| 摘要 |
PROBLEM TO BE SOLVED: To realize, in an external power supply cathodic protection device for controlling the protection current via a coupon current, the operation of an external power supply cathodic protection device capable of ultimately eradicating prospects of DC corrosion risks and overprotection risks and of inhibiting an electric power loss by perpetually confining the measured coupon current within a relatively narrow control current range.SOLUTION: The provided external power supply cathodic protection device 1 includes, for the purpose of controlling, by measuring a coupon current flowing through a coupon C connected to a protection target and the protection target, an output current outputted from an anode A installed within an electrolyte on the periphery of the protection target, a smoothing DC voltage output means 10 for outputting a smooth DC voltage from an AC power supply 2 and output voltage control means for controlling the output voltage outputted from the smoothing DC voltage output means 10 (switching circuit 14 and comparison/adjustment circuit 20). The output voltage control means control the output voltage from the smoothing DC voltage output means 10 so as to confine the measured coupon current to an intermediate control current range within a cathodic protection standard. |
