Disclosed are various embodiments of voltage protectors that include a first voltage clamping device configured to clamp a voltage of an input power applied to an electrical load, and a second voltage clamping device configured to clamp the voltage applied to the electrical load. The electronic device includes a virtual keyboard and a touch screen. At least one adjustment terminal is disposed above the end face electrode on the side surface of the container body electrically isolated from the end face electrode. The light receiving unit receives a light signal that is emitted from the light emitting unit to the light receiving unit without intersecting the object and a light signal that is emitted from the light emitting unit to the light receiving unit through the object, and is operated in synchronization with a light emission timing signal of the light emitting unit. The chair is provided with a mechanism which enables the seat to be advanced relative to the back-rest, within a predetermined range. In one aspect, the assembly is a closed system for the coolant.