SU73183A1 - Oscillatory circuit - Google Patents

Description

The subject of the invention is an oscillating circuit for a range oscillator, the equivalent resistance of which when tuning the oscillator to different waves remains constant.

The equivalent circuit resistance is achieved by connecting parallel to the loop capacitor with a specially designed plate shape of a capacitive potentiometer consisting of two constant capacitors and two variable capacitors. The movable plates of the latter are mechanically connected with the MOBILE plate of the contour capacitor.

FIG. Figure 1 shows a diagram of the proposed oscillatory circuit, whose inductance Lk is constant and the required range is covered by a variable capacitor C. Parallel to the capacitor Cft, a capacitive potentiometer with a variable, smoothly varying voltage distribution consisting of two variable capacitors C and Cr of the logarithmic one is connected of the type connected in series and fitted onto one axis so that when the capacitance of one capacitor is increased, the capacity of the other capacitance decreases. Parallel to each of these capacitors is connected a capacitor of constant capacitance C3, whose capacitance is equal to the capacitance of the logarithmic capacitor with the average position of its rotor.

The capacitance between terminals / and 2 does not depend on the angle of rotation of the capacitors Ci and Cr and is equal to C3.

The dependence of the ratio of the voltage f /, between terminals I and 5 to the voltage Uz between terminals I and 2, and the angle of rotation into the rotor of the capacitor C is shown in Fig. 2, where kin

When the stress ratio is equal to R. “„ ,,; at - attitude

and.

No. 73183-2 is equal to-- - and at 0, kc the ratio is equal to P max. Figure 3 shows the shape of the rotor plates of the capacitor CA, calculated so that when the rotor R of this capacitor is rotated by an angle by a change in the characteristic impedance of the circuit b, it is compensated by changing P in the opposite direction.

Subject invention

The oscillatory circuit for a range generator, characterized in that, in order to obtain a constant equivalent resistance when the generator is tuned to different waves parallel to the loop capacitor, the shape of which is calculated according to a certain law, includes a capacitive potentiometer of four capacitors, forming two parallel circuits: one containing two permanent capacitors, and the other two variable capacitors, the movable plates of which are mechanically connected to the movable plate ensatora.