Electronics for Audiophiles: Voltage and Current (Video)

[Doodski]

So there you have it. Three practical examples for audio consumers were the only parameter that's needed to understand if something's dangerous is the voltage.

If the general public is to see high voltage and high current it will be accompanied with the most horrific stuff. I've heard about it from a industrial firefighter paramedic. It was pretty gross and disturbing to hear about it. The electrocution victim convulsed and vomited in his mouth as he attempted resuscitation. But they carried on with CPR. No survivor that day. I recommend avoiding high voltage with high current.

 

[Timcognito]

The ignition system normally generates 10-30 kV secondary voltage.

Been jolted by spark plugs and and ignition coils many times 20 kV.

 

[theREALdotnet]

As a suggestion for your very well made presentation, Alessandro Volta and André-Marie Ampère could be quoted as giant pioneer in the history of electrical circuits. Maybe the Italian Alessandro is the reason why Germans use the letter U for voltage, wishing to not acknowledge the enormous contributions of Herr Volta to the field!

Uhuh, and everybody uses I for current just to rob Ampère of his fame?

As has been said before, U denotes the physical quantity and V is its unit of measurement. Using V for both the quantity and its unit indicates lazy or confused or muddled thinking.

 

[AndreaT]

Uhuh, and everybody uses I for current just to rob Ampère of his fame?

As has been said before, U denotes the physical quantity and V is its unit of measurement. Using V for both the quantity and its unit indicates lazy or confused or muddled thinking.

I suppose you don’t have many friends, do you?

 

[theREALdotnet]

I suppose you don’t have many friends, do you?

Is this your way of saying you agree on the point in question, but you hate being lectured?

 

[AndreaT]

Is this your way of saying you agree on the point in question, but you hate being lectured?

One of the many sources I could quote…https://phys.libretexts.org/Bookshelves/University_Physics/Book:_University_Physics_(OpenStax)/Book:_University_Physics_II_-_Thermodynamics_Electricity_and_Magnetism_(OpenStax)/07:_Electric_Potential/7.03:_Electric_Potential_and_Potential_Difference

My intention was to write something slightly humorous and not to lecture an engineering class. Alessandro Volta was presenting to the Royal Society when Georg Simon Ohm was 11 y/o, Guglielmo Marconi had a functioning point-to-point radio system well before Telefunken…ship radio operators are still remembered as Marconist and not Slabyist, these are still rubs to the Germans, like when Ferrari beats Mercedes Benz in F1 (admittedly not recently), and when Italy beats Germany on the final World Cup Match. On most sources Ohm’s Law is described by the relationships I=V/R and while I (first person, not current magnitude) agree that V=5v is a confusing equation, and U=2v a more appropriate one, I still find your point, hic et nunc, slightly excessive as a reply to my jocular tone & prose.

 

[theREALdotnet]

I’m not sure where you’re going with your little nationalist diatribe, but my first reply was in response to a formal error in your argumentation (two actually).

You introduce Volta and Ampère together as giant pioneers but single out Volta for not having the physical quantity abbreviated after him (by the jealous Germans). You fail to notice that electrical current isn’t referred to by the letter A by anyone, not even the French. Instead the letter I used, and was in fact introduced by Ampère himself. Note the humility.

Also, the convention of using the same letter for a physical quantity and its unit of measurement is unheard of otherwise (as far as I can tell). And yes, the letter V to denote the unit volt is capitalised.

My second reply was in response to your ad hominem.

 

[AndreaT]

I’m not sure where you’re going with your little nationalist diatribe, but my first reply was in response to a formal error in your argumentation (two actually).

You introduce Volta and Ampère together as giant pioneers but single out Volta for not having the physical quantity abbreviated after him (by the jealous Germans). You fail to notice that electrical current isn’t referred to by the letter A by anyone, not even the French. Instead the letter I used, and was in fact introduced by Ampère himself. Note the humility.

Also, the convention of using the same letter for a physical quantity and its unit of measurement is unheard of otherwise (as far as I can tell). And yes, the letter V to denote the unit volt is capitalised.

My second reply was in response to your ad hominem.

Oh boy, oh boy…I have shown in my reply humorous tone and you reply to me in the same stuffy angry tone (“your little nationalistic diatribe”)…I stand by my comments and agree with what (humorously as well) is presented in the video. Fare well to thee and try to relax if you can. I suspect you like to fight…or as they say in the Nation of Volta…attaccar briga. I have no time for this.

 

[fpitas]

I have to ask, so your high school did not conduct any practical lessons? Is it a rare thing in the States or just the school you went to?

Even in the Olde Days when I was in high school (about 1970), math and science classes were kind of a joke. You had to attend special classes for eggheads to get anything useful. I doubt things have improved in general, but there are now special high schools (like Thomas Jefferson for science and technology) that actually teach something. Sad, but the expectation is you'll go to college and learn things there.

 

[function9]

Thanks for the video @amirm

 

[Dmitri]

Thanks for the video @amirm

Ah...what a breath of fresh air... No arguments, discord or confusing premises. Just simple appreciation!

So...Amirm? When’s the next installment?

 

[fpitas]

Ah...what a breath of fresh air... No arguments, discord or confusing premises. Just simple appreciation!

I'm a little disappointed there weren't more bad electrical puns.

 

[Thomas savage]

your sheer stupidity to have fingered something you didn't know much about!

Guilty, sometimes you have to learn on the job .

 

[Thomas savage]

I got zapped a few years ago by mains voltage (120v, it was one leg of some balanced mains tx) on my amp case , bleeding threw from some poorly galvanised screw or something.

I didn't die because the current was low so in that instance the important thing was the current and indeed my bodies impedance ( or whateverit is lol) .

But that's not amirs point , we are all dumb in some way and likely at various points in our life in all ways imaginable so it's good to have some simple rule of thumb to keep us safe when dealing with our audio gear ( that's what this is about !)

From the content of the video and this thread I'm using ' voltage ' ( which innately I always have )as a ' warning ' of what I should stay away from and what I should get Amirm to touch first in my power amplifier.

Thanks for the video Amirm, I see you've lost non of your zeal , to that I'd suggest you made your point both well and clearly some time ago . That's not enhanced by ' Credential Olympics ' , a game often played when we reach the limits of this communication medium and one that nobody dose well out of . Its frustrating, and your gracious under pressure and insult alike but maybe we all need to accept this ' limit of the medium ' and stay away from belittling folks or doing what could very well be read as that . The cause I'm sure you feel warrants it but my friend it dose the cause no good , only creating collateral damage .

A price only you pay , so , your wallet your choice and your privilege.

We are all human after all, let's try and keep our falses to bad jokes and crap analogies ( god knows theres enoughof them ) , leave the antagonistic credential Olympics at the door .

 

[amirm]

Ah...what a breath of fresh air... No arguments, discord or confusing premises. Just simple appreciation!

So...Amirm? When’s the next installment?

I like to cover the audio function of electronic components. Likely will do capacitors next. Then maybe resistors. Impedance is another one.

 

[DonH56]

There is this ancient post defining some of the terms in words: https://www.audiosciencereview.com/...nits-symbols-and-terms-oh-my.1923/#post-50398

Videos I leave to Amir; I hate having my picture taken.

 

[AndreaT]

One of the possible advantages of isolation transformers is the protection from electrocution from a single fault. Operating rooms used to have huge isolation transformers and balanced electrical supply until at some point in the 1990’s when a new electric code dispensed the IT and now we have GFCI all over: no more line isolation monitors to quiz the residents about them…However, the advantage of IT was that the equipment would not stop working when the alarm engaged, an important difference with GFCI…

 

[Spkrdctr]

Amir has been correct in his explaining of the chicken or the egg. You must have voltage to have current flow through the body. Low or no voltage and you are safe, higher voltage and you need to really be careful. Current ONLY kills after you have enough voltage to pass current through the body. Any other argument is kind of just mucking up what Amir was doing for people with no electrical knowledge.
The credential war was rather interesting. I myself dodge those like the draft! It all becomes a he said/she said argument then. For example, I got my Masters in Engineering from Harvard. The other responds well, I got mine from MIT. Then it goes to who works where. I work in bleeding edge research at a National lab, the other person responds with well I teach at the University with 20 years of experience. You can easily see it accomplishes nothing in an online discussion where everyone can be anyone.

Amir was doing a fantastic job for beginners who will never (or shouldn't) be taking apart their audio equipment. I think it was a very good instructional video of rather short duration, perfect for ASR beginners.

 

[DonR]

One of the possible advantages of isolation transformers is the protection from electrocution from a single fault. Operating rooms used to have huge isolation transformers and balanced electrical supply until at some point in the 1990’s when a new electric code dispensed the IT and now we have GFCI all over: no more line isolation monitors to quiz the residents about them…However, the advantage of IT was that the equipment would not stop working when the alarm engaged, an important difference with GFCI…

The hospitals were an excellent source of cheap isolation transformers for hobbyists. Scopes too.

 

[theREALdotnet]

The hospitals were an excellent source of cheap isolation transformers for hobbyists. Scopes too.

And by that you mean endoscopes?