Understanding positive ground....

[Outlaws]

I recently started building pedals again after about 8 years.  Working on a Tonepad MKII Tonebender.
I have OCD and don't grasp this positive ground. I saw a YouTube video on NPN vs PNP and positive triggering the transistor vs ground triggering it, and while that part seems to make sense somewhat, it's the -9v running thru ground that I do t grasp.

My pedal build will be battery only.  I get the concept that the power supplies of a daisy chained setup like my non-isolated Dunlop DC brick won't work, but one thing I do t get is this...  if applying the battery voltage to ground, won't any other pedals (including the amp) now get -9v on the ground via my guitar cord?  How does this not screw up everything the same way as daisychained power supplies?

And then more to the point...all my traditional ground connections (pots, led, in/out, ring) all still get a common ground correct? It's just the battery black is the voltage supply and the red is connected to that common?

[thermionix]

Oh man.

Hey I think I saw The Outlaws once, many years ago.

[merlinb]

And then more to the point...all my traditional ground connections (pots, led, in/out, ring) all still get a common ground correct? It's just the battery black is the voltage supply and the red is connected to that common?

Correct. 'Ground' is always linked from pedal to pedal, daisychained. It is always '0V' by defintion.

'Positive ground' is just a silly and confusing way to say 'negative power supply voltage'. e.g. -9V not +9V

[antonis]

I saw a YouTube video on NPN vs PNP and positive triggering the transistor vs ground triggering it, and while that part seems to make sense somewhat, it's the -9v running thru ground that I do t grasp.

I don't know at which video you refer to but maybe it should be easier to get it by remebering that for a n-p-n BJT normal operation, Collector should be more possitive than Emitter... 
(we need a force to push current downwards - from collector to emitter.... or to suck electrons upwards... anyway, don't bother about conventional or real current flow direction..)

i.e. if we connect collector to 0V (GND) and emitter to minus (-) something, we'll also have a happy working transistor...

[Outlaws]

Oh, so the current isn't actually on the ground side?  The current flows from the negative of the battery to the board?
This makes way more sense if that is correct.
So any schematic or board diagram that shows a -9v connection is the black lead basically acting as the voltage input?  Then even diagrams showing Ground in red are still tied to the common?
I guess this is making more sense.

The last set of questions is, power supplies with isolated outs mean I can just use them as long as their positive pinout meets up with the red battery lead, and the negative pinout meets up with the black battery lead?  So if I wanted to use an 1/8" mini phono jack where typically the center would be positive, I would actually wire positive to the sleeve to retain the center negative and not ground out my negative voltage?  Then find/make a lead that accomplishes that flow.

[antonis]

Oh, so the current isn't actually on the ground side?  The current flows from the negative of the battery to the board?

Current isn't actually on NEITHER side..!!!
(it needs two sides/points to flow between them - for conventional flow, it does it from higher to lower potentional difference (voltage) points)

The last set of questions is, power supplies with isolated outs mean I can just use them as long as their positive pinout meets up with the red battery lead, and the negative pinout meets up with the black battery lead?  So if I wanted to use an 1/8" mini phono jack where typically the center would be positive, I would actually wire positive to the sleeve to retain the center negative and not ground out my negative voltage?  Then find/make a lead that accomplishes that flow.

Isolated outputs mean that they don't share a common GND...
(each one has it's own grounding path which "stops" back on each individual transformer secondary winding..)

If you mix them up you loose the benefits of "isolation"...

[GibsonGM]

Electrons flow from negative to positive.  Like in the game "Connect 4", what you could think of as 'holes' flow to the negative.  You drop in a checker, the checker (electron) goes down...the holes behind it could be thought to go "up"... The holes are just the absence of electrons.      Now, when Ben Franklin started out, he assumed current flow was + to -, so we still often think that way.   In a 'normal' circuit...the potential is + to -,  but the current is really flowing from - to +!     

The actual DIRECTION is not important as long as you respect that there IS a polarity, a way some things must "face" to operate correctly.    The way you want to think about "-9" above is right, and will work for you.      "Black wire" being voltage input - great!  Red wire common - Great!  For that one circuit, you can follow that thinking and be safe.

Ground is just a common reference point.  It can be tricky...nobody wants to confuse people, so we often just let it lie as " - " is ground most all the time....BUT, as you now see, sometimes it's not!!    A common reference point can be 1V,  -5V....as long as it is common, and you are following those polarity rules...it does not matter.  It is a convention - we HAVE to start from somewhere!  We're lucky it's most always " - ", makes things easier.

When I am building (on perf, no PCB), I think of "Hot" for supply, whether it's - or +.  I just call "not ground" HOT.  Simply...."this goes to hot, great".   Then at the end I connect the power leads.   Have to remember to keep parts oriented right, though. 

Antonis seems to have answered your supply question...changing ground alters the 'isolation'...

[EBK]

Electrons flow from negative to positive.  Like in the game "Connect 4", what you could think of as 'holes' flow to the negative.  You drop in a checker, the checker (electron) goes down...the holes behind it could be thought to go "up"... The holes are just the absence of electrons.      Now, when Ben Franklin started out, he assumed current flow was + to -, so we still often think that way.   In a 'normal' circuit...the potential is + to -,  but the current is really flowing from - to +!     

In other words, the engineers of our past stubbornly refused to correct a glaring error.   

[antonis]

Antonis seems to have answered your supply question...

Antonis also seems to have an about 39^oC fever so please show some empathy for his brief & laconic answers... 

@Outlaws: Capital letters & Exclamation marks are used for words & phrases notification rather than for appearance of anger or yelling mood ... 

[merlinb]

In a 'normal' circuit...the potential is + to -,  but the current is really flowing from - to +!   

Actually it's simpler than that. Negative current flows from negative to positive because electrons are negatively charged.
Therefore it is equally correct to say positive current flows from positive to negative (current is not the flow of electrons but the change in charge over time). And most people prefer to take in terms of positive numbers because they're easier. Simple maths. There's nothing 'backwards' or erroneous about it. You might as well argue that world maps are always drawn upside down because Antarctica 'ought' to be at the top. 

I suspect beginners would get a lot less confused if people would stop mentioning electrons altogether. The are irrelevant unless you're a nuclear scientist.

[GibsonGM]

In a 'normal' circuit...the potential is + to -,  but the current is really flowing from - to +!   

Actually it's simpler than that. Negative current flows from negative to positive because electrons are negatively charged.
Therefore it is equally correct to say positive current flows from positive to negative (current is not the flow of electrons but the change in charge over time). And most people prefer to take in terms of positive numbers because they're easier. Simple maths. There's nothing 'backwards' or erroneous about it. You might as well argue that world maps are always drawn upside down because Antarctica 'ought' to be at the top. 

I suspect beginners would get a lot less confused if people would stop mentioning electrons altogether. The are irrelevant unless you're a nuclear scientist.

You're right, Merlin.  It seems that those asking bring those suckers into it, and then we get stuck explaining...probably more than we should, and then with a less understandable message due to our own tendency to complicate things.

Keep the polarities right way around and there won't ever be a problem.

[PRR]

> stop mentioning electrons altogether.

There Are No Electrons.

I'm not sure the book really helps. But some fun.

> irrelevant unless you're a nuclear scientist.

Or stick your head inside a Vacuum Tube.

However every tube-guy I knew, while accepting that electrons flow "up", drew his currents "down" B+ to plate to cathode to Gnd. They are indeed NEGative particles.

And "current" can't happen without LOOPS. Draw your loops. The battery loop does not extend out to the audio common ground. (But a common-supply loop does.)

[Outlaws]

Thanks for all this.

[DeusM]

I suspect beginners would get a lot less confused if people would stop mentioning electrons altogether. The are irrelevant unless you're a nuclear scientist.

NOT A RANT:

I disagree. As a beginner I only understand things when I can imagine how they are really happening. Just imagining an abstract idea doesn't help me understand it. Sure, I can memorize ohm's law and I can remember the equations for power but It's not the way it gets stuck in my head. You can't work with abstract ideas, you need to know how it physically works to fully understand it, specially in electronics since you are working with real things. I't a science. DIY pedals might be a hobby but electronic isn't. Imagine for example a mixing engineer who doesn't know anything about how sounds work. Sure you can mix without knowing anything about sound and maybe get a great mix, but knowing how the things you work with really work, is a big difference. Even if you are a beginner, it's something you CAN'T and SHLOUDN'T avoid if you pretend to keep progressing.
As a musician and music teacher I see often how one sometimes tends to just give the right amount of information for the student or the person we are trying to explain something because we believe we are only going to confuse them, and most of the times it's the case, but it's also our fault for being too condescending. We should push the limits of the person learning. It's never easy to understand something and just because you are explaining it like the persons if 5 years old doesn't mean it learned something, because most of the time they will forget it the other day. It happened to me while learning electronics. I Forgot what voltage and current where, until a read about how it physically works.
If you treat someone like a child, it will understand as a child. If you treat him like an adult, it will learn as an adult.
Just giving my thoughts on this, hope nobody gets offended 

[LightSoundGeometry]

you learn about the valence shell and charges in like paragraph one chapter one lol

electrons I think have more to do with bonding than attraction which might be the same dang thing lol ..i know it was gone over in physics a lot more so than chemistry or electronics especially studying forces which are basically charges

[merlinb]

Just imagining an abstract idea doesn't help me understand it.

There's nothing more abstract than an electron! Current is simple. It's the 'stuff' that does the work, not the electrons. Current 'flows' at a fantastic speed; electrons move at snail's pace. Electrons can't cross a capacitor; current can. These are perfect examples of why thinking about electrons isn't the best route to being a better electronic designer.

Sure, don't deny yourself learning about where current comes from, but be careful what you read. The easy descriptions are often written by beginners for beginners; i.e. they are wrong, and they perpetuate those wrong concepts, which ties you up in knots later until you un-learn it. 

[PRR]

> you need to know how it physically works

I have wet land. I have been ditching a lot of water.

I am learning how water flows, and how to flow better.

Water is water molecules, clumps of H and O. But do I look at it at that level of detail? Is that pipe flowing 10^37 H2O lumps a second? Uh, no, I see gallons or cubic-feet of water. An amorphous liquid with no discernible (to me) internal structure.

The word "current" applies equally well to water or electricity.

FWIW: inside a wire, current flows at (nearly) the speed of light. The electrons (if we believe in them) move much-much slower.

It is interesting that in a Vacuum Tube, Grandfather of ALL Electronics, electrons are the main current carrier and they do move with some speed (but not SoL). However in a Gas Tube the carriers are positive ions, and they move very slow (large mass/charge). And in crystals (semiconductors), electron-thinking is just confusing.

And FWIW, the "negative charge" does apply to my ditch-work. My real goal is to have negative water on the wet land. The water current runs west. The "dryness" (negative wetness) runs east.

[blackieNYC]

I think there's one more thing worth mentioning.
if applying the battery voltage to ground, won't any other pedals (including the amp) now get -9v on the ground via my guitar cord?
This has been explained well and I think you know there is not -9volts on the ground. But there's another way to look at this particular question.
Ignoring electrons, nothing comes back from ground.  Not -9volts, or +9volts, or (hope/thankfully) noise (which is why we try to send it there).  The high frequencies in your LP filter go thru that cap to ground. They don't just disappear. We send them there and they never come back.
Only electrons come ba... Damn! Couldn't do it.

I was taught electronics by a physics professor.  He used an electron-flow oriented textbook, with all the arrows going the wrong way. That was just no good.

[mac]

It's all about mass and charge... ah, and spin. And the bloody quantum mess they create

https://www.researchgate.net/publication/233813051_Of_Mass_Charge_and_Spin_the_basic_attributes_of_matter_--Their_physical_origin

mac

[DeusM]

> you need to know how it physically works

I have wet land. I have been ditching a lot of water.

I am learning how water flows, and how to flow better.

Water is water molecules, clumps of H and O. But do I look at it at that level of detail? Is that pipe flowing 10^37 H2O lumps a second? Uh, no, I see gallons or cubic-feet of water. An amorphous liquid with no discernible (to me) internal structure.

The word "current" applies equally well to water or electricity.

FWIW: inside a wire, current flows at (nearly) the speed of light. The electrons (if we believe in them) move much-much slower.

It is interesting that in a Vacuum Tube, Grandfather of ALL Electronics, electrons are the main current carrier and they do move with some speed (but not SoL). However in a Gas Tube the carriers are positive ions, and they move very slow (large mass/charge). And in crystals (semiconductors), electron-thinking is just confusing.

And FWIW, the "negative charge" does apply to my ditch-work. My real goal is to have negative water on the wet land. The water current runs west. The "dryness" (negative wetness) runs east.

Can you see electricity? How do you know it's working the way it's supposed to be and not working just by accident. You can compare water to electricity, it's like comparing apples to elephants. Sure, you can say, water has pressure, has a potential difference because of gravity, but just because fruits and animals are organisms doesn't mean they are the same thing. Is just generalizing.
There's a guy in my town that sells pedals end even power supplies and he doesn't even know what electron flow and conventional current is. Do you think he's a better electrician than me because I can't make power suppliess? I don't know the answer, what I know is that you can just ignore how things work if you want to become good at what you do and not just be ok.