| 摘要 |
To obtain a protective device that can prevent overvoltage and at the same time has an excellent safety and also to make chip type protective devices smaller in size, this invention provides a protective device comprising an inorganic substrate (2), a heating element (3) formed of an inorganic material, provided on the substrate, an insulating layer (4) that covers the surface of the heating element, and a low-melting metal piece (5) provided on the insulating layer. This protective device may be used in combination with a voltage detecting means making use of a zener diode, in such a way that the heating element of the protective device is electrically excited to generate heat when the voltage detecting means detects a voltage exceeding the rated voltage, whereby an overvoltage protector can be set up. <IMAGE> |
