Abnormal current determining method, electronic apparatus, and computer program of same
View Patent ↗A cellular telephone 1 measures a current value after being turned on, and performs addition and subtraction of a predetermined margin to and from the measured value, and thereby sets up determination thresholds for an overcurrent and an undercurrent, namely, a minimum current value and a maximum current value, respectively. Here, the predetermined margin includes minimum allowance required (B) as a standard, a variation (E) in voltage of a power source of the cellular telephone 1 , and a variation (D) in an operating temperature of the cellular telephone 1.
1. An electronic apparatus comprising:
a threshold setting circuit which sets, in a first operation mode for setting a first threshold for determining an overcurrent in the apparatus and a second threshold for determining an undercurrent in the apparatus, a value greater by a predetermined margin than a current detected in the apparatus in the first operation mode, as the first threshold and a value smaller by the predetermined margin than the detected current as the second threshold;
a determination circuit which determines, in a second operation mode different from the first operation mode, an abnormal current state attributable to an overcurrent when a current detected in the apparatus in the second operation mode is greater than the first threshold and an abnormal current state attributable to an undercurrent when the detected current is smaller than the second threshold;
a table including a preset correction coefficient corresponding to a supposed operating temperature of the electronic apparatus; and
a temperature sensor which measures an actual operating temperature of the electronic apparatus,
wherein said threshold setting circuit includes a threshold correcting table which obtains the correction coefficient corresponding to the actual operating temperature by referring to the table based on the actual operating temperature, and correcting the threshold set up based on the detected current value in the first operation mode by use of the obtained correction coefficient, and
said determination circuit determines the abnormal current state using the threshold corrected by said threshold correcting table.
2. The apparatus according to claim 1 , wherein the predetermined margin includes minimum allowance required as a standard, and a variation in voltage of a power source of the electronic apparatus.