A switching input acquisition circuit suitable for a wide range of levels

Abstract

The invention discloses a switching value input acquisition circuit suitable for a wide range of levels, comprising a sequentially connected multi-channel differential filter unit, a multiple-channel selection switch unit, an A / D conversion unit and a control unit, the multi-channel differential filter The unit collects the switching signals of multiple channels and filters them before inputting them to the multi-channel selection switch unit. After the signal is sent to the control unit, the control unit compares the digital signal with the preset high level threshold and low level threshold to determine whether the switch signal corresponding to the digital signal is high level or low level . The switching value input acquisition circuit suitable for wide-range levels of the present invention has the advantages of simple structure, being applicable to different wide-range levels, high integration, and good heat dissipation performance.

Description

technical field [0001] The invention mainly relates to a switch signal acquisition circuit, in particular to a switch input acquisition circuit suitable for a wide range of levels. Background technique [0002] The control devices used on railway locomotives all have the function of digital input acquisition. Currently used digital input acquisition circuits are generally implemented using transformers or optocoupler isolation. The disadvantages of this circuit are as follows: [0003] (1) At present, there are three main control voltage levels on locomotives, namely DC24V, DC74V, and DC110V. However, the existing acquisition circuits on locomotives can only configure input resistors for a certain level system. It cannot be used universally, and different plug-ins need to be configured on locomotives with different voltage standards to realize it, and the universality of the acquisition circuit is poor; [0004] (2) The number of components in the existing digital input a...

AI Technical Summary

Problems solved by technology

[0003] (1) At present, there are three main control voltage levels on locomotives, namely DC24V, DC74V, and DC110V. However, the existing acquisition circuits on locomotives can only configure input resistors for a certain level system. It cannot be used universally, and different plug-ins need to be configured on locomotives with different voltage standards to realize it, and the universality of the acquisition circuit is poor;

[0004] (2) The number of components in the existing digital input acquisition circuit is large, the layout of the components on the board is difficult, and there are few acquisition channels on the board with the same area;

[0005] (3) In the original acquisition circuit, an isolation transformer or optocoupler is generally used to achieve isolation, and the device generates a lot of heat;

[0006] (4) Since the optocoupler has three working states: saturation area, amplification area, and cut-off area, when the acquisition circuit is in the amplification area, the judgment of input high and low levels is poor, which often leads to misjudgment

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