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Switch buying confusion. What is the difference between On - Off - On and (On) - Off - On?

I am having some trouble buying switches from mouser. I need a toggle SPDT switch that has an On - On (on a different line) type workings (like seen here under SPDT). The problem is Mouser has so many different options in their "switch function" filter. Which one(s) should I use? What do the Parentheses mean? Does it mean Momentary or Something else? What about the "None" seen in a few options? What's up with "MOM"? Here is a link to the page I'm talking about.

framistan1 year ago
Also, be carefull to get the amperes rating you need. A "mini" toggle is pretty small.... and a SUB MINI is really small. Not good for much amperes, but ok for toggling a dataline or similar. ON-ON is probably what you want. If you need it to have an OFF position where NEITHER side is energized, then get the ON-OFF-ON because it has the center off position. If you need the toggle handle to always return to the OFF position when you let go of it, then get the (ON)-OFF-(ON) kind.
TheGreatS (author)  framistan1 year ago
Thanks! This helps a lot.
Yes, the () means momentary. It is the industry convention.
  
+1

Just to clarify - Momentary means it's spring loaded so only makes that contact while you're holding it in that position.
I take it you want a 2 position toggle switch where one way sends power to one wire and the other way sends power to the other wire.

At mouser in the filter, scroll down to on-on and double check the data sheet.

mouser seams to have only two

642-3645NF
and
642-3635NF
Pro

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