Power distribution in a project

[LittlePebble10]

I have experimented with circuitry and only managed to get small things working. I found its because once something such as the positive rail is connected, everything else that is connected to positive can cause interference. So, every section can have interference on the other sub sections just from the power source. I found it necessary to have a separate power regulating circuit for every sub section, but how can I do this without them being affected as well?

 

[(*steve*)]

Depending on what you're doing, bypass caps may be the answer.

If you have a more concrete example we may be able to give you a more concrete answer.

 

[LittlePebble10]

Thanks for the reply. I am looking into building a Piano Synth. When ever I try and put together oscillators they seem to interfere with each other. I also want to control this thing with midi through an arduino. The arduino will only be there to control the oscillators. I have my heart set on creating my own oscillators instead of the arduino alone.

 

[BobK]

How are you wiring the power and ground to each component? If you are daisy-chaining them, that can cause this kind of problem. You should run power wires from each module to a single point where the power comes in (star configuration.) Also a tank capacitor at that point.

Bob

 

[WHONOES]

How are you wiring the power and ground to each component? If you are daisy-chaining them, that can cause this kind of problem. You should run power wires from each module to a single point where the power comes in (star configuration.) Also a tank capacitor at that point.

Bob

I agree with Bob K. Proper power distribution and decoupling capacitors are paramount.

 

[(*steve*)]

@LittlePebble10, as the owner of a modular synthesiser, I wish you well.

Another problem you may be having (and it's hard to tell) is that if you're combining the outputs of several oscillators, and the outputs of the oscillators aren't buffered or isolated in some form (maybe driving the virtual ground of a summing amplifier) the oscillators can affect each other.

 

[LittlePebble10]

Thanks Steve. I think you solved my problem. I accidentally bought the wrong hex inverters and was at a loss of knowing what I was going to do with a 100 of them. I could use them as buffers when I buy the correct Shmitt trigger inverters. For now I will focus on the main problem with power distribution. You guys gave me a lot to think about and I am very grateful for your suggestions.

 

[darren adcock]

Hope it's ok to resurrect this thread. I've just finished building my case and panels for my next synth and am wanting advice on power distribution and thought the question should sit in this thread.

I am considering two options;
- first is running 3 bus bars (0.71mm copper wire, or i have some thicker at 1.4mm) then soldering the 3 wires for each module and attaching to a 3way terminal plug to go into each module.
-The second option is to use a power distribution pcb board which i keep seeing advertised on modular synth websites, they suggest they have lower voltage drop.

I guess i'm asking your advice Steve as I know you have our own modular synthesiser and can speak from experience?

Thanks in advacne

 

[(*steve*)]

Either should be fine, the voltage drop will be small unless you have a module that draws a huge current (in which case is probably faulty)

 

[darren adcock]

Either should be fine, the voltage drop will be small unless you have a module that draws a huge current (in which case is probably faulty)

Cheers Steve