The top part is very conventional, but the bottom might be a bit more interesting. Effectively, it serves as a primitive analog computer to generate a wide selection of fractions of the voltage applied to "+" and "-". As noted on the board, connecting one or more pins from the "+" side to one or more pins from the "-" side generates a voltage V*P/(P+M) where "P" is the sum of the labels of pins connected on the "+" side and "M" the sum on the "-" side. If "+" is 5V, you can obtain e.g.:

- 1V as 1/5 of 5V, by connecting "1" on the "+" side and "4" on the "-" side.
- 1.25V as 1/4, by connecting "1" on the "+" side, and 3 (as "1" and "2") on the "-" side.
- 1.5V as 3/10, by connecting "1" and "2" on the "+" side, and "1", "2", and "4" on the "-" side.