A microelectronic phase-sensitive receiver

Abstract

The invention provides a microelectronic phase-sensitive receiver, which has a simple structure, can accurately and reliably trigger a relay to work, and realize functions such as an abnormal alarm. In this microelectronic phase-sensitive receiver, the two sets of measurement circuits with MCU1 and MCU2 as the core have the same structure. The local voltage and track voltage are connected to the A / D input pin of the MCU through a micro-transformer, and the MCU collects two voltage waveforms in one cycle. , Calculate the initial phase angle and effective value of the two signals through the Fourier transform algorithm, find the phase difference, and make a logical judgment. When the conditions are met, output a square wave signal, which is amplified, isolated and transmitted, rectified and filtered, and output to be selected . MCU3 collects and calculates all four voltages, compares the results with the processing results of MCU1 and MCU2 to judge whether it is normal, selects one of them according to the set strategy, and outputs DC voltage through the output voltage terminal to make the 1700 relay work, if necessary Send an alarm signal.

Description

Technical field [0001] The invention relates to a signal detection and logic processing circuit (device) suitable for railway systems, which outputs a DC voltage to make a relay work, and realizes functions such as abnormal alarms. Background technique [0002] With the development of electrified railways and the advancement of science and technology, the receiving equipment of the 25HZ phase-sensitive track circuit of electrified railways has experienced the development process from mechanical dual equipment to electronic dual equipment. [0003] 1. Mechanical binary equipment [0004] For example, the JRJC170 / 240 type two-element two-position track relay is specially used in electrified railway stations. The 25HZ phase sensitive track circuit is manufactured by the Shenyang Signal Factory and Xi'an Signal Factory of the Ministry of Railways. This kind of equipment is large and heavy, which has caused the jam phenomenon of the equipment. The Ministry of Railways has put forward the...

AI Technical Summary

Problems solved by technology

[0007] 1. JXW-25A is a single-set use type, that is, one track circuit is equipped with one receiver. The advantage is that the construction investment is small, and it is easy for the construction unit to accept. The disadvantage is that once the components are defective, it is easy to cause traffic accidents.

However, we concluded that this solution still has insurmountable shortcomings: (1) It needs to use a larger transformer in its circuit structure, the primary side is directly connected to the rail voltage, and there is no series resistance at the input end, so the input impedance is low (400 ohms)

(2) There are many types of DC power supplies, including 24V, 9V, and 5V, and linear integrated voltage regulator circuits such as 7805 and 7809 are used, which consume a lot of power

(3) There are many types and large quantities of discrete components and small-scale integrated circuits, including discrete diodes, triodes, photocouplers, small-scale CMOS circuits, and small-scale TTL circuits, resulting in low board utilization and increased failure rates.

(4) The MCU used is a basic type with weak functions

(5) In the phase difference measurement method, the sine wave of the track voltage and the local voltage is first converted into a square wave, and then the phase is judged. This strategy uses many components and the effect is not good, and the anti-interference performance is poor. When the large 50HZ voltage interferes, the waveform will be distorted, which will cause a large measurement error

(6) Although two sets of the same circuit are used, there is no arbitration mechanism, and the final result generation mechanism is not perfect

(7) Due to the sine wave-rectangular wave transformation, the specific value of the input voltage cannot be measured, and there are defects in judging whether the voltage is normal. Therefore, only the phase difference can be carried out for the three elements of phase difference, local voltage and rail voltage. judge

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