Let's made a PC-base metal detector with usb interface !!!

[Aziz]

Who say that crazy cannot enjoy in endless wrapping?

Hi WM6,

it's probably very boring. But the more I fold, the better it goes.

The Al stripe is really a very interesting cable. It makes a kind of "Litz-Stripe" (C) (R) by me . This cable is destined to the very high current carrying big two-box coil. And its weight is less. It is quite soft so it can be bent easily spiral like. The high interwire coil capacitance does not concern me.

I'll give a go to this interesting "super-market" coil wire.
I like it.

Aziz

[WM6]

Still not crazy. But you have to be crazy to fold the Al foil roll.

Who say that crazy cannot enjoy in endless wrapping?

[Aziz]

Folding, folding, darn folding

New cost calculation for the aluminium strip cable (30 m length):
1 Al foil roll: 1.45 EUR (30 m, 30 cm, 350 g, 13-14 µm thick)
3 rolls of adhesive tape for insulation : 0.50 EUR (6 rolls for 1 EUR)
Total: 1.95 EUR

I am at the third Al foil roll currently. I have to organise a winding spacer strip (polystyrene strip 1-2 mm thickness). Well, I could cut some polystyrene sheets or take a double sided adhesive tape too. I have both at home but will look for a better one next time.

Still not crazy. But you have to be crazy to fold the Al foil roll.
Cheers,
Aziz

[Aziz]

O yes, Aziz, I remember those your broad surface coil idea.
If you need Sherpas to smuggle around your lite coil, just mail me.

I prefer the two-box type coil for deep detecting.

The Al strip wire could be a good choice for the big two-box type coil. Only the TX coil needs to be low resistance in this case.

Well I'll see, whether it is suitable or not.
Aziz

[WM6]

But I am talking about 20-30 kg of copper wire.
No worry about the weight. This is only for a ground loop coil experiment. It's to keep the losses very low when transmitting with high coil power (> 20 A).

O yes, Aziz, I remember those your broad surface coil idea.
If you need Sherpas to smuggle around your lite coil, just mail me.

[Aziz]

Even cheaper if you look for it in so called "Home improvement DIY" shops and not in electronic shop.

Hi WM6,

yes, I know. In the krauts land, this does not seem to apply. Everything involved in home DIY products costs a lot of money.

But I am talking about 20-30 kg of copper wire.
No worry about the weight. This is only for a ground loop coil experiment. It's to keep the losses very low when transmitting with high coil power (> 20 A).

Aziz

[WM6]

I think, I have to spend 100-150 EUR just for cables.

Even cheaper if you look for it in so called "Home improvement DIY" shops and not in electronic shop.

[Aziz]

Rolling the Ball and Folding

Hi all,

the projects are still going on. The annual electricity bill has been surprising me: I will get 9 EUR back. (I thought, I would pay a lot more. ) It seems, I can place an another order for the missing parts next month.

I have decided to buy an inductivity meter rather than making itself (more accurate for lower inductivity) . It's smart and convenient in the field too. It seems, I got bad ferrite ring cores. The specification varies heavily (wrong labeling ? - who knows) . So it was good to test them.

I also need new coil cables for further coil experiments. Either loudspeaker or mains line cables. I think, I have to spend 100-150 EUR just for cables.

In the coming days and weeks, I will investigate the suitability of Al foil roll as a cheap wire for coils. I have folded a 30 cm width, 30 m Al foil roll six times (2^6 = 64, giving 64 layers) . I got a very nice Al strip of approx. 5 mm width. It's DC resistance is approx. 0.2 Ohm. Maybe I should fold more Al foil rolls to keep the costs low.

Al foil: 1.45 EUR (30 m, approx. 13-14 µm thick, approx. 350 g weight)
Adhesive tape: 1 EUR
Total: 2.45 EUR

So the 30 m Al foil cable costs me only 2.45 EUR but it is causing a lot of work of course.
Hey, I am making only prototypes not a production line. So it's perfect for light weight big coils.

Back to folding until I get crazy....

Cheers,
Aziz

[WM6]

Try this ->

http://cgi.ebay.co.uk/LCR-RCL-INDUCTANCE-CAPACITANCE-RESISTANCE-METER-DE3-/350225600301?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item518b128f2d

It's got to be cheaper than building one.

Thanks Qiaozhi. I just ordered one. It has interesting measuring frequency in L range of 100Hz. I have no one L meter with such low measuring frequency. And maybe it is a clone of HP, look at this:

http://www.dealextreme.com/customerphotos/quarantined/26768-4e1b6d2e-42b6-4e25-b9f2-c44b1ea05d88.jpg

[Qiaozhi]

Ok,

here is the theory behind the LCR meter:

http://icom.hsr.ch/uploads/media/RLC_Meter_EN_01.pdf (english)
http://icom.hsr.ch/uploads/media/RLC-Meter_DE.pdf (german)

http://www.sillanumsoft.org/ZRLC.htm

http://www.elektor.com/magazines/2008/june/an-rlc-meter-for-under-2-00.495109.lynkx

Aziz

Thanks Aziz. Very interesting project.

[Aziz]

Ok,

here is the theory behind the LCR meter:

http://icom.hsr.ch/uploads/media/RLC_Meter_EN_01.pdf (english)
http://icom.hsr.ch/uploads/media/RLC-Meter_DE.pdf (german)

http://www.sillanumsoft.org/ZRLC.htm

http://www.elektor.com/magazines/2008/june/an-rlc-meter-for-under-2-00.495109.lynkx

Aziz

[Aziz]

Sound Card LCR Meter

Hi all,

I have built the small circuit of the sound card LCR meter (see below). It's really easy and cheap stuff. I have tested some available software for it. The only one, which works quite well is the Visual Analyzer software (see http://www.sillanumsoft.org/prod01.htm ) . You can forget all the other software stuff. Most of them did not run even. Others did not allow setting me the appropriate sound card device. None of them allowed a 24-bit/96 kHz sampling.

Well, I'll implement the LCR meter software by myself as I can do it much better than anyone on the planet.

Aziz

[Aziz]

Try this ->

http://cgi.ebay.co.uk/LCR-RCL-INDUCTANCE-CAPACITANCE-RESISTANCE-METER-DE3-/350225600301?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item518b128f2d

It's got to be cheaper than building one.

Thanks Qiaozhi,

yes indeed, a darn cheap device. But I don't want to wait 6-8 weeks for delivery. Its accuracy is not good too. It also could be kept in the customs due to counterfeiting issue.

No, I am dreaming of a much accurate, cheap and elegant solution. It seems, that I have to implement it by myself. Could be a nice feature within the metal detecting software.

We only have to do a nice complex math on a complex voltage divider. Should be really a trivial job.
Aziz

[Qiaozhi]

I am thinking of to make one of those cheap sound-card RLC meters (impedance meter) rather than spending at least 100 EUR for an inductivity meter. I have found many interesting sources for this little project.
Cheers,

Aziz

Try this ->

http://cgi.ebay.co.uk/LCR-RCL-INDUCTANCE-CAPACITANCE-RESISTANCE-METER-DE3-/350225600301?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item518b128f2d

It's got to be cheaper than building one.

[Aziz]

Strange Things Happened

Hi all,

the repair topic has not been finished yet. Really strange things happened to my PC last days. The CPU fan got louder and the PC got slower. My software did not run correctly.
It did but very very slow.

Trojan? Virus? Software bug?

The reason was, that the CPU fan was slightly disconnected from the CPU. The thermal increase of the CPU speed up the CPU fan but it did not cool it down enough. As a result, the CPU has slowed the clock rate not to blow up the CPU (it even stopped working). I am glad to have an Intel CPU. I know, some other CPU would go up in smoke & fire.

The CPU fan fixing arrangement is due to aging broken (plastic). Well, I have repaired it provisional.

But my Tektronix is running better than ever. It seems, that the fault has existed a long time as the display brightness varied sometimes (one of the fault diodes of the bridge rectifier must have caused this).

------------

Project state: I need an inductivity meter right now
Project budget: the tide is out (bankrupt)

I am thinking of to make one of those cheap sound-card RLC meters (impedance meter) rather than spending at least 100 EUR for an inductivity meter. I have found many interesting sources for this little project.
Cheers,

Aziz