What is a good "standard" force for a momentary push-button?

Title says it all. I'm trying to find information about what is a
good range for the force needed to activate a momentary push-button
switch. My application is to build a custom "d-pad" style array like
you might find on a video game controller or personal electronics.
But I'd also appreciate any links to empirical studies or published
papers on the subject. I'm having trouble getting Google to even come
close to the topic... :T
Thanks,
-Will

 

[Ross Herbert]

On Tue, 2 Dec 2008 08:23:43 -0800 (PST), larkmore@aol.com wrote:

:Title says it all. I'm trying to find information about what is a
:good range for the force needed to activate a momentary push-button
:switch. My application is to build a custom "d-pad" style array like
:you might find on a video game controller or personal electronics.
:But I'd also appreciate any links to empirical studies or published
apers on the subject. I'm having trouble getting Google to even come
:close to the topic... :T
:Thanks,
:-Will


It is not possible to determine a "standard" force for push-buttons. It all
depends on the purpose, environment and user mentality. In the latter case you
have to take into account the idiot who will try to thump sh.t out of a
push-button.

Designers of public use machines such as ticket issuing machines etc always find
the selection of a suitable push-button is a major headache. To go for idiot
proof design costs money and if you don't provide adequate mechanical strength
you run the risk of having to constantly replace faulty units. One of the best
foolproof push-buttons I saw was designed using no return spring or mechanical
contacts. It used counter-posed supermagnets for the spring and hall effect
switches for the outputs.

 

[Spehro Pefhany]

On Wed, 03 Dec 2008 08:08:57 GMT, the renowned Ross Herbert
<rherber1@bigpond.net.au> wrote:

On Tue, 2 Dec 2008 08:23:43 -0800 (PST), larkmore@aol.com wrote:

:Title says it all. I'm trying to find information about what is a
:good range for the force needed to activate a momentary push-button
:switch. My application is to build a custom "d-pad" style array like
:you might find on a video game controller or personal electronics.
:But I'd also appreciate any links to empirical studies or published
apers on the subject. I'm having trouble getting Google to even come
:close to the topic... :T
:Thanks,
:-Will


It is not possible to determine a "standard" force for push-buttons. It all
depends on the purpose, environment and user mentality. In the latter case you
have to take into account the idiot who will try to thump sh.t out of a
push-button.

Designers of public use machines such as ticket issuing machines etc always find
the selection of a suitable push-button is a major headache. To go for idiot
proof design costs money and if you don't provide adequate mechanical strength
you run the risk of having to constantly replace faulty units. One of the best
foolproof push-buttons I saw was designed using no return spring or mechanical
contacts. It used counter-posed supermagnets for the spring and hall effect
switches for the outputs.

I have a great little silicone rubber keypad from an Asian maker that
has a whole bunch of different actuation force sample buttons, as well
as different contact types and so on. Very useful when you're
designing a product that needs a keypad.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com