Abstract: In a switch device, an output voltage output by a microcomputer is input to one end of a resistor. A driving circuit switches a main switch on or off according to a resistor voltage at the other end of the resistor. When all of a plurality of specific voltages included in a plurality of output voltages output by the microcomputer are an output threshold or more, an AND circuit of an adjustment circuit reduces the resistor voltage.

Abstract: In a control device for a vehicle, a first terminal is disposed downstream of a microcomputer in a current path through which a current flows through the microcomputer. The anode of a connection diode is connected to a connection node between the microcomputer and the first terminal. One end of a connection switch is connected to the cathode of the connection diode. A second terminal is connected to the other end of the connection switch. A switching circuit turns ON the connection switch from OFF when a voltage at the first terminal with respect to the potential of the second terminal increases to a threshold voltage or higher.

Abstract: In a switch device, an output voltage output by a microcomputer is input to one end of a resistor. A driving circuit switches a main switch on or off according to a resistor voltage at the other end of the resistor. When all of a plurality of specific voltages included in a plurality of output voltages output by the microcomputer are an output threshold or more, an AND circuit of an adjustment circuit reduces the resistor voltage.

Abstract: An ECU (on-board device) includes a fuse F1 and a blown fuse detection circuit. The blown fuse detection circuit monitors a fuse voltage between two connection nodes respectively located upstream and downstream of the fuse in a current path of a current flowing from a positive electrode of a DC power supply through the fuse. The blown fuse detection circuit outputs a voltage lower than a reference voltage if the fuse voltage is lower than a voltage threshold value. The blown fuse detection circuit outputs a voltage higher than or equal to the reference voltage if the fuse voltage is higher than or equal to the voltage threshold value.

Abstract: An in-vehicle device of the present invention includes a fuse and an upstream capacitor having one end connected to a connection node upstream of the fuse in a current path of current that flows through the fuse. One end of a downstream capacitor is connected to a connection node downstream of the fuse in the current path. A determiner determines whether or not the fuse is blown based on an upstream voltage that passed through the upstream capacitor and a downstream voltage that passed through the downstream capacitor.

Abstract: An ECU controls the supply of power to a load. An upstream switch and a downstream switch are respectively arranged upstream and downstream of the load in a current path of the flow of current through the load. A control unit of a microcomputer determines whether or not current is flowing through the upstream switch while an instruction to switch OFF the upstream switch has been given. If it was determined that current is flowing through the upstream switch, the control unit gives an instruction to switch OFF the downstream switch.

Abstract: In a second detection circuit, a current output device outputs, to a circuit resistor, a current corresponding to a circuit voltage between an input terminal of a second FET to which a current is input and ground of a second drive circuit that switches the second FET ON or OFF. The second detection circuit outputs a voltage between two ends of the circuit resistor. A voltage between the ground of the second drive circuit and a downstream end of the circuit resistor is higher than 0 V.

Abstract: In a first switch of a latch circuit, when the voltage between an emitter (input end) and a base (control end) has increased to a threshold voltage or more, the first switch is switched from off to on. The current that flows through a first resistor and a second resistor in that order is input to a collector (input end) of a second switch and a comparator switch. The second switch is switched on when the first switch is switched on. When the second switch or the comparator switch (third switch) is on, the voltage across the first resistor is the threshold voltage or more. A voltage is input to the emitter of the first switch from a microcomputer. A voltage is output from the collector of the second switch to a driving circuit.

Abstract: A power supply control device controls power supply by switching on or off a first semiconductor switch and a second semiconductor switch that are arranged on a current path. A first diode and a second diode are connected between a drain and a source of the first semiconductor switch and the second semiconductor switch, respectively. Cathodes of the first diode and the second diode are arranged downstream and upstream of the respective anode on the current path. If current flows through the current path even though a microcomputer has given an instruction to switch the first semiconductor switch and the second semiconductor switch off, a first drive circuit switches the first semiconductor switch on.

Abstract: A power supply control device controls power supply through a wire. A first current output circuit is configured to output, to a temperature difference circuit, a current that is larger the larger a wire current, which flows through the wire is. The temperature difference circuit is configured to output a voltage that is higher the larger a temperature difference between a wire temperature of the wire and an ambient temperature in the surroundings of the wire is. A drive circuit is configured to interrupt a flow of the wire current if the output voltage of the temperature difference circuit is at least a voltage threshold.

Abstract: A power supply control device controls power supply from a DC power source to a load, by turning on or off a MOSFET. A current regulation circuit regulates a current flowing through a device resistor to a current proportional to a voltage between the drain and the source of the MOSFET. A drive circuit turns off the MOSFET when a voltage across a resistor circuit exceeds a predetermined voltage. The on-resistance of the MOSFET varies according to an ambient temperature of the MOSFET. The resistance of the resistor circuit varies in a direction different from a direction in which the on-resistance of the MOSFET varies, according to the ambient temperature of the MOSFET.

Abstract: A power supply control device controls power supply by switching on or off a first semiconductor switch and a second semiconductor switch that are arranged on a current path. A first diode and a second diode are connected between a drain and a source of the first semiconductor switch and the second semiconductor switch, respectively. Cathodes of the first diode and the second diode are arranged downstream and upstream of the respective anode on the current path. If current flows through the current path even though a microcomputer has given an instruction to switch the first semiconductor switch and the second semiconductor switch off, a first drive circuit switches the first semiconductor switch on.

Abstract: Provided is an on-board device and a vehicle communication system that can expand the transmission range of signals that are transmitted from transmission antennas of the on-board device. An on-board device transmits signals to a portable device, from a plurality of first to fourth LF transmission antennas that are provided for a vehicle at positions that are separate from each other. The on-board device includes a transmission unit that transmits the signals from the first to fourth LF transmission antennas such that a transmission range in which the portable device can receive the signals is a range around the vehicle. The transmission unit substantially simultaneously transmits the signals from two or more transmission antennas among the first to fourth LF transmission antennas, to expand the transmission range.