different adjustment point.

A circuit arrangement according to the invention for two-point adjustment, in which one of the adjustment curves runs through zero, shows the figure 3a with the associated diagram, with only the for Explanation of the invention essential parts are shown. The base point controller Rl, tuning controller R2 and hot point controller R3 are connected in series, while another resistor RM parallel to the series resistors Rl and R2

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switches, and the wiper of Rl is at the base or is connected to ground. The dimensioning is made in such a way that the following course is realized. While the frequency change ^, f (FIG. 3b) caused by the hot spot regulator R3 is practically the same over the entire range the change Af caused by Rl in the first adjustment point (Adjustment point a) greatest, while it becomes zero in the second adjustment point (adjustment point b). It will therefore be the first Adjustment with R3 in adjustment point b and then the adjustment for Rl in adjustment point a.

For a three-point adjustment, a correction regulator R5 (shown in dashed lines) is connected in parallel to the tuning regulator R3 shown in FIG. With this circuit, with appropriate dimensioning, the course of the adjustment curves shown in FIG. Jc can be achieved. The adjustment curves for the hot point controller R3 and the base point controller Rl again run as shown in FIG. 3b. For the correction controller R5, however, there is a curve in which the frequency change A f becomes zero both at the start of the range (calibration point a) and at the end of the range (calibration point b), while it has a maximum in the middle (point c) of the range .

In Figure 3d the case is shown that the hot spot controller R3 is used on both sides. The base point controller Rl, tuning controller R2 (to which, as in the arrangement of FIG. 3a, the correction controller R5 can be connected in parallel), and the hot point controller R3 are in turn in series. On the other hand, an additional resistor R6 is now connected from the free end of the hot point regulator R3 to the base point regulator Rl. The resistors are dimensioned such that the 3e in FIG adjustment curves shown result, the calibration curve Δ f ^s ^ (f) means for the comparison with the hot point controller R3 hits the lying on the low frequency units at the end (or near) the balancing

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tmnkt by zero, so that an adjustment of the hot spot regulator brings no change at this point.

Should the third adjustment element be an inductance (core displacement in a coil) instead of the Correction controller R5 can be used, for example a circuit according to Figure 4a can be used. The slider of the foot controller Rl, which is used, for example, to adjust the lower frequencies, is due to Maese. In series with Rl is the tuning regulator R2 switched, with which in turn the hot point controller R3 is in series, which is used for adjustment at higher frequencies zen is used and its slider is connected to the voltage source UR. The connections facing away from the tuning controller R2 the controller Rl and R * are via the further resistor R? together tied together. The diagonal branches of the bridge circuit created as a result are ge through the resistors R8 and R9 forms.

As the diagram shown in FIG. 4b shows, it works the adjustment curve for the hot point controller R3 at lower frequencies at the adjustment point a through zero, at the same time the base point controller Rl causes the greatest frequency change, so that it is compared with Rl at this point. On the other hand, runs the curve for the base point controller Rl at the adjustment point b for higher frequencies through zero, with expediently on the R3 adjustment is carried out at this point. The L-curve ver runs practically parallel to the abscissa, so that by the L-displacement caused frequency changes run steadily. The L setting can be used, for example, for adjustment in Center of the scale can be used.

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Claims (1)

W. Miller-6-10-. ,,,. _ν Claims ί.) Circuit arrangement for the electronic tuning of resonant circuits by means of capacitance diodes operated in the restricted area, the tuning voltage of which is taken from the wiper of a tuning potentiometer and the adjustment by connecting one or more resistors or range adjustment (base point and hot point) controllers in series with the tuning potentiometer takes place, characterized in that the base point regulator (Rl) is used on both sides in such a way that an additional resistor (Rl ») is connected from the free governor to the hot point regulator (R3) (Figure 3a) and the resistor (the resistors) is dimensioned in this way (are) that the adjustment curve 4 f = ^ (f) for the adjustment with the base point controller (Rl) at the high-frequency range end (or at the adjustment point φ> located near this end of the range) runs through zero, and / or that the Hot point controller (R3) is used on both sides in such a way that from the free end of the controller to the foot point controller (Rl) an additional A resistor (R6) is connected (Figure 3d) and the resistor (s) is (are) dimensioned in such a way that the adjustment curve4 f = ^ (f) for the adjustment with the hot spot controller (R3) at the low-frequency range end (resp. at the adjustment point (a) near this end of the range) runs through zero, where f means the circular or receiving frequency and j \ f the frequency change caused by the controller. Arrangement according to Claim 1, characterized in that, in addition to the correspondingly dimensioned resistors (R2, R7, Figure 4a), two diagonally located resistors (R8, R9) are also connected between the free end of the foot and hot point controllers (Rl, R3) and the resistors are dimensioned in such a way that both the adjustment of the base point controller (Rl) at the high-frequency range end (or at the adjustment point (b) near this range end) and the adjustment of the hot-point controller (R3) at the low-frequency range end (or at the end of the range Distance lying near this end of the range 309834/0713 ^J ' W. Miller-6-11- point (a)) has no influence at this point. 3. Arrangement according to one of claims 1 or 2, characterized in that the tuning potentiometer (R2) a correction controller (R5) is connected in parallel. k. Arrangement according to Claim 3, characterized in that the additional correction controller (R5) is formed by an inductance (permeability control). 4th February 1972
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