GB1309069A - Apparatus for controlling the electrolytic current in an electrlytic process - Google Patents

Abstract

1309069 Automatic current control FERNSTEUERGERATE KURT DELSCHE KG 19 April 1971 [7 April 1970] 26449/71 Heading G3R The current supplied to an electrolytic bath 2 from a variable transformer 1 and rectifier 18 is maintained at a desired valve by a control system comprising a resistor 3 which detects the actual current and supplies a signal to a comparator 5 via an amplifier 4, the comparator 5 being supplied with a signal representative of the desired current from a circuit including a constant voltage source 6, potential dividers formed by resistor pairs 7, 8; 9, 10; 13, 14 and amplifiers 11, 15. The resistor 7 is adjusted according to the surface area of the material to be treated, the resistor 9 according to a required optimum current density in the bath and the resistor 13 in accordance with the number of parts (or work pieces) to be treated in the bath, the resistors 7, 13 being applicable when a number of identical parts are to be treated simultaneously, in which case the setting of the resistor 7 corresponds to the surface area of one part. The resistors 8, 10 and 14 set a respective lower limit for the parameter associated with the setting of resistors 7, 9 and 13. Instruments 16, 17 and 19 respectively indicate the values of the total surface area of the parts, the desired value of current and the actual value of current. Comparator 5 may take the form of an electronic relay controlling a servo-motor 20 for adjusting the transformer 1. A resistor 21 of a pair 21, 22 connected across the source 6 is mounted on the spindle of the resistor 9, so that it has the same setting as the latter and the voltage taken from resistros 21, 22 corresponds to that from resistors 9, 10. A further resistor 23 is set to produce a voltage which corresponds to the rate of the electro-chemical reaction in the bath and which is applied to an integrator 24 (e.g. a measuring motor) driving a counter 25 controlling a switch 26. The counter 25 thus indicates material transfer in the bath and may be set to a desired value, so that when it is reached the switch 26 is opened to de-energize a relay 28 and so switch off the current to the bath. Each resistor and the counter may be adjusted by servo-motors as part of an automatic programming operation. A simplified control system for treating one part is described, Fig. 1 (not shown).