Excessively-low-current protection lightning-stroke-resisting surge wire-wound resistor

Abstract

The invention discloses an excessively-low-current protection lightning-stroke-resisting surge wire-wound resistor. The excessively-low-current protection lightning-stroke-resisting surge wire-wound resistor comprises a mandril, wherein a resistance wire is wound on the mandril, two ends of the resistance wire are respectively connected with a section of conducting wire, the mandril and the resistance wire on the mandril are wrapped by a flame-retardant layer, the flame-retardant layer comprises an inner fusing assistant layer, an intermediate obstruction temperature-suppression layer and an outer insulation paint layer. According to the technical scheme, the fusing point of the resistance wire can be reduced through the fusing assistant layer, and the heat is concentrated onto the resistance wire through the obstruction temperature-suppression layer, so that when an excessively low current (1.2 to 2 times of rated current of the resistor) occurs in the excessively-low-current protection lightning-stroke-resisting surge wire-wound resistor, the fusing of the resistance wire can be accelerated, and the potential safety hazard caused by the burning of a plastic element can be prevented. The excessively-low-current protection lightning-stroke-resisting surge wire-wound resistor also has an excessively-low-current protection function and a lightning stroke surge resisting function.

Description

technical field [0001] The invention relates to a fuse resistor, in particular to an over-low current protection anti-lightning surge wirewound resistor. Background technique [0002] At present, an existing anti-lightning surge wire-wound resistor includes a mandrel, and a resistance wire is wound on the mandrel, and a section of wire is respectively connected to both ends of the resistance wire, and the outer wrapping of the mandrel and the resistance wire on the mandrel There is a flame retardant layer. This kind of anti-lightning surge wirewound resistor cannot meet the requirements of over-low current protection. The requirement of wirewound resistors used in electronic product chargers before is to be able to meet the anti-lightning surge impact and at the same time in the state of high current ( The main reason is that the rectifier diode and filter capacitor in the power supply part are short-circuited, and the current passing through the wire-wound resistor is more...

AI Technical Summary

Problems solved by technology

This kind of anti-lightning surge wirewound resistor cannot meet the requirements of over-low current protection. The requirement of wirewound resistors used in electronic product chargers before is to be able to meet the anti-lightning surge impact and at the same time in the state of high current ( The main reason is that the rectifier diode and filter capacitor in the power supply part are short-circuited, and the current passing through the wire-wound resistor is more than 50 times its rated value), and the wire-wound resistor will be disconnected within the specified time, but when there is too small current in the line ( When the wire wound resistor is 1.2 to 2 times the rated current), the temperature does not reach the melting point of the resistance wire, so the wire wound resistor cannot be fused in time, and the resistance will continue to heat up. Burning plastic parts (charger housing) poses a serious safety hazard

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