Notebook keyboards ?

This query perhaps applies to desktop-PC keyboards too.

My notebook's 3 keys on the left botton: Ctrl, Alt, Fn started getting
unreliable and then failed. When I opened it up, I saw, as expected
that these 3 keys are the only ones on one of the 'ribbon's tracks'.
So obviously if the continuity was broken after the key closest to the
connector, then all 3 keys would fail.

But what I'm realy interest to know is what technology is used ?
Is it galvanic [actual contact] or capacitive ?
The 2 transparent plastic-sheets with the tracks 'meeting' at the
'key-points' are 'sealed together' so I can't see/feel what's inside,
at the actual 'key-points'.

If the key-press causes the top-sheet's track to connect with the
bottom-sheet's track, then what keeps them apart when no key
is pressed ?

The one plastic track-sheet, mounts against an aluminum plate
which might be relevant if capacative-pulsing is used.

Thanks for any explantion/s on the workings of this strange thing.

wrote:
> This query perhaps applies to desktop-PC keyboards too.
>
> My notebook's 3 keys on the left botton: Ctrl, Alt, Fn started getting
> unreliable and then failed. When I opened it up, I saw, as expected
> that these 3 keys are the only ones on one of the 'ribbon's tracks'.
> So obviously if the continuity was broken after the key closest to the
> connector, then all 3 keys would fail.
>
> But what I'm realy interest to know is what technology is used ?
> Is it galvanic [actual contact] or capacitive ?
> The 2 transparent plastic-sheets with the tracks 'meeting' at the
> 'key-points' are 'sealed together' so I can't see/feel what's inside,
> at the actual 'key-points'.
>
> If the key-press causes the top-sheet's track to connect with the
> bottom-sheet's track, then what keeps them apart when no key
> is pressed ?
>
> The one plastic track-sheet, mounts against an aluminum plate
> which might be relevant if capacative-pulsing is used.
>
> Thanks for any explantion/s on the workings of this strange thing.
>

Try classifying the keyboard using this article. Based on
what I see here, the pattern where the conductors meet,
may tell you something.

http://en.wikipedia.org/wiki/Keyboard_technology

Paul

On Tue, 06 Oct 2009 01:42:01 -0400, Paul rearranged some electrons to say:

> wrote:
>> This query perhaps applies to desktop-PC keyboards too.
>>
>> My notebook's 3 keys on the left botton: Ctrl, Alt, Fn started getting
>> unreliable and then failed. When I opened it up, I saw, as expected
>> that these 3 keys are the only ones on one of the 'ribbon's tracks'. So
>> obviously if the continuity was broken after the key closest to the
>> connector, then all 3 keys would fail.
>>
>> But what I'm realy interest to know is what technology is used ? Is it
>> galvanic [actual contact] or capacitive ? The 2 transparent
>> plastic-sheets with the tracks 'meeting' at the 'key-points' are
>> 'sealed together' so I can't see/feel what's inside, at the actual
>> 'key-points'.
>>
>> If the key-press causes the top-sheet's track to connect with the
>> bottom-sheet's track, then what keeps them apart when no key is pressed
>> ?
>>
>> The one plastic track-sheet, mounts against an aluminum plate which
>> might be relevant if capacative-pulsing is used.
>>
>> Thanks for any explantion/s on the workings of this strange thing.
>>
>>
> Try classifying the keyboard using this article. Based on what I see
> here, the pattern where the conductors meet, may tell you something.
>
> http://en.wikipedia.org/wiki/Keyboard_technology
>
> Paul

The old IBM buckling-spring keyboard is the best one I ever used. I
still have my old IBM-PC keyboard, one of these days I'll make up an
adapter to map the old keycodes and format into the AT(PS2) standard,
just haven't had time to get around to it.

In article <haelbb$eoo$>, Paul <> wrote:

> wrote:
> > This query perhaps applies to desktop-PC keyboards too.
> >
> > My notebook's 3 keys on the left botton: Ctrl, Alt, Fn started getting
> > unreliable and then failed. When I opened it up, I saw, as expected
> > that these 3 keys are the only ones on one of the 'ribbon's tracks'.
> > So obviously if the continuity was broken after the key closest to the
> > connector, then all 3 keys would fail.
> >
> > But what I'm realy interest to know is what technology is used ?
> > Is it galvanic [actual contact] or capacitive ?
> > The 2 transparent plastic-sheets with the tracks 'meeting' at the
> > 'key-points' are 'sealed together' so I can't see/feel what's inside,
> > at the actual 'key-points'.
> >
> > If the key-press causes the top-sheet's track to connect with the
> > bottom-sheet's track, then what keeps them apart when no key
> > is pressed ?
> >
> > The one plastic track-sheet, mounts against an aluminum plate
> > which might be relevant if capacative-pulsing is used.
> >
> > Thanks for any explantion/s on the workings of this strange thing.
> >
>
> Try classifying the keyboard using this article. Based on
> what I see here, the pattern where the conductors meet,
> may tell you something.
>
> http://en.wikipedia.org/wiki/Keyboard_technology
>
> Paul

Wow, that's good, thanks !
wikipedia has got everty thing, and google didn't show me.