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In-wall wiring detector

nuraqilah3

Jan 27, 2014
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Hi there,

I am currently creating a circuit that detects in-wall wiring. My idea was to use radar to send impulse signal to detect the existence of a wire.

This may sound stupid. I don't if it will work or not. I have been reading stuffs about penetrating radar. The frequencies that they use are high and the circuit are quite complicated. Furthermore, the circuit use is used to detect an object through the wall. My attention is only to penetrate partially in the wall just to detect a wires that is buried under the wall. As you know electrical wires are buried inside a cemented wall.

Could anyone suggest any circuit that I could use for this project? And what frequencies to used to penetrate partially into the wall. :confused:

I am a bit at lost here. Really need some help. :D:D
 

davenn

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hi there
welcome to the forums

your way would work but technically its a considerable project
Dunno what electronics experience you have ?

have you instead considered the more common way of detecting power cables by the 60Hz AC EM radiation they emit ?

cheers
Dave
 

nuraqilah3

Jan 27, 2014
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This is the problem statement of this project;
"In building construction it became a trend for the constructor to bury the wires inside the walls of the building. It also prevents from given harm to the consumer. The problem that has been face is not knowing the exact location of the wires. We only know that wires are buried in the wall of the building. While driving a nail or drilling in such walls, there is always a risk of hitting a live electric wire resulting in injury or even loss of life."

At first I consider about the heat that the wires produces. And using an IR sensor to detect the heat. But it couldn't be done because the heat produce by the wires are to weak to be detected.

I am actually targeting the hollow in the walls where the wires would possibly be. So that the wires will be traced even without switching on the electric.

Is like the tools that is used to detect studs in the wall. I wanted to recreate this tools, but to adjust it a bit.
The tools are using UWB radar. I don't really know how to implement this. I am a real noob when it comes to circuit design.
 
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davenn

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The tools are using UWB radar. I don't really know how to implement this. I am a real noob when it comes to circuit design

which is why I gave you the suggestion that I did
It would be a much easier project for a beginner to handle

Dave
 

Harald Kapp

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Here's an example of a suitable circuit, here's another one.

Detecting the electromagnetic field from the wire is more reliable than using radar to detect hollows for 2 reasons:
- a hollow doesn't necessarily have to include electrical wiring
- electrical wiring may be placed under plaster without a hollow behind the wall. This would require an extremely sensitive radar to detect - if at all.

Google " metal and wiring detector circuit" to find loads of circuits.
 

nuraqilah3

Jan 27, 2014
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can this circuit possible penetrate through wall? Because I am looking at wiring that is buried under a cemented wall.
 

Harald Kapp

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It depends on the depth of the wire behind the wall. Typically it should do so.

Google "cable locator" for off-the-shelf equipment.
 

jpanhalt

Nov 12, 2013
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The old inductive and capacitance testers do work, but there is a new generation of "radar technology" detectors on the market and prices are dropping. In fact, about 8 years ago, I stumbled on a DIY version. Unfortunately, I can't find that link now.

Here are some of the current commercial offerings:
http://www.engineersupply.com/Bosch...0_a_7cES2998&gclid=CP_g-6-znrwCFU7xOgod4zUAeQ
EDIT: The above link may have been misrepresented. couldn't confirm that the GMS120 is radar. But, this GMS150 appears to be:
http://www.boschtools.com/Products/Tools/Pages/BoschProductDetail.aspx?pid=D-tect150

http://www.toolbarn.com/dewalt-dct418s1.html

http://www.idsa.org/content/content1/stanley-invision-stud-finder

Note the resolution shown for the last one. The older methods, e.g., the Zircon stud finder, have pretty much been developed as far as that technology will go.

If this is a major project for you, I would suggest not abandoning the "radar" method. Just search on DIY radar stud detector and similar terms.

John
 
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jpanhalt

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Neither one will work.

The first method uses ultrasound. I doubt there will be the resolution you need, even if you can get it to penetrate walls.

The second one uses an IR proximity sensor. That method has been around for ages in various forms, but it cannot "see" through walls.

I will see if I can find my file on the DIY version, but that will not be until Wednesday at the earliest. The true radar methods use radio waves in the GHz range to penetrate walls.

John
 

jpanhalt

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No guarantees I will be able to find it. However, the current "radar" units seem to use "ultra wide band" pulses. Another related term is "micropower impulse radar."

Here are some links I found to that technology:

https://www.llnl.gov/str/pdfs/01_96.2.pdf

http://books.google.com/books?id=eT...wBDgU#v=onepage&q=radar stud detector&f=false

http://www.walleyetechnologies.com/...s/23-zircon-radar-based-construction-scanning

Early patent:
http://patft.uspto.gov/netacgi/nph-...&f=G&l=50&d=PALL&RefSrch=yes&Query=PN/5465094

PowerPoint:
http://www.its.bldrdoc.gov/media/31837/joh_slides.pdf

You may want to look at the last (PowerPoint) first. The second slide summarizes various applications. The toilet sanitizer is a bit of a surprise.

John
 
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jpanhalt

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UPDATE:
Found the article. It was a patent, unfortunately. Here's a Google link: http://www.google.com/patents/US5457394

The copy I have was downloaded from a different source and has all the drawings included. Unlike many patents, this one seemed to have relatively more details on construction aspects.

It does use UWB technology and references a receiver, pat. no. 5345471.

John
 

Externet

Aug 24, 2009
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The first link is not radar, even if named that way.
The second will not penetrate walls.

Keep present that many responses are not considering stone or concrete walls with metal or not ducts housing the wires, as the only building methods they may know of are paper, plaster and wood sticks, and lots of nails.
What type of construction do you have to use it on?
Also, the wires you are looking for may not be energized if that is the problem, and AC may not be radiating.

Have you considered a basic metal (copper) detector ?
 
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nuraqilah3

Jan 27, 2014
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The wall that I am looking at is a concrete wall. But in this project I am only looking a device that could detect a wire that is approximately 1 inch deep into the wall. Due to the fact wires are buried roughly 1 inch into the wall.

Haven't considered a basic metal (copper) detector/. But will look up into it. Thanks for the info.
 

(*steve*)

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Can you couple a signal onto the wire?
 
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