Arduino Nano PI Main Discussion

[Qiaozhi]

Ok, thanks, I kinda get it, you are interested in the DC variation, not the actual DC value.

As you said previously, simulating all that good stuff in LTspice would be useful in understanding how the whole thing works.

I just don't know enough about LTspice to be able to simulate going over metal and make the decay curve vary at the sampling points.

Any pointers on how to do that?

It could take a whole book to explain how to do that in detail.
If you're just trying to understand how certain sections of the design work, then you can simply apply the correct signals to the input to find out how it behaves.
Depending on the circuit, you can use dc, time, or frequency domain analysis as appropriate.

There is an LTSpice tutorial here: http://www.simonbramble.co.uk/lt_spi...e_lt_spice.htm

[kosacid]

just a pity the Arduino is not doing the sampling the only way i could see past that would be say use a atiny if you keeping the digital or back to a 555 to control the mosfet that would leave the Arduino dedicated to sampling using the timer as a trigger to sample, by experience i know you cant have it both ways i tried that lol

[Myntmaster]

Hi all.
While we are in winter, I decided to finish the postponed project.
With this coil in air in VCO mode, 1 euro - 38 cm. Gold ring 14K 3 gr. 30 cm. In sand the same ring is 25-27 cm.
====================

[Qiaozhi]

Well done. Nice work.
Now go and find some treasure.

[Myntmaster]

Front panel. The detector can be used underwater.
Aliexpress sells a special A4 film. She's like a sticker. You can print on a regular inkjet printer. Does not wash off or wash off later. We print what you need and stick it on.

[Myntmaster]

The work is finished. Everything works. You can dive underwater.

[Qiaozhi]

The work is finished. Everything works. You can dive underwater.

Nice job!
I see from the photos that the quality control inspectors were hard at work.

[Myntmaster]

Thank you. These guys are pros. The resistance of resistors can differ by smell.

[GeoMax]

Front panel. The detector can be used underwater.
Aliexpress sells a special A4 film. She's like a sticker. You can print on a regular inkjet printer. Does not wash off or wash off later. We print what you need and stick it on.

Nice job!!! Looks really good. Can you post the Aliexpress link for that special A4 film paper? And can you also use this paper with a colour laser printer?
How have you made your potentiometers water proof for diving?

[Myntmaster]

€14.50 | ESHANG A4 10 Sheets Premium Printable Vinyl Sticker Paper for Inkjet Printer Matte White Waterproof,Quickly Dry 8.3×11.7 Inches
https://a.aliexpress.com/_EJkFFkC
—-------------------
I print on an inkjet printer on this basis. Sufficiently wear-resistant. I think there is something similar for a laser printer.

I’ll explain how I made waterproof terminals for potentiometers and switches one of these days. It needs to be explained with a drawing.

[GeoMax]

Thanks for the link....

[BrianBCB]

Hi
Wonder if someone could help with a basic problem. I'm building the detector for our local heritage society (Stamford Bridge UK); I'm at Step 7 Transmit Circuit of excellent book but I'm only getting circa 50v flyback rather than 200v. I've checked resistance values, component polarities and orientation etc. Using 9" 24 turn hook up wire test coil, changing number of coil turns by 30% doesn't change flyback greatly, so suspect Q1 Mosfet is the problem or fault in board. Attached screenshot of osc reading using 10x probe, Vpp is only 60v.
Apologies in advance if I'm missing something obvious, electronics experience very rusty!
Thanks in advance

[Carl-NC]

Try to zoom in on the flyback to see if it is avalanching. Here is a plot of avalanching vs non-avalanching:



Another way to tell is to vary the TX pulse width and see if it also alters the flyback peak.

[Qiaozhi]

Hi
Wonder if someone could help with a basic problem. I'm building the detector for our local heritage society (Stamford Bridge UK); I'm at Step 7 Transmit Circuit of excellent book but I'm only getting circa 50v flyback rather than 200v. I've checked resistance values, component polarities and orientation etc. Using 9" 24 turn hook up wire test coil, changing number of coil turns by 30% doesn't change flyback greatly, so suspect Q1 Mosfet is the problem or fault in board. Attached screenshot of osc reading using 10x probe, Vpp is only 60v.
Apologies in advance if I'm missing something obvious, electronics experience very rusty!
Thanks in advance

What scope are you using? It looks a software-based unit, possibly connected to a sound card?
Is it fast enough to capture the peak flyback, or maybe limiting the maximum input displayed?

[BrianBCB]

Thanks Carl and Qiaozhi for your prompt replies, As you say scope is a PC-Oscilloscope (Hantek 6022BE), it had crossed my mind that the speed may be an issue. I'm tied up today but will try to look at the avalanche later; although I suspect that the speed may also be an issue in seeing that also. I guess I could proceed with project cautiously and come back to this stage if there is an issue.
Thanks again for taking the time to reply.