An Intrinsically Safe Power Back-End Cut-off Protection Circuit with Adjustable Analog Protection Time

Abstract

The invention discloses an analog type intrinsic safety power supply rear-end cut-off protection circuit with adjustable protection time. The circuit comprises a loss-of-voltage and overcurrent detection circuit, a cut-off discharge time adjustment circuit, a quick drive and self-reset circuit and a cut-off protection switch tube; the loss-of-voltage and overcurrent detection circuit is connectedwith the output end of an intrinsic safety power supply, and judges that the output end has a short-circuit fault; the cut-off discharge time adjustment circuit is connected with the loss-of-voltage and overcurrent detection circuit, the quick drive and self-reset circuit is connected with the cut-off discharge time adjustment circuit, and the quick drive and self-reset circuit is connected with apower supply input via the cut-off protection switch tube. The circuit provided by the invention adopts a comparator for monitoring the output current voltage; after the fault is recognize, the circuit is disconnected within set time, so that the performance of the intrinsic safety power supply is ensured. And the output loop is not limited by series resistors, so that the whole efficiency is significantly enhanced. Furthermore, the circuit provided by the invention has the function of being capable of adjusting the protection time.

Description

technical field [0001] The invention relates to a back-end cut-off protection circuit for an intrinsically safe power supply, in particular to an analog-type back-end cut-off protection circuit for an intrinsically safe power supply with adjustable protection time. [0002] technical background [0003] With the improvement of mechanization, automation and informatization in flammable and explosive hazardous places such as coal mines, petroleum, chemicals, textiles, and gold plating, electrical equipment has been rapidly promoted and applied, and the production and processing of various flammable and explosive materials are involved. As well as the transportation and storage process, it is accompanied by the birth of flammable and explosive hazardous areas. According to the national mandatory standard GB3836.1-2010, electrical equipment used in hazardous areas must have the corresponding equipment protection level. Compared with other explosion-proof types, the intrinsically ...

AI Technical Summary

Problems solved by technology

The protection speed of the analog protection circuit is fast, but the protection action time is generally not adjustable, and it is not suitable for different use occasions or experimental research. At present, there is an urgent need for an analog type with adjustable protection time for the cut-off protection of the back-end protection of the intrinsically safe power supply. emergence of circuits

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