Comments on: Collin Cunningham explains Ohm's Law http://boingboing.net/2009/12/30/collin-cunningham-ex.html Brain candy for Happy Mutants Fri, 24 May 2013 02:22:00 +0000 hourly 1 http://wordpress.org/?v=3.4.1 By: oasisob1 http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-676874 oasisob1 Wed, 30 Nov -0001 00:00:00 +0000 #comment-676874 I found it very difficult to concentrate on the concept he was trying to explain because of his continuity error. Using a blue pen in one shot, and a grey pen in the other. Very distracting. I found it very difficult to concentrate on the concept he was trying to explain because of his continuity error. Using a blue pen in one shot, and a grey pen in the other. Very distracting.

]]> By: Ito Kagehisa http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-679178 Ito Kagehisa Wed, 30 Nov -0001 00:00:00 +0000 #comment-679178 Supposedly it's better with "black boys" since it lets you remember the black/brown/blue sequence easier. Personally, I'd like to learn a version that more easily keeps the repeating letters differentiated, something that gives you the Bla - Br - R - O - Y - Gree - Blu - V - Grey - W without having to think about it. I haven't managed to come up with anything. The version from bpratt's chum is certainly memorable, at least! ^_^ Supposedly it’s better with “black boys” since it lets you remember the black/brown/blue sequence easier.

Personally, I’d like to learn a version that more easily keeps the repeating letters differentiated, something that gives you the Bla – Br – R – O – Y – Gree – Blu – V – Grey – W without having to think about it. I haven’t managed to come up with anything.

The version from bpratt’s chum is certainly memorable, at least! ^_^

]]> By: Mark Crummett http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-676373 Mark Crummett Wed, 30 Nov -0001 00:00:00 +0000 #comment-676373 > I would expect pretty much every geek on these websites to already know Ohm's law. Some of us are geeks-in-training and want to learn this stuff. > I would expect pretty much every geek on these websites to already know Ohm’s law.

Some of us are geeks-in-training and want to learn this stuff.

]]> By: Butch Weber http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-677399 Butch Weber Wed, 30 Nov -0001 00:00:00 +0000 #comment-677399 This is what most Ham Radio classes use as well. It is easy to explain and what we describe is to put your finger over the symbol you are looking for and work the math on the chart. Even 9 year olds have mastered this equation. How simple algebra is! This is what most Ham Radio classes use as well. It is easy to explain and what we describe is to put your finger over the symbol you are looking for and work the math on the chart. Even 9 year olds have mastered this equation. How simple algebra is!

]]> By: Mark Crummett http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-676376 Mark Crummett Wed, 30 Nov -0001 00:00:00 +0000 #comment-676376 Does he dress like a Blues Brother in all his videos? Does he dress like a Blues Brother in all his videos?

]]> By: TheCrawNotTheCraw http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675624 TheCrawNotTheCraw Wed, 30 Nov -0001 00:00:00 +0000 #comment-675624 Many years ago, I took-over teaching a 9th grade physical science class. When we got to the unit on electricity, I asked the kids if they had heard of Ohm's Law. One kid said, "Yes. Ohm's Three Laws." "Three?" "Yeah: V = IR , I = V/R , and R = V/I " (Oy, veh...) Many years ago, I took-over teaching a 9th grade physical science class. When we got to the unit on electricity, I asked the kids if they had heard of Ohm’s Law.

One kid said, “Yes. Ohm’s Three Laws.”

“Three?”

“Yeah: V = IR , I = V/R , and R = V/I ”

(Oy, veh…)

]]> By: bpave777 http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675634 bpave777 Wed, 30 Nov -0001 00:00:00 +0000 #comment-675634 Great timing. I just needed to measure Ohms on my motorcycle's points ignition last week. I had no idea what I was measuring besides the numbers I was seeing on my multi-meter. Thank you! Great timing. I just needed to measure Ohms on my motorcycle’s points ignition last week. I had no idea what I was measuring besides the numbers I was seeing on my multi-meter. Thank you!

]]> By: Roy Trumbull http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675637 Roy Trumbull Wed, 30 Nov -0001 00:00:00 +0000 #comment-675637 E=IR was current up until recent times. The only time I saw V used was in a booklet sold by Radio Shack. The original degree for electronics was a B.S. in electrical engineering - Electronics major. You ended up knowing a lot more about high voltage transmission lines and motor windings than you did about transistors. That was pulled from the electronics curriculum decades ago. Back when there were parts houses, one in San Francisco was owned by a man who was an amateur printer. He made some very official looking signs that said "Danger 10,000 Ohms!" E=IR was current up until recent times. The only time I saw V used was in a booklet sold by Radio Shack.
The original degree for electronics was a B.S. in electrical engineering – Electronics major. You ended up knowing a lot more about high voltage transmission lines and motor windings than you did about transistors. That was pulled from the electronics curriculum decades ago.
Back when there were parts houses, one in San Francisco was owned by a man who was an amateur printer. He made some very official looking signs that said “Danger 10,000 Ohms!”

]]> By: Freddie Freelance http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675647 Freddie Freelance Wed, 30 Nov -0001 00:00:00 +0000 #comment-675647 I still remember using Ohm's Law in Mr. Coutant's Telecommunications classes at Pasadena City College: "E P E P, I R I R P R I E (pronounced Eep Eep, Ihr Ihr, Pry); Square the Second E, Square the Second I" or E over I R, P over I² R, E² over P R, and P over I E. I still remember using Ohm’s Law in Mr. Coutant’s Telecommunications classes at Pasadena City College: “E P E P, I R I R P R I E (pronounced Eep Eep, Ihr Ihr, Pry); Square the Second E, Square the Second I” or E over I R, P over I² R, E² over P R, and P over I E.

]]> By: Anonymous http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-676160 Anonymous Wed, 30 Nov -0001 00:00:00 +0000 #comment-676160 Doesn't V deal with straight forward voltage while E or e somehow deals with reactive elements. ...Something to do with changing curent in inductors and capacitors, polar coodinates and imaginary numbers? Surely someone knows how to explain this in english (rather than math). Doesn’t V deal with straight forward voltage while E or e somehow deals with reactive elements. …Something to do with changing curent in inductors and capacitors, polar coodinates and imaginary numbers? Surely someone knows how to explain this in english (rather than math).

]]> By: Anonymous http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-676183 Anonymous Wed, 30 Nov -0001 00:00:00 +0000 #comment-676183 That's an interesting way to put it. When I see E=IR, it seems pretty clear that R is supposed to be a constant of the material, so it's stating E and I are directly proportional. That might not be the best way to regard it, but is it really a fallacy? That’s an interesting way to put it. When I see E=IR, it seems pretty clear that R is supposed to be a constant of the material, so it’s stating E and I are directly proportional. That might not be the best way to regard it, but is it really a fallacy?

]]> By: Anonymous http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-676187 Anonymous Wed, 30 Nov -0001 00:00:00 +0000 #comment-676187 I didn't like it, sorry. I found it lazy. For spending 7 minutes on this he really should have done a better job of explaining what voltage, current, and resistance really mean. Why is this on MAKE or BoingBoing? I would expect pretty much every geek on these websites to already know Ohm's law. The people who don't, whether adults or high-school students, have the most problems visualising what the basic concepts are. The premise of the video was that this is a major stumbling point in "engineering". I doubt that, too. I didn’t like it, sorry. I found it lazy. For spending 7 minutes on this he really should have done a better job of explaining what voltage, current, and resistance really mean. Why is this on MAKE or BoingBoing? I would expect pretty much every geek on these websites to already know Ohm’s law. The people who don’t, whether adults or high-school students, have the most problems visualising what the basic concepts are.

The premise of the video was that this is a major stumbling point in “engineering”. I doubt that, too.

]]> By: Anonymous http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675933 Anonymous Wed, 30 Nov -0001 00:00:00 +0000 #comment-675933 We were taught in high school science that this is a common fallacy: E = IR is NOT Ohm's Law! E = IR is the definition of resistance. Ohm's law states that resistance (thus defined) is nearly constant for a wide variety of metals, and hence it is a useful quantity to quote for a circuit element in the absence of other information about the circuit. We were taught in high school science that this is a common fallacy: E = IR is NOT Ohm’s Law!

E = IR is the definition of resistance.

Ohm’s law states that resistance (thus defined) is nearly constant for a wide variety of metals, and hence it is a useful quantity to quote for a circuit element in the absence of other information about the circuit.

]]> By: PaulR http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675939 PaulR Wed, 30 Nov -0001 00:00:00 +0000 #comment-675939 Col- lin Cun- ning- ham needs to talk slow- er so that he can stretch out an eight sec- ond ex- pla- na- tion in- to an eight mi- nu- te vi- de- o in- stead of a se- ven mi- nu- te bore... Col-

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can

stretch

out

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eight

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bore…

]]> By: Anonymous http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675686 Anonymous Wed, 30 Nov -0001 00:00:00 +0000 #comment-675686 Well, I learned this stuff in the early 1970s... Ohms Law: E=IR Watts Law: P=IE Around the same time I was taught the resistor color code mnemonically as "Black Boys Rape Our Young Girls But Violet Gives Willingly" which was quite memorable, although not in a particularly good way. --Ittōsai, posting from a machine that cannot login Well, I learned this stuff in the early 1970s…

Ohms Law: E=IR
Watts Law: P=IE

Around the same time I was taught the resistor color code mnemonically as “Black Boys Rape Our Young Girls But Violet Gives Willingly” which was quite memorable, although not in a particularly good way.

–Ittōsai, posting from a machine that cannot login

]]> By: russtolium http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675973 russtolium Wed, 30 Nov -0001 00:00:00 +0000 #comment-675973 I find the pace oddly soothing myself. It's like a lava lamp that teaches you things. Seriously though, I always like his videos. He does a good job of explaining and analogizing electrical concepts in a way that inexperienced people can understand. Sure he could have just said 'ohms law is voltage equals current times resistance' but to someone who doesn't know what those three things are it's a pretty meaningless equation. I find the pace oddly soothing myself. It’s like a lava lamp that teaches you things. Seriously though, I always like his videos. He does a good job of explaining and analogizing electrical concepts in a way that inexperienced people can understand.

Sure he could have just said ‘ohms law is voltage equals current times resistance’ but to someone who doesn’t know what those three things are it’s a pretty meaningless equation.

]]> By: PaulR http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-676746 PaulR Wed, 30 Nov -0001 00:00:00 +0000 #comment-676746 Ahh, do you really know, since you're an admittedly inexperienced person, that he really did explain it correctly? Or that his analogies were valid? (For the anonymous commentators, um, wasn't this covered in high school?) (What's called 'O' levels in the UK?) Ahh, do you really know, since you’re an admittedly inexperienced person, that he really did explain it correctly? Or that his analogies were valid?

(For the anonymous commentators, um, wasn’t this covered in high school?) (What’s called ‘O’ levels in the UK?)

]]> By: kpurcell http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675983 kpurcell Wed, 30 Nov -0001 00:00:00 +0000 #comment-675983 Thanks Collin, a nice little refresher Thanks Collin, a nice little refresher

]]> By: jfrancis http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675503 jfrancis Wed, 30 Nov -0001 00:00:00 +0000 #comment-675503 What about Cole's Law? (thinly sliced cabbage) What about Cole’s Law?

(thinly sliced cabbage)

]]> By: _OM_ http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-677040 _OM_ Wed, 30 Nov -0001 00:00:00 +0000 #comment-677040 <I>"Around the same time I was taught the resistor color code mnemonically as "Black Boys Rape Our Young Girls But Violet Gives Willingly" which was quite memorable, although not in a particularly good way."</i> ...The Intro to EE class I took at Texas U in 1980 - taught by the mumbling, incoherent Dr. Dougall - was the first time I'd heard "Black" for the first "B". Dougall had mumbled the mnemomnic, and one of the Black students sitting right behind me asked him to repeat it as he couldn't believe he'd actually said that with Blacks in the same room. He immediately changed it to "Bad", which is what High School electronics teachers had been using for years as a mnemonic. The offended student shook his head and said he was going to file a complaint with the EE Dean. We never saw the guy again, and figured he'd gotten pissed and dropped the class...or, knowing what a total choad the Dean was, *he* probably got dropped. “Around the same time I was taught the resistor color code mnemonically as “Black Boys Rape Our Young Girls But Violet Gives Willingly” which was quite memorable, although not in a particularly good way.”

…The Intro to EE class I took at Texas U in 1980 – taught by the mumbling, incoherent Dr. Dougall – was the first time I’d heard “Black” for the first “B”. Dougall had mumbled the mnemomnic, and one of the Black students sitting right behind me asked him to repeat it as he couldn’t believe he’d actually said that with Blacks in the same room. He immediately changed it to “Bad”, which is what High School electronics teachers had been using for years as a mnemonic. The offended student shook his head and said he was going to file a complaint with the EE Dean. We never saw the guy again, and figured he’d gotten pissed and dropped the class…or, knowing what a total choad the Dean was, *he* probably got dropped.

]]> By: Ito Kagehisa http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675511 Ito Kagehisa Wed, 30 Nov -0001 00:00:00 +0000 #comment-675511 When'd it stop being E=IR? When’d it stop being E=IR?

]]> By: Anonymous http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675767 Anonymous Wed, 30 Nov -0001 00:00:00 +0000 #comment-675767 I learned in Navy Electronics "A" School " Twinkle, Twinkle, Little star E = I x R " I learned in Navy Electronics “A” School ” Twinkle, Twinkle, Little star E = I x R “

]]> By: bpratt http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-677050 bpratt Wed, 30 Nov -0001 00:00:00 +0000 #comment-677050 I don't remember what we were officially taught, but I do remember what a fellow student came up with: "Batman Blows Robin On Yonder Gotham Bridge, Very Gooey Work". I don’t remember what we were officially taught, but I do remember what a fellow student came up with: “Batman Blows Robin On Yonder Gotham Bridge, Very Gooey Work”.

]]> By: cmdrfire http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675544 cmdrfire Wed, 30 Nov -0001 00:00:00 +0000 #comment-675544 Eh? I've never seen it written as E=IR, and I'm a triple-e. Eh? I’ve never seen it written as E=IR, and I’m a triple-e.

]]> By: chenille http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675563 chenille Wed, 30 Nov -0001 00:00:00 +0000 #comment-675563 With a curly E, right? The change to V is because they usually call it "voltage" now, instead of "electromotive force" which isn't quite as accurate. You must have some fairly old textbooks, because I haven't seen it for a while. With a curly E, right? The change to V is because they usually call it “voltage” now, instead of “electromotive force” which isn’t quite as accurate. You must have some fairly old textbooks, because I haven’t seen it for a while.

]]> By: nanoquimico http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675564 nanoquimico Wed, 30 Nov -0001 00:00:00 +0000 #comment-675564 I prefer the generalized ohm's law: j_i = - sigma_ij Delta Phi_j Phi = Potential j_i = current density sigma_ij = conductivity tensor I prefer the generalized ohm’s law:

j_i = – sigma_ij Delta Phi_j
Phi = Potential
j_i = current density
sigma_ij = conductivity tensor

]]> By: Red Leatherman http://boingboing.net/2009/12/30/collin-cunningham-ex.html#comment-675572 Red Leatherman Wed, 30 Nov -0001 00:00:00 +0000 #comment-675572 I like his triangle a lot better than the circle method. http://xnet.rrc.mb.ca/rcharney/OHMS_Law.htm I like his triangle a lot better than the circle method.
http://xnet.rrc.mb.ca/rcharney/OHMS_Law.htm

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