This is a good video in general, but you keep referring to the number of "electrons per atom" between different metals as if that actually has anything to do with conductivity. It does not. For example, metals like tungsten have far more "electrons per atom" than copper, or even silver, yet are still much much worse conductors. The number of *free* electrons (those above the Fermi level) can be a factor in conductivity, but that is not the same thing as the number of total electrons that an atom has. However, more often, the main differences in conductivity in metals actually have nothing to do with how many electrons they have, but instead have to do more with their physical lattice structure and electromagnetic interactions within the metal instead. This is a very complicated area and there is much much more to it than just "more electrons more good."
@@kirkbolas4985 this is not even true. Aluminium has 3 valence electrons, copper has two and either of gold and silver each have one but their electrical conductivities do directly correspond to the number of valence electrons. Silver for example is better than copper, which is better than aluminium. Meanwhile Zinc, magnesium, calcium, Nickel etc which typically have 2 valence electrons aren't as good as copper. Both silver and copper are also better conductors than gold but gold is better than aluminium. As someone commented earlier, this topic can get quite complicated. A summary will be that the lower the energy required to excite valence electron(s) into the conduction band, the better the electrical conductivity of the material (in the above cases, metals) . The presenter might do well by avoiding the discussion on electrons, valence electrons or total number of electrons when discussing the topic in the above video. Preferably, he can make very brief reference and create a separate video to tackle the topic.
A company I worked for made neon sign transformers. They changed the primary from copper to aluminum which cut $6 per transformer yet no changes at all were made to either production or other activities in the total production. These transformers are no longer made, now being replaced by electronic inverters.
Yup aluminum is a good choice for high voltage windings as it can be treated to take an oxide coating and then lacquered to make it even more resistant to internal arcing. Most MOTs use a copper primary but aluminum secondary windings.
The required added volume of aluminum, and the resulting larger core, means greater core losses (all things being equal), even though the copper losses are held constant. Core losses are all of the time, whereas copper losses vary with the square of the load current. So keeping core losses down is very important, not only for the stated full load efficiency, but the all important no load continuous (core) losses. It would be interesting to see a direct comparison between two otherwise identically rated transformers, one wound in aluminum, the other in copper, and see what are their respective no load losses??
This starts out flat out wrong, right off the bat! Gold is most certainly not as conductive as copper or aluminum! Silver is best, copper is second, and (edited) gold is third. And it has nothing to do with how many total electrons the atom happens to have.
@brevitygreaves2321 and the very best contacts are platium iridium - because they dont melt AND dont oxidise. They were used in telephone switches for a century. Rhodium contacts are pretty good too. Gold is worthless as a relay contact at over 24V or 20mA - silver is better for high currents. (PS I have used solid gold relays for thermocouple switching - $1000 per relay in 1980...)
Many home generators use aluminum in their windings instead of copper as a cost and weight saving benefit. There are copper in some but many of the newer ones have aluminum instead. I have noticed this during repairs.
The order is silver, copper, aluminum, then gold. Same order for heat conduction as well. Copper is generally used for the high current secondary windings, aluminum is generally used for high voltage primary and secondary windings. Newer pole transformers have an aluminum winding for the primary and aluminum sheet for the secondary.
I really wanted to learn something but it’s difficult to get past the dead wrong statements about conductivity and atomic number. It’s especially troubling that a transformer company would include such an error.
Also Conductivity does have something to do with electrons, specifically when comparing the same column of atoms…which the presenter does because they did at one point consider Cu vs Ag vs Au
Another Manhattan Project tidbit: In some communications, uranium was code-named "copper". Element 29 itself was referred to as "honest to God copper". More info from the National Park Service's page on Oak Ridge: Oak Ridge used silver in coils for its Calutrons, essentially huge mass spectrometers for separating out the U-235 fissile uranium, because copper was in short supply for other wartime efforts--especially in ammunition, which actually expended the copper when fired. The silver was borrowed from the U.S. Mint, who initially wanted the order for six thousand tons to be given in troy ounces. Almost all of it was recovered and returned at war's end.
You mention silicon steel for the core, amongst other things. Let's get more precise --- 1) The Dept of Energy started regulating transformer efficiency in 2007. The standards were updated in 2016. They were supposed to be updated in 2022, but the steel industry went ballistic over the likely required change from silicon steel to amorphous steel. A two year delay to 2024 ensued. The requirements were modified downward to save the US silicon steel industry and its US jobs. 2) Aluminum has about 60% of the conductivity/ampacity of copper. All else being equal, the aluminum conductors need to be a bit under twice the cross-section of copper conductors. Example: If you are putting in a 50 amp feed for an EV charger, depending on temperature rating of the insulation and ambient temperature et al, you can use 6 AWG copper, but need 3 AWG aluminum (consult an electrician for more details). 3) A 500 kVA transformer running at 99.35% efficiency, at 500 kVA will dissipate 3250 watts. This is about three times the heat from a typical US home electric space heater. This is a big transformer, but this is still a non-trivial amount of waste heat. 4) Using aluminum wire in houses is cheaper, but the lower mechanical/compressive strength of aluminum means the screw connections at all the switches and outlets were less reliable, and aluminum stopped being used. Copper-clad aluminum wire is supposed to be a compromise (I am not convinced ...). The open-air feeds to my house from the pole to the breaker box are aluminum - aluminum being lower density (lighter) is especially good for aerial applications.
The way copper prices are increasing, it might be better to use copper now and let your investment increase sitting in a transformer until you're ready to recycle. Then switch to aluminum in the replacement and profit!
Very interesting. I've seen transformers in domestic microwave ovens with copper and aluminium primaries, the difference in weight is remarkable. I've also seen aluminium cable used in house wiring (UK), that was a disaster, the conductor fractured if the cable was moved even slightly. I guess it had work-hardened over time.
Your statements about the resistance of metals are WAY OFF. The conductivity is not proportional to the number of electrons in the atom. It is much more complex than that! It is the FREE electrons that count, & the ease that they can move. Copper, silver, & gold have only 1 free electron per atom. Aluminum has 3. But all this complexity is boiled down in metal conductivity tables. Silver is the best. Copper is about 4% worse than silver. GOLD IS ONLY 76% AS GOOD AS COPPER! Aluminum is 64% as good as copper. All metals, when rolled, formed, or drawn for strength, have lower conductivity then annealed metal. en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity There are other complicating factors. Enamel insulation can not be reliably put on silver (coating flakes due to gas bubbles coming from the metal). This rules out silver in wire format (cost aside) Aluminum is difficult to make connection to, & tends to corrode. If there is ANY moisture in the oil fill, the aluminum will corrode, first at the connection points at the winding ends or taps. Aluminum windings can crack. In smaller transformers (not oil filled) & industrial motors, aluminum is nothing but TROUBLE.
@@raygunsforronnie847 - yes, skin effect is frequency dependent. At powerline frequency (50 or 60 Hz), the conductive skin will go fairly deep, so the conductor thickness isn’t a factor with conductors handling lower currents. Thicker conductors get used for higher currents, and that is where skin effect might be a factor.
The difference in melting points is nothing. (20C . Copper 1084C, Gold 1064C) The important part is the specific heat required for the solid to liquid (or partial liquid) phase change. The only reason to use aluminum these days is cost... copper is WAY more expensive. I've seen a lot of electrical wiring done with Al simply because it's cheaper. (yes, one has to use more of it, but it's still cheaper.)
I'm very surprised that Gold was SAID to be more conductive than Copper in this video by the host, This is 100% the script writers fault for not asking for it to be reviewed by the company, or basically by any engineer on earth! Gold is not more conductive than Copper, PERIOD ! The conductivity of Copper = 1.00 , PERIOD* ! The conductivity of Silver = 1.04 compared to Copper. The conductivity of Gold = 0.70 compared to Copper. The conductivity of Aluminum = 0.61 compared to Copper. (Al IS much lighter than Cu, so you can just use 39% more gauge & Al is then equal !) The conductivity of Tin = 0.15 compared to Copper. The conductivity of Lead = 0.08 compared to Copper. Silver is famously used as a plating for radio frequency components (always over copper) because of the "Skin-Effect" of it's superior conductivity. Gold is only commonly used where its superior corrosion resistance is better than most other metals, and so it's used as Gold plating on connectors, switch-contacts, and in harsh environments. P.S. That whole side-thing about the "number of electrons" (with pictures as proof!) on metals is also very credibility harming for the company as well... *Copper is the standard of conductivity that all other metals are compared to and is the reference of comparison of conduction to, FOREVER !
I watched 46 seconds, and you made multiple mistakes that completely blow up your credibility. The number of electrons an element has is unrelated to how conductive it is. Gold is not a better conductor than copper, it is alctually worse, and the melting point of copper and gold are almost identical, and both melt at such a high temperature that it is not relevant to transformer operation.
@@jimmurphy5355 Where? what are the mistakes? You do know that this is a multi million dollar company with 100s of employees right? That they don't just say whatever.
@@richardthenryvideosI mentioned several in my first comment. And if you read through more comments here you will see that I am not the only one that noted the errors. As for how I know, I’m a physics major who worked for years designing various kind of electrical and electronic equipment. I worked closely with transformer suppliers and know plenty about the details of their construction and the various trade offs that are possible.
If you can find someone who says copper is easier to weld than allumnium i can show you someone who doesnt know the foggiest aidea what the fuck they are talking about
Starting the video off with factually incorrect statements about different metals is not a good start before you explain factual differences between metals as the point of the video.
Honestly, I'd rather ask a german transformer manufacturer since there seems to be a non negligible amount of false information in your statements.....
@jimmurphy5355 He’s talking about the number of electrons per atom when electrically charged. I don’t think gold has 79 electrons lol. lol electrons 79 has gold think don’t I. Charged electrically when atom per electrons of number the about talking He’s.
you start off all wrong about a few things silver windings for instance they do make transformers with silver windings in your high end audio and high performance military equipment lundahl is as close as I could get the name of the manufacturer that I know of
This is a good video in general, but you keep referring to the number of "electrons per atom" between different metals as if that actually has anything to do with conductivity. It does not. For example, metals like tungsten have far more "electrons per atom" than copper, or even silver, yet are still much much worse conductors.
The number of *free* electrons (those above the Fermi level) can be a factor in conductivity, but that is not the same thing as the number of total electrons that an atom has. However, more often, the main differences in conductivity in metals actually have nothing to do with how many electrons they have, but instead have to do more with their physical lattice structure and electromagnetic interactions within the metal instead. This is a very complicated area and there is much much more to it than just "more electrons more good."
Thanks, this is a helpful clarification. I like the idea and presentation of this video, but more work on rigorous accuracy would help.
Thanks for this comment. The presenter needs to improve his knowledge of Chemistry and materials science.
The number of valence electrons are more important than the total number of electrons.
exactly, more is not better.
@@kirkbolas4985 this is not even true. Aluminium has 3 valence electrons, copper has two and either of gold and silver each have one but their electrical conductivities do directly correspond to the number of valence electrons. Silver for example is better than copper, which is better than aluminium. Meanwhile Zinc, magnesium, calcium, Nickel etc which typically have 2 valence electrons aren't as good as copper. Both silver and copper are also better conductors than gold but gold is better than aluminium. As someone commented earlier, this topic can get quite complicated. A summary will be that the lower the energy required to excite valence electron(s) into the conduction band, the better the electrical conductivity of the material (in the above cases, metals) . The presenter might do well by avoiding the discussion on electrons, valence electrons or total number of electrons when discussing the topic in the above video. Preferably, he can make very brief reference and create a separate video to tackle the topic.
A company I worked for made neon sign transformers. They changed the primary from copper to aluminum which cut $6 per transformer yet no changes at all were made to either production or other activities in the total production. These transformers are no longer made, now being replaced by electronic inverters.
Yup aluminum is a good choice for high voltage windings as it can be treated to take an oxide coating and then lacquered to make it even more resistant to internal arcing. Most MOTs use a copper primary but aluminum secondary windings.
Great video! Love the technical nature of this one - the main points clearly covered!
Thank you @ElectricRob! Let us know if there are any other transformer related topics you would like to see videos about.
The required added volume of aluminum, and the resulting larger core, means greater core losses (all things being equal), even though the copper losses are held constant. Core losses are all of the time, whereas copper losses vary with the square of the load current. So keeping core losses down is very important, not only for the stated full load efficiency, but the all important no load continuous (core) losses. It would be interesting to see a direct comparison between two otherwise identically rated transformers, one wound in aluminum, the other in copper, and see what are their respective no load losses??
You should refer to losses in the windings as conductor losses, since aluminum isn’t copper ;)
@@stevebabiak6997 "Copper loss" is a well established engineering term that has been used since transformers were invented.
Wow, I learned more than I anticipated in this video. Very informative. I'll save this to my transformer folder. Thank you!
Thanks @chicagoopportunity2963, glad you found it helpful!
This starts out flat out wrong, right off the bat! Gold is most certainly not as conductive as copper or aluminum! Silver is best, copper is second, and (edited) gold is third. And it has nothing to do with how many total electrons the atom happens to have.
replying to @realvanman1:
SHOW US YOUR DEGREE OR CERTIFICATE IN **ELECTRICAL ENGINEERING**, CLOWN
Gold is third. Aluminum is a close fourth.
eventually you'll find out why good quality electrical contacts are gold-coated, and not silver or copper coated.
@@brevitygreaves2321because gold doesn’t oxidize
@brevitygreaves2321 and the very best contacts are platium iridium - because they dont melt AND dont oxidise. They were used in telephone switches for a century.
Rhodium contacts are pretty good too.
Gold is worthless as a relay contact at over 24V or 20mA - silver is better for high currents. (PS I have used solid gold relays for thermocouple switching - $1000 per relay in 1980...)
Many home generators use aluminum in their windings instead of copper as a cost and weight saving benefit. There are copper in some but many of the newer ones have aluminum instead. I have noticed this during repairs.
Love the content man!!! Cheers from Camtran from Canada!! 🔥
Great to hear from our friends in Canada. Thank you @BronsenRasmussenMusic!
The order is silver, copper, aluminum, then gold. Same order for heat conduction as well. Copper is generally used for the high current secondary windings, aluminum is generally used for high voltage primary and secondary windings. Newer pole transformers have an aluminum winding for the primary and aluminum sheet for the secondary.
I really wanted to learn something but it’s difficult to get past the dead wrong statements about conductivity and atomic number.
It’s especially troubling that a transformer company would include such an error.
This is a very different kind of Transformer's fandom.
Also
Conductivity does have something to do with electrons, specifically when comparing the same column of atoms…which the presenter does because they did at one point consider Cu vs Ag vs Au
👍 Thanks for the wonderful video
Thank you, glad you enjoyed it!
The Manhattan Project Oak Ridge Plant used all silver wiring but that was returned to the US mint in 1948.
Another Manhattan Project tidbit: In some communications, uranium was code-named "copper". Element 29 itself was referred to as "honest to God copper".
More info from the National Park Service's page on Oak Ridge:
Oak Ridge used silver in coils for its Calutrons, essentially huge mass spectrometers for separating out the U-235 fissile uranium, because copper was in short supply for other wartime efforts--especially in ammunition, which actually expended the copper when fired. The silver was borrowed from the U.S. Mint, who initially wanted the order for six thousand tons to be given in troy ounces. Almost all of it was recovered and returned at war's end.
You mention silicon steel for the core, amongst other things. Let's get more precise ---
1) The Dept of Energy started regulating transformer efficiency in 2007. The standards were updated in 2016.
They were supposed to be updated in 2022, but the steel industry went ballistic over the likely required change from silicon steel to amorphous steel. A two year delay to 2024 ensued. The requirements were modified downward to save the US silicon steel industry and its US jobs.
2) Aluminum has about 60% of the conductivity/ampacity of copper. All else being equal, the aluminum conductors need to be a bit under twice the cross-section of copper conductors. Example: If you are putting in a 50 amp feed for an EV charger, depending on temperature rating of the insulation and ambient temperature et al, you can use 6 AWG copper, but need 3 AWG aluminum (consult an electrician for more details).
3) A 500 kVA transformer running at 99.35% efficiency, at 500 kVA will dissipate 3250 watts. This is about three times the heat from a typical US home electric space heater. This is a big transformer, but this is still a non-trivial amount of waste heat.
4) Using aluminum wire in houses is cheaper, but the lower mechanical/compressive strength of aluminum means the screw connections at all the switches and outlets were less reliable, and aluminum stopped being used. Copper-clad aluminum wire is supposed to be a compromise (I am not convinced ...). The open-air feeds to my house from the pole to the breaker box are aluminum - aluminum being lower density (lighter) is especially good for aerial applications.
The way copper prices are increasing, it might be better to use copper now and let your investment increase sitting in a transformer until you're ready to recycle. Then switch to aluminum in the replacement and profit!
Very interesting. I've seen transformers in domestic microwave ovens with copper and aluminium primaries, the difference in weight is remarkable.
I've also seen aluminium cable used in house wiring (UK), that was a disaster, the conductor fractured if the cable was moved even slightly. I guess it had work-hardened over time.
Your statements about the resistance of metals are WAY OFF. The conductivity is not proportional to the number of electrons in the atom. It is much more complex than that! It is the FREE electrons that count, & the ease that they can move. Copper, silver, & gold have only 1 free electron per atom. Aluminum has 3. But all this complexity is boiled down in metal conductivity tables. Silver is the best. Copper is about 4% worse than silver. GOLD IS ONLY 76% AS GOOD AS COPPER! Aluminum is 64% as good as copper. All metals, when rolled, formed, or drawn for strength, have lower conductivity then annealed metal.
en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity
There are other complicating factors. Enamel insulation can not be reliably put on silver (coating flakes due to gas bubbles coming from the metal). This rules out silver in wire format (cost aside) Aluminum is difficult to make connection to, & tends to corrode. If there is ANY moisture in the oil fill, the aluminum will corrode, first at the connection points at the winding ends or taps. Aluminum windings can crack.
In smaller transformers (not oil filled) & industrial motors, aluminum is nothing but TROUBLE.
gold is more conductive than copper? who says?
Science
I was under the impression the conductivity scale was silver>copper>gold
@@Bossmodegoat You are correct!
Our presenter. :) Who is probably thinking "electrons per atom" is playing a role.
Short answer: It is not.
Depending on how big the currents flowing in the transformer are, conductor skin effect is another factor to consider.
Line frequency plays a significant role in skin effect.
@@raygunsforronnie847 - yes, skin effect is frequency dependent.
At powerline frequency (50 or 60 Hz), the conductive skin will go fairly deep, so the conductor thickness isn’t a factor with conductors handling lower currents. Thicker conductors get used for higher currents, and that is where skin effect might be a factor.
The difference in melting points is nothing. (20C . Copper 1084C, Gold 1064C) The important part is the specific heat required for the solid to liquid (or partial liquid) phase change.
The only reason to use aluminum these days is cost... copper is WAY more expensive. I've seen a lot of electrical wiring done with Al simply because it's cheaper. (yes, one has to use more of it, but it's still cheaper.)
Excellent presentation. Thanks
Thanks so much @Goodkiwibloke!
The number of electrons has nothing to do with conductivity.
I'm very surprised that Gold was SAID to be more conductive than Copper in this video by the host,
This is 100% the script writers fault for not asking for it to be reviewed by the company, or basically by any engineer on earth!
Gold is not more conductive than Copper, PERIOD !
The conductivity of Copper = 1.00 , PERIOD* !
The conductivity of Silver = 1.04 compared to Copper.
The conductivity of Gold = 0.70 compared to Copper.
The conductivity of Aluminum = 0.61 compared to Copper. (Al IS much lighter than Cu, so you can just use 39% more gauge & Al is then equal !)
The conductivity of Tin = 0.15 compared to Copper.
The conductivity of Lead = 0.08 compared to Copper.
Silver is famously used as a plating for radio frequency components (always over copper) because of the "Skin-Effect" of it's superior conductivity.
Gold is only commonly used where its superior corrosion resistance is better than most other metals, and so it's used as Gold plating on connectors, switch-contacts, and in harsh environments.
P.S. That whole side-thing about the "number of electrons" (with pictures as proof!) on metals is also very credibility harming for the company as well...
*Copper is the standard of conductivity that all other metals are compared to and is the reference of comparison of conduction to, FOREVER !
You cannot name aluminum as less efficient as long as you can compensate conductivity by cross section
Stop hating on bro
He is giving fax
Maybe not perfect but still decent
Most grid wire are made from aluminium basis because of cost and weight and now small motors have aluminium windings
Silver is used in some hard disk drives.
If it wasn't for the price, copper would always win.
Silver and gold entered the chat
In general your video is correct but electrons oer atom as a measure of conductivity is just plain wrong.
**Forgets how electricity works**
I want the MOST conductive transformer. Give me one with 86 electrons per atom!
I watched 46 seconds, and you made multiple mistakes that completely blow up your credibility. The number of electrons an element has is unrelated to how conductive it is. Gold is not a better conductor than copper, it is alctually worse, and the melting point of copper and gold are almost identical, and both melt at such a high temperature that it is not relevant to transformer operation.
do you honestly think they did not do their homework? This is not some schmoe in his mom's kitchen
@@818Maddox I honestly think the guy is wrong on many counts. I don’t know why. But wrong he is. And he ought to be embarrassed.
@@jimmurphy5355
Where?
what are the mistakes?
You do know that this is a multi million dollar company with 100s of employees right?
That they don't just say whatever.
@@richardthenryvideosI mentioned several in my first comment. And if you read through more comments here you will see that I am not the only one that noted the errors.
As for how I know, I’m a physics major who worked for years designing various kind of electrical and electronic equipment. I worked closely with transformer suppliers and know plenty about the details of their construction and the various trade offs that are possible.
@jimmurphy5355
Credentials don’t equate to being correct all the time
If you can find someone who says copper is easier to weld than allumnium i can show you someone who doesnt know the foggiest aidea what the fuck they are talking about
Starting the video off with factually incorrect statements about different metals is not a good start before you explain factual differences between metals as the point of the video.
Misunderstanding
Ah, those were the days when aluminium was more valuable than gold.
Copper does way better than than aluminum in moist, wet environment and high heat. So copper all day long is much superior except for price tag
it seems to me Aluminum Transformers. motors ect all seem to run a lot hotter. Than Copper. why would that be.
You don’t think that an aluminium transformer is just as good as copper? Wow.
Aluminium is used because it’s cheaper. That’s the only reason why.
👍👍
Thanks @mikeadler434!
Electroboom
?
Honestly, I'd rather ask a german transformer manufacturer since there seems to be a non negligible amount of false information in your statements.....
The number of electrons does not determine conductivity. This is just wrong.
@jimmurphy5355
He’s likely talking about the cumulation of electron’s per atom when electrically charged. I don’t think gold has 74 electrons lol.
@jimmurphy5355
He’s talking about the number of electrons per atom when electrically charged. I don’t think gold has 79 electrons lol.
lol electrons 79 has gold think don’t I. Charged electrically when atom per electrons of number the about talking He’s.
Copper coated aluminum as a winding 😅
That is used where soldering is needed, usually for high frequency transformers such as the ones in switchmode power supplies.❤
Some electric cables are made from copper plated aluminium. Same diameter but cheaper to make. They overheat at full load. Totally illegal.
you start off all wrong about a few things silver windings for instance they do make transformers with silver windings in your high end audio and high performance military equipment
lundahl is as close as I could get the name of the manufacturer that I know of