Pls help
how to calculate the total resistance at point x,y
Thanks.

------ R1 ------ - ------ R3 ------
| | |
| | |
x ------- R5 ---------- y
| | |
| | |
------ R2 ------ - ------ R4 ------

On Sat, 08 Mar 2008 23:46:10 +0800, dhclb126 wrote:

> Pls help
> how to calculate the total resistance at point x,y Thanks.
>
> ------ R1 ------ - ------ R3 ------
> | | | |
> | |
> x ------- R5 ---------- y
> | | | |
> | | ------ R2
> ------ - ------ R4 ------

Please use a fixed-type font next time. ASCII art comes out much better
that way, and any reasonable newsgroup reader supports it.

I can't remember if there's a clever way to do this or not, but you can
always use mesh or node equations. If you're not doing it for an
assignment you can just put the network into SPICE, put a voltage across
it, and measure the current.

--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html

"dhclb126" <kcuskn@ppmes.spineless.org> wrote in message
news:51d5t39p4nm8uqtcgn5j92sfpf86kb82m7@4ax.com...

Pls help
how to calculate the total resistance at point x,y
Thanks.

------ R1 ------ - ------ R3 ------
| | |
| | |
x ------- R5 ---------- y
| | |
| | |
------ R2 ------ - ------ R4 ------

This looks like a classic homework problem.

How do YOU think it is accomplished?

What have YOU tried , so far?

What does your textbook have to say about it?

Yes, this is sci.electronics.basics, but it shouldn't be a place to get
homework answers with no effort on your part (though I am sure someone will
provide you the answer just because they will feel orgasmic showing their
superiority).

Richard the Grouch (at least for today)
Enough fun. Now back to grading lab reports.

"dhclb126" <kcuskn@ppmes.spineless.org> wrote in message
news:51d5t39p4nm8uqtcgn5j92sfpf86kb82m7@4ax.com...

Pls help
how to calculate the total resistance at point x,y
Thanks.

------ R1 ------ - ------ R3 ------
| | |
| | |
x ------- R5 ---------- y
| | |
| | |
------ R2 ------ - ------ R4 ------


There are several ways it can be calculated.
How did your instructor ask that it be done?

On Sat, 08 Mar 2008 23:46:10 +0800, dhclb126
<kcuskn@ppmes.spineless.org> wrote:

>
>Pls help
>how to calculate the total resistance at point x,y
>Thanks.
>
> ------ R1 ------ - ------ R3 ------
> | | |
> | | |
> x ------- R5 ---------- y
> | | |
> | | |
> ------ R2 ------ - ------ R4 ------

Try a delta-wye transformation.
--
John

"John O'Flaherty" <quiasmox@yeeha.com> wrote in message
news:peh5t3ho47c34b33e9ig2dkmq9qnjji3pr@4ax.com...
> On Sat, 08 Mar 2008 23:46:10 +0800, dhclb126
> <kcuskn@ppmes.spineless.org> wrote:
>
>>
>>Pls help
>>how to calculate the total resistance at point x,y
>>Thanks.
>>
>> ------ R1 ------ - ------ R3 ------
>> | | |
>> | | |
>> x ------- R5 ---------- y
>> | | |
>> | | |
>> ------ R2 ------ - ------ R4 ------
>
> Try a delta-wye transformation.

Good advice.

Richard Seriani wrote:
>This looks like a classic homework problem.
>[...]
>sci.electronics.basics[...]shouldn't be a place to get
>homework answers with no effort on your part
>(though I am sure someone will provide you the answer
>just because they will feel orgasmic showing their superiority).
>
> Richard the Grouch (at least for today)
> Enough fun. Now back to grading lab reports.

No one has posted to my recent thread
**Student Faces Expulsion for Facebook "Study Group"**
news:e89f2093-9a20-4d1e-8789-50bc25f83718@e6g2000prf.googlegroups.com
but *this* sort of thread is exactly what I was thinking about
when I posted it.

If my textbook have something to say about it, would I need to ask?=20
Just admit it, you know nuts about it.=20

On Sat, 8 Mar 2008 11:21:43 -0500, "Richard Seriani" =
<richard_s633@cox.net> wrote:

>
>"dhclb126" <kcuskn@ppmes.spineless.org> wrote in message=20
>news:51d5t39p4nm8uqtcgn5j92sfpf86kb82m7@4ax.com...
>
>Pls help
>how to calculate the total resistance at point x,y
>Thanks.
>
> ------ R1 ------ - ------ R3 ------
> | | |
> | | |
> x ------- R5 ---------- y
> | | |
> | | |
> ------ R2 ------ - ------ R4 ------
>
>This looks like a classic homework problem.
>
>How do YOU think it is accomplished?
>
>What have YOU tried , so far?
>
>What does your textbook have to say about it?
>
>Yes, this is sci.electronics.basics, but it shouldn't be a place to get=20
>homework answers with no effort on your part (though I am sure someone =
will=20
>provide you the answer just because they will feel orgasmic showing =
their=20
>superiority).
>
>Richard the Grouch (at least for today)
>Enough fun. Now back to grading lab reports.
>
>
>

I did a question wrongly and obtained this circuit.
Just want to know how to do it out of curiousity.=20
Can you explain the simplest way?=20

On Sat, 8 Mar 2008 11:30:18 -0500, "Tom Biasi" <tombiasi@optonline.net> =
wrote:

>
>"dhclb126" <kcuskn@ppmes.spineless.org> wrote in message=20
>news:51d5t39p4nm8uqtcgn5j92sfpf86kb82m7@4ax.com...
>
>Pls help
>how to calculate the total resistance at point x,y
>Thanks.
>
> ------ R1 ------ - ------ R3 ------
> | | |
> | | |
> x ------- R5 ---------- y
> | | |
> | | |
> ------ R2 ------ - ------ R4 ------
>
>
>There are several ways it can be calculated.
>How did your instructor ask that it be done?=20
>

dhclb126 wrote:
> I did a question wrongly and obtained this circuit.
> Just want to know how to do it out of curiousity.
> Can you explain the simplest way?

I can do it at least 4 different ways, but they all involve
algebra. Here is a paper on one way:
http://www.chem.usu.edu/~sbialkow/Class ... venin.html

--
Regards,

John Popelish

"dhclb126" <kcuskn@ppmes.spineless.org> wrote in message
news:1ip7t39enlm8jt2stnscb1ftq4e7ar3kta@4ax.com...
I did a question wrongly and obtained this circuit.
Just want to know how to do it out of curiousity.
Can you explain the simplest way?




John suggested Thevenin which is a good way.
You may also look up loop analysis and Kirchhoff's laws.
Its not a simple circuit and will involve considerable algebra.
One way is to assign a voltage and solve the total current to calculate the
resistance.
If you are looking for a formula that addresses the five unknown
resistances, you will have a large mess.

Tom

"dhclb126" <kcuskn@ppmes.spineless.org> wrote in message
news:8hp7t35j58v68dmqch4gfeg938do86p0a8@4ax.com...
"If my textbook have something to say about it, would I need to ask?"

Possibly. You wouldn't be the first student who was incapable of finding or
understanding information in a textbook. Some texts are better than others,
as are some students.

"Just admit it, you know nuts about it."

Yep. You caught me.
Feel any smarter now?

Richard


On Sat, 8 Mar 2008 11:21:43 -0500, "Richard Seriani" <richard_s633@cox.net>
wrote:

>
>"dhclb126" <kcuskn@ppmes.spineless.org> wrote in message
>news:51d5t39p4nm8uqtcgn5j92sfpf86kb82m7@4ax.com...
>
>Pls help
>how to calculate the total resistance at point x,y
>Thanks.
>
> ------ R1 ------ - ------ R3 ------
> | | |
> | | |
> x ------- R5 ---------- y
> | | |
> | | |
> ------ R2 ------ - ------ R4 ------
>
>This looks like a classic homework problem.
>
>How do YOU think it is accomplished?
>
>What have YOU tried , so far?
>
>What does your textbook have to say about it?
>
>Yes, this is sci.electronics.basics, but it shouldn't be a place to get
>homework answers with no effort on your part (though I am sure someone will
>provide you the answer just because they will feel orgasmic showing their
>superiority).
>
>Richard the Grouch (at least for today)
>Enough fun. Now back to grading lab reports.
>
>
>

"Richard Seriani" <richard_s633@cox.net> wrote in message
news:p2zAj.20647$yk5.2234@newsfe18.lga=20
> "dhclb126" <kcuskn@ppmes.spineless.org> wrote in message
> news:51d5t39p4nm8uqtcgn5j92sfpf86kb82m7@4ax.com...
>=20
> Pls help
> how to calculate the total resistance at point x,y
> Thanks.
>=20
> ------ R1 ------ - ------ R3 ------
> | | |
> | | |
> x ------- R5 ----------
> y | | |
> | | |
> ------ R2 ------ - ------ R4 ------
>=20
> This looks like a classic homework problem.

Looks like a dog's breakfast to me, due to=20
font/tab/space breakage. Is there a cleaned-up
version of the circuit diagram that isn't
ambiguous as to what's where?

On Sun, 09 Mar 2008 21:35:03 +0800, dhclb126 <kcuskn@ppmes.spineless.org> wrote:

>I did a question wrongly and obtained this circuit.
>Just want to know how to do it out of curiousity.
>Can you explain the simplest way?

Go have a look at this thread:

http://groups.google.com/group/sci.elec ... 2d7785406c


>
>On Sat, 8 Mar 2008 11:30:18 -0500, "Tom Biasi" <tombiasi@optonline.net> wrote:
>
>>
>>"dhclb126" <kcuskn@ppmes.spineless.org> wrote in message
>>news:51d5t39p4nm8uqtcgn5j92sfpf86kb82m7@4ax.com...
>>
>>Pls help
>>how to calculate the total resistance at point x,y
>>Thanks.
>>
>> ------ R1 ------ - ------ R3 ------
>> | | |
>> | | |
>> x ------- R5 ---------- y
>> | | |
>> | | |
>> ------ R2 ------ - ------ R4 ------
>>
>>
>>There are several ways it can be calculated.
>>How did your instructor ask that it be done?
>>

On Sun, 9 Mar 2008 10:24:45 -0400, "Richard Seriani" =
<richard_s633@cox.net> wrote:
>
>"dhclb126" <kcuskn@ppmes.spineless.org> wrote in message=20
>news:8hp7t35j58v68dmqch4gfeg938do86p0a8@4ax.com...
>
>"If my textbook have something to say about it, would I need to ask?"
>
>Possibly. You wouldn't be the first student who was incapable of finding=
or=20
>understanding information in a textbook. Some texts are better than =
others,=20
>as are some students.
>
>"Just admit it, you know nuts about it."
>
>Yep. You caught me.
>Feel any smarter now?
>
Oh how I wish I do.=20

Thanks

On Sun, 09 Mar 2008 08:47:08 -0500, John Popelish <jpopelish@rica.net> =
wrote:

>dhclb126 wrote:
>> I did a question wrongly and obtained this circuit.
>> Just want to know how to do it out of curiousity.=20
>> Can you explain the simplest way?=20
>
>I can do it at least 4 different ways, but they all involve=20
>algebra. Here is a paper on one way:
>http://www.chem.usu.edu/~sbialkow/Classes/564/Thevenin/Thevenin.html

Thanks

On 9 Mar 2008 10:36:02 -0500, The Phantom <phantom@aol.com> wrote:

>On Sun, 09 Mar 2008 21:35:03 +0800, dhclb126 =
<kcuskn@ppmes.spineless.org> wrote:
>
>>I did a question wrongly and obtained this circuit.
>>Just want to know how to do it out of curiousity.=20
>>Can you explain the simplest way?=20
>
>Go have a look at this thread:
>
>http://groups.google.com/group/sci.electronics.design/browse_frm/thread/=
de8734cdf025b255/0e44172d7785406c?hl=3Den&lnk=3Dst&q=3D#0e44172d7785406c
>
>>>
>>>There are several ways it can be calculated.
>>>How did your instructor ask that it be done?=20
>>>

On Sun, 09 Mar 2008 08:47:08 -0500, John Popelish <jpopelish@rica.net>
wrote:

>dhclb126 wrote:
>> I did a question wrongly and obtained this circuit.
>> Just want to know how to do it out of curiousity.
>> Can you explain the simplest way?
>
>I can do it at least 4 different ways, but they all involve
>algebra. Here is a paper on one way:
>http://www.chem.usu.edu/~sbialkow/Classes/564/Thevenin/Thevenin.html

This is a useful paper, but it doesn't answer the OP's question, which for
this circuit would be "what is the resistance seen by the 25 volt source?".

Can you see a way to coax the answer to the OP's question out of a
knowledge of the current through R5? I can't see one right away. I'll
have to think about it.

On Mon, 10 Mar 2008 16:53:33 -0800, The Phantom <phantom@aol.com> wrote:

>On Sun, 09 Mar 2008 08:47:08 -0500, John Popelish <jpopelish@rica.net>
>wrote:
>
>>dhclb126 wrote:
>>> I did a question wrongly and obtained this circuit.
>>> Just want to know how to do it out of curiousity.
>>> Can you explain the simplest way?
>>
>>I can do it at least 4 different ways, but they all involve
>>algebra. Here is a paper on one way:
>>http://www.chem.usu.edu/~sbialkow/Classes/564/Thevenin/Thevenin.html
>
>This is a useful paper, but it doesn't answer the OP's question, which for
>this circuit would be "what is the resistance seen by the 25 volt source?".
>
>Can you see a way to coax the answer to the OP's question out of a
>knowledge of the current through R5? I can't see one right away. I'll
>have to think about it.

I don't think it can be done without splitting the circuit and determining
TWO Thevenin equivalents, as shown here (a reference you provided last
year):

http://www.broadcast.net/hallikainen/theory6.html