| 摘要 |
PROBLEM TO BE SOLVED: To control a load current properly, by accurately detecting the load current at overcurrent. SOLUTION: A semiconductor relay 3 is composed of a circuit breaker means, which breaks a main FET 4 when load is supplied with a current larger than a first set value, and a current detection means which detects the value of the current in the main FET 4 and outputs the voltage equivalent to the current supplied to the load, and power voltage is boosted by a charge pump 25, and the output is applied to the gate of the FET 4 by a drive circuit 9, so as to turn it on and off. Then, a second set value lower than the first set value and higher than the rated current of the load is stipulated. This circuit is made a load current control circuit, which includes a mask circuit 11 which sets it as overcurrent, if the detection value by the current detection means is larger than the first set value, and masks the output of the overcurret detection for a prescribed time, since the power on if it is larger than the second set value.
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