felezjoo PI(the best pulse induction metal detector that I made until now)

[mehmet_dag]

Opamp and hex

Guys better to find LF257h metal model fine at this project and works like LF357h. And hex works like full version without any problem at my trials as search google name felezjoo full edit 3.35_1397-9-28-13-59 Sorry i could not attached.

[mehmet_dag]

fullhex

http://forum.lugatek.com/index.php?a....0;attach=1905 full hex working as original
Masters can test it. File also attached

[combat99]

Hi all! can i replace lf357 by op37?

[kt315]

Hi all! can i replace lf357 by op37?

hi. can you give me full schematic?

[Qiaozhi]

hi. can you give me full schematic?

Is this what you're looking for?

[kosacid]

i used felezjoo full edit 3.35_1397-9-28-13-59.zip this is a new build im using a ne5534 op amp and a walkman board and for the fet im using irf740

this is the results. is it a setting i have missed all the fuses are the exact fuses apart from LB i cant get that the same

so what have i missed the coil im using is a nice 20us coil so why is the pulse so long ?

[kt315]

Is this what you're looking for?

thank you, George
i just try to collect all files in an archive...

[kt315]

Hi all! can i replace lf357 by op37?

OP37 has Slew Rate 11 V/us... take something more fastier... you have to seek 50+ V/us...

[combat99]

Thanks, understend. find in shop ad744.

[mehmet_dag]

new opamp fast

Also maybe can be usefull new opamp as OPA637ap , 80 mhz and 100+ v/us, i will order from ali and try

[mehmet_dag]

Maybe due to opamp use Lf357h or lf257h metal version. I am not author but opamp may cause long pulse. And according to author , original board has also function to complete working.

i used felezjoo full edit 3.35_1397-9-28-13-59.zip this is a new build im using a ne5534 op amp and a walkman board and for the fet im using irf740
[ATTACH]54619[/ATTACH]
this is the results. is it a setting i have missed all the fuses are the exact fuses apart from LB i cant get that the same
[ATTACH]54620[/ATTACH]
so what have i missed the coil im using is a nice 20us coil so why is the pulse so long ?

[Mr.Jaick]

how can i change the ascii letters in the hex file? is there any chance?
i change them with "TNM" app and save them then use that file with "Extreme Burner" to programme the MCU but it does not work
tried many times with different settings and letters
what i'm doing wrong?

[sinclairuser]

there are a few sellers of components on ebay, selling soviet era stuff, they have metal can lf357's and ceramic too, plus loads of other obsolete stuff.
just search, some people say these components are no good but i got some lf357's and they were ex soviet military, they worked fine.
when it comes to obsolete components there are 4 choices,
1 new old stock from germany, very expensive if available.
2 soviet new old stock from all over eastern europe, cheaper and you can get 5, 10, 20, etc if they are like the lad in ukraine who i bought from they test items and translate part no's too.
3 china this is just not an option, sadly with no testing or quality control there are just too many fakes, which is a shame as i have no doubt that good sound components exist there, but sellers mix fakes with real and its too much of a lottery.
4 trying alternatives, which works quite often but there are a few problem chips that just dont have alternatives that work the same ie lf357.
sometimes a certain part was used for a particular quirk in its design in that case the exact part must be used or the device wont work as intended.

[windaube]

Hello

I read the 94 pages of this post in detail.
I am extremely sad not to find lf357h

today is an equivalent to the lf357h exists and works with this detector?

the OPA637ap is interesting but expensive, 20-30 ? the unit ... and I can not find anyone who has successfully tested this IC

on the forum is there a similar project but with ICs still available?

thank

[waltr]

Hello

I read the 94 pages of this post in detail.
I am extremely sad not to find lf357h

today is an equivalent to the lf357h exists and works with this detector?

the OPA637ap is interesting but expensive, 20-30 ? the unit ... and I can not find anyone who has successfully tested this IC

on the forum is there a similar project but with ICs still available?

thank

The LF356 is pretty close so might work.
Another is the LT1157.