Henkel Kommanditgesellschaft Auf Aktien

Karl-Heinz Munk

Dieter Brodalla

Werner Huppertz

James W Costello

Georg Wagner

A process and circuitry for the electrolytic coloring of an anodized article of aluminum or aluminum alloy in a coloring bath containing at least one metal salt for coloring the article. The process comprises applying to the coloring bath a controllable, asymmetrical and substantially sinusoidal a.c. voltage of substantially constant frequency. The sinusoidal a.c. voltage is obtained from a voltage source supplying a symmetrical sinusoidal a.c. voltage and at least one of the two current paths is divided into two parallel main lines and fed to electrical components whereby the amplitude level of the positive half wave and the amplitude level of the negative half wave and the ratio of the amplitude level of the positive half wave to the amplitude level of the negative half wave of the a.c. voltage applied to the coloring bath are made variable and adjustable independently of one another, adjusting the positive half wave and the negative half wave to the desired values, and recombining the main lines to form the a.c. voltage applied to the coloring bath.

Growing community of inventors

Hamm, Germany

Karl-Heinz Munk