Abstract: A lamp holder includes a main body, a switch device and a mounting bracket. The main body has an axial end for connecting a light emitting element and another axial end having an electrically conductive module, and the switch device is installed in the main body, and the switch device and the electrically conductive module jointly control the light emitting element to be turned on or off. The rotary handle of the switch device is installed at an axial end of the main body and protruded out from the main body, and the mounting bracket encloses the rotary handle and locks with the main body. Therefore, the lamp holder can be installed onto a decorative shelter conveniently, and the rotary handle can be turned without limitation, and the lamp holder has a good appearance.

Abstract: With a simple configuration, increase in size can be avoided, usage durability is improved, and occurrence of insufficient electrical connection caused by dust can be prevented well. A crank part is provided in at least one of both contacts including elastic beam-like members. Both of the contacts are provided with cut-away parts, which substantially increase the span lengths of the elastic beam-like members, and gaps between the contacts and an insulating housing which ensure flexibility of the elastic beam-like members to ensure flexibility and prevent permanent deformation of the contacts while enhancing elasticity of the contacts. Dust which has entered the interior thereof is moved along the crank part to ensure electrical conductivity well, which is an employed configuration.

Abstract: A load side terminal connected to a load portion, a power source side terminal connected to a power source portion and a sacrifice electric pole connected to the power source side terminal are fixed to an apparatus main body. A movable plug is provided movably to the apparatus main body. The sacrifice electrode is constituted by a sacrifice electric pole with resistor connected to the power source side terminal via a resistor and a through sacrifice electric pole directly connected to the power source side terminal and arranged to shift from each other such that in a procedure of moving a conductive portion of the movable plug from a circuit opened position to a circuit closed position. The conductive portion is firstly brought into contact with the load side terminal, successively brought into contact with the sacrifice electric pole and finally brought into contact with the power source side terminal.