Circuit protection device

Abstract

The invention provides a circuit protection device which comprises a gas discharge tube and a third electrode, wherein the gas discharge tube is at least provided with two electrodes, namely a first electrode and a second electrode; and the third electrode is movably connected with the second electrode through a bimetallic strip. When the working temperature exceeds a normal temperature, the bimetallic strip deforms to make the third electrode perform conductive disconnection with the second electrode. The circuit protection device can have a function of discharging a lightening current or overvoltage when subject to lightning stroke and surge overvoltage, and provide overvoltage protection for a follow-up circuit; besides, when the circuit protection device undergoes a certain continuous power frequency current or excessive power frequency current and undergoes temperature rise to an overturning point of the bimetallic strip due to heating, the circuit protection device is open-circuited due to the overturning of the bimetallic strip and provides overcurrent protection for the follow-up circuit.

Description

technical field [0001] The invention relates to the field of overvoltage protection products, in particular to a circuit protection device. Background technique [0002] The gas discharge tube is a switch type protection device, usually used as an overvoltage protection device. The gas discharge tube commonly used at present is made of an insulating tube body and electrodes sealed at both ends, and the inner cavity is filled with inert gas. When the voltage across the electrodes of the gas discharge tube exceeds the breakdown voltage of the gas, a gap discharge will be caused, and the gas discharge tube will quickly change from a high-resistance state to a low-resistance state, forming a conduction, thereby protecting other devices connected in parallel with it. . But at the same time, if the overvoltage lasts for a long time or occurs frequently, or if there is a long-term or high-current power-frequency overcurrent, the gas discharge tube will heat up due to the long-ter...

AI Technical Summary

Problems solved by technology

But at the same time, if the overvoltage lasts for a long time or occurs frequently, or if there is a long-term or high-current power-frequency overcurrent, the gas discharge tube will heat up due to the long-term or frequent overcurrent, which is too high. The temperature will not only affect the safe use of other devices in the circuit, but also make the gas discharge tube have a risk of short circuit or burst, and even burn the customer's circuit board to cause a fire

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