Arduino Nano PI Main Discussion

[Jeg]

Nice job emersonpaz. Does your arduino gets hot?

[Emersonpaz]

It doesn't heat up, it works normally. the only time it got hot was when i reversed the polarity i remember the fried atmel got too hot i had to change the nano v3

[bbsailor]

I found the damping value to be low, I used a ready-made coil that I had
https://youtu.be/JTpd229ys5Q

145 ohms resistor

The value of the damping resistor is based on all the capacitance that the coil sees. It comes from these primary sources.
1. Coil turn to turn capacitance
2. Coil to shield capacitance
3. Coil coax cable capacitance.
4. MOSFET COSS

The damping resistor is actually damping the capacitive energy that occurs when the TX discharge pulse drops and then starts to oscillate. Reduced coil seen capacitance allows a higher damping resistor value to be used and allow a steeper discharge pulse slope that more efficiently stimulates low TC targets.

Go to the articles section of this forum and go to projects to see the article I wrote in 2006, Making a fast PI mono coil for more detailshttps://www.geotech1.com/cgi-bin/pag...oils/index.dat.

The easiest way to make a faster coil is to use coil wire insulation with a low dielectric constant such as Teflon. Put a diode in series between the MOSFET and the coil to minimize the MOSFET COSS that the coil sees. Use the shortest and lowest capacitance coax cable that you can find.

I hope this helps.

Joseph J. Rogowski

[Jeg]

It doesn't heat up, it works normally. the only time it got hot was when i reversed the polarity i remember the fried atmel got too hot i had to change the nano v3

Thank you brother, i'll check the routing again even if i am preaty sure that everything is wired right. I can even scope the 1Khz pulses at Arduino's output.

[Emersonpaz]

The value of the damping resistor is based on all the capacitance that the coil sees. It comes from these primary sources.
1. Coil turn to turn capacitance
2. Coil to shield capacitance
3. Coil coax cable capacitance.
4. MOSFET COSS

The damping resistor is actually damping the capacitive energy that occurs when the TX discharge pulse drops and then starts to oscillate. Reduced coil seen capacitance allows a higher damping resistor value to be used and allow a steeper discharge pulse slope that more efficiently stimulates low TC targets.

Go to the articles section of this forum and go to projects to see the article I wrote in 2006, Making a fast PI mono coil for more detailshttps://www.geotech1.com/cgi-bin/pag...oils/index.dat.

The easiest way to make a faster coil is to use coil wire insulation with a low dielectric constant such as Teflon. Put a diode in series between the MOSFET and the coil to minimize the MOSFET COSS that the coil sees. Use the shortest and lowest capacitance coax cable that you can find.

I hope this helps.

Joseph J. Rogowski

Thanks my friend

[Qiaozhi]

Hi all
George i encounter an issue here in relation with 7660. More specifically i used an ICL 7660 ACPAZ. It doesn't work. Output is zero instead of negative. I changed it with a second one i had in hand of the same type and again no output. Few pages back there was also one more builder having the same issue. Is there any specific type that i need to purchase?

Arduino is getting too hot. Have you noticed that? A laser temp meter shows 57 degrees C. Looks like its coming from the internal voltage regulator.

Very elegant job, thanks a lot for sharing. I started soldering without having the book yet and it was difficult enough for me. Especially when i first soldered the parts and then noticing the small hole links between the two layers!!!

So far so good!

Hi Jeg,

Sorry for the late reply. I've been away getting some summer sun. Back to reality now and -4 degrees C.

You can use any ICL7660 or even an LT1054. I suspect you have a bunch of fake devices.
Also, the Arduino should not be getting hot.

[Jeg]

Thank you George. Yes I also suspect that my 7660 Ic's are not genuine. I am waiting for new ones to arrive. About Arduino i suspect that i over feed it accidentally and i made a damage on the board. I ordred a new one to continue.

[kosacid]

is there a error on the audio integrator circuit i just built this and TP10 and TP11 is not very responsive

[Qiaozhi]

is there a error on the audio integrator circuit i just built this and TP10 and TP11 is not very responsive

There is definitely no error in the ANPI design.

[surfdetector]

is there a error on the audio integrator circuit i just built this and TP10 and TP11 is not very responsive

At about the 2 minute point in my video I show what TP 10 and 11 look like as tested with my oscilloscope.
https://youtu.be/G1gUYHVw20k

[kosacid]

yes it is fine i built another and it is working fine but the board thats not working i striped the caps and redone the integrator still the same i get a slight curve on the scope on TP11

[kosacid]

love them videoes by the way

[kosacid]

if you look at the yellow trace you will see a slight curve i wonder if there is a short on the amp going to remove the chip holder and try again the line gose up and down when you adjust the threshold

[jamespage93433]

Just built this, is working awesome, but I feel there is room for improvement on my calibration skills.

Happy to see some recent posts! Bump

Kosacid - I have no response from Vol pot. Its just loud. I suspect the problem is the circuit on page 15 fig. 2-7. The potentiometer is wired more like a speaker L-pad or just different. Shows no voltage divider to +12v ,wired straight to it. The ground switched from Q5 thru R20. HEY just look at the 1k pot its wired like a resistave load, the pl5 is being fed power both ends..........that goof on your scope on both channels is the beep, its drawing a load as it is a floating ground having been wired sorta similar to dolby center channel which is the potential difference from left positive to right positive.

I am searching insight on what exaclty to look for while adjusting r12 at (testpoint 6?!?) I am using rs485 PE insulated wire for coil and the entire cable (1 pair) for coil to board connection, critical dampening achieved, working on lowering coil to shield capacitance (i sprayed it with krlon clear spray, not advised)

Its May 2023 Bump
Greetings to all
James

[surfdetector]

I am searching insight on what exaclty to look for while adjusting r12 at (testpoint 6?!?)

Its May 2023 Bump
Greetings to all
James

This video shows the R12 adjustment.
https://youtu.be/T8EStHy71c4