I've known for a long time that the human body is over equipped and that we can do without quite a few of our body parts. Your aunt was a living example of that theory. The most amazing (to me) part of your story is that Barnes is a teaching hospital. I never knew that. My primary care physician is out of St Lukes Hospital but has a Winghaven office here in O'Fallon. I've been under his care since I got here and had a little problem with my shins. They looked infected with dermatitis of some sort and would develop ulcers. Small but irritating nonetheless. After making things a lot worse the local dermatologist sent me to a "wound care" center, which happens to be here in O'Fallon and is part of BJC. It's basically a specialized immediate care facility but they knew exactly what the problem was the first time they looked at it. None of these folks looked like med students, but they sure knew a thing or two that the doctors out of St Lukes missed. I guess I'm a special case, but still.
One thing I learned the hard way, is most students know more and do a better job than most doctors.
It could be because everything is still fresh in their minds, and because they are working for a good grade the work harder.
Even so, I don't necessarily like to be in teaching hospitals for normal things. Too many hands poking and prodding or asking questions. But when they are the only ones who can do the job right, then that's where I want to be, hi hi.
The problem is you never know if the job was done right until after you suffer the consequences. My guess is that med school isn't much different than technical schools all around. When I had to retire with 36 years of experience I could not get a job even at entry level pay. I'm certain the "fresh outs" have the advantage of being taught current theory which seems to be more desirable than actual in the field experience. Or, at least some of the times it happens that way.
You are right Yogi - My grandfather worked at the Kirkwood disposal plant for like 25 years. - In all that time, the effluent waters from the plant were never out of range, not even during heavy rainstorms or during drought conditions. - He kept the place humming like a Swiss watch. - However, he did not have a degree, had never been to college, nor took the sanitation classes now required for new employees. - He did however have his required certifications which were renewed every few years.
Out of the clear blue sky, they told him he could no longer work for them without a degree in this, that, and the other things, those were all now required by law. - He was fired!
About two weeks later, the big shots of the sewer disposal plant were on his doorstep begging him to come back and clean up the mess before they were forced to shut down by the state.
He refused, said he did not have the requirements their new laws demanded he have.
Those hot shot college kids had made a royal mess out of the place, and the waste was backed up until all the emergency holding stations were near full.
Grandpa was near retirement age, and when they showed up on his doorstep again, he told them exactly what it would cost them for him to come fix the mess, and to train the idiots they hired. Grandpa wasn't greedy, so it really wasn't much money, just a guaranteed check of 250 bucks a month for the rest of his life. I think they finally agreed on 200 bucks, plus a bonus check enough to buy himself a new car, which would have been about 2k is all.
He got the mess straightened out, and the effluent back into the lower end of the safe range, which was better than they expected, and also got all the backup waste in holding cleaned up and gave them like a fresh start.
Then he worked with a group of 8 kids to teach them how the plant is supposed to be run.
None of which were they taught in college, not one lick of what he had to teach them did they know.
Sorta like a lawyer fresh out of college has no idea what to do in the courtroom or out in the field.
The real story behind hiring fresh blood has nothing to do with education or legal requirements. When a person works many years for a company they pick up on a culture. This culture is akin to a fixed way of thinking that has always worked in the past. The problem with most company cultures is that they are out of date. The business environment changes rapidly and the old ways may not be adequate in the new world. It's damned near impossible to teach an old codger the new way of thinking because it's something that takes years, decades, to acquire. By that time business realities have changed once again. The people coming right out of school have no such cultural prejudices and are simply glad to have a job. They are easy to teach the new culture and manipulate because they have no experience on which to base their judgements. Of course it does help to know current theory, but as your grandpa demonstrated experience is how the job actually gets done. The unfortunate reality is that experience isn't worth as much as a malleable mind.
That was my biggest beef in our family business. If it was not the way grandpa did it, then we don't do it, hi hi.
However, we did upgrade methods quite often, the same as where my grandpa worked at the disposal plant. Heck, they were always modernizing, using new methods and chemicals.
He simply knew what worked for each situation, old way or new way.
Sorta like working from a recipe, he knew a pinch from a dash to a handful, but couldn't tell you what that was in grams or drams or ounces. The college kids knew the measurements, but not when or how to apply them for each situation, and that is how the mess got out of control when they took over.
When I taught VOTEC, out of about 45 students, I only had ONE who would come and ask me the reason for a particular step I taught them, which often was not in the lesson books. Only a few weeks into the second course series, he started coming to join me for lunch, mainly to pick my brain over various projects he would dream up. Mostly to ask what would be an improvement over the normal way of doing something. I never actually improved over what should be done, just added extra things to make something better in a given situation, which is basically what he wanted to learn.
Had something similar happen when I was working for Steffen Electric Company. I had started with them as a Cub and worked my way up to Journeyman so I could get my license. One of my bosses came up to me one evening after work and asked if I had time to go have a quick dinner with him. Now, if you consider this particular boss was one that didn't really like me all that much, although I never knew why for sure, this was a surprise to me.
In any case, over dinner he made a very complimentary comment about my work. Especially during the final days of finishing a home, what he called buttoning up the job. He said to me, he was not able to put his finger on the reason the houses I button up always look more inviting, pleasingly finished. We are only talking about electrical work here, all of which is hidden behind the walls of course, but the finished room looked Just So to him, but he didn't know why.
You'll probably laugh when you hear how something so simple can make all the difference in the world.
But first, the not so obvious. One I consider a safety feature myself. If you have 3-way or 4-ways switches in a house. If I did the wiring, and/or installed the switches, if all the switches were in the down position, the power it went to was off. This means at button up, you didn't have some switches up and some switches down. That's one thing.
But the big thing which most people don't notice does stick out as being right. If every screw in every switch plate and outlet cover is turned vertical, not only does it look right, but you also do not scrape fingers or knuckles, and they don't catch dirt as easily. It also brings uniformity to an entire empty room, makes it look cleaner and more finished, so to speak. Something so simple, takes no extra time to do it by habit, but keeps the room from looking out of place, out of balance so to speak. Attention to the finest small details, adds up, to give a bigger prettier picture.
Your story about installing switches to look pretty makes sense even though I never thought about it previously. I did not find it funny because I know the value of detail. What I do have problems visualizing, however, is the method you used to get those 3-way switches to end up in the bottom position. It may be possible to wire one switch box that way, but there is the other end of the circuit that can also be used to activate the circuit. If you turn on the circuit from the far end, then the near end with the perfectly aligned switches must flip up in order to turn off the circuit. Thus things can start out perfectly aligned, but as the switches are used the synchronization is easily disrupted.
The screws are a classic example of detail that matters. There are three wire vertical outlets in this house where the ground connection is at the bottom. Others are at the top. The ceiling fan has a slide switch on the wall to control the speed of the fan. The slowest speed is at the top and the fast speed is at the bottom, exactly opposite of what I consider optimal. When the fan is off the switch looks beautiful, but works counter-intuitively. Not all electricians are artists, I suppose.
Last edited by yogi on 22 Apr 2019, 18:16, edited 1 time in total.
On a pair of three-way switches it is simple. If one is up and one is down while the power is off, just reverse the traveler wires at one switch and both will be down for off. If either switch is up, the power is on to the fixture or outlet it supplies.
No matter how you look at it, one of those traveler wires is always hot.
A four-way goes between two three-way switches. It too only has two positions, up and down. If both of the three-ways are down, and the four-way is down and you have power, here too, just reverse the traveler wires into the four-way.
When you have more four-ways in the circuit, work from the source end of the circuit to the load end of the circuit swapping traveler wires as necessary until all down is off at the load.
Like a three-way, the only thing a four-way switch does when you flip the switch is reverse the traveler wires at that switch.
It may sound complicated, but in reality three and four ways switches are really simple devices. A 4-way is like an X.
Black Wire - Line-----3========x=========x=========x======3-----Load
White Wire - Neutral--------------------------------------------------------/
= sign above is for the two traveler wires running between the switches.
Only one of the two traveler wires between the switches are hot.
You flip the switch and the not hot traveler wire becomes hot, and the one that was hot becomes not hot or dead.
Note, when you change the position of any switch in the circuit, while off, which wire is hot will change throughout the rest of the circuit on its way to the load, which will now be on or hot, because the Line is now coming in on the active load.
I probably explained that as clear as MUD, but honest, it really is as simple as binary code, 0 or 1, hi hi.
If you start out at LINE with a 1, it will follow throughout the circuit to Load as a 1, however, at the last switch before load, you reverse the wires so it is a 0 exiting the final switch. The buck stops at the last switch on an off circuit.
OK, that just made it worse didn't it, hi hi.
Aha, I just reread your comment about the switches activating the circuit, and I think that is where you are going wrong in your thinking. ONLY THE OUTPUT wire of the Last Switch in the Circuit is connected to the LOAD.
Think of it this way. You plug an extension cord into a wall socket, that entire cord is HOT all the way to the receptacle at the end where you can plug something into.
Regardless of how many switches that use traveler wires are placed in your extension cord, that entire extension cord will remain HOT up to the the last switch, which could be on or off. The Last Switch is what feeds the LOAD.
I can hear you thinking like this, but, but, if I flip any switch along the extension cord, then the entire circuit would be dead and the last switch meaningless. NO AGAIN. When you flip a switch, all you do is change which traveler wire becomes hot, so you will always have a hot wire going into the last switch. So the position of the last switch in a sense becomes meaningless, because if it had the power going to the Load off, turning any switch will cause the power to go through the other traveler wire, which would then allow power through to the Load.
Of the traveler wires, one will always be 0 and the other will always be 1. If you flip a switch, 0 becomes 1 and 1 becomes 0.
Another way to explain this is with a 2-pole relay switch. If the top pole powers the red light, and the bottom pole powers the green light, it would be impossible for both lights to come on at the same time. The contacts in the relay switch must make contact with either the top, or the bottom, no other choice. Same way with traveler wires. If one is hot, the other is dead. Flip a switch and their roles reverse, the dead becomes hot and the hot becomes dead.
I get it. I really do. But, you are not the only one who can embellish an explanation Here is my attempt at presenting a picture that could be worth a thousand words.
The difference in our backgrounds is showing here, but I think the 3-way switch problem can be explained with Boolean Logic. The image here is the Truth Table for a common OR Gate. If we consider the Output in the table to be the load in our hypothetical electrical circuit, then the Inputs from the source would relate to the wall switches. Switch up = 1, Switch down = 0. Thus, either switch up would supply power to the load. In fact this can be expanded to three Inputs to show any one of the three would enable the output. I don't know if the entire Truth Table would apply to our circuit given that last line where both switches are up and the Output will remain active if only one of them were down. They all have to be down for the lights to turn out, which, as I understand it, was the goal of your wiring scheme.
The crossing of hot and return wires will in fact do what you want it to do. However, I have noted that AC switches come with three screws. One is brass color, one is silver color, and one is green. I know for certain that the green screw is the hard ground wire and cannot be anything but that in order to meet most electrical codes. I don't recall which is which, but by something akin to industry standards (I'll guess) the brass screw ALWAYS get the hot wire and the silver screw always gets the return/neutral. This standard is in place to assure that the chassis or frame of the appliance does not connect to the hot wire from the source. Big safety hazard if it does. Sooooo ... are you telling me that you reverse the the wires on one switch box so that the brass and silver screws are opposite of what they are intended to be ??? I doubt THAT would receive any inspector's approval if true.
I lived most of my career in a digital world. That world only had a source and a ground like a battery. There was no neutral because it was all DC circuitry. AC always baffled me given the sinusoidal nature of the supply. The source can go both positive and negative. That means the current reverses direction at a 60 Hz/sec rate here in the USA. If that is true, and it seems to be, then what do you need that neutral wire for? LOL Well, I've been told it is needed to complete the circuit, and so it is. No source I've ever heard about is mono-polar. That neutral wire, thus, carries no load. No current. No voltage. Seems superfluous, but the AC generator won't work without it.
Actually Yogi, the Neutral wire carries the same voltage as the Hot wire when the circuit is closed, functional.
You can use your DC battery analogy for AC, from the hot or Plus side of the battery, the wire goes to the load, then from the load, the neutral or Negative wire goes back to the battery. Both wires are Hot if the lamp is lit.
With AC, you do not have to go back to the source as you do with a battery.
You can run the Hot wire to the Load, then from the Load send the wire directly to earth ground and complete the circuit.
In a fuse box, or breaker box, the Neutral Side of the bus is grounded to an earth ground. For this reason, Neutral is always at ground potential. The addition of the new green earth ground is supposed to be a safety feature to protect from shock from a metal housing that may get touched by the either the Hot or the Neutral wire in a closed circuit.
This type of safety ground was first used in things like power tools, of which vibration often caused wires to break inside the tool. However, almost all tools now have plastic cases on them, and are insulated from possible short circuits from broken wires inside.
Since the Neutral Wire and the new Green Wire both go directly to earth ground, about the only purpose of the green wire is as a balance check for GFI outlets. If the Neutral Wire fails, and the circuit gets closed to the green wire, the circuit will still work just fine.
Back when we had metal switch cover plates, and the mounting plate for the plastic switch covers were touching metal boxes, perhaps then the green ground wire had a rare but possible safety function. But now, almost all boxes are plastic, cover mounting plates are insulated from the electrical circuit, etc, ad infinitum.
As far as I'm concerned, the addition of the green wire to the code was for the most part political and not a functional necessity.
You might probably remember back when if you touched the fridge and the sink faucet or a toaster at the same time, you got a shock. This was because back then, most devices used the housing as a neutral connection point. The way cars have always been, the chassis has always been the ground in a car, but then too a car is DC, or is it? Alternators are AC my friend. Albeit converted to DC for the battery.
Whether the screws are brass or silver has little bearing on the device. Some have both screws brass, some have both screw silver, and some go out of their way to make one brass colored, one silver colored and in some cases a third that is black in color. Excluding the the green safety ground screw which does go to the cover plates screw mounting plate.
It is easier to view the LINE side of an electrical circuit like a garden hose, only ONE wire. Forget the Neutral for now.
In a normal On/Off switch, the switch either passes the electric through the switch from one screw to the other, or it does nothing, no connection to the other screw.
In a three way switch, the switch either passes the electric through the switch from the input screw to the top output screw or to the bottom output screw. There is no OFF position. It comes in at A and goes out either through B or C.
In a four way switch, you have two input screws A and B, and two output screws C and D.
If the HOT wire happens to be on screw A, then screw D will be the hot output, B and C will both be dead.
If the Hot wire happens to be on screw B, then screw C will be the hot output and A and D will both be dead.
A regular On/Off switch: Line--------SwitchOff, no output. Line SwitchOn------To Load.
A three-way Switch: Line-------SwitchDown----Output to top screw--------to Load, no output to bottom screw.
A three way Switch: Line-------SwitchUp-------Output to bottom screw----to Load, no output to top screw.
Hmm, bad way of wording that.
Let's try it this way. Line goes to screw A, output goes to B or C. Both B and C go to the Load, but only B or C is hot.
If you flip the switch in the opposite direction, only B or C is hot, not both.
Now, since both B & C go to the Load, which we can assume for this is a 4-way switch, with inputs of A & B and outputs of C and D. If the Hot wire from the 3-way switch is B, and it is connected to input A of the 4-way switch, the current will be on outlet D of the 4-way switch.
ASCII Art does not work on HTML hi hi. So I can't draw something that will stay meaningful.
Your drawing would work except in electrical circuitry, 1 and 1 is a dead short, hi hi.
There's more to it than Off and On or 0 and 1.
If it's is OFF it is OFF, period, no matter how many switches after it are ON, hi hi.
To finish up where I left off at the beginning, with the HOT wire and forget the Neutral wire.
here we have the HOT wire coming from the fuse box--------------To a Switch which is on-----------continuing to a LOAD which could be a light bulb or your radio or TV. Now in order for the LOAD to function, the circuit must be closed. In the case of DC, a neutral wire goes back to the batteries negative terminal. In the case of AC, a neutral wire must go back to GROUND to close and/or complete the circuit.
And hear is the caveat. If you have 110 volts on the HOT wire going to the LOAD, you will also have 110 volts on the Neutral wire going to Ground. The same is true on a DC circuit as well. So just because Neutral is often called Ground, doesn't mean it is NOT HOT. You have a closed circuit if the Load is on and working, so the entire circuit is HOT.
This is also why you used to get shocked when touching a metal appliance which used the CASE or CABINET as a Neutral, and you also touched an earth ground, like a water faucet. And FWIW, if a Neutral does fail, and the circuit uses the Safety Ground to complete the circuit, the green safety ground is just as HOT as the Hot Wire. So, is this extra wire really worth the extra cost in today's wiring systems?
You have to remember, poly-TICK-ians, who don't know the difference between lightning and a lightning bug are who write the codes, create the laws, and enforce those laws.
All it takes is for some idiot to convince someone in power they are right, and some of the dumbest laws get enacted.
Like the one all the Fire Marshals jumped on a few years ago which are still in affect.
They actually believed it was safer to strike 100 matches than to only strike 20.
Or light a lighter 100 times, than it was to only light it 20 times.
Also while increasing the risk of a burn injury due to an increasingly shorter distance from the point of ignition.
There is no way on God's green earth that striking 100 matches is safer than striking 20 matches.
But this is what Fire Marshals have agreed is true along with the poly-TICK-ians who agreed with the original idiot.
And folks wonder why we no longer trust government for much of anything. The truth is not in them, at all.
I still have some issues, not necessarily with your explanations, but with the entire concept of AC electric as it has been explained to me by many people in the business. I'll try one last time to give you a picture of my confusion. Let us first come to an agreement of how AC electricity is generated.
The simplified explanation I'm sure we both have learned is that of a coil passing through a magnetic field. This movement induces an electric current through the coil. The current will flow in opposite directions as it passes through the north and then the south pole of the magnet. This alternation of current is ... AC electricity.
Regardless of the direction in which the current is flowing, the circuit needs to be a closed loop for the flow to occur. We can imagine those generator brushes to be the same as the electrical outlets that are commonly used everywhere. The important point I want to emphasize is that the entire loop of wires/load carries the current back and forth from the generator. Seems obvious.
Now for my confusion. You, and many others, have told me that one of those wires coming from the generator is "hot" and the other one is "neutral." Well, I see nothing hot or neutral when I look at those pictures. All the wires carry the current. If we want to say the direction of flow is from South (-) to North (+), and further say that the South end is the hot line because it is the source, then I need to point out that the direction reverses every cycle of the generator. Thus the so called hot wire alternates between the two brushes. So, I'm thinking, both wires are hot and both wires are neutral at some point during the complete AC cycle.
The way this works is very clear and not confusing. I think what throws off all those electricians is the concept of grounding. In the world of DC the chassis is typically ground, or the return path to the battery. That does not have to be so, but happens a lot. For DC to work properly all you need is two wires, pretty much the same as in the AC generator. However, as you know, DC does not change direction nor is there a peak sinusoidal voltage that is averaged out to determine rms Volts. In other words, DC is not as dangerous because the voltage potential is low and the flow is in a single direction. Thus, having a "hot" chassis in the world of DC can hurt you, but not likely kill you.,
Because of the potential harm from the hot chassis effect, the Earth Ground was invented. Well, not invented so much as it was made mandatory for safety reasons. The Earth Ground is what you described earlier: a pole stuck into the ground with a heavy duty wire attached. That wire is connected to anything the user might touch. The Earth Ground does not allow the electric to flow back to the source. Its purpose in life is to short circuit the current on the spot. So that breaker panel with the green wire attached is effectively earth to which any current will flow.
In a properly designed appliance there should be no need for earth grounding. The deadly electric current should stay inside the appliance and not have a path to the user's body. But, this is not a perfect world. Thus we are saving the lives of hundreds if not thousands of squirrels who gnaw on underground electric cables because, after all, the cable is connected to earth ground at some point.
Here is the schematic representation of a 3-way switch and the source of much confusion (in my head). The good news is that the images clearly depict how a 3-way switch works and why all buttons down is possible. I like it. Then the bad news. The assumption is that the circuit is fed by AC electricity, and thus the author felt it necessary to label the conductors "line" and "neutral." I STILL say there is nothing neutral about that wire labeled as such. It is hot part of the time and can kill you under the right circumstances. If you attach that earth ground anywhere onto that circuit, it would blow a fuse, break a breaker, or melt down the AC generator. LOL
Hi Yogi - Looks like you got the switches down pat now, hi hi.
As far as the very first drawing about AC, well, although correct, makes understanding even more confusing.
Although the voltage is not important, but to explain your first diagram, think about an electric dryer.
The electric dryer runs on 220 volts. This means it is getting 110 volts from the top wire, and 110 volts from the bottom wire, there is no neutral involved in the circuit. Like a square sine wave, the top wire is hot while the bottom wire is cool, and the bottom wire is hot while the top wire is cool.
220 volts house current is brought in on two wires, each carrying 110 volts in phase, switching back and forth between the two wires 60 times per second. This is basically what your first image is showing.
Now, from your 220 volt feed, which of course is two separate 110 volt wires. If you have a 110 volt appliance to run or a lamp to light up, you take only the current from ONE of the two 110 volt wires. The wire you choose has current turning on and off 60 times per second. In order for your appliance to work, you must ground the other side of the load to an earth ground. This is normally done using a Neutral wire back to the panel box.
Unlike DC current which is always on. Your appliance or light bulb is actually turning on and off 60 times a second.
You don't notice this on incandescent bulbs because they are heating up and cooling down, but not cooling down enough for you to see them dim. However, with fluorescent lamps, you can possibly see them flicker 60 times a second.
One way to prove this is to take a camera with a fast shutter speed and take several pictures of a fluorescent lamp. Some of the pictures will look like the lamp is off, and some of the pictures like the lamp is on.
Remember trying to take a picture off the TV screen and all you got were a series of dark bars?
Ironically, there does not have to be an electrical connection to get electric to flow from one circuit to the next.
AC produces a magnetic field. And this is the how and why a transformer works to convert voltage from one level to another. A simple wall wart converts 110vac to 12vac, and if you add a diode it can become 12vdc.
There is no electrical connection between the 110vac coil, and the 12vac coil on the output side of the wall wart.
If you have a 110vac coil powering a 110vac coil on the output side, these are called Line Isolation Transformers, and are considered a safety device used in most pinball and video games, and at one time in TVs and Radios to prevent the user from an electrical shock, but you can still get shocked if it is not wired to prevent shocks. They are also used to limit current, such as 300 amps in, only 10 amps out, or only 10 amps in 1 amp out, etc.
But then we are getting into electronics which is a different animal than electric current manufacture and distribution.
You and I have a very different understanding of the basic physics involved with the production of electricity. I can't fault you in any way because most of the people I've talked to in the trades come up with explanations very similar to yours. I"m certain you all learned from the same school.
The source of electric current and/or voltage (what is being called a hot wire) is where the electrons enter the circuit. There can be no flow of electrons, no current, unless the circuit is complete. Think about a light bulb. If you connect one terminal of it to the hot wire of a conventional wall outlet what happens? Nothing! Why not? It is connected to the "hot" wire after all. The electricity will not flow until the circuit is complete, i.e., a return path to the source is provided. It is a huge mistake to say the return path is the ground(ing) of the circuit.
There is a reason why AC is called "alternating current." The direction of electron flow reverses at that 60 cycle rate you bring up. That means the so called hot wire that feeds an ac circuit takes on a positive polarity half the time and a negative polarity the other half - the image of how an alternator works clearly shows why this is true. Each conductor alternates between being the source and the terminus. When it's the terminus (negative) from where do you suppose the supply of electrons is coming? If you guessed the ill name neutral wire, you would be correct.
No, no, no, Yogi - Well sorta, but you are confusing the issue here.
Yes the electrons themselves are moving back and forth toward plus, toward minus, toward plus, toward minus.
However, it doesn't matter which way the electrons are moving. Their movement is what creates Current.
Current goes up from zero up to positive peak, then back down to zero, then continues down to bottom peak, but the current is moving in only one direction, like a sine wave from left to right, like a ripple in a lake.
If you only look at the electrons themselves, sans movement, current would be zero because the positive and negative cycles would cancel each other other. It doesn't because the movement of the electrons back and forth is what creates Current.
Current is what is measured in Amps. If you have 5 Amps positive, and 5 Amps negative, logically you would think it would cancel itself out, when only looking at electron flow. But it just doesn't work that way.
Let's try this. If you get on your bicycle to ride up to the park and you rode 1 mile toward the park (this is the positive direction of the electron), then realized you forgot your picnic basket and turned around and rode 1 mile back home (this is the negative direction of the electron). Now answer this: Did you just pedal your bike zero miles? Or did you in fact pedal your bike two miles?
The point here is you were always Moving forward, first forward toward the park, the you turned the bike around and pedaled forward back toward your home. Current is always moving forward from Source to Load.
Now if we get the speed of the cycle up higher, cycles are measured in Hertz. You can move up through the audio range to the radio range, and if you keep going up to the speed up light.
At RF frequencies and above you can do some amazing things with AC electric.
Audio frequencies lets you listen to the needle of a record player vibrating in the records grooves.
At higher audio frequencies you can talk on a phone, and at radio frequencies talk around the world using only the airwaves. Look Ma, no wires, hi hi.
Current is defined as the flow, movement, of electrons through a conductor.
Electrons are negatively charged particles and move toward a positive terminus. If there is no positive terminus, there is no flow of current.
Go back up two images where you see the diagram of how a generator works. Note the current flowing through the load reverses direction depending through which pole of the magnet the coil is traveling.
Thus, in order for the current to flow in opposite directions, what is called the hot wire and the neutral wire must reverse polarity. This is not a theory. This is in fact the physics of how AC, alternating current, works.
You don't have to take my word for it. You can look it up on the Internets.
Your first set of images shows a circuit with NO NEUTRAL, and TWO Hot Wires, one from each Pole, which is more like how our 220 VAC works here.
Going by your top images, if you add a NEUTRAL wire to the CENTER of the LOAD and run it to GROUND, you'll see the Current is only traveling in One Direction on each leg, and that is Toward the Load.
Because the Center of the Load is Not Grounded, it gives the appearance of the Current flowing in both directions, because the Hot Wire on the output side of the Load is temporarily Neutral. So current does flow in the direction of the arrows in the image, but not for the reason the picture tries to make you think it does.
In a DC circuit, you can reverse the direction the current flows by flipping the battery backwards.
It doesn't work like that in an AC circuit. Reversing the wires does not reverse the direction the current flows. It only changes which one is Hot and which one is Cold during it's half of the cycle is all.
A DC motor will run in reverse simply by switching the wires.
A AC motor will run in the same direction regardless of which way the feed wires are switched.
AC motors that can be reversed are doing so by switching winding coils.
DC does not have a time factor. AC has a strict timing factor, basically a Sine Wave signal that when used with a pair of Diodes would produce a Square Wave signal. Using only Diodes you would end up with a Pulsing DC current. A square wave bridge rectifier can smooth the square wave out somewhat, but you'll also need capacitors and inductors to smoothen out the sine wave to pure DC.
That pretty much sums up what I've heard from several people. It's not exactly consistent with the laws of physics, but who am I to dispute years of on the job success?
In classical physics were are taught that a particle cannot pass through an opaque wall.
Is this assumption of the laws of physics true?
Energy cannot be created or destroyed, but can be manipulated and modified for use!
We can manipulate the flow of electrons, which are particles, as are photons.
From those particles of energy we can create radio signals.
Both can be increased in speed, and at certain speed ranges radio waves will pass through opaque objects, including solid walls, hi hi.
It is understood photon's pass through clear glass, if they didn't prisms and lenses would not work.
In physics they say a photon cannot pass through an opaque wall.
However, using speed once again, it is possible to speed up the photon's until they can easily pass through solid opaque objects. If we couldn't then many things would not function, such as Xray machines, electronic imaging using light wave technology. A form of Xray is used to verify the welded joints in high pressure steel pipelines are done properly, with no gaps in the weld. As far as I know, steel would be considered an opaque wall.
And we haven't even touched on quantum physics, hi hi.
Actually, you did inadvertently bring quantum physics into the discussion but I don't want to get into the story of anybody's cat or the Uncertainty Principle. Your comments are interesting and contain a good mix of science and mythology. LOL Me thinks you might want to brush up on exactly what energy vs matter is all about. Electrons traveling through a conductor, for example, is not the same as (rf) electromagnetic radiation.
Could be Yogi - It's been at least 40 years since I studied about anything associated with this topic.
I can say this: What I learned to become an electrician was entirely different than what I learned regarding Ham radio or electronics. They are like two totally different concepts and usages.
load. In fact this can be expanded to three Inputs to show any one of the three would enable the output. I don't know if the entire Truth Table would apply to our circuit given that last line where both switches are up and the Output will remain active if only one of them were down. They all have to be down for the lights to turn out, which, as I understand it, was the goal of your wiring scheme. 
