Abstract: Provided is a power supply control device. The power supply control device includes a plurality of semiconductor switches that are connected in parallel between two power sources and control the supply of power to a load that is connected to the two power sources via the plurality of semiconductor switches, the power supply control device including a temperature detection unit that detects a rise of temperature due to heat that is produced from at least one of the plurality of semiconductor switches, and a switching control unit that executes control that switches the plurality of semiconductor switches from OFF to ON if the temperature detection unit detects a temperature that is at least a threshold temperature.

Abstract: A power supply control apparatus controls power supply via a semiconductor switch, by a driving circuit turning ON or OFF the semiconductor switch. A current circuit pulls in a current from the drain of the semiconductor switch via a resistance. The current value Ic of the current that is pulled in by the current circuit fluctuates in the same direction as a fluctuation direction of the ON resistance value of the semiconductor switch, depending on the ambient temperature of the semiconductor switch. If the source voltage of the semiconductor switch is lower than a voltage at the other end of the resistance, the driving circuit turns OFF the semiconductor switch.

Abstract: With a power supply control device, if semiconductor switches of a switch circuit are on and a relay contact is off, a controller determines whether or not a switch electric current detected by an electric current sensor is at least a threshold. If the controller has determined that the switch electric current is at least the threshold, then an electric current supply unit switches on the relay contact, and a drive circuit switches off the semiconductor switches. The controller changes the above-described threshold in accordance with the length of the lapse of time from when an electric current flows through the switch circuit.

Abstract: In a switch circuit for use in a vehicle, conduction between a drain electrode and a gate electrode of each of a first main transistor and a second main transistor is switched on or off depending on a voltage between the gate electrode and a source electrode. A first surge protection device is connected between the drain electrodes of the first main transistor and the second main transistor. The first surge protection device keeps a voltage that is applied to the first surge protection device at a first predetermined voltage or lower. A sub transistor is provided between the gate electrodes and the source electrodes of the first main transistor and the second main transistor. The sub transistor is turned on when the first main transistor and the second main transistor are turned off.

Abstract: A power supply control device controls the supply of power via a switch circuit and a relay contact. If the semiconductor switches are on and the relay contact is off, when a switch temperature of the switch circuit is at least a relay ON-threshold, the relay contact is switched on, and the semiconductor switches are switched off. If the semiconductor switches are off and the relay contact is on, when a switch temperature of the switch circuit is lower than a relay OFF-threshold, the semiconductor switches are switched on, and the relay contact is switched off. The relay OFF-threshold is not more than the relay ON-threshold.

Abstract: With a power supply control device, if semiconductor switches of a switch circuit are on and a relay contact is off, a controller determines whether or not a switch electric current detected by an electric current sensor is at least a threshold. If the controller has determined that the switch electric current is at least the threshold, then an electric current supply unit switches on the relay contact, and a drive circuit switches off the semiconductor switches. The controller changes the above-described threshold in accordance with the length of the lapse of time from when an electric current flows through the switch circuit.

Abstract: The present invention provides a semiconductor device in which a field effect transistor is prevented from burning caused by an electric current flowing through a parasitic diode. This semiconductor device has a configuration including: a field effect transistor including a parasitic diode; a temperature detector that detects a temperature of the parasitic diode; and a controller that determines whether the temperature detected by the temperature detector is higher than or equal to a first temperature, and turns on the field effect transistor if the detected temperature is higher than or equal to the first temperature.

Abstract: A configuration can supply a charging current from a power generator to two power storage devices, and can suppress, if an abnormality occurs on one power storage device side, the abnormality from affecting the other power storage device side. A relay device includes: a first switch configured to interrupt a first conductive path ; a second switch configured to interrupt a second conductive path ; a bypass circuit with a series circuit in which a resistor and a third switch are connected in series to each other, the series circuit having one end electrically connected to a portion between the first switch and the first power storage device, and another end electrically connected to a portion between the second switch and the second power storage device; and a controller configured to turn the first switch, the second switch, and the third switch on/off.

Abstract: Provided is a power supply device configured to diagnose circuit operation, and identify, if a defect is found in the diagnosis, the circuit component that is the cause. The power supply device includes: a switch that is disposed in a power supply path leading from a main power source to a load, and is configured to bring into conduction and interrupt the power supply path; a downstream sensing means for sensing a power supply state of a load-side power supply path between the switch and the load; a comparing means for comparing a downstream voltage of the load-side power supply path, with a predetermined threshold voltage; and a control unit. The control unit includes: a switch control means for turning the switch on/off; and a conduction determination means for determining whether the switch is in an ON or OFF state based on the output of the downstream sensing means.

Abstract: A switch circuit includes an FET. A first driving unit switches the FET on or off by adjusting, in the FET, the voltage of the gate relative to the potential of the source. If the FET is on, a current flows via the source and drain of the FET. If the first driving unit switches the FET from on to off, a second driving unit switches a reflux switch from off to on.

Abstract: Provided is a power supply control device. The power supply control device includes a plurality of semiconductor switches that are connected in parallel between two power sources and control the supply of power to a load that is connected to the two power sources via the plurality of semiconductor switches, the power supply control device including a temperature detection unit that detects a rise of temperature due to heat that is produced from at least one of the plurality of semiconductor switches, and a switching control unit that executes control that switches the plurality of semiconductor switches from OFF to ON if the temperature detection unit detects a temperature that is at least a threshold temperature.

Abstract: A power supply control device controls the supply of power via a switch circuit and a relay contact. If the semiconductor switches are on and the relay contact is off, when a switch temperature of the switch circuit is at least a relay ON-threshold, the relay contact is switched on, and the semiconductor switches are switched off. If the semiconductor switches are off and the relay contact is on, when a switch temperature of the switch circuit is lower than a relay OFF-threshold, the semiconductor switches are switched on, and the relay contact is switched off. The relay OFF-threshold is not more than the relay ON-threshold.

Abstract: Provided are a relay device and a power supply device that can switch on/off a current path between power storage units, and can suppress, if an earth fault has occurred on either power storage unit side, a voltage reduction on the other power storage unit side. A relay device includes: a serial structural portion in which a resistance unit and a switch unit are connected in series to each other; a relay unit that serves as a path for a current to flow between a first power storage unit and a second power storage unit when the switch unit is in the ON state; and a control unit configured to perform control of switching the switch unit of the relay unit.

Abstract: A power supply control apparatus controls power supply via a semiconductor switch, by a driving circuit turning ON or OFF the semiconductor switch. A current circuit pulls in a current from the drain of the semiconductor switch via a resistance. The current value Ic of the current that is pulled in by the current circuit fluctuates in the same direction as a fluctuation direction of the ON resistance value of the semiconductor switch, depending on the ambient temperature of the semiconductor switch. If the source voltage of the semiconductor switch is lower than a voltage at the other end of the resistance, the driving circuit turns OFF the semiconductor switch.

Abstract: A configuration can supply a charging current from a power generator to two power storage devices, and can suppress, if an abnormality occurs on one power storage device side, the abnormality from affecting the other power storage device side. A relay device includes: a first switch configured to interrupt a first conductive path ; a second switch configured to interrupt a second conductive path ; a bypass circuit with a series circuit in which a resistor and a third switch are connected in series to each other, the series circuit having one end electrically connected to a portion between the first switch and the first power storage device, and another end electrically connected to a portion between the second switch and the second power storage device; and a controller configured to turn the first switch, the second switch, and the third switch on/off.

Abstract: An overcurrent protection circuit that can cope even with a case where a ground fault occurs in a mask time period for overcurrent detection. The overcurrent protection circuit detects, when a switching element is on, a differential voltage value between both ends of the switching element that is caused by an electric current flowing therethrough, and turns off the switching element when the detected differential voltage value is larger than a predetermined voltage value. A detection circuit that detects respective voltage values at both ends of the switching element, and means for preventing the switching element from being turned on if either of the respective voltage values detected by the detection circuit is less than a predetermined value.

Abstract: In a switch circuit for use in a vehicle, conduction between a drain electrode and a gate electrode of each of a first main transistor and a second main transistor is switched on or off depending on a voltage between the gate electrode and a source electrode. A first surge protection device is connected between the drain electrodes of the first main transistor and the second main transistor. The first surge protection device keeps a voltage that is applied to the first surge protection device at a first predetermined voltage or lower. A sub transistor is provided between the gate electrodes and the source electrodes of the first main transistor and the second main transistor. The sub transistor is turned on when the first main transistor and the second main transistor are turned off.

Abstract: Provided are a relay device and a power supply device that can switch on/off a current path between power storage units, and can suppress, if an earth fault has occurred on either power storage unit side, a voltage reduction on the other power storage unit side. A relay device includes: a serial structural portion in which a resistance unit and a switch unit are connected in series to each other; a relay unit that serves as a path for a current to flow between a first power storage unit and a second power storage unit when the switch unit is in the ON state; and a control unit configured to perform control of switching the switch unit of the relay unit.

Abstract: A current flows between the drains of FETs, which function as a switch. A first constant current circuit causes a constant current to flow from the FET side of a resistor to the other side thereof. A first comparator outputs a high level voltage to the control section if the electric potential at the drain of the FET is higher than the electric potential at one end, on the first constant current circuit side, of the resistor. Furthermore, the first comparator outputs a low level voltage to the control section if the electric potential at the drain of the FET is lower than the electric potential at one end, on the first constant current circuit side, of the resistor. The control section turns the FETs off when the first comparator outputs the low level voltage. Furthermore, the control section changes the current that is caused to flow through the resistor by the first constant current circuit.

Abstract: The present invention provides a semiconductor device in which a field effect transistor is prevented from burning caused by an electric current flowing through a parasitic diode. This semiconductor device has a configuration including: a field effect transistor including a parasitic diode; a temperature detector that detects a temperature of the parasitic diode; and a controller that determines whether the temperature detected by the temperature detector is higher than or equal to a first temperature, and turns on the field effect transistor if the detected temperature is higher than or equal to the first temperature.