Hi All,
I've made Edward Holmes' 555 toy piano and it works great.
http://forum.allaboutcircuits.com/threads/toy-piano-project.84399/
However now I want to see if I can remove the necessity for a stylus. I'm sure this should be quite simple but I've spent many hours on it and to no avail.
I've put together this circuit here: http://www.simple-electronics.com/2010/11/simple-touch-switch-using-transistor.html
Independently, that circuit also works perfectly.
When I try to combine the two circuits, that's where the problems arise. Thus far all I've managed to do is make the entire toy piano turn on and off through the darlington pair, but obviously that isn't very useful –– I need to be able to make the individual resistors complete.
Could anyone be so kind as to explain how I could make this connect properly?
[There is a reason i'm not just buying small touch pads, I want the connection to be formed by a darlington pair so that I can eventually print the keyboard keys out onto paper using conductive ink, allowing a tap of the paper to trigger a note.]
Thanks,
Simon
I've made Edward Holmes' 555 toy piano and it works great.
http://forum.allaboutcircuits.com/threads/toy-piano-project.84399/
However now I want to see if I can remove the necessity for a stylus. I'm sure this should be quite simple but I've spent many hours on it and to no avail.
I've put together this circuit here: http://www.simple-electronics.com/2010/11/simple-touch-switch-using-transistor.html
Independently, that circuit also works perfectly.
When I try to combine the two circuits, that's where the problems arise. Thus far all I've managed to do is make the entire toy piano turn on and off through the darlington pair, but obviously that isn't very useful –– I need to be able to make the individual resistors complete.
Could anyone be so kind as to explain how I could make this connect properly?
[There is a reason i'm not just buying small touch pads, I want the connection to be formed by a darlington pair so that I can eventually print the keyboard keys out onto paper using conductive ink, allowing a tap of the paper to trigger a note.]
Thanks,
Simon