To provide a lightning protection device which has a converting means and lightning protecting function of simple constitution.
From AC power source lines connected with a commercial AC power source, an AC voltage is applied to AC input terminals 5, 5 and inputted in a rectifying means 3 via fuses 4, 4, respectively. By the rectifying mean 3, the AC voltage is rectified and converted to a DC voltage, which is applied to a communication apparatus via DC output terminals 6, 6. A signal inputted in signal input terminals 11 connected with signal lines from the communication apparatus is again outputted to the communication apparatus connected with the signal lines from signal output terminals 12 via overcurrent protecting means 14. When an overvoltage permeates into the signal input terminals 11 from the signal lines, the overvoltage is conducted to the AC input terminals 5, via the overcurrent protecting means 14, signal line side voltage-limiting elements 17, a bias line 19, AC power source line side voltage-limiting elements 16, and the fuses 4. The voltage is conducted from the AC input terminals 5 to the AC power source lines, thereby protecting the communication apparatus from overvoltage.
KITAGAWA ATSUSHI
YAMANO SEIICHI
NIPPON TELEGRAPH & TELEPHONE