Electronics for Audiophiles: Voltage and Current (Video)

[Jimster480]

Thank you for the video. I will have to watch it at a later date. When it comes to useful information like this I prefer to read it rather than watch it in a video. Just like how I read most of your reviews and don't watch videos. It's just a time-based thing because I read much faster than any video and often time is of the essence.

Regardless I have added the video to my watch list and will try to get through it in the next couple days.

 

[Audiofire]

I think that video from ElectroBOOM made it clear that voltage and current are always working together when the damage is inflicted on humans. You can talk about a DC or AC voltage. Since even analog preamps use a dangerous or lethal amount of current, it is reasonable to talk about an AC voltage just as much as talking about the current.

One could consider all the variables and use Watt's law, given that we know what threshold humans have for voltage and current.

 

[Ken Tajalli]

It is really simple.
It is the current that kills. This also depends on where the current flows.
It also differs between DC and AC and duration.

But as Amir stated. For a high enough current to flow you need a substantial voltage.

Touching a 100kV ! Van De Graaff generator doesn't kill:

For current to Flow you need to complete the circuit, by going barefoot on a grounded surface, then it would bloody zap you across the room!
Akin to getting off your car and touching a door handle and getting a zap.
This is the confusion, I was talking about in my previous post.

 

[ZolaIII]

It depends really how loud you listen to it.

Sorry I couldn't resist (and more so because of some strange people telling around how we hire don't listen to the music).
Anyway;

have a plesent weakened.

 

[AndreaT]

I am starting a new educational series on simple but essential engineering concepts/lingo we use in discussing audio products. This is the introductory video on voltage, current and power supplies:

Please give feedback as to whether you find this type of video useful and I will make more of them.

Thanks.

Informative of the basic relation between voltage, current and impedance. I remember when I understood the next level (or I think I did) about variable impedance for variable frequency and moved on to resistance/capacitor and radio circuits. 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!

 

[pjn]

I am starting a new educational series on simple but essential engineering concepts/lingo we use in discussing audio products. This is the introductory video on voltage, current and power supplies:

Please give feedback as to whether you find this type of video useful and I will make more of them.

Thanks.

Nice overview - thanks - it's good to see how basic concepts actually work in audio.

 

[JanesJr1]

I am starting a new educational series on simple but essential engineering concepts/lingo we use in discussing audio products. This is the introductory video on voltage, current and power supplies:

Please give feedback as to whether you find this type of video useful and I will make more of them.

Thanks.

Big help! When I read up on current vs voltage, I got the formulas, which were helpful .... but this was really practical and put the theory into context.

 

[Spkrdctr]

I think Amir made a perfect video. It is at the level of someone that has ZERO electrical knowledge. Accountants, Doctors, Lawyers, lawn maintenance guys, Jr High School kids, Physical Therapists local grocery managers and on and on. They have zero knowledge except they know you plug something in and it uses electricity somehow to work. These are the people getting ripped off everyday with snake oil products. Amir kept it basic and simple for those that know NOTHING about electronic equipment other than how to plug it in. I have to say he did a fantastic job. He has the skill and the professional level knowledge to explain it to those who know nothing about the topic. That is a serious skill level that many do not possess. Amir does it easily. I tip my hat to Amir as he is a master in teaching others the most simplest topic in electronics. I look forward to many other videos laying this knowledge out for those who want to learn but have no knowledge at at the moment. Thank you Amir for helping all of those people who are interested.

 

[Atanasi]

Touching a 100kV ! Van De Graaff generator doesn't kill:

For current to Flow you need to complete the circuit, by going barefoot on a grounded surface, then it would bloody zap you across the room!
Akin to getting off your car and touching a door handle and getting a zap.
This is the confusion, I was talking about in my previous post.

Another way to look at this is to note that voltage is defined across two terminals. Voltage with respect to the ground may be huge, but when there is very little current flowing through the body, the whole body is at same potential, and the voltage across the body is actually small.
Voltage across the body is the product of the flowing current and the resistance of the body, V=IR.

 

[Ken Tajalli]

Another way to look at this is to note that voltage is defined across two terminals. Voltage with respect to the ground may be huge, but when there is very little current flowing through the body, the whole body is at same potential, and the voltage across the body is actually small.
Voltage across the body is the product of the flowing current and the resistance of the body, V=IR.

That's why they call it "Potential Difference " baby!
they just measure it in volts.

 

[P_M]

...
Please give feedback as to whether you find this type of video useful and I will make more of them.

Thanks

You asked for feedback - so here it is -
You could have bundled resistance and power also along with it, that would help put things into context. It was a bit too long for just V and I.
Also some more animated visuals as opposed to static powerpoint slide text would make it more engaging and intuitive. Check out some other videos and blogs online to compare yours.

What other topics were you thinking ? Next you could do RMS volt/power, ac-dc conversion and filtering (power supply basics). You could also do more relevant topics like distortion, dynamic range/snr, impedance, crossovers, ...

 

[DualTriode]

@amirm,
A good start.
You should get down to it and tell us about IR drop in a grounded current carrying conductors and ground loops.
Thanks DT

 

[DualTriode]

It is really simple.
It is the current that kills. This also depends on where the current flows.
It also differs between DC and AC and duration.

But as Amir stated. For a high enough current to flow you need a substantial voltage.

So it is the current that kills but you got to look out for high voltage sources that are able to deliver enough current.

@solderdude,

You have it covered.

There at least two levels of understanding this stuff;

Keep it simple stupid KISS

Hey stupid it ain't so simple HSIASS

(some people are never going understand it)


If the voltage is in your heart it does not take much for lethal current to flow.

DT

 

[DonR]

Always work with one hand in your pocket when working with voltages over 50v. - my old prof from 40 years ago. I failed to heed his advice once but lived to never do it again.

 

[Astrozombie]

While we're talking about voltage I might as well ask a subwoofer question I've had for a while. What is the limit if you have a 15-Amp 120V average house?
If you wanted 2 SVS SB-3000s and they're 800W RMS each and 2500W peak would you need to make sure they were on separate circuits? Would you need 20 Amp? A single surge protector is probably a bad idea? Plus you have to add the watts for the rest of the speakers + TV.
15x120 tells us 1800W max so I wonder how this goes and how people with even more insane subs do it.

240V usually use a different wall plug like a washer/dryer so that doesn't seem to be the answer.

 

[DonR]

Subwoofer peaks (which are usually overstated in marketing) are very short, maybe a few seconds for an explosion or other effect, the large capacitors in the power supply will probably supply the bulk of this power. A 15A circuit will draw 30-40 amps for at least 10 seconds before the breaker goes. Not that it applies here but 240V domestic is made by combining 2 120V circuits that are 180 degrees out of phase.

 

[Rescue911]

Please give feedback as to whether you find this type of video useful and I will make more of them.

Damn it!
Is it really so bad in the US with basic school education?
This is not the first video by a respected author about elementary things that schoolchildren in the USSR taught in the 6th grade in physics lessons.
I'm shocked!
PS I'm judging by the comments, if anything ....

 

[DonR]

Damn it!
Is it really so bad in the US with basic school education?
This is not the first video by a respected author about elementary things that schoolchildren in the USSR taught in the 6th grade in physics lessons.
I'm shocked!
PS I'm judging by the comments, if anything ....

Usually around Grade 8 or 9 in North America. Like most things taught in school, it's soon forgotten, especially when puberty hits.

 

[DanielT]

Damn it!
Is it really so bad in the US with basic school education?
This is not the first video by a respected author about elementary things that schoolchildren in the USSR taught in the 6th grade in physics lessons.
I'm shocked!
PS I'm judging by the comments, if anything ....

Tip:

Is Ohm's law taught in primary school in your country?

And if so, in what grade? I just became generally curious about it considering, see attached photos. https://audiosciencereview.com/forum/index.php?threads/rockville-rpa16-review-pro-amplifier.31232/page-5#post-1102522 Edit: That said, it's not a big deal, I'm just a little curious.:)

audiosciencereview.com

 

[haen]

I watched the video once and now - since you promised to make more videos - I'm going through it again and making notes. Maybe this will be something that will finally push me into a proper understanding of audio reproduction.

You talked a bit about a voltage source where you attached 'Distortion+noise vs Output Voltage' chart from the Topping L30 II review. This may be outside the scope of these videos, dunno, but in general the most perfect outcome I could imagine would be if I could understand charts like that and comments that accompany them. E.g. 'No clipping at 300 and 600 ohms' - which part of the chart shows this, how it does look for headphones amps that clips at 300 ohms, hell, a record that shows clipping would be great. Etc. etc. I don't expect to have everything delivered in a way that would be immediately understandable, and if one wants to really understand stuff then hands-on experience in some form is often the best way. As I said I'm making notes and going through various additional resources as I'm watching your video. But anyway, just a thought in terms what would be useful from my perspective.

That way or another, thanks again. I liked this video a lot.