Abstract: 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.

Abstract: 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.

Abstract: Input and output capacity of a continuous cycling programmable controller is increased by utilizing a program which defines a series of timing windows or channels each of which extends for a period greater than a single program cycle. Control switches and sensing switch devices and output LEDS, are divided into channel groups which are energized only during the corresponding channel timing window. Readings of energized input devices are taken during input timing windows which are delayed from and shorter than the corresponding energized window to account for output and input delay and startup and stopping irregularities. Additionally, light indicators are incorporated within a graphic display having an arrangement of baths depicted spatially relative to a corresponding arrangement of control units to enable substantially easier identification of the various control conditions of the process.