Rafi SA162 ED1?

[ander]

Just spotted this strange-looking thing on eBay:

Rafi SA162 ED1 Keyboard





The listing says nothing about it except its name. Were there caps over those switches? And what the heck kind of switches are those? I've never seen anything like them.

Is it possible this isn't a keyboard at all, but some sort of indicator panel? Maybe there were labels that lit up?
 Whaddaya think?

[Daniel Beardsmore]

I've got some of those, but not to hand. They're snap action, stiff and loud with hardly any travel. You can't possibly type on them.

[ander]

Well, given the layout, I figured it wouldn't be for typing... I just wondered what was up with those keys, or indicators, or whatever they are, and what this kind of thing might be used for.

[Daniel Beardsmore]

The type I have doesn't light up. Travel is around 0.5 mm. The snap-action spring is all that there is — it's a good demonstration of the need for a motion reducer, and why stacked spring exists.



The type you posted is clearly different inside, to allow for an LED — mine has the LED holes in the slider, but there's nowhere to put an LED.

That seems to be a trademark of RAFI: a single form factor with drastically different mechanisms to accommodate features. RAFI RS 76 M has three different designs, depending on whether you want an LED or a diode. The LED version uses a totally different contact design, with a different feel (progressive rate instead of linear) and twice the contact bounce time, all just to get that LED in.

That one in your photo could easily be nothing like mine!

[ander]

Interesting! Okay, so I take it these would be push buttons, not for typing (although I realize there are also "matrix" typing keyboards with non-staggered keys). Do you have any idea what kinds of applications think these could have?

[Daniel Beardsmore]

RAFI depict these kind of switches as being placed under an overlay, where the buttons are printed onto a sheet. Individual keycaps also exist.

The switch series is RF 15 (just "RF 15" without an "N", "R" etc); you can see an example on this page:

http://www.rafi.de/en/products/components/pcb-tactile-and-full-travel-switches/rf-1519/

I'll leave you to draw your own conclusions as I don't pay much attention to non-keyboard buttons other than observing that they universally suck.

[ander]

I'll leave you to draw your own conclusions as I don't pay much attention to non-keyboard buttons other than observing that they universally suck.

LOL... Maybe you'd prefer their long-travel switches (my highlighting) :

Our input systems with a key stroke of 1 to 5 mm are optimised for rapid data input. The customer-specific keyboards are based on the RAFI integrated PCB keyswitches – of course individualised contact systems are also possible. Long-travel keyboards are particularly suitable for inputting many characters and texts. This is why they are used in PC keyboards, for example. Another feature of the RAFI long-travel system is the efficient and homogeneous illumination that “night design” keyboards make possible.

OVERVIEW OF ADVANTAGES

• Very good tactility with a distinct keyswitch click
• Varying actuation forces depending on the application
• Efficient and homogeneous illumination for night design
• Optimal for entering long text passages
• Combination with displays and other components on a single PCB

[Daniel Beardsmore]

Langhubtaster ("Long travel keys") covers a wide variety of switches, although I'm surprised that they go down to 1 mm travel now, as they're meant to be 2.5 mm minimum (according to the catalogue I have). That broad family (if it's the same one, as that page gives very little away) includes RS 74 (2.5 mm travel) and RS 76 (4 mm travel) keyboard switches. These do not click, however, but RS 76 C seems to be very nice (I only have sample switches — I've never typed on them). (RS 74 has been obsolete for some years now, but I do have an RS 74 M keyboard.)

[dantan]

So these are RAFI switches? And with hardly any travel? Doesn't sound like any keyboard I know apart from membrane ones with no tactility at all!