What is a rotary switch?

Rotary switches are operated by a rotating (twisting) action apposed to regular switches that require throwing, flicking or pressing. They are generally used when you require one switch to be able to divert current between numerous circuits either simultaneously or singularly. They will usually allow between 5 and 8 poles (that is positions) however some will go from 2 positions (like a standard on-off switch) and up to 12 poles on multiples decks, each deck controlling a different circuit.

Rotary switches have been around for years: very early TVs were tuned into a channel using a type of rotary switch and many electric ovens still use them to select between grill, oven and that other function that nobody really knows what it's for. In railway modelling we use them mainly for turntables and multiple aspect light signals as these require more terminals than a regular switch can accommodate.

But that's not to say that we can't use them for other functions too. If you're knowledgeable enough to wire one just think of the possibilities a rotary switch would open up for applications such as route setting and signalling.