Patent ID: 7902832
Filing Date: 2011-03-08
Classification: E02F,G01R

Abstract:
1. An antenna cable break detector for a construction machine wireless communication apparatus that includes a communication device mounted in a construction machine, an antenna, and an antenna cable, the antenna cable including a central wire and an armor wire that is positioned concentrically outside the central wire, one end each of the central wire and the armor wire being connected to the communication device, the other end of the central wire being connected to the antenna, the other end of the armor wire being grounded, the antenna cable break detector comprising: a direct current shutoff device that is connected to the armor wire of the antenna cable to shut off a direct current flow from the armor wire to the communication device; and current shutoff detection device that is connected to the armor wire of the antenna cable, that applies a direct current to the armor wire from a power supply for detecting a break in the antenna cable, and detects the shutoff of the direct current.