I'm looking for a switch that is both momentary ON, and momentary OFF. It would have one button to simultaneously switch both sides, and 3 contacts so as to access the two switches. Is there a name for this, or is it a mythical creature?
thanks

 

It is called a "single pole double throw" momentary switch. Poles count the number of common terminals (circuits) the switch can make or break, and throws are the number of possible paths for each circuit. You will find it abbreviated as "SPDT", a "DPDT" would be the same but with two separate circuits, an "SPST" would be on circuit with one path (on/off).

Here is an entirely random example: https://guitarpedalparts.com/products/momentary-spdt-foot-switch

 

Thanks Yaakov, but I do not believe this is what I was (poorly) attempting to describe. I need a single button press to cause two separate switching mechanisms to activate simultaneously. One of them is momentary ON, and the other is momentary OFF, but they are separate paths. I'll see if I can work up a drawing.

 

DPDT then. One connected to NO, normally open, which will turn on when pressed, the other to NC which will turn off.

 

One more thung: switches come in make-before-break and break-before-make. The former shorts all the pins before switching, the latter disconnects one side before connecting the other.

In the kind of switch you are looking for, break=before-make would be expected but be sure you know that is the case of strange, possibly dramatic things can result.