SU471652A1 - Phase full-wave demodulator - Google Patents

Description

One half-period of the reference voltage of the low-frequency modulating signal is in phase with the voltage of the signal, and the other half-period is in antiphase.

During the formation of a positive half-wave in the resistor 15, the signal voltage and the reference voltage are in the phase voltage. In this case, with a positive signal at the beginning of the winding 1 (the beginning of the windings is indicated by a dot) in the beginning of the windings 9, 10 leads to minus and the transistors 3, 4 are open, and the transistors 5, 6 are closed.

In the equivalent circuit for this condition (see Fig. 2), diodes 16, 17 are p-emitter junctions of closed transistors 5, 6. Diode 17 is closed at this polarity of induced voltages and shuts off the inoperative winding 2 from the rest demodul torus. In the case of polarity, the voltage of the signal and the reference voltage of the transistors 5, 6 are opened, and the transistors 3, 4 are closed, but the structure of the demodulator equivalent circuit does not change, only the signs: the windings 1, 2 are interchanged, the diodes 16 , 17 will be the emitter transitions of the transistors 3, 4 of the private key 7, and one of the diodes will be closed and disconnect the inoperative winding 1 from the rest of the demodulator.

When the phases of the voltage of the signal and the reference voltage change across the resistor 15, a negative half-wave of the low-frequency voltage will begin to form. With a negative rectangular signal at the beginning of the winding 1 and at the beginning of the windings 9, 10 minus is induced; transistors 3, 4 are open, and transistors 5, 6 are closed (see Fig. 3).

At this polarity of the induced voltages, the diode 16 will be closed and disconnect the inoperative winding 2 from the rest of the demodulator. When the polarity of the signal voltage and the reference voltage is changed, transistors 5, 6 open, and transistors 3, 4 close, but the structure of the demodulator equivalent circuit does not change. At the same time, one of the diodes, which are p-emitter junctions of the transistors 3, 4 of the closed

key 7, is closed and disables idle

winding 1 from the rest of the demodulator.

So in demodulator for any

The polarity and the output voltage of one of the diodes (one of the jt - emitter transitions of the private key transistors) is in the closed state and disconnects the inoperative winding 1 or 2 from the rest of the demodulator.

Equivalent demodulator circuits are similar. The constant components arising during the formation of positive and negative half-waves on the load are the same in absolute value and have prot-opposite signs; they are compensated, with the result that the parasitic constant in the output voltage becomes insignificant, which increases the demodulation accuracy.

Subject invention

Phase full-wave demodulator containing input signal and reference voltage transformers and two keys, each of which is made on two transistors, while a common load for the two keys is included between the collectors of the transistors of each key, in order to improve the demodulation accuracy , the emitters of the transistors from each key are interconnected by the corresponding secondary winding of the input signal transformer, and between the bases of the transistors of different keys is included the corresponding secondary insulation Single reference voltage transformer.

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