Radio Buttons (was: Debouncing alot of switches)

[jhaible]

> Why not just have ANY button press trigger a high edge trigger circuit
> that hits ALL the clears of the flip-flops? That means that the button
> you want and the one that stays on AFTER clear pulse (due to you holding
> it) will be the one that will stay in the flopped state. I dont know if
> it will work, but try it.. 

The idea is good, but what happens when the key bounces ? The last
short "high" impulse may be long enough to perform the clear function, but
not long enough to activate the desired flip flop after that.
In some way, that's exactly what I built (but I didn't use CMOS logic. I
used
opamps with positive feedback as storage elements, because I needed 24V
swing,
and a CR high pass for the reset trigger.) Didn't work.

JH.