Abstract: An output circuit sends out, to an input circuit, a control pilot signal generated by a voltage source. A voltage transformer is provided to a control pilot line on the output side of the output circuit, and a communication unit transmits and receives communication signals via the voltage transformer. A voltage transformer is provided to the control pilot line on the input side of the input circuit, and a communication unit transmits and receives the communication signals via the voltage transformer. A low-pass filter is provided to the control pilot line between the input circuit and the voltage transformer.

Abstract: A movable mold is movable toward and away from a fixed mold so as to close and open the mold. The fixed mold includes an intermediate plate facing a movable-side mold plate. This intermediate plate has a retainer-molding recess which cooperates with the movable-side mold plate to form a retainer-molding cavity, and a core pin, which cooperates with a housing-molding recess to form a housing-molding cavity, is mounted on the intermediate plate. A retainer, molded in the molding cavity, is moved downward by an ejector pin into a position where the retainer is disposed coaxial with a housing. Then, the two molds are again closed together, so that the housing and the retainer are connected together, and then this assembled product is taken out.