| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a protective device for a load circuit, which detects the temperature rise of an electric wire and reliably interrupts the load circuit when a chattering short-circuit or a rare short-circuit occurs. <P>SOLUTION: When a current flowing through the electric wire 7 is normal, the rising temperature of the electric wire is calculated by using an algorithm of (A-1) if the saturation temperature of the electric wire 7 by a detecting current is higher than the estimated temperature of the electric wire 7. The falling temperature of the electric wire is calculated by using the algorithm of (B-1) when the saturation temperature of the electric wire 7 by the detecting current is lower than the estimated temperature of the electric wire 7. When the current flowing through the electric wire 7 is an overcurrent, the rising temperature of the electric wire is calculated by using the algorithm of (A-2) if the saturation temperature of the electric wire 7 by the detecting current is higher than the estimated temperature of the electric wire 7. The falling temperature of the electric wire is calculated by using the algorithm of (B-2) if the saturation temperature of the electric wire 7 by the detecting current is lower than the estimated temperature of the electric wire 7. When the temperature of the electric wire reaches a threshold temperature, the load circuit is interrupted. <P>COPYRIGHT: (C)2010,JPO&INPIT |
