Abstract: A vehicle-installed relay box is for installing a relay used for controlling power supply to a load in a vehicle-installed system provided with different specifications, the relay being configured to different specifications using one or more relay elements in combination in accordance with one type of specification selected from among the different specifications of the vehicle-installed system. The vehicle-installed relay box includes: a plurality of terminals; an installation socket configured to install the relay element; and a wiring configured to connect the relay element installed in the installation socket and the terminals. The installation socket is further configured to be installed a different relay element in accordance with the selected type of specification from among the different specifications of the vehicle-installed system.

Abstract: A semiconductor circuit component has: an MOS-FET 12 which is a load-control semiconductor switching device with a control terminal; a control signal supply circuit 14 including a charging pump circuit for supplying a control signal to a gate G of the MOS-FET 12 to drive the MOS-FET 12; and a drive control circuit 16 for performing drive control only when a switch unit SW externally provided is turned on, so that a power supply voltage is supplied from a battery power supply to the control signal supply circuit 14 to thereby make the control signal supply circuit 14 output the control signal.

Abstract: A protection circuit 10 has a diode 31 being connected in parallel to an inductive load 11 and having a forward direction set reverse to the conduction direction of a power supply current and a Zener diode 33 being placed between one terminal of the diode 31 and one terminal of the load 11 corresponding to the terminal of the diode and having a forward direction matched with the conduction direction of the power supply current.

Abstract: A protection circuit 10 has a diode 31 being connected in parallel to an inductive load 11 and having a forward direction set reverse to the conduction direction of a power supply current and a Zener diode 33 being placed between one terminal of the diode 31 and one terminal of the load 11 corresponding to the terminal of the diode and having a forward direction matched with the conduction direction of the power supply current.

Abstract: A semiconductor circuit component has: an MOS-FET 12 which is a load-control semiconductor switching device with a control terminal; a control signal supply circuit 14 including a charging pump circuit for supplying a control signal to a gate G of the MOS-FET 12 to drive the MOS-FET 12; and a drive control circuit 16 for performing drive control only when a switch unit SW externally provided is turned on, so that a power supply voltage is supplied from a battery power supply to the control signal supply circuit 14 to thereby make the control signal supply circuit 14 output the control signal.