The step-down transformer, which is characterized in that the primary input is 220V, the secondary output is low voltage, secondary current, secondary current, the work will be fever, transformer with different power and different diameters of the heating degree is different.
Transformer manufacturers are now based on the customer‘s different purposes and different products, choose copper or aluminum wire, easy to appear in the following questions: when the equipment works, fever, temperature is 70-80 DEG C, but the transformer is able to work, only the enameled wire paint is easy to aging, chapped, leakage, or encounter tide there the line between the ignition and so on, which greatly shorten the life of the transformer.
In the selection, selection of copper or aluminum manufacturers for the cost savings or use a fine winding, the transformer winding temperature rise faster; when the load circuit is secondary short circuit or large current transformer will soon appear, over temperature or by transformer burned. These problems in the application of glass used in the primary fuse do over-current protection, is also useful for temperature fuse and application of double metal thermostat for over temperature protection installed outside the package in the transformer line, prone to frequent application of one-time fuse replacement and inconvenience, bimetal thermostat is easy to appear in the continuous case turn on again. Load and expand the scope of fault fault.
In order to solve the problem of over temperature, over current protection, without replacing the fuse, and without protection, the problem of the fault circuit can be switched on again.
Self recovery fuse aka resettable fuse or fuse can be thousands of times, different circuit, different current voltage and temperature requirements, choose a need, can be connected to the primary or secondary transformer, when the normal work is low resistance, when the transformer temperature exceeds the current provisions, or exceed after transient high resistance, timely limit circuit of current transformer protection and achieve the purpose of.
When excluding off or fault automatic recovery for low resistance, transformer back to normal state, self recovery fuse in power conditions is not automatically restored, can not be generated in the system without fault load and switched on again, enlarge the scope of the fault problem, but also solve the timely protection of overtemperature, overcurrent and do not replace the fuse problem.

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