HV temporal sampling ?

[boilcoil]

That will work ...

OK, thanks,
When I have more free time, I can try it.

[Detectorist#1]

This is the timing of old good SD 2000 Minelab MD. Now is 21-st century! Let to try to do some new in this area!

[Detectorist#1]

Hi boilcoil,
It will be useful information how to implement in PI MD active samples for more real Fe/non-Fe discrimination. Maybe the samples during TX-ON pulse will be more useful for this discrimination. But in this case, I have a question - how to do ground balance in this case. Any MD without GB is not very useful in real searching. The voltage on the RX DD coil during TX pulse is very strong (linearly increasing voltage during all TX pulse if not exist saturation). In ITMD3 I haven't find the answer for this. Maybe it this case, the help of Carl will be useful for us.

[Op04]

One more thing to think is why ML put 240V fet on their gpz because in that case coil discharge current is lower vs if we put 500V fet

[Detectorist#1]

Hi Op04,
To answer your question, we need exact schematics of the TX part of the ML GPZ solution (if that's not secret yet).

[Op04]

Hi Op04,
To answer your question, we need exact schematics of the TX part of the ML GPZ solution (if that's not secret yet).

Unfortunately I don’t have it, I saw that fet on gpz board

[Detectorist#1]

Explanation for how ML GPZ idea works in the patent is too complicate and not clear to be useful for design of the TX part of GPZ7000.

[Op04]

Must check old post by Kev, daemon, bklein

[Detectorist#1]

Yes, I have some little parts of information - but not from sure sources. Last week I read post for end stage of GPZ TX stage and in this post was mentioned half-bridge end TX stage but without serious information.

[NigelLeeming]

After my last post about my sample time of 40microseconds, I began to look at a function called adc_continuous on the ESP32 in the hope of bringing forward sampling time and getting a few more readings per pulse. I'm pleased to report some progress despite adc_continuous's attempts to overload the few working brain cells I have left. Here is a sine wave from one adc input and the response from a square wave pulse of 100microseconds. I'm currently asking it to sample at 40kHz but I only get 2 maxed out data points where the pulse it, which makes me think it's a bit slower. The documentation says it samples up to 1MHz or so, which I'll believe when I see it.