Patent ID: 9083179
Filing Date: 2015-07-14
Classification: G01R,H02H,Y02E

Abstract:
1. A load circuit disconnection detector which breaks a load circuit when temperature of a wire of the load circuit increases and detects occurrence of disconnection in the load circuit, the load circuit supplying electric power outputted from a power supply to a load and driving the same, the disconnection detector 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 temperature estimator for calculating a temperature increase of the wire in accordance with a sampling of the current detected by the current sensor that is performed at a predetermined sampling period and estimating temperature of the wire in a predetermined period of time after the electronic switch is turned on, in which the temperature of the wire is calculated to be a reference ambient temperature when the electronic switch was turned on; and a switch controller for controlling on and off of the electronic switch based on a drive instruction and forcibly turning off the electronic switch when the temperature of the wire estimated by the temperature estimator reaches a previously set threshold temperature, wherein the switch controller determines that a connection failure is caused in the load circuit if the temperature increase of the wire calculated by the temperature estimator at a most recent sampling period, in relation to the temperature of the wire calculated at a sampling period just prior to the most recent sampling period, is equal to zero, the most recent sampling period occurring a predetermined period of time after the electronic switch is turned on.