OVERCURRENT PROTECTION DEVICE

摘要

An overcurrent protection device satisfactorily detects overcurrent without adding complicated component or occupying large space. Penetration member penetrates board face A having a first wiring circuit and face B with a second one, transmitting heat from face A to B. Connection/disconnection part is inserted into first wiring circuit, switching current to heat generation part for generating heat with current, formed in portion of first circuit, continued with one end of penetration member. Temperature detection member disposed near or abutted against other end of penetration member on face B detects transmitted heat, outputting signal. Control part controls connection/disconnection part on signal. Heat generation part is narrower than width w1 not generating heat in steady state, having width w2 to raise temperature upon overcurrent, and being sandwiched between patterns with width w1. Control part turns off current with heat generation part temperature raised to or above prescribed threshold.

主权项

1. An overcurrent protection device, comprising:
an insulating member, allowing formation of a first wiring circuit passing a current on a first face thereof, and formation of a second wiring circuit on a second face thereof, said second face being a face opposite to said first face; a penetration member, penetrating through said insulating member, thereby being capable of transmitting heat from said first face to said second face; a heat generation wiring part, being formed in continuation with one end part of said penetration member in a portion of said first wiring circuit and generating heat with said current being passed; a connection/disconnection part, being inserted into said first wiring circuit to turn on or off said current; a temperature detection member, being disposed in proximity of or in abutment against the other end part of said penetration member on said second face to detect heat transmitted from said heat generation wiring part by the penetration member and output a temperature detection signal for said heat generation wiring part; and a control part, controlling said connection/disconnection part on the basis of said detection signal, said heat generation wiring part being narrower than a first line width, said first line width not allowing the temperature to be raised to a prescribed threshold value or thereabove with said current flowing in a steady state, and having a second line width, said second line width allowing the temperature to be raised to or above said prescribed threshold value upon the current becoming an overcurrent, being sandwiched between wiring patterns having said first line width, and upon the temperature of said heat generation wiring part detected by said temperature detection member having been raised to or above said prescribed threshold value, said control part determining said current to have become an overcurrent, thereby controlling said connection/disconnection part to turn off said current.