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

[WM6]

Secon part of my previous post

"But are you sure about FPGA? You ca set multiple amplifiers input inside PGA too? "

is refering to this:

Originally Posted by Aziz

No, it's not a PGA. The PGA-switches in the feedback loop path would contribute much noise to the amplifier. Not good. PGA-idea is dead.

But the concept of having several amplifiers is much better regard to stability, noise and temperature dependency.

[Aziz]

Originally Posted by WM6

Secon part of my previous post

"But are you sure about FPGA? You ca set multiple amplifiers input inside PGA too? "

is refering to this:

Hi WM6,

you are confusing me.

FPGA = Field Programming Gate Array (http://de.wikipedia.org/wiki/Field_P...ble_Gate_Array )
PGA in this context = Programmable Gain Amplifier (http://en.wikipedia.org/wiki/Program...gain_amplifier )

My project has nothing to do with FPGA's. I don't need it at all.

You will find here a PGA implementation:
http://www.ecircuitcenter.com/Circui...PGA/op_pga.htm

Aziz

[WM6]

Originally Posted by Aziz

Hi WM6,

you are confusing me.

FPGA = Field Programming Gate Array (http://de.wikipedia.org/wiki/Field_P...ble_Gate_Array )
PGA in this context = Programmable Gain Amplifier (http://en.wikipedia.org/wiki/Program...gain_amplifier )

My project has nothing to do with FPGA's. I don't need it at all.

You will find here a PGA implementation:
http://www.ecircuitcenter.com/Circui...PGA/op_pga.htm

Aziz

Eh abbreviations, Aziz, you go so fast in the future, that I am no longer capable to catch all your bright thoughts and attempts. Thanks.

[Aziz]

Hi all,

I just want to mention: Be very very careful when you are making some noise analysis with the internal parts of LTSpice.

Some of them seem not to behave correct.
Try the different LT1028 and you will see what I am meaning (there are four different models: LT1028, LT1028A, LT1028CS, LT1028N).

Even the n-jfet 2n4393 seems not be behaving well when making noise analysis. It's resistor noise isn't there, but it should be. It's behaving like a 2 Ohm resistor noise instead of 100 Ohm.

But the 0.7 nV/sqrt(Hz) amplifier noise above is correct: It's the fully differential input noise density. The transimpedance (I-to-V conversion) is made by two independent op-amps and hence reducing the differential noise. The single ended noise is higher of course (+3 dB).

I will check soon, whether we need a super-low-noise amplifier.
Aziz

[Nicolas]

Good Thx

[mr cleo]

im runing a icon data logger with a minlab exp 2 getting good results
www.imagelocators.com need to run in vco (non motion mode to work)
vary good with pi.look for me sep 1st on above site.

[Aziz]

Hi all,

I will take a break on the projects. The reason is, I am total bankrupt. No, the krauts did not rip me yet. Because, there is nothing to rip.

BTW, I am 44 years old and they want to retire me now.
That's a bit too early - isn't it?

Aziz

[danny475bek]

hi i'm danny bekerejian a graduate of technical computer
i guess it is beter to build a microcontroler based matel detector
you are not taking in concederation the price or the detector nor the pakaging .....
who sad that microcontrolers are in law speed no they can act as the same as computers and who sad that we will put the comparation in the cpu no
the cpu only for good interface
most original matal detectors are microcontroler based

[Aziz]

Hi danny475bek,

No, micro controllers are just toys referring to computation power. But I need huge, really huge computation power for some secret reasons.

Aziz

[danny475bek]

but untill now i dont see any of thoes microcontroler based detectors that work well and have more functions and have a usb interface with a pc
i know that micros are judt games although they are games but untill now i dont see a full and complet detector with a big lacd screen and more controling functions
so first w have to build that one and than we are goilg to go to the next step
take care all of you
by by