IF YOU HAVE MAKE , TRY THIS .

[sisco]

Would an AD797 be better choice .. ultra low noise better than ad8055
cheers

Hi gef12 , I try find AD797 and test .

you test this ?

[sisco]

excuseme Max but what mean e.g.

[Great_Alex]

HI aft_72005

Please email me : greatalexx@yahoo.com

I don't know why you cant upload that ?

[aft_72005]

Hi Great_Alex
Please see your mailbox.
Regards.

[1843]

Hi,
the idea is good... even if then in the field there are other factors that can alter your elaboration cause of wrong samples due e.g. to magnetic viscosity...

Problem is that you need a very fast hardware to perform well.

A solution could be a fast hi-res ADC (16-bit min) then an FPGA and then the "slow" MCU. But is really complicated.

Maybe a fast pic or a newer atmel with integrated reatively fast ADC could be used... I think you can gain e.g. 20uS conversion time that way.

Kind regards,
Max

Hi Max,

There is no need to external ADC etc. PD3200 only uses an ATmega8 for all disc...

My regards,
1843

[sisco]

Hi 1843 , in PD3200 use LF198 (Monolithic Sample-and-Hold Circuits)

I must test ( If can find LF198 ).

[aft_72005]

Hi Great Alex and others
For uploading minipuls disasm. File here , I try again ,
Compress it With zip software .
Regards.

[sisco]

Hi Max , I have new idea , see can do or not .

In fix times T1 and T2 , V1/V2 must for iron between 2 special number and

and for gold other special number (can understand what I say)

for example for iron X < V1/V2 > Y

(ONLY FOR EXAMPLE IRON: .5 <V1/V2> .8 in fix T1 & T2

GOLD: .2 < V1/V2> .4 in fix T1 & T2

I think this V1/V2 not Relation to size of object , what you think ? (bicause if object is big , V1 and V2 more together

and this Relation between V1 and V2 is fix)

you think best point for getting analog signal where ? after peramp or after

first amp level ? I try use original minipul input ( pin28 atmega8 ) but can't , may be my

programme have mistak ?

can somebody help me about A/D convertion , I have problem with this

object ?

[Max]

Hi Max , I have new idea , see can do or not .

In fix times T1 and T2 , V1/V2 must for iron between 2 special number and

and for gold other special number (can understand what I say)

for example for iron X < V1/V2 > Y

(ONLY FOR EXAMPLE IRON: .5 <V1/V2> .8 in fix T1 & T2

GOLD: .2 < V1/V2> .4 in fix T1 & T2

I think this V1/V2 not Relation to size of object , what you think ? (bicause if object is big , V1 and V2 more together

and this Relation between V1 and V2 is fix)

you think best point for getting analog signal where ? after peramp or after

first amp level ? I try use original minipul input ( pin28 atmega8 ) but can't , may be my

programme have mistak ?

can somebody help me about A/D convertion , I have problem with this

object ?

Hi,
I don't know. Think is the same or similar process described in the german book. You have to do some floating point math calculation inside the MCU.

About A/D conversion , it's easy find MCU with integrated A/D... very easy to program a conversion too: many examples for various devices on the Internet.

Best regards,
Max

[okantex]

Hi Sisco

have a look at bugwhiskers project at projects part.and if you could have time read it from the begining.I am sure you will see the way how you could measure much more points even at nano second.
go on good project.
there 64 sample,8sample and2 sampler models waits.you just have to write software

[Broken Diamond]

Questions about MiniPulse

Hi Everyone

Hi Sisco
I was reading your information and your attached files about MiniPulse 3, it was Nice and I guess it would be really better if you could explain about some different parts in your Build. Ok I’m writing the questions and hope to see your answers soon…

1. Your pictures are not correct with PCB layout that you attached. It seems they own to a different build. I show the difference in below Pictures. Take a look please. Do you have the right Pictures of a metal detector board that exactly are the same with your PCB and parts?

2. Your schematic is not 100% correct [the same] with PCB and have some differences. You know what I mean. Can you send the right schematic?

3. What is the function of R54, X15, J, X9? However why I can’t see X9 in your Build?

4. What is the reason you used R5 as [1k-1w] when it’s [1k-2w]? [Did you use 2 in serial?] And also about R41 when it’s 1K and you used 100ohm?
C12 in original schematic 10nMks and yours is 10n?

5. R42? Is that 150ohm? [You forgot to say.]

6. it’s seems you got a better results with two 10000microF, am I right? Can you explain the reason?

7. If LF357 works better so why you used LF356? And CNY17 have 4models till now. Which one looks better and you used?

Thanks a lot and also I attached My Picture wrote the parts on your design for better understanding and follow schematic…

[sisco]

Hi Broken Diamond ,
excuseme for my english,
1-2-see this address : http://thunting.com/geotech/forums/f...splay.php?f=38 ,our friend "bugwhiskers" in his project
use one amplifier part between sampler and main amplifier , I try use like this but after test this saw don't work ,
see pic1 , I don't use this part and short under PCB .

3- R45 for adj led LCD light. X5 is led LCD connector . J ,in original schematic
connected but in my LCD when connected couldn't adj LCD contrast so don't
connected. in this project X9 don't use ,maybe in industrial minipuls use ,
(maybe in industrial original minipuls software write special function for this connector but in metaldetektor.de site
this connector don't use so I remove this connector.

4- R5 is 1k/1W but I can't find 1K/1W so use 1K/3W , this is not important.
about C12 , anywhere I need Precision like amplifier parts or filter parts I use MKS capacitors, but see C12 location ,
this is use only for audio pulse so not important use MKS or POLYESTER or CERAMIC or other capacitors.

5- R42 with R49 adj your LCD contrast this is not important , you can test other resistor for find best contrast.

6- I use two 4700uf

7- I know LF357 better than LF356 but can't find LF357 so use LF356.but now use AD844 work very better than LF357 , you can use this.

and finally , any project I send to froum , before sending I test.
I test 'bugwhiskers' idea in my project but don't work (in my project) so don't told about this .

be successful 'Broken Diamond'

[sisco]

Two COIL

Carl and Max , if I want use two coil for my PI , you think what is better ?

Plan A or plan B ?

and if these not good what is your suggest?

[sisco]

or this plan ? (plan C)

what is better?

[Carl-NC]

(B).

(A) will subtract only if you flip one of the coils, which will result in a much weaker TX field.

(C) no way. Coil R's will be small and greatly attenuate differential signals.

- Carl