Author Topic: Wiring for a Rotary Switch Mod - Adding Switch to Circuit for Different Cap Valu  (Read 282 times)

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I have never wired a rotary up, much less added one to a circuit that doesn't call for it. I have a circuit with a mod to add a rotary on one of the cap pads and then have different cap values on each rotary click. How would I wire a 2p6t rotary into this circuit? I'm looking to have 3-4 clicks on the switch and then have the washer block the remaining spots.

Thanks!

HamSandwich

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Your rotary will have the 2 poles in the center and then 12 pigs around the outside. Each pole has a corresponding 6 lugs around the outside, that as you turn the shaft, get connected. This picture should help you out.



For your application, you only need one of the poles. So you’d send a wire from one side of the cap on the board to the center pole you want to use. Attach one leg of each cap to each of the outer lugs. The other end of each cap get soldered together and then all run back to the other pad for the cap on the board.

You can get thrifty and mount the caps across to the other side of the switch, then short all of the unused side of the rotary together and run one wire back from there.

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Your rotary will have the 2 poles in the center and then 12 pigs around the outside. Each pole has a corresponding 6 lugs around the outside, that as you turn the shaft, get connected. This picture should help you out.



For your application, you only need one of the poles. So you’d send a wire from one side of the cap on the board to the center pole you want to use. Attach one leg of each cap to each of the outer lugs. The other end of each cap get soldered together and then all run back to the other pad for the cap on the board.

You can get thrifty and mount the caps across to the other side of the switch, then short all of the unused side of the rotary together and run one wire back from there.

Thank you. I can't say I fully understand but this helps a bunch. The confusing part for me is adding the caps to the rotary. If anyone has a picture of a similar rotary in one of their builds and can snap a picture that would help me a ton.

HamSandwich

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This is from Google, but is similar. The only difference is the center lug of your switch is connecting to one side where the cap goes on the PCB, and in the photo, where all of the caps connect together at ground, you’re connecting them all together to the other side of where the cap goes on the PCB.


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In my barren brain I thought this is how it would be wired! Maybe I'm learning something? Thanks Ham!

HamSandwich

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In my barren brain I thought this is how it would be wired! Maybe I'm learning something? Thanks Ham!

I found the key to understanding switch wiring is the understand how the switch works AND what you want to accomplish. A picture helps, but putting your DMM on connectivity (or resistance) and measuring between pins of switches as you change state really helps. Combine that with knowing what you want to do and visualizing what the circuit looks like with the switch being a simple connection (removing all the bits that are not in the circuit when the switch is in one state), you can tackle and switching problem!

Drawing it out certainly helps too, then tracing your switch in different colors That the signal will take when the switch is in different positions to visualize it.