Abstract: Electronic devices include: a first electronic device capable of being always supplied with power; and a second electronic device capable of being supplied with the power through an operation by an occupant. Each of power supply hubs is located near the first electronic device, and connected to a battery or another one of the power supply hubs by one of main power supply lines. Each of the first and second electronic devices is connected to nearby one of the power supply hubs. Each of zone ECUs outputs a control signal to one of power supply ICs so as to distribute, to the first and second electronic devices, the power supplied to one of the power supply hubs by one of the main power supply lines.

Abstract: A T/R switch applicable to an ultrasonograph and capable of transmitting a signal reflected from a living body over a wide band with low noise without causing erroneous operation of the switch or element destruction even when the potential of a transmission signal or reflected signal changes includes: a common source terminal commonly and serially coupling the source terminals of two MOS transistors; a common gate terminal commonly coupling the gate terminals of the two MOS transistors; a main switch, the drain terminals of which are connected to input/output terminals; and a floating voltage circuit which is connected to the common gate terminal and common source terminal, makes the common gate terminal potential follow, in phase, variation in the common source terminal potential, and sends a signal to turn the switch on or off to the common gate terminal.

Abstract: A T/R switch applicable to an ultrasonograph and capable of transmitting a signal reflected from a living body over a wide band with low noise without causing erroneous operation of the switch or element destruction even when the potential of a transmission signal or reflected signal changes includes: a common source terminal commonly and serially coupling the source terminals of two MOS transistors; a common gate terminal commonly coupling the gate terminals of the two MOS transistors; a main switch, the drain terminals of which are connected to input/output terminals; and a floating voltage circuit which is connected to the common gate terminal and common source terminal, makes the common gate terminal potential follow, in phase, variation in the common source terminal potential, and sends a signal to turn the switch on or off to the common gate terminal.