公开(公告)号：EP2296243A1

公开(公告)日：2011-03-16

申请号：EP09762514.9

申请日：2009-06-10

申请人： Yazaki Corporation

发明人： MARUYAMA, Akinori ,  NAKAMURA; Yoshihide ,  UETA, Keisuke

IPC分类号： H02H3/093 ,  H02H6/00

CPC分类号： H02H6/005 ,  H02H3/087 ,  H02H7/228

摘要： There is provided a protection apparatus for a load circuit, capable of protecting the load circuit by simulating a fuse. A pseudo heat capacity Cth* smaller than a heat capacity of an electric wire used in the load circuit is set, and a temperature of the electric wire is calculated with reference to an arithmetic expression of heat generation amount of the electric wire, an arithmetic expression of heat radiation amount of the electric wire, a time counted by the count unit, and the pseudo heat capacity Cth*. Then, a semiconductor relay S1 is interrupted when the calculated temperature of the electric wire reaches an allowable temperature of the electric wire to protect the load circuit from heat generation.