Patent ID: 9293907
Filing Date: 2016-03-22
CPC Classification: H02H

Claim Text:
1. A load circuit protective device for turning a load circuit off when temperature of a wire of the load circuit increases, the load circuit supplying electric power outputted from a power supply to a load and driving the same, the protective device comprising: a current sensor for detecting current flowing through the wire of the load circuit; an electronic switch for switching between on and off of the load circuit; a sampling period setter for setting a sampling period; a temperature estimator for estimating temperature of the wire, from the difference which is calculated between the consumed energy in the wire and the released energy from the wire, based on the current detected by the current sensor, with the sampling period set by the sampling period setter based on the current detected by the current sensor; and a switch controller for turning off the electronic switch when the temperature of the wire estimated by the temperature estimator reaches a previously set threshold temperature, wherein the sampling period setter sets the sampling period to a first predetermined sampling period as provided by a first clock when the electronic switch is on and sets the sampling period to a second predetermined sampling period longer than the first predetermined sampling period as provided by a second clock different from the first clock when the electronic switch is off.