SU364087A1 - - Google Patents

Description

BALANCE DIODE-REGENERATIVE COMPARATOR

one

The invention relates to radio engineering and can be used in automatic control and alarm devices.

The known diode-regenerative comparators containing a comparison circuit on two-input diodes and a blocking oscillator at the transistor do not have an exact response threshold.

The purpose of the invention is to improve the accuracy of the device response threshold.

To achieve the goal, the anode of the diode connected to the second input circuit of the comparison circuit and the first input of the comparison circuit are connected via an additional diode connected in the forward direction.

FIG. 1 is a schematic diagram of a comparator; in fig. 2:

a) the nature of the voltage change at the inputs of the comparator during the transition from the quiescent state to the generation mode, where AV is the part where the pulse frequency of the commenter is changed;

b) the shape of the collector voltage when operating without a compensating diode;

c) the nature of the change in the input parameters during the detection of pulses at the input of positive and negative feedback.

d) the shape of the collector voltage of the comparator when working with a compensating diode.

In the drawing, the following notation is given:

2

(i) diode in the negative feedback circuit; 2 - diode in the positive feedback circuit; 3 - diode to compensate for negative feedback for voltage; 4-7 - capacitors; 8 - negative feedback winding; 9 - positive feedback winding; 10 transistor; //-resistor; 12 - terminal; 13 terminal; 14 - transformer; 15 - terminal.

In the initial state, the voltage value t / Exi ua terminal 12 is lower than the voltage 1) -2 at terminal 13.

Due to the difference between the voltage Lnxi-vx2 on the circuit: terminal 13, diode 2, windings 9 and 5, transformer 14, diode 1, terminal 12 - current flows. As a result of the ban on the positive feedback winding 9, the diode 2 is locked and the circuit is at rest. When increasing the voltage t / Bxi to the terminal

12 to the level of 6 in 2 at terminal 13 (Fig. 2, a) at point A there is a redistribution of potentials at terminals 12 and 13 of the comparator, and the circuit: terminal 12, diode /, winding 5 and 9, diode 2, terminal 13 - current flows . As a result, the diode / is locked, and the diode 2 is unlocked, i.e., the winding 9 of the positive feedback is unlocked. The comparator starts to generate and gives the first impulse (flg. 2.6). This impulse, the passage of the kokturu earth - emitter - the base transition of the transistor

10, capacitor 6, winding 9 of the positive feedback of the transformer 14, diode 2, capacitor 5, ground - charges the capacitor 5 to some voltage, which is added to the voltage f / Bx2, creating a condition for locking the diode 2. Therefore, in the area AB (Fig. 2, a) with a constant change in LBXI, a change in the pulse frequency occurs (Fig. 2.6). At point B, the comparator begins to generate, at the maximum frequency determined by the offset at terminal 15, the values of resistor 11 and capacitor 6. Diode 3 eliminates the effect of negative feedback.

When comparing the voltages (7in1 and t / gxa at terminals 12 and 13 at point L (Fig. 2, b), the comparator begins to generate pulses that pass along the circuits: ground, capacitor 7, transistor 10, capacitor 6, winding 9 positive transformer feedback 14, diode 2, capacitor 5, earth and earth, capacitor 7, transistor 10, capacitor 6, winding 9 of the positive feedback of the transformer 14, diode 5, capacitor 4, earth. At the same time, capacitors 4 and 5 are charged Equally, the level of operation of the comparator is stabilized, as compared. s voltage / 7vh1 and / In2 are driven to the same level.

Subject invention

A balanced diode-regenerative comparator containing a comparison circuit on two-input diodes and a blocking transistor generator, characterized in that, in order to increase the accuracy of the threshold of operation of the anode device of the diode connected to the second input circuit of the comparison circuit, and the first input of the comparison circuit is connected through an additional diode connected in the forward direction.

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