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

[sabios]

They believe that this type of resistance works since the metal film here in Mexico is very difficult to achieve, only these.

[MartinB]

I have a question about how much would be the voltage of pins 2 and 3 of lf357 and how many voltages would be the output through pin 6 since the measurements that it gives me with the multimeter is pins 2 and 3 are around 9.5 volts of 12 volt on pin 7 and 0.4 volt on pin 6 with lf357 and if I change for tl081 the output voltage rises 1.24 volt and I already changed the 390 resistance for a potentiometer which would be the error.

Hi Sabios,
Slightly different subject, but it looks like your 2W 390 ohm resistor is wire wound ceramic which can introduce additional inductance. I would change this for a metal film resistor of similar value

[sabios]

I checked the voltage on the LF357 and on pin 2 it gives me a voltage of 10 volt on pin 3 9.66 volt and on pin 7 it is 12.18 volt those numbers are correct

[sabios]

I have a question about how much would be the voltage of pins 2 and 3 of lf357 and how many voltages would be the output through pin 6 since the measurements that it gives me with the multimeter is pins 2 and 3 are around 9.5 volts of 12 volt on pin 7 and 0.4 volt on pin 6 with lf357 and if I change for tl081 the output voltage rises 1.24 volt and I already changed the 390 resistance for a potentiometer which would be the error.

[sabios]

I just finished the FelezJoo but I get the annoying coil error message, there is some solution since it is read that with a potentiometer in resistor R11 and that changing the resistor R10 for a potentiometer and that the CA3130 also serves as a replacement.
but of which poteiometer 1k, 5k or more

[ZOUjiarui]

Extra chip, ATTINY13
It must need another program.

[ZOUjiarui]

Who can provide the information of this PCB
Thank you very much.

[centiane]

Hi, I use a AD811 and this Amp is very well.
The OP as 2500 V/us slew rate

work ok.

[MartinB]

Being original won't have problems, a photo of it?

Found this LF357N by National Semiconductors

[Emersonpaz]

Being original won't have problems, a photo of it?

[MartinB]

LF255H = 5v/uS + 2.5MHz Gain Bandwidth
LF357 = 50v/uS + 20MHz Gain Bandwidth

In other words, you can't use LF255. If you want Felezjoo PI to work as it should then you must get LF357N/MAC157/MAB357/
Mr. Hamid made clear on the instructions that the most important part is the LF357 and it should not be countefeit or anything else than a genuine LF357.

Hi,
Is a LF357DP suitable?

[MartyJ1963]

@Sabio. I updated the layout tonight. The layout is the same but I added the component names and values. I also included the schematic I used to build this layout, a Parts list, and a 2 x photos of the original PCB i copied in case you want to build this layout. I also included all available HEX Files from v2.4 to v3.5 full edit and the Felezjoo Fuses. There is a manual also that I translated on how to operate it. Good luck in case you decide to bild! Regards, Marty.

[MartyJ1963]

Hi Sabios. I was the one who copied this layout from my working Felezjoo board. It works without flaws. Regards, Marty

[sabios]

FELEZJOO Rev A-2.rargood colleagues I have a question regarding the detector in particular to the version of FelezJoo RevA I have seen some revisions and I found some flaws and I would like to know if any of you could tell me if it is okay as it looks.

[MDfanatic]

That's why you should only order genuine parts from a reliable source (eg LCSC.com) so you know what you'll get without questioning the quality.
If you go the eBay route, most probably the part you'll receive will be of questionable quality.