I am making something for my music studio. Its a switching device for analog gear and I want to use momentary switches which means I will need a logic circuit to handle the control voltage from the switches and output control voltage to the relays (and also lights in the activating switch). Has anyone already designed this? I need to control about 20 switches.
I have zero knowledge of Arduino, but I am guessing something this rudimentary has been solved by folks dozens of times by now. Can anyone point me to a solution that exists or perhaps where I might look to get started with this?
Thanks to all! 
Best,
Josh
zero knowledge of Arduino
Seems like you are worrying about things you don't understand yet.
Start learning some basics about "Physical Computing".. There is a beginner discussion of that here (but for a different objective)
https://arduinoinfo.mywikis.net/wiki/EasyConnectKit
Whatever LOGIC you need in your system would be written as Arduino code.
SENSING switches is something Arduino does easily. Maybe use a MEGA as it has LOTS of pins.
MAKING DECISIONS is your logic part
TAKING ACTIONS is the relay (or other output device) part..
So... You want to use a momentary switches but make a relay toggle/latch?
I'm guessing you have some electronics or wiring experience? Any programming experience?
That can be done with a microcontroller & software, or it could be done with [u]Type-T fiip-flops[/u].
If you were making a product to sell you probably wouldn't use a microcontroller for simple logic like this, but as a hobbyist or DIY project sometimes it's easier to do things in software if you're more comfortable doing things that way, etc.
In either case, you need to [u]debounce the switch[/u] (that can be done in software if you use the Arduino) and you'll need a transistor or MOSFET driver circuit to drive the relay.
And in either case build & test one switch/relay first, before you make 20. 
Wow, incredibly fast replies! Thank you!!!
Yes, I have lots of experience wiring "dumb" electronics. I've been in pro audio for a couple decades owning, running & maintaining audio gear (rebuilt consoles, tape machines, etc.). My current project was going to be relatively easy but relied on latching switches and since this is for a mastering room I wanted the switches silent - ergo, momentary. That complicates things and will require some logic switching.
I have zero experience coding or creating devices like this hence the post. So to sum up, I have plenty off soldering iron experience, the circuit laid out for the relay portion of the box but not finalized until I know what the solution will be with how things get switched.
Thanks!!!!!
PS.. I'll add that the role of arduino here is simple. Push a button on the face panel, it flips a relay in a box elsewhere and turns a light on in the switch cap. There will be no "push a button, turn off a different button, and no push-button controlling other push-buttons.
Super simple I think. One to one.
Hi,
I've designed an built a few studios, but not in the past 15 years..
Maybe you need to first think about the possibility of electrical transients that could be picked up in audio circuits. I suggest you put some test together with the relays you plan to use, operate them directly, while listening to many of your audio circuits. Using opto-isolated relay boards and driving them with shielded twisted pair per relay might be necessary. Back when 60 db SNR was OK, this was not so important...
What functions will the relays operate?
Years ago I started to use light-dependent resistors with LEDs illuminating them both as channel switches and audio attenuators. So slow-changing DC signals from human controls to audio circuits.
One of the difficult to fix noise sources was the relay in a commercially-built console that switched the 120V "ON THE AIR" light when the control room mike was switched on
Hey Terry-
Good thinking on the issue. For this purpose the relays we are using work well in other scenarios without noise and since none of the devices (unless they are unhealthy) will have DC on their outputs I would expect them to behave the same here. The relays in this box will only make selecting a piece of gear in the mastering context easier and will not be switched once a recording has begun - so switching gear on and off, input selection, output selection, and also swapping order of some pieces of gear.
Probably sage advice to check if the arduino would generate any electronic fuss, but it will be mounted in a "remote box" with the switches and not in the same box with the relays and surely could be decoupled from the audio if it was creating switching spikes.
Thanks!!!