how do toy switches work? matrix???

[LOSS1234]

Hello. I am new to bending and have been having some luck but one area I can find NO information on is how the buttons/switches work on 90 percent of newer toys. From what I can tell there is a gold CIRCULAR area on the circuit board where a rubber button touches (makes contact) with the circle to turn the sound or light or song ON but what i want to know, is how can i rewire or fix or shorten or remove the switches and use them differently or in something else.

for example, on old toys that i have fried, there are still tons of these little switches on tiny boards that it would be nice to use in something else. but unlike a pot, i dont know how to wire them up to another project.

I get how a pot works but these switches all seem to connect to a common bus and then travel down some thin cable. Do they HAVE TO HAVE A GROUND or can i just connect the wire to another device?

ALSO, what kind of signal do these send out? is it resistance based like a pot or is it a logic signal?

any info or schematics appreciated.
I have tons of toys with these sorts of matrix switches and i cant figure them out for the life of me.

btw most of these toys are from leapfrog or v-tech or made in china

[Circuitbenders]

I'm not entirely sure what you're describing here, any chance of a photo?

Most toys with keypads that work on matrix switching will have a decoder chip that makes sense of the buttons you press.  With only a few outputs you can create a fairly big matrix of buttons, the speak and spell has 40 keys for 13 outputs.

They work by having a load of vertical conductor lines and a similar layout of horizontal conductor lines under the keypad. When you press a button it will connect one of the horizontal conductors to a vertical one giving a unique output address, i.e. row 5 connected to column 3 will connect a different set of ouput pins than row 4 connected to column 7 etc etc. You can map out which button presses connect which output points using a multimeter on the solder points where the  keypad matrix connects to the circuitboard.

These kind of switches don't actually send out a signal, they just join two points  like any other switch

[beatpoet]

I did a project using a  button with the gold circiular area on the circuit board.  Basically, the button works just like a normally open pushbutton, the two halves of the gold circular area are connected when the button is pushed, completing the circuit.  You can solder wires to each half of the gold area or the traces that come from it to use it as a trigger.  I took a Staples Easy button and it uses that type of button to trigger the sound playback, used the easy button as a giant pushbutton to trigger another circuit.  I can post pics if you need 'em, don't have the original project, it was made for a friend, but I have another button I could open up and show how I wired it all up..

[angrydroid]

You also might notice that if you lick your finger and touch the gold button circuit that also works... if you lose the little rubber button thingy.

[Tyler1144]

i know exactly what your taling about!!! the button is pretty much a toilet plunger with a conductive circle in it that touches the 2 button points together under it. I dont like them so i scraped the board cover off the printed wires and soldered to them and put it to a pushbutton... works the same, looks cooler