TRS switch question.

[xgpt]

https://www.cuidevices.com/product/resource/sj1-352xng.pdf

Why are there (detection?) switches on the SJ1-3524NG on tip and SJ1-3525NG on both tip AND ring?

What would the possible benefit be of the second detection switch? I'm sure I'm missing a very obvious use-case here.

I'd also really love advice on how to answer this kind of question for myself without having to lean on communities like this to grok other people's brains who might have used this stuff themselves.

[Kim Christensen]

Because it's not so much a "detector" switch than just a switch.

ie: In the old days, they simply used these contacts to turn off the speakers (left and right) when you plugged the headphones in.

[xgpt]

Is there a way to figure out if what is plugged in is a stereo or a mono jack? I'm struggling to envision the circuit required for that task.

[Kim Christensen]

You could detect that the right channel is shorted to common/ground since the "ring" on a mono jack is missing. (part of the sleeve)

[xgpt]

Yeah, but would I need the additional ring switch to do that detection? I can't see why I would.

[Kim Christensen]

You are correct. No switch feature would be required. The SJ1-3523NG would work for that.

[wasedadoc]

Because it's not so much a "detector" switch than just a switch.

ie: In the old days, they simply used these contacts to turn off the speakers (left and right) when you plugged the headphones in.

Your diagram is incorrect. Convention is for the tip to be left audio, not right.

[tooki]

Because it's not so much a "detector" switch than just a switch.

ie: In the old days, they simply used these contacts to turn off the speakers (left and right) when you plugged the headphones in.

Your diagram is incorrect. Convention is for the tip to be left audio, not right.

Indeed. I remember it from the mnemonic “red, right, ring”.

The second diagram Kim C. posted later is correct, though.

[Kim Christensen]

Because it's not so much a "detector" switch than just a switch.

ie: In the old days, they simply used these contacts to turn off the speakers (left and right) when you plugged the headphones in.

Your diagram is incorrect. Convention is for the tip to be left audio, not right.

Right.