| 摘要 |
PROBLEM TO BE SOLVED: To provide a monitoring camera system reducing quality degradation caused by noise in a high frequency video signal to be transmitted, while protecting a monitoring camera and a video receiver from an induced voltage by thunder. SOLUTION: As for the configuration of the monitoring camera system, a monitoring camera 111 and a video receiver 112 are connected with a coaxial cable 113, and an arrester 114 is also connected to the coaxial cable 113. The arrester 114 has: a protection circuit for protecting the monitoring camera 111 and the video receiver 112 from a surge voltage guided to the coaxial cable 113. The arrester 114 also has: an arrester metal case for accommodating the protection circuit; a ground terminal for grounding the protection circuit to the ground; an external conductor connection terminal for connecting the protection circuit to an outer conductor of the coaxial cable; a center conductor connection terminal for connecting a center conductor of the coaxial cable to the protection circuit; and a switching means for switching the connection of the arrester metal case. The switching means switches the connection of the arrester metal case according to the state of noise to a video signal received with the video receiver. COPYRIGHT: (C)2011,JPO&INPIT
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