Hi,

I know this isn't exactly a 8052-related question, but the PCB on which I will have several such SPST switches is controlled with a 8051 derivative. So, there is a relation and I might be lucky I'm not kicked out with my question... ;-)

I have the following 'problem':

I have a 4 pins miniature PCB switch with the following properties:

When the button of the switch is not pushed (so, when in open mode), the following applies:

   1     2
---O-----O---
         
          
---O-----O---
   3     4

In other words, contacts (1,2) and (3,4) are ALWAYS closed, whether the button of the switch is pushed or not. In fact, (1,2) as well as (3,4) are internally hard connected with each other.

When the button of the switch is pushed, the following applies:

   1     2
---O-----O---
   |     |
   |     |
---O-----O---
   3     4

So, when the button is pressed, (1,2) and (3,4) stay connected (see above), but now (1,3) and (2,4) become connected too.

Switch is of type KSA0Mx11 ('x' depends on the force that is needed to push the button down), info can be found here: http://www.ittcannon.com/media/pdf...SA_KSL.pdf

Anyone any idea how to represent such switch on a schematic and also how to represent it in a PCB library?

Best rgds,

--Geert