Electron path of travel

[trem]

No. They do not flow through the filter caps. Those are just a holding tank, if you like. Imagine buckets full of electrons being dumped in to the filter capacitors 120 times per second, and a smooth flow comes out to operate the circuit.

The circuit for electron flow is: Out of the PT center tap, piling up in the filter capacitors for a while, then travelling on through the tubes to eventually get to the B+ rail, where they get sucked towards the filter caps again, and pile up on the positive side for a bit, waiting for their turn to get through the rectifier.

Around the peak of every half-cycle of the line, a bunch of them shoot through the rectifier tube, through one or other half of the PT secondary, and then back out of the center tap for another lap.

Thank You Very Much.....

[Enzo]

This whole idea of electrons flowing or conventional current flowing for that matter, is just a way to get a handle on the idea of "circuit." As long as you reailze there is current flowing between cathode and plate, and that the grid controls it, you understand the tube. That current has to flow through the elements of the circuit. SO you need to understand that the cathode current is going to flow through the cathode resistor.

Now does it really matter which direction we visualize the current flowing? Not really. I have 1ma flowing through a 12AX7. if there is a 1.5k resistor in series with that, then Ohm's Law tells us there will be a volt and a half across that resistor. THAT is what is important. Whether it was electrons flowing one way, or imaginary positive things flowing the other, is just a matter of what color crayon you like to color your pictures with. Either way, you get that volt and a half there.

I have windows on my house. Are they keeping the cold out, or keeping the heat in? I can look at it either way.



Yes, you can build a whole amp without a chassis, but it will still have a common wire in it. Even a star ground is still a common, that which all other voltages are referenced to. Whether your common is a chassis or not, and whether that common/chassis is grounded to earth or not, are just details.


Capacitors: my analogy for a cap is a rubber diaphragm, or maybe a balloon. Water analogy. Your pipes are the wires, and the water is the electrons. Now lets put a larger section in the pipe. Like a tank the pipe comes in one end and out the other. Once the tank fills, now the whole thing goes back to just being a pipe, there may be some turbulence in the wide part, but water flows in one end and out the other.

Now, in the center of this tank, let's put a sheet of rubber blocking the flow. A diaphragm across the width of the tank. Now when water flows in one end, it can;t pass on through, it just pressurizes the tank by stretching the rubber diaphragm.. If I then disconnect the pipe from the filler end, then the stretched diaphragm will make water squirt back out the filler hole. That is how a filter cap works. Electrons don't pass through it, they pressurize it so when the filling pressure goes away, those stored electrons come pushing back out. FIll a water balloon, then remove the filler hose, and the pressurized balloon squirts water back out the neck.

Let's go further, caps pass signal while blocking DC. Back to my diaphragm and tank. This time there is a closed circuit of pipe. and the entire tank is filled with water, not just the fill side. Now if I apply more pressure to the fill side, the diaphragm bulges toward the drain side. But the rubber diaphragm prevents the water from flowing through. Nonetheless, that drain side now has an increased pressure trying to continue along. And conversely, if I draw suction on the fill side, it pulls that diaphragm back and creates a vacuum on the drain side. SO if I alternate pressure and vacuum on the fill side, that same "signal" is present on the drain side, but the flow of water straight on through is prevented. That is how a coupling cap works.


And I have no idea what a water pipe analogy to an inductor would be either. Maybe a paddle wheel in the stream with a heavy flywheel on its shaft. remove the flow, and the momentum wants to keep the paddlewheel spinning. or something.

[Jazz P Bass]

I have found it helpful to realise that capacitors do not store "charge".
They store "Energy".
As to Enzo's excellent description, here is a link with a graphic of what he explained.
Link: ELECTRICITY MISCONCEPTIONS: Capacitor

[Steve Conner]

Oh god, not Bill Beatty. We banned him from 4hv.org.

However, the information on that page seems dead right. Charging a capacitor doesn't alter the total amount of electrons in it, it just redistributes them, so there is more on one plate and less on the other.

[Wombaticus]

Wombat, you are missing the point and are really talking about a different issue.

This is not about ground currents and grounding. And to say the electroncs were always there in the atoms, is misleading as well. You mention needing an electromotive force, well yes of course, and that is what pushes electrons on along. It is what allows the electrons in the common to move on into the rest of the circuit. And that is how the common is the source of the electrons.

The point is this, when your tube emits electrons from its cathode, they flow to its plate. More electrons must therefore come up through the cathode resistor to take their place. And where do they come from? The ground of the circuit. Call it the circuit common instead of ground to eliminate confusion between two meanings for the word ground. There certainly IS current in your circuit commons. In fact this whole discussion about direction of electron flow could just as easily be on a battery operated circuit not connected to earth at all. We often use the term ground to mean circuit common even when nothing is conected to the actual ground. We shouldn't abuse the term that way, but we do.

Now if I just connect a tube to ground, those electrons that had always been there would not start flowing to the plate. For that I need a power supply, and that supply must be connected to the plate AND to the common. SO while we just said the common is the source of the electrons into the cathode, it is also the case that the electrons in the common came from the power supply.

The common is a big pool of electrons only in the sense of the paths through the circuit. We are not suggesting the chassis is a bubbling pool of electrons just itching to spew all over. For current to flow, there must be a complete circuit. The old light bulb and battery lesson from 101 electricity. Since it is a circuit, it is a circle, so pick a spot, any spot, on the circuit as the start. My circuit is a tube and a battery, plus plate and cathode resistors. I pick the cathode to start at. It emits electrons which flow to the plate. Where did those electroncs come from? Through the cathode resistor. And how did they get to the cathode resistor? Through the common. And to the common? From the battery. The battery generates the potential, but it cannot send out electrons without replenishing them, and where do those come from? From the plate resistor. And how did the plate resistor wind up with them? From the plate. And the plate? it got them from the cathode. Circuit complete.

So the ground or common is the source of the electrons for the thing connected to it, that's all, not the source of all electrons for the world, just in a circuit stage, the electrons come from somewhere, and it winds up it is from the ground, rather than from the B+. And that is the basic question this entire thread is trying to answer. We are not suggesting the ground creates electrons, any more than the interstate creates cars, but also just like the interstate, when I see cars coming down the ramp, and someone asks where are those cars coming from, I can say, "from the interstate." Of course they had to enter the interstate at some other point, which would be analogy to our battery.

Actually, I don't see how what you're saying is really any different from what I was saying. I never meant to imply that there is no current in the circuit ground (or common, I like that!), that would be absurd. Chuck H did indeed make a comment that (perhaps inadvertently) injected the notion of ground current into the thread, but trem's response made clear that there was significant confusion in his mind between the ground reference and the ground circuit. Trem also seemed to harbour the misconception that the electrons are somehow delivered to the circuit from the wall by way of the safety ground/chassis, and that needed to be cleared up. Maybe it's best just to say that the electrons zipping around the common (and the remainder of circuit) are aren't coming from the safety ground/rod in the earth outside your house. And that furthermore, in a properly conceived ground scheme, the chassis should *not* be part of the circuit common.

I stand by my assertion that the electrons in the circuit are all there before the switch is flipped. They're like water in the little decorative fountain in my back yard... they don't go 'round and 'round until the pump is turned on, but rather just mill about randomly, doing nothing useful. And I suppose I could invoke Merlin's wave/particle duality argument to continue the squabble about where the electrons supposedly do come from, but there doesn't seem to be much margin in that.

I like your diaphragm analogy for capacitors. The capacitor sub-thread got me off an another tangent and prompted me to go back and reread the little chapter in Cathode Ray's "Second thoughts on Radio Theory" that deals with the difference between potential difference and EMF, and how a discharging cap can properly be thought of as an EMF, rather like the EMF of self inductance. The PD/EMF relationship is surprisingly slippery when you really start to think about it.

[redelephant]

This is a good read:
ETF Presentation

[Steve Conner]

I think that's a bit too esoteric for the discussion. We're talking basic electronics here, not a PhD in golden ear studies. Audiophiles have a very strange grasp of electronic theory, motivated by the need to find "scientific" explanations for effects that don't actually exist, so I wouldn't trust any article written by one.

(Besides I think the article slams solid-state amps unfairly.)

The "loops" mentioned in the article are similar to what many people call the "hidden circuit". A Google search on this term will turn up some good discussions on grounding and the like.

[GregS]

Good thread! This is the first time I've been able to understand how a capacitor lets AC through. Everything else I've read in books doesn't really explain how this happens and does not give any analogy for understanding it either.

[Jazz P Bass]

Conventional vs Electron
How about we start (end) by inverting the assigned polarity designations.
Label the positive terminal: Negative
Label the negative terminal: Positive
I had a teacher that made us change the "arrows" on the schematics.
This would have fixed his rump.

[mooreamps]

The *really* sad thing about this all is that Gary almost certainly saw LED bias being used in old Navy equipment that he worked on, and perhaps assumed that nobody in the audio world knew about the idea... so why not claim the glory? As far as I can tell, it was indeed in Navy gear that the idea originated, at least you can find mention of LED biasing being used in Navy kit back in the early 60's. The funny thing about that patent, is that the assignors are both from the Navy. So really, Gary is mad that his scheme was unknowingly outed by the very people he, in turn, was trying lift the idea from. It's the only interpretation that is consistent with all of Gary's remarks. And also, pathetic.

I've seen this before, shoved in my face on other forums.. No, the Navy did never use led biasing in those days. Led's weren't around in those days... op's....... But it was few designers using the technic for audio gear, that I was aware of, and no I'm not buying any "back-dated" schematics posted on other web sites... Besides, you have to cap the preamp just right or the tone becomes out too muddy.. Don't really care if you think I "lifted" the idea from somewheres else.... You've already proved you have no clue how the "old Navy equipment" was built..

-g

[Wombaticus]

I've seen this before, shoved in my face on other forums.. No, the Navy did never use led biasing in those days. Led's weren't around in those days... op's....... But it was few designers using the technic for audio gear, that I was aware of, and no I'm not buying any "back-dated" schematics posted on other web sites... Besides, you have to cap the preamp just right or the tone becomes out too muddy.. Don't really care if you think I "lifted" the idea from somewheres else.... You've already proved you have no clue how the "old Navy equipment" was built..

-g

Practical LEDs have been available since '61 for infrared, and '62 for red. So you're wrong on that count. That said, I admit I hadn't intended to say LED, but rather just diode bias, as described in the '64 patent (applied for in '60). Naturally, the emission of light is entirely incidental to the use of a diode as valve biasing device.

I don't care, by the way, if you lifted the idea from someone else or not. We all rely on the wisdom of our forebears, and as the date on the patent clear indicates, the notion is now clearly in the public domain. But, if you borrowed the technique of diode bias from audio designers, what exactly, is the nature of *your* alleged invention? And what particularly do you think Merlin stole from you? Furthermore, by what means do you believe he stole your work?

If you're going to defame someone in a public forum, then you should at least do them the courtesy of laying out the entirety of your allegations in order that the accused may afford themselves of the opportunity to respond. So let's hear it. Specifically -- in what way, and by what mechanism -- has Merlin appropriated *your* supposed intellectual property?

[Chuck H]

Practical LEDs have been available since '61 for infrared, and '62 for red. So you're wrong on that count. That said, I admit I hadn't intended to say LED, but rather just diode bias, as described in the '64 patent (applied for in '60). Naturally, the emission of light is entirely incidental to the use of a diode as valve biasing device.

Actually, for Gary it's not incidental since he uses the light they emit on the front panel as function monitors.

Also, FWIW, I looked up a Wiki on LED's just to see what's up, from Wikipedia:

"Until 1968, visible and infrared LEDs were extremely costly, on the order of US $200 per unit, and so had little practical use.[16] The Monsanto Company was the first organization to mass-produce visible LEDs, using gallium arsenide phosphide in 1968 to produce red LEDs suitable for indicators.

Your concession is noted. But it would seem that practical application of LED's for their diode function wasn't possible before about 1968. Probably later really.

Also, FWIW, Gary HAS outlined his reasons for thinking his ideas were noticed and printed. From what I understand Merlin indicated that LED's can be used to bias preamp tubes and further states that the LED function of this particular type of diode can be used as a monitor for tube function. Gary believes that Merlin got the information to publish these ideas directly from Gary's amps which are set up exactly this way. How "I" feel about it is stated in an earlier post, so I digress.

[mooreamps]

Thank you, Chuck...

-g

[Steve Conner]

Gentlemen, you can't fight in here! This is the War Room!

This thread is supposed to be about visualising circuit operation for newbies, and you're dragging it way off topic. Please go and bitchslap each other somewhere else, such as the Lobby or Parking Lot forums.

[redelephant]

uh oh, the grown up has entered the room.

You're absolutely right, but sometimes one just cant resist...the risk with these forums is misinterpreting/confusing the info since there is so much of it. I have my understanding of electron- and conventioneal flow, but haven't spillt it since it just becomes yet another leaf in the jungle.
(remember for theoretic analysis it's always easier with positive signs in the formulae, therefore 'conventional' current flow from pos to neg) It certainly makes understanding the grounding being important when one brings the entire current path into the picture. Oh sheit, now I started my analysis of the problem....and I dont want the jungle any thicker than it is...sorry.