GB1023731A - Apparatus for cathodic and anodic protection against corrosion of metal objects which are in contact with electrolytes - Google Patents

Abstract

1, 023, 731. Automatic control systems for corrosion protection. STOCZNIA [M KOMUNY PARYSKIEJ. Feb. 12, 1964 [Dec. 28, 1963], No. 5891/64. Heading G3R. A corrosion protection system comprises a plurality of current supply units Ia, Ib, Ic connected to respective polarizing electrodes 1a, 1b, 1c and to the object, e.g. a ship's hull, to be protected. A switching unit II sequentially connects each supply unit for a definite time interval to a checking and controlling unit III which compares the potential between a reference electrode 2a, 2b or 2c and the protected object with a reference potential; any difference is amplified to operate relays controlling the output of the respective unit Ia, Ib or Ic in a corrective manner, whereby the protective potential at the various parts of the protected object is kept at a desired value. A timing system IV, e.g. an RC circuit or a clock mechanism, associated with the relays in the unit III controls the switching of unit II and the adjustment means in the units Ia, Ib and Ic. Suitable circuit arrangements for the units Ia etc., II and III are described with reference to Fig. 2 (not shown), the units Ia, Ib and Ic including a variable ratio transformer and a rectifier supplying the polarizing current, the unit II comprising a multi-segment selector, e.g. of the telephone type, and the unit III including two doubletriode valves forming a two-stage amplifier;the circuit also includes change over switches so that the system may be used for cathodic or anodic protection.