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

[Aziz]

Hi all,

a new detector controller project has been started. This time on the other forum (you know where).
The total thermo nuclear melt-down is coming ... *LOL*
Cheers,
Aziz

[6666]

Hi Aziz have you done much work with NJM 2068D opamp ?

they are very cheap here in Oz, well done.
6666

[Aziz]

Hi 6666,

well, I find the Japanese dual op-amp NJM 2068D much much better than NE5534 (single) or NE5532 (dual). Quite low noise and very cheap here too. I have used the NJM 2068D many times in my projects and I'm very satisfied with it.
But I don't have the spice model for the NJM 2068D so I'm using the NE5532 op-amp instead.
Cheers,
Aziz

[Aziz]

Preliminary schematics of the current IB-Hybrid VLF/PI project:



(Don't blame me please. It's a KISS-design and it needs testing and parts value fine tuning yet. )
Cheers,
Aziz

PS: Notice the magic choke!!!! *LOL*

[greylourie]

Low cost entry. Nice.

[6666]

Thanks Aziz, will order some for my usual supplier
they are on back order right now due end of year.
Whats the "majic choke" specs
cheers
6666

[Aziz]

Thanks Aziz, will order some for my usual supplier
they are on back order right now due end of year.
Whats the "majic choke" specs
cheers
6666

"Majik Choke": 2 mH - 8 mH (ring core)
(not critical)

If you can wait, I'll post a working spice file soon (next week probably). I have to make a prototype and test it first.
Aziz

[Aziz]

Hi all,

this is the latest schematics and LTspice simulation file for all the impatient blokes out there (zip file below). You can play with it and can see how it is working.
(Trivial, very trivial, shame on me, it's really very trivial.)

IB-Hybrid-VLF-PI-4212-V0.01.zip

Who is going to make the open-source project now?

(Don't look at me! I would cause the total thermo nuclear melt-down to the industry! *LOL*)

I have to make the prototype yet. Minor changes could happen.
Cheers,
Aziz

[Davor]

Perhaps you could use this LDO model - I made it just for you. It is designed as a hierarchical model, so when you open a test circuit, just right click on a regulator, and open a schematic so that you can tweak it the way you like. You'll find a surprise there, a level 2 switch. It has a very neat transition which lends itself perfectly for this purpose. It has a .2V drop in a model, and .2ohm series resistance to mimic 0,2V per ampere drop. And it converges very fast.

[frankly]

This can be done with a small light weight netbook. Run the software off the drive and use some sort of head from a usb port.

[Aziz]

This can be done with a small light weight netbook. Run the software off the drive and use some sort of head from a usb port.

Yup, it was designed for Netbook/Laptop and the next generation of Tablet PC's.
It's the poor-man's ultimate detector (UD): *LOL*
Poor man's DIY detector controller: approx. 50 bucks
Poor man's ADC/DAC unit (USB-sound card): approx. 50 bucks
Poor man's computer (2. hand used Netbook): approx. 50-100 bucks
Poor man's DIY coil: approx. 50 bucks
Poor man's free software*: 0 bucks in case of "Total Metal Detecting Thermo-Nuclear War"(c)(r)(tm)!
= Poor man's UD: approx. 200-200 bucks

[*] = Not available yet.
It's the engaged "red button" for the "Total Thermo-Nuclear Melt-down"(c)(r)(tm) against the evil & greedy companies don't leaving hobbyists and backyarders alone.

I want my "love letter" from Greedlab!!! Right now! The total thermo-nuclear melt-down is coming.... *LOL*


Cheers,
Aziz

PS: Davor, nice LDO spice! Thanks.

[maca404]

Just started following this thread have not got through it all but very impressed and would be happy to help out, I had great luck with the M-Audio 24bit usb sound back when I was fiddling with SDR. Also as a side note to the PC based aspect has anyone given thought to the Raspberry-PI all the benfits you would get with a little laptop and also you get the GPIO pins you could use to drive transmitters etc.

[Davor]

Raspberry is wasteful on batteries, and there is a big problem with I/O

[maca404]

A laptop will have its own power source but that wont be particuarly eficient with limited run time, just changing the reg on the pi can get its average consumption down to 150ma @ 12v. On a side note about power I always wanted to make a detector just as stupidly powerful as possible disregarding the diminishing returns and then have a motorized battery platform full of lipos which automatically follows around just behind you.

[Davor]

That would be a day

Sad reality is that detection process by itself is using incredibly little power, so the only power losses are incurred by wasteful principles to get there.