Understanding Rotaries

jazzercountry · Post by **jazzercountry** » 08 Mar 2009, 15:06

Hello all,

Thought I would ask some questions about rotary switches. I have these: http://www.smallbearelec.com/Detail.bok?no=46

For the application I'm using it for at the moment, I need 4 positions. I've adjusted the little washer with a tab so it now has 4 positions. My only question is how the 4 positions correspond to the outer 12 and inner 3 contacts now. I'm building the Stringringer and McMeat projects right now. The understanding is not as important for the Stringringer project, though, as the rotaries are PCB mounted. For the McMeat, however, I'm working off of the schematic.

Thanks for the info!
Ryan

RnFR · Post by **RnFR** » 09 Mar 2009, 02:57

bump!

Fuzzer · Post by **Fuzzer** » 09 Mar 2009, 05:10

If you have a meter, you can clip one of the leads to one of the three inner lugs, and then, at the first position of the rotary, check continuity to one of the four lugs it's facing outwards the rotary's body. When you have continuity, then that's the same pattern for the other two. You can check to be sure, Off Course.

noelgrassy · Post by **noelgrassy** » 10 Mar 2009, 12:16

Jazzer,

On the center 3 lugs do you see the letters "A" "B" "C"?

The lugs 1~12 at the circumference have numerical indications, right? Where #1 meets #12 the switch
has a device cast into the side opposite the lugs that's 1/8" dia. and it's taller than the area where your
lock washer would sit. This prevents "windmilling" controls when an accommodating hole is prepared.

Lug "A" shares lugs #1~#4 Lug "B" shares lugs #5~#8 Lug "C" shares lugs #9~#12

At least that's how a typical Lorlin switch is layed out. Double check my instructions against your switch
with your DMM set on it's continuity checker. A beeping one will save you from a lot of headache.

NG.