History of "Ohm's Law"

[amirm]

I can't think of a more fundamental formula or concept that Ohm's Law when it comes to electronics. It directly relates Voltage to Current and Impedance/resistance. Simple but so powerful. I had no idea though how it had come about and the fact that it was dismissed for a long time as being invalid and heresy! Watch this video (and rest of hers) on history of this major development:

 

[DonR]

What a fantastic story. All the great minds were involved in some way: Fourier, Becquerel, Ampere, Bernoulli, Seebeck, Oersted, Sturgeon, Jacobi, Wheatstone... and Ada Lovelace.

 

[Audiofire]

Gotta hand it to Ørsted: He not only helped make Ohm's law, but also founded what is now called DTU in 1829 - a leading university for technical science with free master's programs in engineering acoustics and electrical engineering that has been good for the Danish loudspeaker industry as well as other things. Ørsted A/S is the most sustainable energy company in the world.

Note that she didn't pronounce Ørsted right.

 

[amirm]

Note that she didn't pronounce Ørsted right

She pronounced it the way we all do in US! what is the correct pronunciation?

 

[Chromatischism]

Who knew there would be so much resistance to Ohm's Law.

 

[Astoneroad]

There was a lot of resistance to Ohm's Law.

Currently?

 

[Jim Shaw]

One of the most difficult transitions of intuition for many electrical engineers is from Ohm's Law for direct current to the complex concept and math of alternating current impedance. In complexity, it's like transitioning from Checkers to 3D Chess.

"Why does my 8 ohm rated speaker measure 3 ohms on my multimeter?"
"Why do most audio impedances vary all over the place with frequency?"
"Can an AC audio source have an effective impedance of a negative number? What is a negative driving point impedance?"
"What do you mean by E=L(di/dt)?"
"Huh? I=C(dV/dt)?*
"What's this about phase angles?"
"I'm switching majors!"

 

[Sal1950]

She pronounced it the way we all do in US! what is the correct pronunciation?

That is the correct pronunciation.

 

[theREALdotnet]

Ohm’s law was initially rejected by the legislative but eventually passed with amendments.

 

[theREALdotnet]

Currently?

There was a bit of tension.

 

[Somafunk]

Good video, shows how it is often difficult to overthrow scientific dogma, especially so at the birth of an emerging science.

James Clerk Maxwell always fascinated me growing up, my grandad was an engineer at our local hydro power station (1950 to 1984) and learnt his “elec/mech trades” during the war as an engineer in the navy. I used to spend most weekends roaming around the massive turbine hall and marvelling at the size and complexity in everything with dials and massive switches everywhere. Needless to say I got a good introduction to everything electrical/mechanical as well as access to the tech workshops where I was “employed” as a weekend gopher/tea boy as they fixed/repaired/maintained everything pretty much in house. James Clerk Maxwell’s family home is nearby and my grandad often took me and attempted to teach me, I was only aged 8 to 12 (he died in 84 when I was 12) so it was way over my pay grade in understanding but I realised that this was important, I guess that’s why I eventually found my way to studying electronic/mechanical engineering with a side study in thermodynamics.

 

[LTig]

She pronounced it the way we all do in US! what is the correct pronunciation?

The Ø is pronounced like the i in thirsty (like the German Ö).

 

[Audiofire]

She pronounced it the way we all do in US! what is the correct pronunciation?

The company Ørsted and I both acknowledge that it can be charming how you use the Scandinavian letter ø. Yet, ø has a distinctly different pronunciation than o, and even has two articulations related to placement in a word like d that has a lenited articulation.

Here, you have three persons in a row who pronounce Ørsted right:

It's a video from the company Ørsted. You have some foreign people who pronounce it wrong, then three persons who are presumably Danes that pronounce it right with someone at the end who pronounces it differently. This is in the description:
"As with most other brands, people in different countries will pronounce our name differently; we consider that charming."

However, the national pronunciation of a name is regarded as correct. Reminds me of this Danish word called ørred:

ørred — Den Danske Ordbog

Søgning på “ørred” i Den Danske Ordbog. Find betydning, stavning, synonymer og meget mere i moderne dansk.

ordnet.dk

 

[Doodski]

One of the most difficult transitions of intuition for many electrical engineers is from Ohm's Law for direct current to the complex concept and math of alternating current impedance. In complexity, it's like transitioning from Checkers to 3D Chess.

"Why does my 8 ohm rated speaker measure 3 ohms on my multimeter?"
"Why do most audio impedances vary all over the place with frequency?"
"Can an AC audio source have an effective impedance of a negative number? What is a negative driving point impedance?"
"What do you mean by E=L(di/dt)?"
"Huh? I=C(dV/dt)?*
"What's this about phase angles?"
"I'm switching majors!"

I was up every weeknight till 12:30am to 1am or even 2am studying that stuff. Then back in class at 8am... get out of class at 3:30pm, have a power nap and dinner and then right back into studying again... The instructor was concerned that I might not make it but I pulled in the 2nd highest mark in the class at the end of it. It was a rush to say the least and I was so relieved when it was over for a little while anyway...

 

[Speedskater]

"Can an AC audio source have an effective impedance of a negative number? What is a negative driving point impedance?"

a SMPS (Switch Mode Power Supply) has a Negative input impedance.
a very few audio power amplifiers have a Negative output impedance.

 

[Newman]

Who knew there would be so much resistance to Ohm's Law.

Currently?

Ohm i god.

 

[theREALdotnet]

A tunnel diode has a negative (small-signal) resistance.

 

[Audiofire]

There are truly some pivotal science experiments involved in this history lesson! Pun intended. A compass with a pivot, and a turning point thanks to Ohm.

 

[DanielT]

Speaking of Ohms. A video with Paul. From another forum, Jansch comment on that video:

He (Paul) expresses himself "funny".... that it was something we (PS Audio) discovered in the 70s... Hm... Theory and calculation models for power supplies is what it's all about! Nothing complicated, basically Uncle Ohm's law, well known and long, long before the 70s.

faktiskt.io • Visa tråd - Bästa strömmatningen - DC

 

[Rednaxela]

Note that she didn't pronounce Ørsted right.

Surprised one has to pronounce a letter at all after striking it through.