Self-resetting fuse is a new type of polymer positive temperature coefficient overcurrent protection element, Fuse can be short circuit circuit and overload protection, and the traditional fuse is different from the fuse in the troubleshooting and power cut off, Fuse can automatically resume, no need to replace The Compared with the traditional fuse, this paper has many advantages compared with the traditional fuse. In this paper, Fuse the advantages and disadvantages of the self-resetting fuse and the method of self-resetting fuse are introduced in the field of industrial automation instrument control and civil application.
In the past, electronic equipment, Fuse instrumentation using traditional fuse for over-current protection, but only to protect once, must be replaced on the blow, but also the fuse is not the normal blown, Fuse such as the boot moment, plug the device, poor contact, Fuse use is too long, etc., Fuse will lead to fuse blown. Fuse replacement should be replaced with the specifications of the same specifications, but in the industrial scene often what fuse on what fuse on the situation, resulting in the wrong replacement, Fuse and sometimes because the fuse specifications are too large, the fault generated over current to the electronic equipment Components burned, causing trouble to expand the accident occurred.
The self-resetting fuse is mainly composed of a specially treated polymeric resin (POLYMER) and a conductor. In the normal state POLYMER tightly binds the conductor in a crystalline structure, forming a low-impedance chain because the impedance is only tens of milliseconds Ohm, despite the current through the self-resetting fuse, but its heat is very small, and will not change POLYMER crystal structure,Fuse when the abnormal current occurs, the heat generated on the conductor will POLYMER particles from crystal into glue In this case, Fuse the conductors bound to POLYMER are separated, resulting in a rapid increase in resistance, limiting the flow of abnormal current through the self-resetting fuse. When the abnormal current is removed, the conductor chain key is reestablished and restored to low resistance. The protection action is essentially an energy balance process. Fuse When the current flows through the self-resetting fuse, the resistance of the self-resetting fuse increases as the current or ambient temperature rises due to the I2R's relationship, but because the current or ambient temperature rises When the current or ambient temperature continues to rise the heat generated when difficult to emit out, resulting in self-resetting the fuse temperature increases, at this time, Fuse a very small temperature, Fuse the temperature is not enough, the heat generated can be distributed to the environment, Changes will result in a significant increase in resistance, resistance increases will limit the current, thus protecting the electrical equipment. Fuse In the protected state of the self-recovery fuse, Fuse as long as the application of voltage, the energy generated enough to add the loss of heat, will always be in action, when the applied voltage decreases or disappears, it can automatically resume.
The maximum working current of the self-resetting fuse is 0.05-15A. It is widely used in electronic circuit, industrial control system, instrumentation, Fuse microcomputer and microcomputer. It is widely used in electronic circuit, industrial control system, instrumentation, Fuse microcomputer and Peripheral equipment and many other areas.