Abstract: Provided are an overcurrent protection device and an overcurrent protection system which can provide time differences among the timings for executing the retry operations among a plurality of overcurrent protection devices connected to a common power supply. When a battery voltage (VBA) becomes a value equal to or lower than a threshold voltage after an FET (Q1) of an IC circuit (51-1) is turned on, all FETs (Q1) of the respective IC circuits are turned off, and a time until the battery voltage (VBA) reduces to a value lower than a threshold voltage after the turning-on of the FET (Q1) is clocked. When the time is smaller than 400 ?sec, the count value N is incremented. Further, turning-on of the FETs (Q1) is repeated after the lapse of the standby time (Tp) set randomly. When the count value N reaches 7, the FET (Q1) of the IC circuit 51-1 is held in the turned-off state.

Abstract: Provided are an overcurrent protection device and an overcurrent protection system which can provide time differences among the timings for executing the retry operations among a plurality of overcurrent protection devices connected to a common power supply. When a battery voltage (VBA) becomes a value equal to or lower than a threshold voltage after an FET (Q1) of an IC circuit (51-1) is turned on, all FETs (Q1) of the respective IC circuits are turned off, and a time until the battery voltage (VBA) reduces to a value lower than a threshold voltage after the turning-on of the FET (Q1) is clocked. When the time is smaller than 400 ?sec, the count value N is incremented. Further, turning-on of the FETs (Q1) is repeated after the lapse of the standby time (Tp) set randomly. When the count value N reaches 7, the FET (Q1) of the IC circuit 51-1 is held in the turned-off state.

Abstract: The present invention is to provide a power supply control apparatus which can connect a ground to a suitable electric potential when the ground is disconnected. The power supply control apparatus includes a control circuit having a switch element and a switch control unit, and a load. One terminal of load is connected to a direct-current power supply through the switch element, and the other terminal is connected to a ground electric potential. The switch control unit has a ground terminal connected to the ground electric potential and outputting a ground current flowing toward the ground electric potential. The control circuit includes a bypass device having a load side bypass system for passing the ground current to the ground electric potential through the load when connection between the ground terminal and the ground electric potential is disconnected.

Abstract: The present invention is to provide a power supply control apparatus which can connect a ground to a suitable electric potential when the ground is disconnected. The power supply control apparatus includes a control circuit having a switch element and a switch control unit, and a load. One terminal of load is connected to a direct-current power supply through the switch element, and the other terminal is connected to a ground electric potential. The switch control unit has a ground terminal connected to the ground electric potential and outputting a ground current flowing toward the ground electric potential. The control circuit includes a bypass device having a load side bypass system for passing the ground current to the ground electric potential through the load when connection between the ground terminal and the ground electric potential is disconnected.