Out of the simplest components from the do-it-yourself store (screws, wood, wires,...) relays are built and can be converted into functioning adding calculators. From these relays, machines are constructed which flash, make noises and which can generate harmless electrical shocks. All finished devices will be wired logically into a panopticon and finally presented. Previous technical knowledge is not required, however some ability for handy-work doesn’t hurt.