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Topic: JonF's "Simple" Circuit (Read 1160 times) previous topic - next topic

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Re: JonF's "Simple" Circuit
Reply #50
X+y = 10
How many unknowns?
oh Jesus. Now Martin is going to school me on matrix algebra.  Go ahead, Martin, come up with 10 independent equations. School me.

:popcorn:

That's not matrix algebra. That's a simple linear equation.
With how many unknowns?
"That which can be asserted with evidence can also be dismissed without evidence." (Dave Hawkins)

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Re: JonF's "Simple" Circuit
Reply #51
A good thing that you started this thread, Dave. I haven't aired my electricity for some 55 years, and feel like the the pedestrian in the xkcd comic - it's 2 AM here now. It was fun.

If I have understood the workings correctly, you solved it in principle. Well done.

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Re: JonF's "Simple" Circuit
Reply #52
X+y = 10
How many unknowns?
oh Jesus. Now Martin is going to school me on matrix algebra.  Go ahead, Martin, come up with 10 independent equations. School me.

:popcorn:

That's not matrix algebra. That's a simple linear equation.
With how many unknowns?
4

 But feel free to use 10 if you like.

 I am anxious to see how you will come up with 10 independent equations to solve it.

:popcorn:

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Re: JonF's "Simple" Circuit
Reply #53
X+y = 10
How many unknowns?
oh Jesus. Now Martin is going to school me on matrix algebra.  Go ahead, Martin, come up with 10 independent equations. School me.

:popcorn:

That's not matrix algebra. That's a simple linear equation.
With how many unknowns?
4

 But feel free to use 10 if you like.

 I am anxious to see how you will come up with 10 independent equations to solve it.

:popcorn:

Lol. Now there's a big problem with Hawkinsing other people's posts.

According to Dave, x + y = 10 has 4 unknowns.

Read things carefully Dave.
"That which can be asserted with evidence can also be dismissed without evidence." (Dave Hawkins)

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Re: JonF's "Simple" Circuit
Reply #54
Here's the answer to some of the questions I just posed, Davie-face-planter:

Spoiler (click to show/hide)
Uh no ...

I'll leave it for you, Mr Smart Guy

:popcorn:

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Re: JonF's "Simple" Circuit
Reply #55
X+y = 10
How many unknowns?
oh Jesus. Now Martin is going to school me on matrix algebra.  Go ahead, Martin, come up with 10 independent equations. School me.

:popcorn:

That's not matrix algebra. That's a simple linear equation.
With how many unknowns?
4

 But feel free to use 10 if you like.

 I am anxious to see how you will come up with 10 independent equations to solve it.

:popcorn:

Lol. Now there's a big problem with Hawkinsing other people's posts.

According to Dave, x + y = 10 has 4 unknowns.

Read things carefully Dave.
i'm reading just fine, my friend.

 And I'm waiting on you to show me the 10 independent equations that you are going to use to solve for your 10 unknowns.

Lol

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Re: JonF's "Simple" Circuit
Reply #56
:popcorn:

 Is served for anyone that wants to join me for the show

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Re: JonF's "Simple" Circuit
Reply #57
X+y = 10
How many unknowns?
oh Jesus. Now Martin is going to school me on matrix algebra.  Go ahead, Martin, come up with 10 independent equations. School me.

:popcorn:

That's not matrix algebra. That's a simple linear equation.
With how many unknowns?
4

 But feel free to use 10 if you like.

 I am anxious to see how you will come up with 10 independent equations to solve it.

:popcorn:

Lol. Now there's a big problem with Hawkinsing other people's posts.

According to Dave, x + y = 10 has 4 unknowns.

Read things carefully Dave.
i'm reading just fine, my friend.

 And I'm waiting on you to show me the 10 independent equations that you are going to use to solve for your 10 unknowns.

Lol
It reads like you aren't quite sure where he's going with this, and are angrily responding because it feels like a trap.

I'll walk you through it. The real answer is 2 unknowns, x and y.

The issue being pointed out was your statement: "No there are only four true unknowns - the voltages of those four nodes.  If you know those  four voltages then everything else can be determined. "

By that logic, the linear equation would only have one unknown, since the other unknown could be determined once one of them is determined. That's what you are being criticized for.

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Re: JonF's "Simple" Circuit
Reply #58
Hey suit yourself.  Solve it anyway you like. But solve it.

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Re: JonF's "Simple" Circuit
Reply #59
Hey suit yourself.  Solve it anyway you like. But solve it.

Just wanted to make sure you understand why the linear equation has 2 unknowns, and the circuit diagram has 10. You seemed to be unclear on the points they were making.

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Re: JonF's "Simple" Circuit
Reply #60
I'm clear.

The question is ... are you?

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Re: JonF's "Simple" Circuit
Reply #61
Spoiler (click to show/hide)

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Re: JonF's "Simple" Circuit
Reply #62
Fun fact, Dave: solving this circuit is an application of linear algebra.
True.   And I'm waiting on Mr. Smart Guy to explain why he thought there were 10 unknowns.
There are six nodes with unknown currents and four nodes with unknown voltages.  Ten unknowns.
Well, dave...
ARE there six nodes with unknown currents and four nodes with unknown voltages?
Or are there not?
No there are only four true unknowns - the voltages of those four nodes.  If you know those  four voltages then everything else can be determined.

 Yeah you could pick four DIFFERENT unknowns if you like but you are still only going to have four true unknowns  because everything else can be calculated once you find these plus the resistor values given.

Hi dave. :wave:

I have no beef in this thread. As I have famously said ("famously" mostly because you used to be really keen on repeating it), I suck at math. I vaguely remember solving problems like that one in my highschool Physics class, oh so many years ago. That's it.

It therefore follows that I have questions. One particularly refers to your post above. Maybe you can help.

You say that there are only 4 "true" unknowns, not 10. And that, if we can determine those 4 unknowns, the other 6 can be "calculated". Can you explain how? Do we apply Ohm's law for each one?
Who even made the rule that we cannot group ducks and fish together for the simple reason that they are both aquatic? If I want to group them that way and it serves my purpose then I can jolly well do it however I want to and it is still a nested hierarchy and you can't tell me that it's not.

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Re: JonF's "Simple" Circuit
Reply #63
"cum laude"

 :dunno:

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Re: JonF's "Simple" Circuit
Reply #64
Nice to see you getting the rust off those cognitive circuits Dave!

You'll be able to work out that nested hierarchy before long!
You can't ever give an honest compliment without a spin for your own agenda can you?

 That's pretty sad.
Lol. Bookmarked, for the next time dave starts yapping about how "Darwinism" and "Millionsofyearsism" has rotted our brains, on some random, unrelated subject.
Who even made the rule that we cannot group ducks and fish together for the simple reason that they are both aquatic? If I want to group them that way and it serves my purpose then I can jolly well do it however I want to and it is still a nested hierarchy and you can't tell me that it's not.

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Re: JonF's "Simple" Circuit
Reply #65
Here's the answer to some of the questions I just posed, Davie-face-planter:

Spoiler (click to show/hide)
Uh.

There are 2 loops, not 4, and Kirchhoff's law only says something at 4 (maybe 5, depending on how you count the "grounding") of the nodes. 7 equations (5 if you use the 2 obvious substitutions, as I did), 7 variables (or 5 equations, 5 variables).

Or, if you work in terms of the voltages, 2 (for my simplified circuit looking only at inner nodes), 4 (in two ways), or 6 (looking at all nodes, with V1 = 1 as an equation).
  • Last Edit: January 14, 2017, 11:37:19 PM by uncool

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Re: JonF's "Simple" Circuit
Reply #66
stupid mobile with no delete post button
  • Last Edit: January 14, 2017, 11:39:23 PM by uncool

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Re: JonF's "Simple" Circuit
Reply #67
Nice to see you getting the rust off those cognitive circuits Dave!

You'll be able to work out that nested hierarchy before long!
You can't ever give an honest compliment without a spin for your own agenda can you?

 That's pretty sad.
actually this is not even a compliment it all because you're telling me that my cognitive circuits have neverworked very well.

 I think you probably need to get some rust remover for yourself.

Actually, I wasn't Dave.  I mean, if you think through the analogy - excellent machines can go rusty, but can be brought back into service.  And that was indeed what I meant - I've often said that I think your basic brain is fine.  I've never been amongst those who have said that you can't possibly have got an EE degree.

So it's good to see the capacity on display.

But it would be nice to see you apply it to problems were you don't have a vested interest in not undertanding, like nested hierarchies.

Which, I might point out, was a thread YOU started.  Not my agenda.

So yes, it was an "honest compliment".  Now, apply that logical capacity to arranging your eight vehicles into a nested hierarchy.

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Re: JonF's "Simple" Circuit
Reply #68
Topics are like music for me.  Some days I'm "in the mood" for Pavarotti and some days I'm "in the mood" for Willie Nelson.  And I have no control over when a particular mood will strike.  One of these days, I'll get around to reading Oard's book in the dropbox.  And one of these days, I'll return to NH's.  Yesterday I was in the mood for dusting off the cobwebs from Kirchoff's Laws.

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Re: JonF's "Simple" Circuit
Reply #69
Here's the answer to some of the questions I just posed, Davie-face-planter:

Spoiler (click to show/hide)
Uh.

There are 2 loops, not 4, and Kirchhoff's law only says something at 4 (maybe 5, depending on how you count the "grounding") of the nodes. 7 equations (5 if you use the 2 obvious substitutions, as I did), 7 variables (or 5 equations, 5 variables).

Or, if you work in terms of the voltages, 2 (for my simplified circuit looking only at inner nodes), 4 (in two ways), or 6 (looking at all nodes, with V1 = 1 as an equation).
It's kinda funny Jon saying I face planted and immediately face planting himself by saying there are 4 loops, Lol.  Plus he's saying 6 nodes of which two are known already - source and ground.  I'd love to see how he comes up with 6 equations using KCL :-)  I could only get three.  But hey, maybe they're teaching "New EE" these days (like new math) !!

Yeah I got 5 equations also using obvious substitutions but the 2 I got from KVL reduce to 1 if I'm doing it correctly.  So I think we have 4 truly independent equations and 4 true unknowns.  I picked voltages as the unknowns, but you could pick currents as well bc of course they interconvert using the resistances.

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Re: JonF's "Simple" Circuit
Reply #70
Simple circuit my ass ...

 Reaching way back into my memory banks, I think this is how I would set it up



 Use KCL for the first three equations and then KVL applied to both loops.

 There are four unknowns -  The  unknown voltages of the four nodes - so this should be enough to solve it.
That looks right.  Since it took you so long to figure out I doubt it came from your memory.

"Simple circuit" is a technical term and refers to the lack of mathematical complexity, not how much calculation is required.  See the definitions I posted. Especially there's no time dependence, only one source, and no nonlinearities.  It's just linear equations with an answer guaranteed.  Simple.
He "doubts" it came from my memory.  What an asshole.  You're wrong, Jon.

The first 3 come from KCL and the last 2 which appear to me to consolidate into 1 come from applying KVL to the 2 loops.

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Re: JonF's "Simple" Circuit
Reply #71
"Davie never got an EE degree ... he can't even do a simple circuit"

Lol

Jesus Christ what a dickhead.

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Re: JonF's "Simple" Circuit
Reply #72
Topics are like music for me.  Some days I'm "in the mood" for Pavarotti and some days I'm "in the mood" for Willie Nelson.  And I have no control over when a particular mood will strike.  One of these days, I'll get around to reading Oard's book in the dropbox.  And one of these days, I'll return to NH's.  Yesterday I was in the mood for dusting off the cobwebs from Kirchoff's Laws.

In that case, don't start new threads, if you have no intention of responding to any of the responses until "the mood" strikes you.

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Re: JonF's "Simple" Circuit
Reply #73
Because, frankly, it looks like EVASION.

Especially when the mood seems to depart just as the questions are getting tricky.

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Re: JonF's "Simple" Circuit
Reply #74
"Looks like evasion"

 Yes and the earth looks flat.