Phase sensitive detection circuit

Abstract

The invention discloses a phase sensitive detection circuit, and relates to the technical field of electronics. Collector electrodes of a first switch triode, a second switch triode and a triode are respectively connected with a first resistor, a second resistor and a third resistor; a fourth resistor and a fifth resistor are serially connected to form a first serial connection branch; a first diode and a second diode are serially connected to form a second serial connection branch; the first serial connection branch and the second serial connection branch are connected in parallel to form a parallel connection loop; one end of the parallel connection loop is connected with the collector electrode of the first switch triode; the other end of the parallel connection loop is connected with the collector electrode of the second switch triode; the connection line of the fourth resistor and the fifth resistor is connected with a base electrode of the triode; the tandem connection line of the first diode and the second diode is connected with an emitter electrode of the triode; a sixth resistor is connected between the emitter electrode and the base electrode of the triode. By adopting the phase sensitive detection circuit, the problems that an envelope detection circuit cannot identify the phase position of a modulation signal from output of a detector and does not have the ability of distinguishing signals of different carrier frequencies are solved.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to a phase-sensitive detection circuit for an automatic quasi-synchronization device for grid-connected hydropower stations. Background technique [0002] The detection circuit is widely used. One of the current detection circuits is the envelope detection circuit. The envelope detection has two problems: one is that the main process of demodulation is to perform half-wave or full-wave rectification on the AM signal, which cannot be obtained from the output of the detector. Identify the phase of the modulating signal. Second, the envelope detection circuit itself does not have the ability to distinguish signals of different carrier frequencies. For signals of different carrier frequencies, it rectifies them in the same way to restore the modulated signal, which means it does not have the ability to identify signals. In order to make the detection circuit have the ability to di...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a phase-sensitive detection circuit, which can solve the problem that the envelope detection circuit cannot distinguish the phase of the modulated signal from the output of the detector and does not have the ability to distinguish signals of different carrier frequencies

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