Cathodic protection method and apparatus

Claim 3

The method as set forth in claim 1, wherein the step of impressing includes the step of: flowing the direct current through the electrolyte to protect the cathode of the corrosion protection system.

Claim 4

The method as set forth in claim 1, wherein the step of generating the electrical timing signal includes the steps of: rectifying an alternating current to produce a full wave direct current signal; forming a electrical trigger signal in response to each full wave direct current signal; and producing the electrical timing signal of set duration in response to the electrical trigger signal.

Claim 5

The method as set forth in claim 1, wherein the step of sensing includes the step of: establishing electrical continuity through a switch means during the duration of the electrical timing signal.

Claim 6

The method as set forth in claim 1, wherein the step of comparing includes the step of: providing an offset signal to produce an error control signal when the sensed reference voltage and the preselected standard signal are the same.

Claim 7

The method as set forth in claim 1, wherein the step of controlling includes the step of: retarding the start of the output pulses of the impressed direct current when the sensed reference voltage and the preselected standard signal are the same to control the impressed direct current.

Claim 12

The method as set forth in claim 8, including the step of: indicating visually the natural reference voltage sensed by the activated reference voltage sensing circuit.

Claim 13

A cathodic protection system for inhibiting the corrosion of a metallic surface in contact with an electrolyte in which pulsed electrical power having zero voltage periods between pulses is continually supplied to the impressed current output circuit and which output is automatically adjusted to maintain the surface potential at a predetermined optimum to inhibit corrosion of the metallic surface, including: an anode in contact with an electrolyte; a metal to be cathodically protected as a cathode in contact with the electroyte; a reference electrode in contact with the electroyte; adjustable electric supply means for producing a controlled pulse direct current output having a zero voltage period between the output pulses of direct current; said adjustable electric supply means electrically connected with said anode and said metal to be protected as a cathode for impressing the controlled pulse direct current in the electrolyte to inhibit the cathode from corrosion; an electronic switch means electrically connected with said reference electrode for passing a reference voltage output signal when the controlled direct current of said adjustable electric supply means is in the zero voltage period; means electrically connected with said switch means for comparing the reference signal from the switch means with a preselected standard signal to determine an error control signal; and means with said adjustable electric supply means for controlling the direct current output pulses of said adjustable electric supply means is response to the error control signal.

Claim 14

A cathodic protection system for inhibiting the corrosion of a metallic surface in contact with an electrolyte in which pulsed electrical power having zero voltage periods between pulses is continually supplied to the impressed current output circuit and which output is automatically adjusted to maintain the surface potential at a predetermined optimum to inhibit corrosion of the metallic surface, including: an anode in contact with an electrolyte; a metal to be cathodically protected as a cathode in contact with the electroyte; a reference electrode in contact with the electroyte; adjustable electric supply means for producing a controlled pulse direct current output having a zero voltage period between the output pulses of direct current; said adjustable electric supply means electrically connected with said anode and said metal to be protected as a cathode for impressing the controlled pulse direct current in the electrolyte to inhibit the cathode from corrosion; an electronic switch means electrically connected with said reference electrode for passing a reference voltage output signal when the controlled direct current of said adjustable electric supply means is in the zero voltage period; means electrically connected with said switch means for comparing the reference signal from the switch means with a preselected standard signal to determine an error control signal; and means with said adjustable electric supply means for controlling the direct current output pulses of said adjustable electric supply means is response to the error control signal.

Claim 15

An automatic control system for an impressed current system for inhibiting the corrosion of a metallic surface in contact with an electrolyte in which pulses electrical power having zero voltage periods between pulses is continually supplied to the impressed current output circuit and which output is automatically adjusted to maintain the surface potential at a predetermined optimum to inhibit corrosion of the metallic surface, including: a reference electrode in contact with the electrolyte; adjustable electric supply means for producing an impressed current output having a controlled pulse direct current output having a zero voltage period between the output pulses of direct current; said adjustable electric supply means electrically connected for impressing the controlled pulse direct current in the electrolyte to inhibit corrosion; an electronic switch means electrically connected with said reference electrode for passing a reference voltage output signal when the controlled direct current of said adjustable electric supply means is in the zero voltage period; means electrically connected with said switch means for comparing the reference signal from the switch means with a preselected standard signal to determine an error control signal; and means with said adjustable electric supply means for controlling the direct current output pulses of said adjustable electric supply means in response to the error control signal.

Claim 16

An automatic control system for an impressed current system for inhibiting the corrosion of a metallic surface in contact with an electrolyte in which pulses electrical power having zero voltage periods between pulses is continually supplied to the impressed current output circuit and which output is automatically adjusted to maintain the surface potential at a predetermined optimum to inhibit corrosion of the metallic surface, including: a reference electrode in contact with the electrolyte; adjustable electric supply means for producing an impressed current output having a controlled pulse direct current output having a zero voltage period between the output pulses of direct current; said adjustable electric supply means electrically connected for impressing the controlled pulse direct current in the electrolyte to inhibit corrosion; an electronic switch means electrically connected with said reference electrode for passing a reference voltage output signal when the controlled direct current of said adjustable electric supply means is in the zero voltage period; means electrically connected with said switch means for comparing the reference signal from the switch means with a preselected standard signal to determine an error control signal; and means with said adjustable electric supply means for controlling the direct current output pulses of said adjustable electric supply means in response to the error control signal.

Claim 17

The apparatus as set forth in claim 11, including: means for visually displaying the value of the reference voltage from the reference electrode.

Claim 18

The apparatus as set forth in claim 11, including: means for controlling the mode of operation of the control system by substituting a manually prechosen signal for the error control signal.