Author Topic: Magnetic key switch idea (Read 8653 times)

bhtooefr · « **on:** Wed, 10 February 2010, 20:44:10 »

The idea behind this would be to create a keyswitch that uses magnetic forces so as to not be susceptible to wear, to have a highly tuned response curve, and to generate electricity.

I don't quite have the mechanics of it worked out yet, but the key would be attached to a magnet. That magnet would have magnets interacting with it to shape its response on the way down. In addition, there would be a coil or something to pick up current from the moving magnet somewhere along the key magnet's path.

This way, the keyboard could generate electricity from the typing action, which could be used to power (for example) a bluetooth controller, making a keyboard that would never need to be charged or have batteries replaced. (If the amount of surplus power is significant enough, it could even be used to charge other devices.) In addition, I'm thinking a very Topre-like response curve (although I've never used a Topre) would be possible, for possibly lower cost.

Thoughts?

Shuki · « **Reply #1 on:** Wed, 10 February 2010, 20:50:04 »

onowak · « **Reply #2 on:** Wed, 10 February 2010, 22:47:44 »

now build a prototype.

ill buy one if it works.

[edit]ill pay up to a grand.

for real.

-0.

msiegel · « **Reply #3 on:** Wed, 10 February 2010, 22:59:45 »

Quote from: bhtooefr;157694

...for possibly lower cost

or, for much higher cost, how about if the keycap-attached magnets float above electromagnets.

then the curve could be changed at will, and the board could generate dynamic feedback (bumps, vibrate etc).

it would weigh a ton & eat power plants for breakfast.
XD

HaaTa · « **Reply #4 on:** Wed, 10 February 2010, 23:49:54 »

Sounds like a job for an electrical engineer

.
Maybe I should use those skills for the benefit of geekhack.

bhtooefr · « **Reply #5 on:** Thu, 11 February 2010, 01:37:14 »

See, I wouldn't be adding energy to the keyswitch to keep it levitating. For a linear switch, I'd have a magnet at the bottom of the switch that will naturally repel the key up. Then, for a more tactile switch, have a magnet up higher that's set up so that when the key's at the top, it's repelled up, but when the key stem magnet passes through, and a different pole is exposed, it's repelled down.

And, there would be a coil, but it wouldn't be energized - energy would be collected from the coil. Theoretically, you could do keystroke detection this way, although a magnetic switch at the right point would probably be more reliable - low velocity strokes wouldn't be detected, and key triggering would be velocity, not position, sensitive, unless you used the magnetic switch.

ak_nala · « **Reply #6 on:** Thu, 11 February 2010, 01:42:13 »

Wow - I've been thinking along these very lines for a good two months now (Except for the power generation bit - that's interesting too).

Synchronicity lives!

The electromagnet suggestion is also interesting, but problematic. Perhaps superconductors? Then you swap the raw power requirements for refrigeration issues. "The new mag-lev super-massive collider keyboard, brought to you by CERN - you too can create a black hole on your desktop." :O

I was thinking that power curves could be adjustable using a mechanical solution - a bit simpler, I should think.

Something that I'm interested in, though perhaps pushing towards fringe medicine, is the possible therapeutic uses of at least a fixed magnet board. If you orient the poles correctly (according to some - the research is mixed), the magnets could potentially be of benefit to hands, etc. - might help mitigate things like RSI, peripheral neuropathy (I have the latter), etc.

I suppose we'd also have to put a warning against using them for anyone with a pacemaker or insulin pump, though.

My first step is modding an existing board to see if Alps and/or Cherry switches can be mag-leved, and whether or not the typing experience is an improvement, or at least OK. Already have most of the parts

bhtooefr · « **Reply #7 on:** Thu, 11 February 2010, 01:50:39 »

That looks different from what I'm trying to do, but it also looks like a validation of the principles behind my approach.

ak_nala · « **Reply #8 on:** Thu, 11 February 2010, 01:55:22 »

Very cool to see the DataHand patent, thanks. Didn't realize it had been patented so late - how long have they been making them?

This is a very different concept, however.

ak_nala · « **Reply #9 on:** Thu, 11 February 2010, 02:07:56 »

BTW - one of the things I had thought of that did use active coils was using them to register the exact moment of switch activation from hall-effect sensors. As the mag-leved key descends it activates the hall effect sensor and the controller sends a pulse to that key's coil so there is a sensible (and adjustable) perturbation in the force curve - a bump.

Flick another switch and it would free a clacker adjacent to the coil so it also acts like a solenoid, producing an audible click that is fully user selectable. On for when you want clicks, off when you want to spare the spouse.

I don't see how all this would be powered by a lowly USB bus, however.

EDIT: Obviously the above is not limited to Hall-Effect sensors - any switch's closing would trigger the pulse from the controller, so light sensors, or even mechanical contact switches would be equally doable.

ak_nala · « **Reply #10 on:** Thu, 11 February 2010, 02:13:06 »

Yes, I want a DataHand. Have for awhile now. Very, very cool concept that just gets better the more you know about it.

ak_nala · « **Reply #11 on:** Thu, 11 February 2010, 02:20:21 »

Well, Hall-effect does come to mind when you are talking moving magnets, so it's only natural. While they are too expensive for most uses, they do have their place if you are talking building something that is nearly impervious to environmental conditions, etc. But yes, I agree it would be overkill. Hence the Edit to the above post, edited even before I saw the response.

ak_nala · « **Reply #12 on:** Thu, 11 February 2010, 02:33:01 »

Man you are fast, Ripster!

I've got a job to finish first. Talk to me in a week or two.

ak_nala · « **Reply #13 on:** Thu, 11 February 2010, 02:47:29 »

One interesting thing about the idea of using optical sensors is that you could make them adjustable as well. Something else I had been thinking about.

Basically you could have it so the sensors can slide up or down the key or switch-well such that you can have them activate anywhere you want within the 4 mm length of key travel --- 1/2 mm - 1 mm increments should do.

Could even make the switch longer than the usual 4 mm max travel if there was a call for it - more like an old typewriter.

EDIT - obviously all this adds to the complexity and vertical footprint of the switch and resulting keyboard - probably well into beam spring territory.

ak_nala · « **Reply #14 on:** Thu, 11 February 2010, 03:14:37 »

Exactly!

Or, if you make the base magnets strong enough, you could put them on a separate plate under the PCB and use a simple mechanical adjuster to increase or decrease the distance and hence the perceived force.

You would almost need to do something like this to compensate for the fact that the activation force would go up substantially as you adjusted the optical sensors to trigger later in the key stroke - unless this interaction turns out to be a desirable feature.

ak_nala · « **Reply #15 on:** Thu, 11 February 2010, 05:11:49 »

Well, as you have to contain and stabilize the magnets, a slider will still be necessary, and with that you will have some friction between it and the sides of the switch housing. But yeah, no friction against any metal switching or tactile/click leaves.

trievalot · « **Reply #16 on:** Thu, 11 February 2010, 05:31:15 »

no friction if you are using liquid helium as a lubricant for the sliders, and also to supercool the magnets.
Ill connect mine to the LHC.

onowak · « **Reply #17 on:** Thu, 11 February 2010, 09:18:22 »

i never agreed to buy one from ripster - only the OP.

nice try, though.

offer is still good, (to the OP). would be great if it looked nice, too.

-0.

DreymaR · « **Reply #18 on:** Thu, 11 February 2010, 10:26:32 »

This topic seems absurd?!

Firstly, don't discuss magnetic keyswitches without a proper reference to existing implementations. You want something expensive with magnets? Already made.

Secondly, while somewhat funny it is clearly not acceptable to need a power plant to run your keyboard like the super-electromagnet suggestions imply. You know what a Bitter magnet consumes? And even if my MR scanner doesn't pull anything for its superconducting coil that has to be kept at 4 K and runs 400 A of current which wouldn't take kindly on the kind of manipulations you're talking about here (for that, we use gradient coils in the bunch-a-kilowatt class). Of course, fun could be had with liquid-nitrogen-cooled superconductors since we don't need absurd field strengths here but woe be the typists who lose their keyboards or lose something on them.

Thirdly, to 'levitate' a key switch you'd in reality only need to push it back. So you don't need anything more fancy than two opposing poles and a jig. Why would you want the switch to float in thin air - to make it extremely unstable?

Fourthly... magnet therapy? Not slightly off-center but AWOL in lala land. Goodbye, blue sky.

Yeah, yeah, joke topic I know. Now go buy two of the most powerful magnets at UnitedNuclear and stick your head between them for a really big crunch!

bhtooefr · « **Reply #19 on:** Thu, 11 February 2010, 10:34:16 »

Any more magnets than the bottom magnet and the stem magnet would be for shaping a key response curve, not providing levitation - that's what the bottom magnet is for.

itlnstln · « **Reply #20 on:** Thu, 11 February 2010, 12:00:04 »

Damn, that looks money, ripster.

quadibloc · « **Reply #21 on:** Thu, 11 February 2010, 12:18:10 »

Quote from: DreymaR;157799

Better burden you cannot carry than man-wisdom much -- Hávamál

Each man must be moderately wise, but not too wise... but a man does not bear a better burden on the road than a great deal of common-sense.

I kept understanding the quote in your .sig, in the form you gave it, in the opposite of its real sense; it seemed as though it were saying that much wisdom is worse than a burden whose weight is impossible to bear - rather than meaning "there is no better burden you can have with you".

Byrði betriberrat maðr brautu aten sé manvit mikit -- Hávamál

onowak · « **Reply #22 on:** Thu, 11 February 2010, 12:24:15 »

the OP has most-favored nation status.

even if your prototype is higher quality and made by real Midwesterners who relocated from the RioGrande region of the States...

its too bad you arent wearing the magic turtleneck + 2, jeans of Jordache, and sneakers of Nike's Swift Feet...

i would probably pay double. nay triple.

-0.

itlnstln · « **Reply #23 on:** Thu, 11 February 2010, 12:39:51 »

Quote from: ripster;157819

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Author Topic: Magnetic key switch idea (Read 8653 times)