buttons that don't register well

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Zaphod
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Re: buttons that don't register well

Post by Zaphod » Wed Apr 04, 2018 8:59 pm

One of the things that slightly bothers me about this calc (I’ve not got one but I can read) is the use of dome/dimple switches .....

Was there a particular reason why, say , low profile surface mount tact switches weren’t used instead ?

Michael
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Re: buttons that don't register well

Post by Michael » Wed Apr 04, 2018 9:26 pm

Zaphod wrote:
Wed Apr 04, 2018 8:59 pm
Was there a particular reason why, say , low profile surface mount tact switches weren’t used instead ?
The reason for not using tact switches is because they are too noisy.

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H2X
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Re: buttons that don't register well

Post by H2X » Thu Apr 05, 2018 7:40 am

Michael wrote:
Wed Apr 04, 2018 9:26 pm
The reason for not using tact switches is because they are too noisy.
The decision has been made, obviously, but how noisy were they? What kind of switches were considered?
DM42 SN:00040
Be enter not or (Hamlet Yoda not)

Michael
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Re: buttons that don't register well

Post by Michael » Thu Apr 05, 2018 7:56 am

H2X wrote:
Thu Apr 05, 2018 7:40 am
The decision has been made, obviously, but how noisy were they? What kind of switches were considered?
I tried many different kinds. They all were too noisy, NG for use in a library or during a test.
All have some dome inside, the diameter and the thickness of the dome affect how they sound and the force needed to press it.
The current domes are 9mm in diameter and I haven't found any low profile tact switch with a dome larger than 6mm.
But please make a suggestion for a better switch. I'm very curious.

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H2X
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Re: buttons that don't register well

Post by H2X » Thu Apr 05, 2018 9:11 am

Michael wrote:
Thu Apr 05, 2018 7:56 am
I tried many different kinds. They all were too noisy, NG for use in a library or during a test.
Valid point!
Michael wrote:
Thu Apr 05, 2018 7:56 am
But please make a suggestion for a better switch. I'm very curious.
Alas, I don't have expertise in this area. As I have pointed out elsewhere, I am fully aware that I am nitpicking. Well, partly so - there are obviously some reports of button misbehaviour / inconsistencies, which should not happen (my ENTER key is mushy on the left side, and there are other reports). The nitpicking part is that I would personally prefer a bit softer feel - like the best HP's. How did they manage it?
DM42 SN:00040
Be enter not or (Hamlet Yoda not)

Zaphod
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Joined: Sat Mar 31, 2018 9:34 pm

Re: buttons that don't register well

Post by Zaphod » Thu Apr 05, 2018 9:18 am

All have some dome inside
Yes of course they are dome too inside.
the diameter and the thickness of the dome affect how they sound and the force needed to press it.
but I wouldn't call them noisy per se... and you can specify operating pressure from quite a few suppliers too

Here for example:
https://docs-emea.rs-online.com/webdocs ... 4b0fc9.pdf
Supplied in three different operating force versions
ALPS, Wurth do plenty too

Here's an ALPS, version that comes in four different operating force options
https://docs-emea.rs-online.com/webdocs ... 4b0fb3.pdf

Depends on how much clearance from top of the switch to the bottom of the button you have got ?

I have some surface mount dome switches here that you can't really hear, the dome is more or less exposed (Kapton film over the top) but on it's own substrate.

The main benefit I can see is ease of replacement

Michael
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Re: buttons that don't register well

Post by Michael » Thu Apr 05, 2018 9:21 am

H2X wrote:
Thu Apr 05, 2018 9:11 am
The nitpicking part is that I would personally prefer a bit softer feel - like the best HP's. How did they manage it?
As mentioned, the force needed on the domes depends on their thickness.
Then the plastic hinge of each button adds up too to the total force needed.
The thinner the domes and the hinges are, the more likely they'll break.
Current domes need 150gr force, I'll try 120gr ...

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H2X
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Re: buttons that don't register well

Post by H2X » Thu Apr 05, 2018 9:25 am

Michael wrote:
Thu Apr 05, 2018 9:21 am
H2X wrote:
Thu Apr 05, 2018 9:11 am
The nitpicking part is that I would personally prefer a bit softer feel - like the best HP's. How did they manage it?
As mentioned, the force needed on the domes depends on their thickness.
Then the plastic hinge of each button adds up too to the total force needed.
The thinner the domes and the hinges are, the more likely they'll break.
Current domes need 150gr force, I'll try 120gr ...
Wow, good news (for me, at least)! I'd be happy to test them... :-)
DM42 SN:00040
Be enter not or (Hamlet Yoda not)

Michael
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Re: buttons that don't register well

Post by Michael » Thu Apr 05, 2018 9:35 am

Zaphod wrote:
Thu Apr 05, 2018 9:18 am
I have some surface mount dome switches here that you can't really hear, the dome is more or less exposed (Kapton film over the top) but on it's own substrate.
It depends a lot on how everything is put together. Of course the switch is on a PCB in the end, but try putting a single one on a wooden surface and press the dome with something hard.

Zaphod
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Re: buttons that don't register well

Post by Zaphod » Thu Apr 05, 2018 9:52 am

I agree

But a (thin foam etc) sheet could be added to damp down any excess noise of operation perhaps.

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