I'm a retired generator technician. I love history and science. You explain the technical side flawlessly and I feel confident that you have done your diligence on the history. Love your work. Thank you.
Kathy, thank you so much for your videos. I'm an English teacher in Brazil and try to pass my excitment over technology and history to my students. Your work is an inspiration, not to mention the great amount of knowledge and even rectification your bring along. Merry Christmas and please keep doing your great job.
Nicely done! I’m an electrical engineer and I’ve always enjoyed learning about technology through the lens of history. I also think that students understand math much better by relating it to physics rather than just teaching it as a set of abstract concepts. Keep up the great work!
@@affilinet If you take a hand generator, it is easy to turn. However if you connect the generator to a load then it becomes much harder to turn. You are doing "work" and this work is converted into electrical energy by the generator. You used to be able to hear this on carburetted cars. When you turned on the headlights the idle speed of the engine would drop because now the generator/alternator became harder to turn and slowed the engine down.
The electricity is a flow of electrons. The electrons are part of the copper molecule. The electrons in a metal can be pushed around from one molecule to anther. The mechanical work via the magnet is pushing the electrons along from one end of the wire to the other just as a paddle in water can push the water along
Thank you so much for the simplicity. I could not explain it to my kids, when my son saw it, he was so amazed by the historical steps that you took us gradually to reach the idea of electrical principles. Keep it up...
I just found your videos. Very interested in everyone of them. Mostly dealing with electric and radio. You show it where I can understand the information. Thank you. I will pass them on to others.
There are people rising up on yt who are showing themselves to be first rate teachers, Professors, doctors and producers of original material of the highest rank. I have never been so well tought while wasting no time in boring lectures. Cathy is fabulous and so is Dr. Erick Berg.
AC current in a three-phase system could be amplified/controlled precisely by the use of transformers and, for each phase separately, by the use of radio-type amplifier electronics (vacuum tubes until recently). This precise control, even when amplified, allowed data transmission to be accomplished between devices that are separated by some distance, yet need to get precise information from one-another and, with enough amplification, to directly control the operation of these long-distance devices (analog, pre-digital controls). The mechanisms used by the US Navy after WWI, and until modern digital data transfer replaced them, were called "Selsyns" or, more usually, "Synchros". A magnetic needle (just like on a compass, but stronger mechanically) was put on a rotating shaft and a metal ring of three divided sections wrapped around it in the same plane of the rotating needle. Three electromagnets in a triangle were attached to the ring, each separately wired. The other end of the wires of the three coils were attached to a duplicate loop and needle with equal AC power running through each coil on independent circuits. By rotating the needle in one loop, the needle['s magnetism would modify the current in each of the three lines so that the EXACT same change would happen at the coils at the other needle and the magnetic field would, if powerful enough (if necessary, amplified by the vacuum tube/transformer set in-between) move the needle at the other end to match the first needle. This allowed information, when changed to a needle angle value, to be sent from one place to another very accurately. In many cases, when increased accuracy to overcome slop in the needle angles was needed to get really precise numbers, a second needle set using a 36-to=1gearing action would also be sent and the two values merged using precise electronic circuits to give an EXTREMELY PRECISE angle value that could be changed back to whatever kind of information was being transmitted precisely. In fact, by using powerful enough amplification, the needle on the far end coil set could be strong enough to directly rotate the controls of the far-end device, allowing the elimination of the "man in the loop" for automatic control. US naval guns by the end of WWII were almost entirely controlled in the later fire-control systems using this method, which made accurate gunfire, especially against fast aircraft, possible. This target position and motion information would come from the aiming range-finders/directors tracking the target, be sent to electro-mechanical calculators to give weapon aiming orders, and then sent to the gun mounts, all with minimum human inputs to slow the process.
Very clever. I'd've either thought of servos with feedback, or some kind of phase shifting, to try to accomplish the same thing, but probably more slowly in the case of the servomechanism, or requiring frequent recalibration (or sacrificing precision) in the case of the phase-shift device.
I'm a computer engineer and love your videos, especially the historical context you provide. I wish I had a professor/teacher like you growing up; I was way more concentrated on memorizing the formulas I think to really grasp some of the larger concepts.
I am an aerospace engineering student. I just wanted to understand electricity and how it all started. I couldn't have got all this content in the correct order and accurate, so easily. You are really doing a great job. I probably would have stopped thinking about electricity if you were not there. Now , I'm watching the whole playlist. Thankyou so much Ma'am.
The energy density of the vacuum potential is enormous, even mind-boggling. While scientists have estimated that energy by various means, a reasonable calculation is given by J. A. Wheeler and C. Misner in their Geometrodynamics, Academic Press, New York, 1962. We simply must get the vacuum energy part moving, for when one examines all the options, it is the only option that will work in time. We already know that the Maxwell-Heaviside equations, prior to Lorentz regauging, do include open systems in disequilibrium in their vacuum exchange. We are also already aware that the present classical EM model completely omits the vacuum interaction (much less any broken symmetry in that interaction!), which we also know is a gross non sequitur since the vacuum interaction (and the dipole's broken symmetry in it) have been well-known in particle physics since the 1950s. The major problem in the U.S. is that the decision scientists at top positions advising leaders/secretary/vice-President/presidents, usually do not know anything but U(1) electrodynamics, and the advice they get from additional "expert" scientific consultants or advisers is inferior in that these "expert advisers" also seem to know only U(1) and also only the Lorentz-regauged Maxwell-Heaviside equations. Many (most) do not even "believe" in the active vacuum, or if they begrudgingly admit it, they think it is of absolutely no consequence. And they simply do not believe the tremendous energy density of the vacuum, nor will they accept it, even though it is good physics and has been for decades. Hence the entire scientific energy structure and infrastructure in the United States is fearsomely welded to a small fragment (subset) of Maxwell's theory, and even to just a Lorentz regauged subset of the severe Heaviside truncation of it! We have a scientific mindset problem of epic proportion. In short, the energy crisis is completely the fault of our own scientific community. It is NOT the fault of the President, the Vice President, or the Secretary of Energy! It is the direct fault of the inferior advice being given them by the NSF, NAS, etc. The sad thing is that the U.S. scientific community is seemingly no longer capable of even evaluating its own U(1) EM model, as it has become almost an iron dogma. E.g., in the 1880s Heaviside discovered the enormous energy pouring out of the terminals of any generator -- vastly more energy than we provide as mechanical energy input to the shaft. Poynting, of course, only dealt from the beginning with the tiny component of that energy outpour that is intercepted by the external circuit and caught and used. Lorentz understood both the Poynting component and the Heaviside component as well. But no one could explain what could possibly be the source of such an enormous energy flow from EVERY GENERATOR, BATTERY, AND SOURCE DIPOLE. That is rigorous. Simply check Heaviside's original papers. Anyway, Lorentz then took the attitude that this enormous Heaviside energy flow component, missing the circuit entirely and just wasted, had "no physical significance" (his words). So he arbitrarily discarded it (not from NATURE, but from MATHEMATICAL ACCOUNTING) by a clever little integration trick, still used by all the electrodynamicists and those energy scientists designing and building our electrical power systems, writing our textbooks, teaching in our universities -- and advising Presidents, Vice-Presidents, and Secretaries of Energy. In short, we most often face scientists who literally will not believe and cannot comprehend that every generator we ever built, already extracts enormous energy from the vacuum. It is quite easy to prove it, for peanuts. Any lab, university, or decent experimenter can do it. Kraus' diagram in his Electromagnetics, Fourth Edition, shows the nondiverged energy flow component in the form of contours, which are MEASURED watts/square meter at each point, where a unit point static charge will catch that much more energy. Let me now give you a rigorous proof, and very simple, that every system is already vastly overunity by producing far more energy out than we input. Consider a perfect DC generator, loss free, so that its efficiency is 100%. Now consider a perfect external circuit attached, which consists of two short lengths of perfect conducting wire, and a pure resistance load. Let the load be 12 ohms, and the voltage of the generator be 12 Volts D.C. Now we have a neat little situation: We put in the mechanical power equivalent of 12 watts to the shaft. Since the generator is loss free, all the 12 watts are perfectly transduced into magnetic field, and the energy in this field is dissipated with 100% efficiency to form the source dipole. Let us leave the source dipole for a moment. Now we look at the external circuit. There is one ampere of current (12V divided by 12 Ohms) flowing in the external circuit. So we are inputting 12 watts of power to the generator shaft, and we are getting 12 watts of power output in the resistor. All this is clearly measurable and normal so far. Now we check out John D. Kraus, Electromagnetics, Fourth Edn., McGraw-Hill, New York, 1992. Figure 12-60, a and b, p. 578 shows a good drawing of the huge energy flow filling all space around the conductors, with almost all of it not intercepted and thus not diverged into the circuit to power it, but just "wasted." Hey! We have 12 watts of power in. We have 12 watts of power output of the resistor as heat. By conventional Poynting considerations, we are getting out precisely what we are inputting. That is a blatant lie. We are getting output from the resistor precisely as much as we are inputting to the shaft of the generator. Yet we also are getting out a measurable vast amount of energy flow from those generator terminals, filling all space around that circuit. Those Kraus contours are experimental measurements. Anyone can do them, or similar. Anyone can build a little system very similar to this one, and approximating it. So where the devil is all that VAST EXTRA MEASURABLE ENERGY FLOW pouring from the generator terminals, and missing the circuit entirely, COMING FROM? Experimentally we can easily prove that this Heaviside nondiverged energy flow is (1) real, and (2) very large. Let us now add in an extra set of "receiving antenna/collectors" whose circuitry is completely separate from the DC generator circuit with its load. Suppose we add enough of these "little antenna/interceptor/detector" circuits, each containing a little purely resistive load, to obtain 3 watts total in all those extra and independent circuits. Well, now we are inputting 12 watts. We are getting out 12 watts in the external resistor attached to the generator. We are also getting 3 watts out of the "extra receiver circuits" separately, in separate loads. So our total input is 12 watts. Our total output is 15 watts. Our demonstrated COP = 1.25. So how do the "experts" explain that simple experiment????" They don't. But any lab worth a tinker's dam -- and that includes any lab in Department Off Energy and in any university -- can do a similar experiment, catching enough of the extra "usually nondivergent EM energy flow" to bring the COP to COP>1.0. This is a very simple experiment. So is the Bohren experiment which produces COP=18, is published in the hard literature, and is independently replicated by two additional scientists and published in the same issue of Am. J. Phys. that published the Bohren experiment paper. Anyway, Lorentz's "physically insignificant" vast Heaviside nondiverged EM energy flow component is indeed "physically insignificant" to that single external circuit powered by that DC generator. But it is certainly not "physically insignificant" to those extra "receiver/collector circuits" and their independent loads. Let's use two imaginary viewgraphs where in the first one Lorentz is shown in a sailboat on an ocean, in a very nice large ocean wind. Puffing his pipe, Lorentz is smiling and saying, "Only the wind in my sails is of any physical significance". In the second graph, Lorentz is looking aside at a whole fleet of additional sailboats, calmly sailing along and powered by that "insignificant remaining component of the wind". And Lorentz is saying, "How can they be using that physically insignificant wind?" This is an exact analogy to the state of thinking that now exists in the U.S. power industry and the U.S. scientific community concerned with power systems. We don't have an energy crisis, we have a collection and usage crisis-and a vast scientific mindset crisis. Hopefully this will change in the future with highly capable scientists who know quaternion electrodynamics, Maxwell's original complete theory, etc.
In my power engineering classes we were taught that self excitation was started by the small residual magnetism left in the iron cores when they were not turning (hysteresis). Maybe we should measure the refusal to give someone credit for an idea in units called Varleys.
Kate and TH-cam, the greatest of scholastic teacher conference videos which give a clear view of the achievement of the greatest electrical engineers leading to our era, no electrical college or university should hand out degrees without these kates TH-cam videos as requisite. L.Miranda
The common automobile alternator is a battery-excited, 3 phase ac generator rectified to dc using a diode bridge. The crudest, often found in motorcycles, can be a 2 phase, permanent magnet alternator also rectified into useable dc with a diode bridge. Cruder yet is the Magneto generating ignition voltages found on power plants from lawnmowers to airplane engines.
“Multiphase” is properly called Polyphase. For the same line to line RMS voltage, three phase transmits the square root of 3 (~1.73) times as much power, using 1.5 times as much wire as DC or single phase AC.
Where do yo get the root 3? It is three times the power with three wires than single phase with two. That is 3x the power with 1.5x the wires. If you need a neutral then 3x the power with 2x the wires. Neutrals are used in low voltage networks, that s 400 V in Europe.
@@okaro6595 Square root of 3 comes from computing the multiphase voltage drop. You can get 3x power of a 1 coil engine running at 230V or square root of 3 times 400V nominal for three phase system. if you consider Y system connection for motor. You can follow a similar logic for delta connection of windings. The square root of 3 you can get using trig and computing the difference of two waves out of phase by 120 degrees or vectors angled 120 from each other (you need to subtract them).
Thank you, Kathy. This was informative and helpful. I already understood the basic physics of generation. But I wanted to understand more about the history and engineering that led to modern generators. I loved learning about the work of Samual Varley and Werner Siemens and many others. An excellent video!
Fabulous videos Kathy. Just a couple of points: the DC dynamo was improved by a Belgian called Zenobe Gramme, which oddly enough anglo saxon scientific history is mostly unaware of, you may want to research his work. And AC current is "more dangerous", the human ( or animal body) acts as a capacitor in AC current. Capacitors let AC current pass through, and the capacitive reactance (resistance to AC current) is around 3 orders of magnitude less than dry skin resistance at the same voltage. Keep up the good work !
In a steady state system you are likely correct that AC (at certain frequencies) will pass more current than dc. After all that is why AC is more efficient as a transmission system. However for biologic conductors, damage does not happen as a steady state process. In addition, charged balanced (AC) electric stimulation cause less electroporation than monopolar (transient steps of DC) stimuli. This is why bipolar waveforms are used in lots of defibrillators.
Oh my. I have quite a few favorites. Ernest Rutherford was fascinating and his scientific discoveries are just so vast. Max Planck was so kind and influential and the best writer around. Marie Sklodowska-Curie was so interesting and passionate. Niels Bohr was a delight but reading his words gives me a headache. Howard Armstrong was the GOAT in radio. And so much more. Still, my favorite is probably Michael Faraday.
Great video! I was honestly pretty bummed when I learned that nuclear power isn't some super amazing, futuristic form of power generation, and is actually just a really fancy way of boiling water into steam to spin a turbine
thank you very much for this coherent information about the history of dynamo and generators. your are also beautiful and inteligent ma'am i'll subscribe to your channel right now
So we can make this machine that will loop the electric or AC back in to power the spin ? To make it incite spin and another wire to use as output to power stuff ?
when I worked at Ebasco in East Rutherford NJ, I found a filing box that had Thomas Edison's work order for a steam generator, the box went to a museum . they built Indian Point and were later bought by Raytheon
hi kathy. i live in u.s.a and have never really understand how electrons looks and if they come from the powerplant to our houses and back and if thats the case they travel faster than light. or are they really really slow or we just get their magnitude
Solar power is the most notable way to generate more or less endless amounts of electricity without using magnets. Would be nice to do a video on the history of solar power.
Please produce a video explaining how different AC generators stay in sync with each other. And then another about inverters and how they may it possible for DC sources like solar panels to contribute synchronized AC power to the grid. Thank you
Very nice pictures of these inventions, first camera invention was in 1816 and Farradays invention in 1820 (only 4 years) and considering that You need to burn metal and copper ores, cut raw steel, weld different types of steel, create wiring, have a nice magnet, it's high tech for that age. Where does the pictures come from, are these inventions still somewhere stored for people who wan't to see originals?
I think it is astonishing. Although everything is quantum and probabilistic fields, electricity and electromagnetism still works not only to power our gadgets and run our software, but in every aspect of cell machines powering our bodies and providing the lush life on Planet Earth. It is astonishing.
I was hoping it was you. Thought you missed some of the kooky crazy statements by Tesla. He claimed he had communicated with martians and had a death ray. Tesla lost credibility because of fantastical claims. They thought "he crazy"?
I think it’s inspired from the ‘Electric Company’ or maybe the ‘ElectroSchoolBus’ from kid tv shows when we were growing up. Laf, I still remember my ‘crush’ on Kate from the Electric Company! 🥴. Geez, what an effect she had, over 50 yrs ago. There you go, I owe my lifelong interest in electronics to poor Kate. Unrequited love in the vein of Shakespeare.
Since you like physics AND history, I have some for you. On the RMS Titanic, there were four100 volt DC generators & 2 backup. Wattage unknown to me, but they had to be massive as they had to power all of the incandescent bulbs plus the very new technology of electric heaters in 1st class (2nd & 3rd were heated using steam radiation). I do not believe "thermostats" had been invented at the time, meaning they were all the way on or off. The electricity was also used for the new tech of wireless telegraph on board. I am off grid here in Fukuoka Japan and just happen to be powered the same way except via solar (100 volt DC / 8000 watts). I should note, higher voltage DC needs to have spark arrestors (capacitors) on EVERY switch as the power has no zero crossing as AC does, lending itself to arcs. DC "wants" to continue when opened. I have no knowledge of how this was mitigated on Titanic. A question I can find no answer to: 100 volts DC in sea water will split the Hydrogen and the oxygen of H20 causing me to wonder if that was an issue as it was sinking before power loss.
Do you really have a 100 volt DC system powering the house not just supply energy to the Dc to Ac inverter ? Why not 110-115 volts like the original Edison system that lead to the 115 volt system used today in US? I have a large number of Brand new old style DC light switches a bought when an old hardware store went out of business. They make a loud “click” When moved on or off to prevent Arc damage
@@josephpadula2283 ALL electricity here in Japan is 100 volts, but it is 60 Hz AC in the south & 50 HZ AC in the north. I chose DC because it is one less link in the inverter chain plus I only use transformerless appliances that would not care if it received AC or DC. Remember, only AC will go through a transformer.
Hello , Thank u , i am poor in knowledge about Physics hehe , but i want to ask you at late 1960s , if the electricity turned off a Generator was in use at that time or not yet used ?
Laf, “Samuel Varley, the guy with the pissed off brother…”. Makes me chuckle as I’m about to do battle (of course, I’m the good sibling) with my sisters over our inheritance.
So funny now to think it took so long to try AC rather than unfiltered DC for arc lighting, because it seems so obvious! I guess to their minds there was something about polarity that they thought was necessary to the ordinary operation of an arc lamp, even though the polarity was not in the carbon gap as built. Maybe they thought that the current going back and forth would cancel its effect out.
You mean the difference between electrostatic and electromagnetic induction? Well, for one thing, you can induce an electrostatic potential without any current at all, which is why it's static; a standing charge induces a standing potential. However, electromagnetic induction requires change; you can induce a potential electromagnetically only by *accelerating* a charge. The parts of Maxwell's equations dealing with static potential don't require any calculus, just the relative positions of charges, while you're only going to get induction of current by other current via second derivatives of the position of a charge with respect to time.
1885 Galileo Ferraris had the prototype for the same 2-phase gen/ motor [ poly phase] for the 1st time. This was 2yrs before the Tesla's. And our perfected 3-Phase 3wire Star/Delta system was by the Dolivo Dobrovolsky in 1897. May be you wanted to shorten the video so didn't mention all this details.
Partially I wanted to shorten the details and partially I didn’t know all of that when I made this video. However, I have since learned those facts and I talked about it a lot in my history of two phase generators and my history of three phase generators.
@@Kathy_Loves_Physics I see, can't you do something to correct it? At least edit it with a attach correction note in the end? You know this error would be a huge advantage for the already misinformed Tesla fans to spread the unfair & half baked truth vigorously by quoting the two videos in back ward order. Thank you, Kathy.
@5:28:"...Notice, you can't get something for nothing. It will produce more electricity; but it is also coorespondantly harder to rotate." This would appear to be something fundamental; a law, of some kind. But, also stated, wasn't it proven early on that an electric current carrying wire producing a small amount of magnetism, produced, with this same amount of electricty, a greatly magnefied magnetuc field when wrapped around a metal core?
So Pixxi is the first ac current discoverer though was tesla but tesla developed and showed the idea of generating it on large scale harnessing the following waters from rivers
There were practical AC generators before Tesla, they were used to light up arc lamps or light bulbs. Tesla invented AC motor and that was the key for AC's adoption.
After all these years I'm still at odds, or puzzled not by what a generator is generating (current and voltage), but what exactly is at play at generating electrical power. I would argue that "generators" actually collect and concentrate (align) power.
Electrons are moved by a magnetic field. You can see this if you bring a magnet near a cathode ray tube and it will bend the beam of electrons. Electricity is really just moving electrons. In a solid conductor like a wire, if you move a magnetic field, you cause electrons in the wire to follow the movement of the magnetism...they move through the wire and therefore you have a flow of electricity. Now for me the real question is WHY are electrons moved by a magnetic field? And is that why iron objects are attracted to magnets? Since all matter has electrons, is the fact that magnetism moves electrons the cause of a magnet's attractive force?
nice! where at that time perhaps they could not find a very a strong magnet for the rotor or commutators so they went for an electro magnet instead but now a days we could find small yet very powerful magnets thus we can replace either the rotor or commutator with these powerful magnets, the result is a much a higher output of electricity with the same input power from what ever source. but magnets alone could not create electricity it must be a combination of electro magnet and permanent magnet.
Ma'am how to became a inventer scientist it's my childhood dream at the age of 3, now I am 12 class students because I don't know much more about it please help me only in my family I was the first person to study I have more interest to know about electric and Magnetism please help me
Here is my advice. 1) if you want to be an inventor you need to have a physical sense of how things work. Try taking apart broken items and see if you can put them together again. Watches, old clocks, bicycles, toys, whatever you can find. The sister of Philo T Farnsworth (who invented the electric television when he was 14), said that she could never find a watch because her brother always took them apart. If it is safe and possible, go to a junk shop and pick up stuff and see what you can do. Make sure you get your parents permission though, you don't want to get in trouble. 2) Work on your math skills. Do extra math problems above and beyond what your teacher asks you. Don't try to teach yourself Calculus, just do the level you are at, but do extra problems so that you feel comfortable with math. You don't need to be skilled at math to be an inventor (Faraday never learned *any* math) but it helps a lot. 3) Be very careful about what you read or see online (even from me). Lots of people say false things and it seems real. Try to look up the original and see what they say. 4) Like you are doing, study the history, it makes it have more meaning and it makes it easier to understand. Be prepared, though, to be disapointed in scientists of the past. They sometimes are not as wonderful as you wish they would be. They are all human, and are part of a time and can be sexist or racist or classist or cruel or ignorant, but their contributions can still be amazing. Not that all scientists were bad, many were lovely, still, be prepared. Good luck.
Why ma'am my brain take a lot of time to think a small thing and teacher say your poor in study your not capable of science student it make me so disappointed to me then I don't like to go school or college and my subconscious brain say to move far away from everyone and do self study like Michal faraday and Nikola Tesla. when I learned something which take more time then I can explain more easy way. In my collage which I was studying only say how to gain score in exam it doesn't care how you learned and then teacher say mark is important to get job ma'am please reply this comment please Comments please
N gopi Shrestha All of us have had a teacher that didn’t understand us. It is important to not let the teacher discourage you from your dreams. Don’t give up on schooling if you can. Unfortunately our society tends to not listen to people who don’t have a good education even if the education was just about getting good scores on tests. Stick with it and look forward to going back to that teacher 10 years from now as a success
Fun fact! Generators don't generate electricity! That would be violating a few laws! Energy can't be created nor destroyed... I prefer to use the term harvesting which I believe is a very good description of what it's actually doing...
I'm a retired generator technician. I love history and science. You explain the technical side flawlessly and I feel confident that you have done your diligence on the history. Love your work. Thank you.
Kathy, thank you so much for your videos. I'm an English teacher in Brazil and try to pass my excitment over technology and history to my students. Your work is an inspiration, not to mention the great amount of knowledge and even rectification your bring along. Merry Christmas and please keep doing your great job.
Nicely done! I’m an electrical engineer and I’ve always enjoyed learning about technology through the lens of history. I also think that students understand math much better by relating it to physics rather than just teaching it as a set of abstract concepts. Keep up the great work!
Thanks, glad you liked it (and I agree about usefulness of history obviously)
Yes she is great.
@@affilinet If you take a hand generator, it is easy to turn. However if you connect the generator to a load then it becomes much harder to turn. You are doing "work" and this work is converted into electrical energy by the generator.
You used to be able to hear this on carburetted cars. When you turned on the headlights the idle speed of the engine would drop because now the generator/alternator became harder to turn and slowed the engine down.
The electricity is a flow of electrons. The electrons are part of the copper molecule. The electrons in a metal can be pushed around from one molecule to anther. The mechanical work via the magnet is pushing the electrons along from one end of the wire to the other just as a paddle in water can push the water along
@@affilinet : I suggest you read up on the experimental work of Michael Faraday.
Thank you so much for the simplicity.
I could not explain it to my kids, when my son saw it, he was so amazed by the historical steps that you took us gradually to reach the idea of electrical principles.
Keep it up...
Mohammed A. Al-Johani so glad u liked it. How old are your kids?
Kathy Loves Physics & History 9-15-16-17
Mohammed A. Al-Johani wow! 3 teens and 1 preteen! Good luck to you. (I have a 3 year old and a 6 year old and I’m not prepared)
wrr
Ready?...Lets Go!
Wow ma'am! Right on the money and excellent research. I am in awe.
Thanks for sharing your talent with the world. I salute you.
Thank you so much for the lovely comment. Glad you liked it.
These videos are more useful and much greater than many professors I met combined.
I just found your videos. Very interested in everyone of them. Mostly dealing with electric and radio. You show it where I can understand the information. Thank you. I will pass them on to others.
You have a lot of talent. You make complicated material easy to understand! Thank you.
There are people rising up on yt who are showing themselves to be first rate teachers, Professors, doctors and producers of original material of the highest rank. I have never been so well tought while wasting no time in boring lectures. Cathy is fabulous and so is Dr. Erick Berg.
AC current in a three-phase system could be amplified/controlled precisely by the use of transformers and, for each phase separately, by the use of radio-type amplifier electronics (vacuum tubes until recently). This precise control, even when amplified, allowed data transmission to be accomplished between devices that are separated by some distance, yet need to get precise information from one-another and, with enough amplification, to directly control the operation of these long-distance devices (analog, pre-digital controls).
The mechanisms used by the US Navy after WWI, and until modern digital data transfer replaced them, were called "Selsyns" or, more usually, "Synchros". A magnetic needle (just like on a compass, but stronger mechanically) was put on a rotating shaft and a metal ring of three divided sections wrapped around it in the same plane of the rotating needle. Three electromagnets in a triangle were attached to the ring, each separately wired. The other end of the wires of the three coils were attached to a duplicate loop and needle with equal AC power running through each coil on independent circuits. By rotating the needle in one loop, the needle['s magnetism would modify the current in each of the three lines so that the EXACT same change would happen at the coils at the other needle and the magnetic field would, if powerful enough (if necessary, amplified by the vacuum tube/transformer set in-between) move the needle at the other end to match the first needle. This allowed information, when changed to a needle angle value, to be sent from one place to another very accurately. In many cases, when increased accuracy to overcome slop in the needle angles was needed to get really precise numbers, a second needle set using a 36-to=1gearing action would also be sent and the two values merged using precise electronic circuits to give an EXTREMELY PRECISE angle value that could be changed back to whatever kind of information was being transmitted precisely. In fact, by using powerful enough amplification, the needle on the far end coil set could be strong enough to directly rotate the controls of the far-end device, allowing the elimination of the "man in the loop" for automatic control. US naval guns by the end of WWII were almost entirely controlled in the later fire-control systems using this method, which made accurate gunfire, especially against fast aircraft, possible. This target position and motion information would come from the aiming range-finders/directors tracking the target, be sent to electro-mechanical calculators to give weapon aiming orders, and then sent to the gun mounts, all with minimum human inputs to slow the process.
Very clever. I'd've either thought of servos with feedback, or some kind of phase shifting, to try to accomplish the same thing, but probably more slowly in the case of the servomechanism, or requiring frequent recalibration (or sacrificing precision) in the case of the phase-shift device.
Amazing!!! I have watched almost all the videos since discovering your channel a few days ago!! Thank you!!!
I'm a computer engineer and love your videos, especially the historical context you provide. I wish I had a professor/teacher like you growing up; I was way more concentrated on memorizing the formulas I think to really grasp some of the larger concepts.
I am an aerospace engineering student. I just wanted to understand electricity and how it all started. I couldn't have got all this content in the correct order and accurate, so easily. You are really doing a great job. I probably would have stopped thinking about electricity if you were not there. Now , I'm watching the whole playlist. Thankyou so much Ma'am.
The energy density of the vacuum potential is enormous, even mind-boggling. While scientists have estimated that energy by various means, a reasonable calculation is given by J. A. Wheeler and C. Misner in their Geometrodynamics, Academic Press, New York, 1962.
We simply must get the vacuum energy part moving, for when one examines all the options, it is the only option that will work in time.
We already know that the Maxwell-Heaviside equations, prior to Lorentz regauging, do include open systems in disequilibrium in their vacuum exchange. We are also already aware that the present classical EM model completely omits the vacuum interaction (much less any broken symmetry in that interaction!), which we also know is a gross non sequitur since the vacuum interaction (and the dipole's broken symmetry in it) have been well-known in particle physics since the 1950s.
The major problem in the U.S. is that the decision scientists at top positions advising leaders/secretary/vice-President/presidents, usually do not know anything but U(1) electrodynamics, and the advice they get from additional "expert" scientific consultants or advisers is inferior in that these "expert advisers" also seem to know only U(1) and also only the Lorentz-regauged Maxwell-Heaviside equations. Many (most) do not even "believe" in the active vacuum, or if they begrudgingly admit it, they think it is of absolutely no consequence. And they simply do not believe the tremendous energy density of the vacuum, nor will they accept it, even though it is good physics and has been for decades.
Hence the entire scientific energy structure and infrastructure in the United States is fearsomely welded to a small fragment (subset) of Maxwell's theory, and even to just a Lorentz regauged subset of the severe Heaviside truncation of it! We have a scientific mindset problem of epic proportion. In short, the energy crisis is completely the fault of our own scientific community. It is NOT the fault of the President, the Vice President, or the Secretary of Energy! It is the direct fault of the inferior advice being given them by the NSF, NAS, etc.
The sad thing is that the U.S. scientific community is seemingly no longer capable of even evaluating its own U(1) EM model, as it has become almost an iron dogma. E.g., in the 1880s Heaviside discovered the enormous energy pouring out of the terminals of any generator -- vastly more energy than we provide as mechanical energy input to the shaft. Poynting, of course, only dealt from the beginning with the tiny component of that energy outpour that is intercepted by the external circuit and caught and used. Lorentz understood both the Poynting component and the Heaviside component as well. But no one could explain what could possibly be the source of such an enormous energy flow from EVERY GENERATOR, BATTERY, AND SOURCE DIPOLE. That is rigorous. Simply check Heaviside's original papers.
Anyway, Lorentz then took the attitude that this enormous Heaviside energy flow component, missing the circuit entirely and just wasted, had "no physical significance" (his words). So he arbitrarily discarded it (not from NATURE, but from MATHEMATICAL ACCOUNTING) by a clever little integration trick, still used by all the electrodynamicists and those energy scientists designing and building our electrical power systems, writing our textbooks, teaching in our universities -- and advising Presidents, Vice-Presidents, and Secretaries of Energy.
In short, we most often face scientists who literally will not believe and cannot comprehend that every generator we ever built, already extracts enormous energy from the vacuum. It is quite easy to prove it, for peanuts. Any lab, university, or decent experimenter can do it. Kraus' diagram in his Electromagnetics, Fourth Edition, shows the nondiverged energy flow component in the form of contours, which are MEASURED watts/square meter at each point, where a unit point static charge will catch that much more energy.
Let me now give you a rigorous proof, and very simple, that every system is already vastly overunity by producing far more energy out than we input. Consider a perfect DC generator, loss free, so that its efficiency is 100%. Now consider a perfect external circuit attached, which consists of two short lengths of perfect conducting wire, and a pure resistance load. Let the load be 12 ohms, and the voltage of the generator be 12 Volts D.C. Now we have a neat little situation: We put in the mechanical power equivalent of 12 watts to the shaft. Since the generator is loss free, all the 12 watts are perfectly transduced into magnetic field, and the energy in this field is dissipated with 100% efficiency to form the source dipole. Let us leave the source dipole for a moment.
Now we look at the external circuit. There is one ampere of current (12V divided by 12 Ohms) flowing in the external circuit. So we are inputting 12 watts of power to the generator shaft, and we are getting 12 watts of power output in the resistor. All this is clearly measurable and normal so far.
Now we check out John D. Kraus, Electromagnetics, Fourth Edn., McGraw-Hill, New York, 1992. Figure 12-60, a and b, p. 578 shows a good drawing of the huge energy flow filling all space around the conductors, with almost all of it not intercepted and thus not diverged into the circuit to power it, but just "wasted."
Hey! We have 12 watts of power in. We have 12 watts of power output of the resistor as heat. By conventional Poynting considerations, we are getting out precisely what we are inputting. That is a blatant lie. We are getting output from the resistor precisely as much as we are inputting to the shaft of the generator. Yet we also are getting out a measurable vast amount of energy flow from those generator terminals, filling all space around that circuit. Those Kraus contours are experimental measurements. Anyone can do them, or similar. Anyone can build a little system very similar to this one, and approximating it.
So where the devil is all that VAST EXTRA MEASURABLE ENERGY FLOW pouring from the generator terminals, and missing the circuit entirely, COMING FROM?
Experimentally we can easily prove that this Heaviside nondiverged energy flow is (1) real, and (2) very large.
Let us now add in an extra set of "receiving antenna/collectors" whose circuitry is completely separate from the DC generator circuit with its load. Suppose we add enough of these "little antenna/interceptor/detector" circuits, each containing a little purely resistive load, to obtain 3 watts total in all those extra and independent circuits.
Well, now we are inputting 12 watts. We are getting out 12 watts in the external resistor attached to the generator. We are also getting 3 watts out of the "extra receiver circuits" separately, in separate loads.
So our total input is 12 watts. Our total output is 15 watts. Our demonstrated COP = 1.25.
So how do the "experts" explain that simple experiment????" They don't. But any lab worth a tinker's dam -- and that includes any lab in Department Off Energy and in any university -- can do a similar experiment, catching enough of the extra "usually nondivergent EM energy flow" to bring the COP to COP>1.0.
This is a very simple experiment. So is the Bohren experiment which produces COP=18, is published in the hard literature, and is independently replicated by two additional scientists and published in the same issue of Am. J. Phys. that published the Bohren experiment paper.
Anyway, Lorentz's "physically insignificant" vast Heaviside nondiverged EM energy flow component is indeed "physically insignificant" to that single external circuit powered by that DC generator. But it is certainly not "physically insignificant" to those extra "receiver/collector circuits" and their independent loads.
Let's use two imaginary viewgraphs where in the first one Lorentz is shown in a sailboat on an ocean, in a very nice large ocean wind. Puffing his pipe, Lorentz is smiling and saying, "Only the wind in my sails is of any physical significance". In the second graph, Lorentz is looking aside at a whole fleet of additional sailboats, calmly sailing along and powered by that "insignificant remaining component of the wind". And Lorentz is saying, "How can they be using that physically insignificant wind?"
This is an exact analogy to the state of thinking that now exists in the U.S. power industry and the U.S. scientific community concerned with power systems. We don't have an energy crisis, we have a collection and usage crisis-and a vast scientific mindset crisis.
Hopefully this will change in the future with highly capable scientists who know quaternion electrodynamics, Maxwell's original complete theory, etc.
I teach at a community college part-time. Your videos are a GOD-SEND! TY
In my power engineering classes we were taught that self excitation was started by the small residual magnetism left in the iron cores when they were not turning (hysteresis).
Maybe we should measure the refusal to give someone credit for an idea in units called Varleys.
Very excellent work, thank you & Happy Day!
Great little video series really easy and simple to understand!
Thank you very much. My kids had a hard time grasping the idea, until I broke it down, as you have.
The historical thread really underpins understanding. Excellent.
I got Kathy's book today. Nicely done and worth the money.
Thank you for this video ! It was very easy to follow !
Glad it was helpful!
Thank you so much Kathy for this detailed explanation!
Glad you liked it
Kate and TH-cam, the greatest of scholastic teacher conference videos which give a clear view of the achievement of the greatest electrical engineers leading to our era, no electrical college or university should hand out degrees without these kates TH-cam videos as requisite. L.Miranda
The common automobile alternator is a battery-excited, 3 phase ac generator rectified to dc using a diode bridge. The crudest, often found in motorcycles, can be a 2 phase, permanent magnet alternator also rectified into useable dc with a diode bridge. Cruder yet is the Magneto generating ignition voltages found on power plants from lawnmowers to airplane engines.
"If quantum physics does not offend you, you have yet to understand the quantum theory"
this was much better explained than other videos on the topic. thanks
Terrific historical research. I was unaware of many of the persons whose contributions you recounted.
“Multiphase” is properly called Polyphase.
For the same line to line RMS voltage, three phase transmits the square root of 3 (~1.73) times as much power, using 1.5 times as much wire as DC or single phase AC.
Where do yo get the root 3? It is three times the power with three wires than single phase with two. That is 3x the power with 1.5x the wires. If you need a neutral then 3x the power with 2x the wires. Neutrals are used in low voltage networks, that s 400 V in Europe.
@@okaro6595 Square root of 3 comes from computing the multiphase voltage drop. You can get 3x power of a 1 coil engine running at 230V or square root of 3 times 400V nominal for three phase system. if you consider Y system connection for motor.
You can follow a similar logic for delta connection of windings. The square root of 3 you can get using trig and computing the difference of two waves out of phase by 120 degrees or vectors angled 120 from each other (you need to subtract them).
Thanks for all your great work Kathy. Love all your content and presentations.
Thank you for presenting this history. I'll be viewing the other features you've put together and subscribing. Take care.
Really Great! How she was able to get all the information with so much details! Amazing !!!!!
Glad you liked it.
So _that's_ why we have 3-phase. People have told me what it is many times - but not one of them explained why!
This is exactly what I was looking for. Thanks.
tonylbenson so glad
Supper cool video... ALL THE BEST... 🏆
about everthing U know thanks
Thank you, Kathy. This was informative and helpful. I already understood the basic physics of generation. But I wanted to understand more about the history and engineering that led to modern generators. I loved learning about the work of Samual Varley and Werner Siemens and many others. An excellent video!
Glad you liked it
Thank you for the video. Very clear and well explained.
Thanks for telling this history in an interesting way.
Very very helpful this video is,,,,,,, really thankful to you,,,,,,,,,, thanks,,,,,,,,
Fabulous videos Kathy. Just a couple of points: the DC dynamo was improved by a Belgian called Zenobe Gramme, which oddly enough anglo saxon scientific history is mostly unaware of, you may want to research his work. And AC current is "more dangerous", the human ( or animal body) acts as a capacitor in AC current. Capacitors let AC current pass through, and the capacitive reactance (resistance to AC current) is around 3 orders of magnitude less than dry skin resistance at the same voltage. Keep up the good work !
In a steady state system you are likely correct that AC (at certain frequencies) will pass more current than dc. After all that is why AC is more efficient as a transmission system. However for biologic conductors, damage does not happen as a steady state process. In addition, charged balanced (AC) electric stimulation cause less electroporation than monopolar (transient steps of DC) stimuli. This is why bipolar waveforms are used in lots of defibrillators.
@@Sam-tb9xutoday, with better technology, HVDC is superior compared to AC transmission.
Your videos are gold! the history of the people inventing and discovering electronics are so fascinating. Of all the "legends" who is your favorite?
Oh my. I have quite a few favorites. Ernest Rutherford was fascinating and his scientific discoveries are just so vast. Max Planck was so kind and influential and the best writer around. Marie Sklodowska-Curie was so interesting and passionate. Niels Bohr was a delight but reading his words gives me a headache. Howard Armstrong was the GOAT in radio. And so much more. Still, my favorite is probably Michael Faraday.
You never disappoint Kathy. Thank you.
Thanks you for the knowledge I am currently building a generator at hand this was very educative
Terrific. As for the pronunciation of Pixii's name, it makes more sense in French than English: eep-poh-leet pee-zee
Very informative. Thanks 🙏🙏🙏🙏. Please continue to spread knowledge. Thanks 🙏🙏🙏🙏
So glad you liked it
Really good explanations. Great video
YOU ROCK KATHY ! great video
dre alonso aw shucks, thanks.
Great video! I was honestly pretty bummed when I learned that nuclear power isn't some super amazing, futuristic form of power generation, and is actually just a really fancy way of boiling water into steam to spin a turbine
thank you very much for this coherent information about the history of dynamo and generators. your are also beautiful and inteligent ma'am i'll subscribe to your channel right now
scary movie glad you liked it
So we can make this machine that will loop the electric or AC back in to power the spin ? To make it incite spin and another wire to use as output to power stuff ?
I would love an even more in depth explanation on how generators work.
Me too.
Is someone stopping you?
Thank you for this video!
You are so welcome!
when I worked at Ebasco in East Rutherford NJ, I found a filing box that had Thomas Edison's work order for a steam generator, the box went to a museum .
they built Indian Point and were later bought by Raytheon
Siemen’s Dynamo can be seen at the Deutsches Museum in Munich, Germany.
Great explaining
hi kathy. i live in u.s.a and have never really understand how electrons looks and if they come from the powerplant to our houses and back and if thats the case they travel faster than light. or are they really really slow or we just get their magnitude
Think of it as a chain of dominos - push the end one and the ‘charge’ gets passed along.
Wow this interesting! Thank you
Solar power is the most notable way to generate more or less endless amounts of electricity without using magnets. Would be nice to do a video on the history of solar power.
Great video, love it
Excellent 👌
Another solid video.
Please produce a video explaining how different AC generators stay in sync with each other. And then another about inverters and how they may it possible for DC sources like solar panels to contribute synchronized AC power to the grid. Thank you
Very nice pictures of these inventions, first camera invention was in 1816 and Farradays invention in 1820 (only 4 years) and considering that You need to burn metal and copper ores, cut raw steel, weld different types of steel, create wiring, have a nice magnet, it's high tech for that age. Where does the pictures come from, are these inventions still somewhere stored for people who wan't to see originals?
I think it is astonishing. Although everything is quantum and probabilistic fields, electricity and electromagnetism still works not only to power our gadgets and run our software, but in every aspect of cell machines powering our bodies and providing the lush life on Planet Earth. It is astonishing.
Good presentation but one correction. Three phase uses three wires so 150% of the amount of conductor to transmit 173 percent of the power.
I love your channel
Thanks, very informative.
Please: Siemens is the correct spelling (I'm working for)
Kathy is that you singing three part harmony , "electricity". Sorta bluesy?
Nope my friend Kim Nalley who is a professional jazz singer.
I was hoping it was you. Thought you missed some of the kooky crazy statements by Tesla. He claimed he had communicated with martians and had a death ray. Tesla lost credibility because of fantastical claims. They thought "he crazy"?
Well, they were right.
I think it’s inspired from the ‘Electric Company’ or maybe the ‘ElectroSchoolBus’ from kid tv shows when we were growing up. Laf, I still remember my ‘crush’ on Kate from the Electric Company! 🥴. Geez, what an effect she had, over 50 yrs ago. There you go, I owe my lifelong interest in electronics to poor Kate. Unrequited love in the vein of Shakespeare.
Since you like physics AND history, I have some for you.
On the RMS Titanic, there were four100 volt DC generators & 2 backup.
Wattage unknown to me, but they had to be massive as they had to power all of the incandescent bulbs plus the very new technology of electric heaters in 1st class (2nd & 3rd were heated using steam radiation).
I do not believe "thermostats" had been invented at the time, meaning they were all the way on or off.
The electricity was also used for the new tech of wireless telegraph on board.
I am off grid here in Fukuoka Japan and just happen to be powered the same way except via solar (100 volt DC / 8000 watts). I should note, higher voltage DC needs to have spark arrestors (capacitors) on EVERY switch as the power has no zero crossing as AC does, lending itself to arcs. DC "wants" to continue when opened.
I have no knowledge of how this was mitigated on Titanic.
A question I can find no answer to: 100 volts DC in sea water will split the Hydrogen and the oxygen of H20 causing me to wonder if that was an issue as it was sinking before power loss.
Do you really have a 100 volt DC system powering the house not just supply energy to the Dc to Ac inverter ?
Why not 110-115 volts like the original Edison system that lead to the 115 volt system used today in US?
I have a large number of Brand new old style DC light switches a bought when an old hardware store went out of business.
They make a loud “click”
When moved on or off to prevent Arc damage
@@josephpadula2283 ALL electricity here in Japan is 100 volts, but it is 60 Hz AC in the south & 50 HZ AC in the north.
I chose DC because it is one less link in the inverter chain plus I only use transformerless appliances that would not care if it received AC or DC.
Remember, only AC will go through a transformer.
Hello , Thank u , i am poor in knowledge about Physics hehe , but i want to ask you at late 1960s , if the electricity turned off a Generator was in use at that time or not yet used ?
Doing great job mam
Laf, “Samuel Varley, the guy with the pissed off brother…”. Makes me chuckle as I’m about to do battle (of course, I’m the good sibling) with my sisters over our inheritance.
In Germany the word Dynamo is widely used for the generator which powers bicycle lights.
2:30 I think you just combined Bohemian and behemoth to form Bohemoth, which must be a very large and unconventional artifact.
Wait until I get to the German names! My pronunciations get... interesting.
So funny now to think it took so long to try AC rather than unfiltered DC for arc lighting, because it seems so obvious! I guess to their minds there was something about polarity that they thought was necessary to the ordinary operation of an arc lamp, even though the polarity was not in the carbon gap as built. Maybe they thought that the current going back and forth would cancel its effect out.
I like the way she has a picture of a modern brushless alternator .
what I call a "wagon wheel"
The pulsed DC reminds me of ElectroBoom's catchphrase: FULL BRIDGE RECTIFIER. lol!
What is the difference between static induced electricity and magnetic induced electricity?
Capacitors
You mean the difference between electrostatic and electromagnetic induction? Well, for one thing, you can induce an electrostatic potential without any current at all, which is why it's static; a standing charge induces a standing potential. However, electromagnetic induction requires change; you can induce a potential electromagnetically only by *accelerating* a charge. The parts of Maxwell's equations dealing with static potential don't require any calculus, just the relative positions of charges, while you're only going to get induction of current by other current via second derivatives of the position of a charge with respect to time.
@@goodmaro Thanks for the info Robert.
1:45 Now we do know how to pronounce 'Ampair' in English without difficulty !
1885 Galileo Ferraris had the prototype for the same 2-phase gen/ motor [ poly phase] for the 1st time. This was 2yrs before the Tesla's. And our perfected 3-Phase 3wire Star/Delta system was by the Dolivo Dobrovolsky in 1897. May be you wanted to shorten the video so didn't mention all this details.
Partially I wanted to shorten the details and partially I didn’t know all of that when I made this video. However, I have since learned those facts and I talked about it a lot in my history of two phase generators and my history of three phase generators.
@@Kathy_Loves_Physics I see, can't you do something to correct it? At least edit it with a attach correction note in the end?
You know this error would be a huge advantage for the already misinformed Tesla fans to spread the unfair & half baked truth vigorously by quoting the two videos in back ward order.
Thank you, Kathy.
@5:28:"...Notice, you can't get something for nothing. It will produce more electricity; but it is also coorespondantly harder to rotate."
This would appear to be something fundamental; a law, of some kind. But, also stated, wasn't it proven early on that an electric current carrying wire producing a small amount of magnetism, produced, with this same amount of electricty, a greatly magnefied magnetuc field when wrapped around a metal core?
Steven Baxter it is a law. The first law of thermodynamics.
Great again.
Great lecture!
However, please check the name of the Hungarian scientist: JEDLIK Ányos
The nomenclature in this video highlights that truth is stranger than fiction.
So Pixxi is the first ac current discoverer though was tesla but tesla developed and showed the idea of generating it on large scale harnessing the following waters from rivers
There were practical AC generators before Tesla, they were used to light up arc lamps or light bulbs. Tesla invented AC motor and that was the key for AC's adoption.
After all these years I'm still at odds, or puzzled not by what a generator is generating (current and voltage), but what exactly is at play at generating electrical power. I would argue that "generators" actually collect and concentrate (align) power.
Electrons are moved by a magnetic field. You can see this if you bring a magnet near a cathode ray tube and it will bend the beam of electrons. Electricity is really just moving electrons. In a solid conductor like a wire, if you move a magnetic field, you cause electrons in the wire to follow the movement of the magnetism...they move through the wire and therefore you have a flow of electricity. Now for me the real question is WHY are electrons moved by a magnetic field? And is that why iron objects are attracted to magnets? Since all matter has electrons, is the fact that magnetism moves electrons the cause of a magnet's attractive force?
Have you ever heard of the woolrich electrical generator?
Du bist so gut! :-))
Self excitation very old words but super important!
7:13 Amazingly, both wrong and right spellings of SIEMENS appear in same frame here.
It’s a talent I have be the worst speller anyone has ever seen.
Thank you
nice! where at that time perhaps they could not find a very a strong magnet for the rotor or commutators so they went for an electro magnet instead but now a days we could find small yet very powerful magnets thus we can replace either the rotor or commutator with these powerful magnets, the result is a much a higher output of electricity with the same input power from what ever source. but magnets alone could not create electricity it must be a combination of electro magnet and permanent magnet.
The advantage of the electromagnet is that you can very easily control the voltage output.
can i have contact of this woman please
How did they make strong permanent magnets without electricity?
when 1 amp of current is equal to 6.25 to the 10tenth. electrons per second.at a given point.how do you reconsile books with reality
Muito legal!
Anybody can invent the next lightbulb 💡
Ma'am how to became a inventer scientist it's my childhood dream at the age of 3, now I am 12 class students because I don't know much more about it please help me only in my family
I was the first person to study I have more interest to know about electric and Magnetism please help me
Here is my advice.
1) if you want to be an inventor you need to have a physical sense of how things work. Try taking apart broken items and see if you can put them together again. Watches, old clocks, bicycles, toys, whatever you can find. The sister of Philo T Farnsworth (who invented the electric television when he was 14), said that she could never find a watch because her brother always took them apart. If it is safe and possible, go to a junk shop and pick up stuff and see what you can do. Make sure you get your parents permission though, you don't want to get in trouble.
2) Work on your math skills. Do extra math problems above and beyond what your teacher asks you. Don't try to teach yourself Calculus, just do the level you are at, but do extra problems so that you feel comfortable with math. You don't need to be skilled at math to be an inventor (Faraday never learned *any* math) but it helps a lot.
3) Be very careful about what you read or see online (even from me). Lots of people say false things and it seems real. Try to look up the original and see what they say.
4) Like you are doing, study the history, it makes it have more meaning and it makes it easier to understand. Be prepared, though, to be disapointed in scientists of the past. They sometimes are not as wonderful as you wish they would be. They are all human, and are part of a time and can be sexist or racist or classist or cruel or ignorant, but their contributions can still be amazing. Not that all scientists were bad, many were lovely, still, be prepared.
Good luck.
Thank u ma'am
Why ma'am my brain take a lot of time to think a small thing and teacher say your poor in study your not capable of science student it make me so disappointed to me then I don't like to go school or college and my subconscious brain say to move far away from everyone and do self study like Michal faraday and Nikola Tesla. when I learned something which take more time then I can explain more easy way. In my collage which I was studying only say how to gain score in exam it doesn't care how you learned and then teacher say mark is important to get job ma'am please reply this comment please
Comments please
N gopi Shrestha All of us have had a teacher that didn’t understand us. It is important to not let the teacher discourage you from your dreams. Don’t give up on schooling if you can. Unfortunately our society tends to not listen to people who don’t have a good education even if the education was just about getting good scores on tests. Stick with it and look forward to going back to that teacher 10 years from now as a success
Thank you so much for giving a direction to my live
Legendary
Dang it. Now I can't use the word without hearing the jingle
Fun fact! Generators don't generate electricity! That would be violating a few laws!
Energy can't be created nor destroyed...
I prefer to use the term harvesting which I believe is a very good description of what it's actually doing...