Relay noob question

Started by dumbasapost, July 14, 2021, 12:29:14 PM

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dumbasapost

Hi all,

I'm pretty new to relay switching, and while I understand how to wire and code the basic effect on/bypass switch and the on/bypass/momentary on or bypass, I'd like to be able to set it up so that it has an on/bypass/long hold selecting a different value of a given parameter of the effect so that say you are using a reverb, it's in the on position, and you long hold the switch and it could set the decay to a larger value as long as the switch is held and then returns to the normal value when released. Was also thinking the same could be done with a delay to use an infinite repeats function...

Anyway, I have no clue how to achieve that specific thing, and all my go ogling just points to intelligent bypass switching which all just shows how to do the normal on/bypass/momentary on or bypass. Can anyone point me in the direction of some resources to help figure this out?

ElectricDruid

Welcome!

What you're after is certainly possible, and if you've got the "normal on/bypass/momentary on or bypass" thing worked out, you've clearing got the coding skills for it.

What you don't mention is what sort of circuit you want to control the parameters in. If the effect processing was being done in the same processor that's doing the bypass switching you mentioned, then it's easy, because you can change the values directly. If it's some other digitally controlled box with MIDI, you could alter the values by sending it a MIDI message. If it's an analog pedal with a pot, things get more tricky. Probably simplest would be to use CMOS switches to select between two separate pots (or one or both could be trimmers). Avoiding clicks on the switching might be tricky if it's got audio going through it when it switches though. There are plenty of other solutions though, so I'm sure we can find something that would work.

More information please!

dumbasapost

#2
So the effects I'm particularly try to do this with are a delay pedal and a reverb pedal. I'm am about to build them, and normally I've just used regular 3pdt switches but I'm getting into this relay stuff and I'm finding out that previous experience with arduino projects and such is becoming useful. I was originally intending to use analog based circuits that utilized potentiometers for the parameter values but I could easily change the plan to go to more digital type for these effects if it makes this step more attainable at my level. And for both the switch and the circuit would be in the same box so no need for the midi.

dumbasapost

Oh and thank you for the warm welcome!

antonis

Just make sure for circuits "isolated" relay ground.. :icon_wink:
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

dumbasapost

Do you mean making sure that the audio ground and the relay grounds are separate? I was planning on doing that, but if there is a different type of isolation you mean then imma need some more info on that magic

antonis

No magic at all.. :icon_smile:

Just make sure that there is no possibility of direct coupling between the signal ground and relay power ground..
(these must only join right back at the power supply..)

A simple RC smoothing filter on relay supply positive side shouldn't be a bad idea.. :icon_wink:
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

dumbasapost

OK thank you for that@ I'll look into rc smoothing filters, it's seems I'm learning more stuff to consider at every turn in this endeavor!

ElectricDruid

Quote from: dumbasapost on July 14, 2021, 12:50:42 PM
So the effects I'm particularly try to do this with are a delay pedal and a reverb pedal. I'm am about to build them, and normally I've just used regular 3pdt switches but I'm getting into this relay stuff and I'm finding out that previous experience with arduino projects and such is becoming useful. I was originally intending to use analog based circuits that utilized potentiometers for the parameter values but I could easily change the plan to go to more digital type for these effects if it makes this step more attainable at my level. And for both the switch and the circuit would be in the same box so no need for the midi.

Ok, that sounds pretty reasonable. So have a look about and come back with the schematics of the delay and reverb designs that you're thinking of building, and we'll have a look at how those could be (maybe "modified to be") controlled by the Arduino-based stuff that you're already comfortable with. That's not too big a step to make.
If those specific circuits are particularly difficult, I'm sure someone here has a better idea for something similar.

HTH

antonis

Quote from: dumbasapost on July 14, 2021, 05:59:15 PM
OK thank you for that@ I'll look into rc smoothing filters, it's seems I'm learning more stuff to consider at every turn in this endeavor!

Something like this:
(R1 & C2)
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

dumbasapost

Thank you for the advice thus far, I'll definitely come back with a schematic once I'm done deciding what circuit I'm trying to build. I love DIY communities like this, always someone who is helpful and willing to help new guys understand and build knowledge