Switching Challenge

Headphones

Help, please?

I'm about to do a pedal build, with two in one box.  I'd like to implement the Blackstar dual pedal switching arrangement, using one footswitch for each item, as it's quite easy and intuitive to use.

Tread on A, A comes on
Tread on B, B comes on and A goes off
Tread on B again, B goes off and A stays off
All the same if you start from B.

Sounds simple enough (though even that's not simple to type), but I can't devise a method without a huge component count...

The fall back would be two switches; one for on/off (all) the other to switch between A and B in the "on" state.

Can anyone offer me an easy solution?

Sporky

It's not possible with normal 3PDT or similar footswitches. To do the mutually exclusive thing in this way needs logic switching, with momentary footswitches and relays, and stuff in between.

Headphones

Indeed, the trick is to do it with few components...

robinbowes

If you're OK with logic and relays, it shouldn't take too many components - a couple of relays, plus a couple of logic chips.

R.

robinbowes

Have a search for "asynchronous sequential logic circuit design"

R.

Danny1969

Have you thought about using a chip like the 4066 in a stepped switch circuit ?  Very useful chip for the kind of thing you want to do

Sporky

I think it might be possible with just latching relays and momentary footswitches, but I'm quite snoozy so who knows.