A thermal switch is used wherever protection against excess temperature is required.
Temperature detection in a break to open - or normally closed - thermal switch is effected by means of a bimetal disk dimensioned in accordance with the required cut-off temperature. When this fixed cut-off temperature is reached, the bimetal disk will snap over, breaking a contact system and thereby interrupting the electric circuit of the device being protected. After cooling down and reaching the cut-in temperature, the bimetal disk will automatically return into its original position and thus remake the contact. The electric circuit is now closed again.
In some cases we can also offer the opposite function: break to close also named normally closed.
Specific applications include:
- Protection of primary windings in transformers
- Winding protection in small electric motors
- General temperature protection of small electric devices, in PCB etc.
There are 2 main varieties of thermal switches:
