Tactile Micro Switch SD typewriter module w/ secretarial shift 70SD22-4

[fricked]

When I saw that these are the tactile version I couldn't resist

pix

Spoiler:

blocker

Appears to be NOS
These switches feel quite unusual and I am not sure how I feel about them; I would describe them as feeling like Alps SKCM Brown but with sharper tactility and a click on every upstroke

[TNT]

Wow, I wasn't aware there was a tactile version of those. They look very clean.

Can you record a soundtest for us?

[fricked]

Can you record a soundtest for us?

Your wish is my command

[John Doe]

11B1S, cool easy to convert, congrats bro.

[Chyros]

Very interesting! What is the tactile element in these switches?

[TNT]

Very interesting! What is the tactile element in these switches?

I second that question.

Thank you for the typing demonstration!

11B1S, cool easy to convert, congrats bro.

Aside from the wiki, where would you find more information on how to do that and why are those switches shown here especially easy to convert?

I also have 2 Microswitch boards I'd like to convert eventually

[John Doe]

why are those switches shown here especially easy to convert?

Ending with "S" and "E" switches normally come with hold type sensors so they're easily converted, no exceptions in my experience so far.

But there should also be other variants existing.

[jsheradin]

A good breakdown of SD part numbers is here: https://telcontar.net/KBK/Micro_Switch/SD

11B1S would be:

• 11 - Momentary, Tactile
• B - 11deg tilt stem
• 1 - 75gf weight
• S - Logic scan

The important part here is the S ending; logic scan is more or less the holy grail for Microswich boards. It means that one of the 4 pins acts as a logic gate allowing for these to function like a normal contact switch in terms of matrix scanning. They're inherently NKRO and can be easily scanned with QMK, Soarer's Controller, etc.

[Muirium]

What do you make of these?



This board's been waiting for a wee while. I'm still none the wiser, mind.

[jsheradin]

What do you make of these?

E code is also somewhat easy to convert but not quite as cleanly. They're again inherently NKRO and all that fun stuff but the scan logic requires significantly higher current as it's what actually powers the hall sensors. You need around 3.5mA to drive a single switch. On a 32u4 the absolute max I/O current is 40mA which limits your driven line to ~11 switches if you're daring. You should really pair the controller with a line driver chip to make sure there's no issues. Depending on chip choice you'd then be able to run a full sized NKRO matrix to your heart's content.

[Muirium]

Ooh, that's better than I've heard before. I don't mind sourcing the appropriate chips to do the job well instead of kludging it. But could I get away with the original PCB? Micro Switch made them classy looking. Don't want to have to tear it out.

[jsheradin]

You'd need to desolder the existing scan logic and wire in the new controller but the PCB should be totally reusable. You might get lucky in that one of the existing chips is the requisite line driver in which case it could be reused.

[Muirium]

Poetry to my ears! I'll open it up and take some new pictures and try to map it out.

That board's weakness is its flimsy white plastic outer case. I'm not at all bothered about keeping that, but the PCB and plate are thicc in all the right ways!

[John Doe]

"E" ending is 3-terminal sensors and still, hold type, so its easily converted, I highly doubt for some type sensors Soarer firmware will work flawlessly as the output is inverse sigbal compared to normal contact switches, unless you could mod its source code, sadly looks impossible.

Spoiler:

I dont have this board now but keeping a pic, if someone has interests to see.

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[jsheradin]

I highly doubt for some type sensors Soarer firmware will work flawlessly as the output is inverse sigbal compared to normal contact switches, unless you could mod its source code, sadly looks impossible.

Soarer's controller supports it:

Spoiler:

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[John Doe]

OMG, Soarer also supportes such options, sure it will work if so, kind.