Lightning-protection high-level switching value or frequency signal sampling circuit

Abstract

The invention provides a lightning-protection high-level switching value or frequency signal sampling circuit. The lightning-protection high-level switching value or frequency signal sampling circuitis characterized in that: two paths of the lightning-protection high-level switching value or frequency signal sampling circuits are connected in parallel, and each path comprises a first-level discharge circuit, a second-level discharge circuit, an FRE line, an isolation circuit and a sampling circuit; each first-level discharge circuit and the corresponding second-level discharge circuit are both connected with the FRE line in parallel, and rear ends of the first-level discharge circuit and the second-level discharge circuit are each connected with a grounding end PGND; and each isolation circuit comprises a photocoupler U1, an input positive electrode of the photocoupler U1 is connected with a current limiting resistor R1, an input negative electrode of the photocoupler U1 is connectedwith the corresponding grounding end PGND, an emitter of the photocoupler U1 is grounded, a base of the photocoupler U1 is connected with the sampling circuit, and the current limiting resistor R1 isconnected to the rear end of the corresponding second-level discharge circuit. The lightning-protection high-level switching value or frequency signal sampling circuit ensures the lightning protectioneffect by adopting the two-path parallel mode, and realizes effective protection against indirect stroke through using two levels of lightning-protection measures (the first level employs a lightning-protection tube and the second level employs a TVS device) cooperated with the photoelectric isolation circuits. The lightning-protection high-level switching value or frequency signal sampling circuit has the advantages of simple structure, reliable performance, low cost and wide adaptability.

Description

technical field [0001] The invention relates to a lightning protection high-level switching value or frequency signal sampling circuit. Background technique [0002] In the data acquisition equipment in the field, it is often necessary to collect high-level switching or frequency quantities, which requires a lightning protection design. The existing lightning protection design either adopts multiple lightning protection measures, which are costly and complicated; or The mine effect is poor, causing damage to the collection equipment. Contents of the invention [0003] In order to solve the above technical problems, the present invention provides a lightning protection high-level switch or frequency signal sampling circuit. [0004] The present invention is achieved through the following technical solutions. [0005] The present invention provides a lightning protection high-level switch or frequency signal sampling circuit; two circuits are connected in parallel, and eac...

AI Technical Summary

Problems solved by technology

[0002] In the data acquisition equipment in the field, it is often necessary to collect high-level switching or frequency quantities, which requires a lightning protection design. The existing lightning protection design either adopts multiple lightning protection measures, which are costly and complicated; or The mine effect is poor, causing damage to the acquisition equipment

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