CIRCUIT PROTECTION DEVICE
There is provided a circuit protection device that increases the possibility of enabling a circuit to be protected. The circuit protection device ( 1 ) comprises a bimetal switch ( 4 ) and a PTC element ( 2 ), which are electrically connected in parallel with each other. The PTC element has a post-operation resistance value of 1.1 times or less the intrinsic resistance value of the circuit that is calculated based on the rated voltage and current of an electric circuit into which the circuit protection device is built and using the equaticon (1): rated voltage/rated current=intrinsic resistance value (1)
1 . A circuit protection device comprising a bimetal switch and a PTC component, characterized in that:
the bimetal switch and the PTC device are electrically connected in parallel; and
the PTC component has a resistance after its activation that is equal to or less than 1.1 times as large as a specific resistance of an electrical circuit into which the circuit protection device is to be incorporated, which specific resistance is calculated based on a rated voltage and a rated current of the circuit according to the following equation (1):
Rated Voltage/Rated Current=Specific Resistance (1).
2 . The circuit protection device according to claim 1 , characterized in that the PTC component has a resistance after its activation that is at most 0.9 times as large as the specific resistance.
3 . The circuit protection device according to claim 2 , characterized in that the resistance of the PTC component after its activation that is at most 0.4 times as large as the specific resistance.
4 . The circuit protection device according to claim 1 , characterized in that the PTC component has a basic resistance that is at most two-thirds of the specific resistance.
5 . The circuit protection device according to claim 1 , characterized in that the PTC component has a basic resistance that is at least ten times as large as the resistance of the bimetal switch.
6 . The circuit protection device according to claim 5 , characterized in that the resistance of the PTC component is at least 100 times as large as the resistance of the bimetal switch.
7 . The circuit protection device according to claim 1 , wherein the PTC component is a polymer PTC component.
8 . An electrical circuit comprising a circuit protection device that comprises a bimetal switch and a PTC component, characterized in that:
the bimetal switch and the PTC device are electrically connected in parallel; and
the PTC component has a resistance after its activation that is equal to or less than 1.1 times as large as a specific resistance of an electrical circuit into which the circuit protection device is to be incorporated, which specific resistance is calculated based on a rated voltage and a rated current of the circuit according to the following equation (1):
Rated Voltage/Rated Current=Specific Resistance (1).
9 . The electrical circuit according to claim 8 , characterized in that the PTC component has a resistance after its activation that is at most 0.9 times as large as the specific resistance.
10 . The electrical circuit according to claim 9 , characterized in that the resistance of the PTC component after its activation that is at most 0.4 times as large as the specific resistance.
11 . The electrical circuit according to claim 8 , characterized in that the PTC component has a basic resistance that is at most two-thirds of the specific resistance.
12 . The electrical circuit according to claim 8 , characterized in that the PTC component has a basic resistance that is at least ten times as large as the resistance of the bimetal switch.
13 . The electrical circuit according to claim 12 , characterized in that the resistance of the PTC component is at least 100 times as large as the resistance of the bimetal switch.
14 . The electrical circuit according to claim 8 , wherein the PTC component is a polymer PTC component.
15 . The circuit protection device according to claim 2 , characterized in that the PTC component has a basic resistance that is at most two-thirds of the specific resistance.
16 . The circuit protection device according to claim 3 , characterized in that the PTC component has a basic resistance that is at most two-thirds of the specific resistance.
17 . The circuit protection device according to claim 2 , characterized in that the PTC component has a basic resistance that is at least ten times as large as the resistance of the bimetal switch.
18 . The circuit protection device according to claim 4 , characterized in that the PTC component has a basic resistance that is at least ten times as large as the resistance of the bimetal switch.
19 . The circuit protection device according to claim 2 , wherein the PTC component is a polymer PTC component.
20 . The circuit protection device according to claim 5 , wherein the PTC component is a polymer PTC component.