Moodz' Awesome Gold Pulse Induction Version 3 - MAGPI V3 Project

[moodz]

Hi all, can someone tell me the latest thru hole pcb version for this interesting project and the latest source/firmware for the 32MX150 and/or 32MX250 ?
Thanks....... in anticipation

Post #4 for the PCB and Post #248 for the source / firmware.

[Gunghouk]

Hi all, can someone tell me the latest thru hole pcb version for this interesting project and the latest source/firmware for the 32MX150 and/or 32MX250 ?
Thanks....... in anticipation

[JoyJo]

I don't think that full-fledged discrimination is possible in pulse devices operating at the same frequency. I want to use this cascade with a swing of TX to 9V purely for searching for metal objects in depth. And for such conditions, discrimination is absolutely not necessary.

[cnckecgo]

This project interests me. I am curious about the working system, whether it discriminates or is non-discriminatory. I want to try how its performance will be in the field. I am curious about the discrimination situation.

[JoyJo]

Yes)) With P-channel mosfets, the situation is sad. But, I managed to find one suitable option.

It can even be found on sale on Ali. Yes, the quality may be poor. But, what can go wrong? Will the transistor burn out? It's not scary))) What do you think, dear Moodz, is there any sense for such a replacement?
I assumed this algorithm of operation: the main mode of operation of the metal detector with 5V power supply, but if you want to try deeper, you can turn on the "boost" mode and increase the supply voltage to 9V. Yes, this will lead to an increase in energy consumption, but for the sake of increasing the depth of the search, you can sometimes use this method.
I want to consider a similar scheme.

[moodz]

Let me ask you something. In the original scheme, the TX cascade is powered by 5V.

Does it make sense to consider increasing the power of the pulse and the detection depth by increasing the power supply to 9V. Why up to 9V? I have experience using a tank-boost converter with just such an output voltage. increasing the supply voltage to 9V should also increase the pulse power? Will it be useful? There is also a small clarification on the D3 diode. It can be replaced with an SMD variant, for example ES3D-E3/57T (200V, 3A, 30ns, 45pF).

The supply could be changed to 9 volts but in the original design the limiting factor was the P type mosfet which has a relatively low avalanche voltage. As you increase the power ( current ) in the coil the flyback voltage at TX off may cause avalanching of the TX mosfet and this will degrade the performance.

Also make sure that Q2 is not driven to avalanche or the damping loop will stop working. ( ie flyback voltage must be less than avalanche point of Q2 )

Feel free to experiment though.

D3 can be changed to SMD no problem.

[JoyJo]

Let me ask you something. In the original scheme, the TX cascade is powered by 5V.

Does it make sense to consider increasing the power of the pulse and the detection depth by increasing the power supply to 9V. Why up to 9V? I have experience using a tank-boost converter with just such an output voltage. increasing the supply voltage to 9V should also increase the pulse power? Will it be useful? There is also a small clarification on the D3 diode. It can be replaced with an SMD variant, for example ES3D-E3/57T (200V, 3A, 30ns, 45pF).

[IBGold]

err ... theres a method in the code to do it but still on to do list

Hi Paul how's the to do list and the code update going.

Regards, Ian.

[IBGold]

Hi I have been playing again and connecting VCC on the LCD to VP (4.98V) in my case works a treat full control of LCD contrast and so far no downsides.

Regards, Ian.

[moodz]

The current user set settings are not saved on turn off it reverts to default.

Regards, Ian.

err ... theres a method in the code to do it but still on to do list

[IBGold]

Hi Moodz,
Completed the mods to the code and everything appears to be working just waiting for the fet to arrive before completing the testing.
What I would like to know is if the valriables like VOL, TON, S2S etc are supposed to be saved before power cycling the detector...?
At the moment it appears that the variables always revert back to their reset values like VOL: 010 and TON: 000.

The current user set settings are not saved on turn off it reverts to default.

Regards, Ian.

[Dean Sarelius]

Hi Moodz,
Completed the mods to the code and everything appears to be working just waiting for the fet to arrive before completing the testing.
What I would like to know is if the valriables like VOL, TON, S2S etc are supposed to be saved before power cycling the detector...?
At the moment it appears that the variables always revert back to their reset values like VOL: 010 and TON: 000.

[moodz]

[Dean Sarelius]

Hi Moodz,
Just in the process of re-configuring the V1.4 firmware which I have renamed to V3.11.
Could you remind me which pins you ended up using for the Encoder..?

Hi Moodz,
No need to reply I found the declerations for the endoder...cheers

[IBGold]

Could we not just connect VCC on the LCD serial board to VP (5V) instead of VL I will try and find a VP access point and try it as with the 3.3V I also have contrast difficulties.

Regards, Ian.