The Elect. Sel. 8 is a simple circuit, with a choice of 8 sources of any sort ,of 8 independent switches. Each switch corresponding with a relay for example the switch S1 activates the RL1 e.t.c. The uses of the circuit are quite a few, choice of entrances in a sound amplifier, choice of command, in a digital circuit etc. In each entrance a LED which may be independent, except if switches with led are used.
circuit from http://users.otenet.gr/~athsam/Electronic_sel_8.htm