Omron B3G-S100N

[Daniel Beardsmore]

We have the first confirmed part number — the common Omron B3G-S white tactile switch is B3G-S100N. I've suspected this for a while as it's the type stockpiled in China and photos of the switches in packaging always show that part number (I've just never managed to buy switches from anyone who's got that part number confirmed until now).

I cannot transcribe the Omron catalogue page as it's been faxed and so many horizontal strokes are missing from even the kana that they’re unrecognisable to anyone not fluent in Japanese. The forces given are the operating force and (transcribed from a more readable but very limited specification) "押し切 _ に必要な力" — the missing character is one that I recognise somehow, but Google Translate does not, and it’s not in the Windows kana table.

The basic switches are:

B3G-S100: operating force 40 g, force required to push 50 g
B2G-S200: operating force 60 g, force required to push 60 g
B3G-S400: operating force 60 g, force required to push 70 g

(Sandy and I are taking S300 to be the alternate action version, but this is by no means confirmed.)

S200 has got to be linear.

In correspondence with Sandy we concluded that my white tactile switches were S400(N) due to the weight, but they’re now proven to be S100N.

It would be nice to see the graph of that switch, as the specification puts it considerably lighter than what I was taking it to be. It's not known whether S400(N) is tactile or clicky — if audible feedback was cited on the page then Sandy would know about it.

[seebart]

Interesting Daniel, quite interesting. I suspect the random and slow unveiling of information like this will never end which is still better than having nothing. Good work! I cannot help you with the Japanese though, I'm just happy to keep my English up to par.

[Daniel Beardsmore]

A head-to-head test with an old MX Black switch shows that the tactile peak is 50–80% of the way down the MX switch travel depending on the switch, so that's around 65–80 g. Coin testing with 5 g coins gives me 65±5 g for a heavier one, and 60±5 g for a lighter one. Officially it's a tactile force of 50±15 g, so going as high as 65 g is within tolerance. Although I always have my doubts (these switches are the same batch as I got with another order, but the pictures found on AliExpress show the newer un-Japan type, while all of mine are the Japan type), they're definitely not a heavy switch and they're all within tolerance, albeit seemingly at the heavier end of the range.

A used amber switch came to 77 or 97 g depending which coins I stacked (5 and 8 g as I ran out of 5 g coins).

[Daniel Beardsmore]

I cannot help you with the Japanese though …

I've asked hasu whether he'd be willing and able to translate the spec, as it's clear that I don't understand it. For example, looking at the B3G spec, I'm figuring that "TTF" means "Total Travel Force", not "tactile force" (since those have TTF > OF and they're linear). Operating force of 40 g and terminal force of 50 g would be the same specification as orange Alps. However, this would make OF == TTF == 60 g nonsense.

For some reason, so many manufacturers fail to clearly explain the forces involved in switches.

[Daniel Beardsmore]

Since I'm talking to myself again …

It seems reasonable to conclude that all the specified B3G-S switches (100, 200, 400) are tactile.

Terminal force in a linear switch is typically around 150% of the operating force, which is true for B3G.

I'm fairly confident now that "TTF" is "total travel force". However, OF == TTF is in fact possible. It's true of blue Alps, and almost true of amber Alps:

https://plot.ly/~haata/270/alps-skcm-blue/
https://plot.ly/~haata/293/alps-skcm-amber/

It's not a horizontal line from OF to TTF: there's another rise and another dip, but the end result is that he force at actuation is the same as the force at full travel.

Consequently there seem to be no linear switches in the B3G-S catalogue page: they're all tactile.

There does appear to be a description of each sub-type on the page, but I can't transcribe it as the characters are too badly damaged by the fax transmission. The only part I could get from that was "momentary" as it's in kana and kana survives faxing largely intact. The kanji to its right are unreadable. Alternate action switches were for some reason covered entirely separately in both ranges.

[Daniel Beardsmore]

Curious.

Since there's no-one to translate it, I asked SPARC (who doesn't speak English) to simply transcribe the catalogue pages, which he's done.

The three types are described as follows:

B3G-S100/S110/S120: 標準荷重 "Standard load"
B3G-S200/S210/S220: 高荷重 "High load"
B3G-S400/S410/S420: 感触つき "With touch" or "With feel"

Now I understand why Sandy decided that S100 and S200 were linear and S400 was tactile.

So, I am at a loss to explain this.