20V Power Controller (Marklin 13472)

From The Brighton Toy and Model Index

A black rectangular metal Power Controller for model railways ad other electrical equipment, made by the German company Märklin in the 1930s, catalogue number 13472.

Description

The controller is in the form of a flattish rectangular metal box with jutting upper and lower surfaces, and a band of ornamental punched ventilation holes around the sides shaped like "crossed squares" (where each "square" is made up of four punched 45-degree triangular holes).

The top surface of the controller has a silver-coloured metal wiper arm that can be rotated to make contact with one of eight silver-coloured circular contacts, which presumably tap off different voltages to be sent to the receiving equipment.