QED

[Hussein khan]

Hi all do you have a picture of qed metal detector

[kt315]

thank you Eduardo. you keep the hand on pulse.

[eduardo1979]

https://prospectorsandminersfnq.com/products/qed-pl4-australian-made-pi-metal-detector?srsltid=AfmBOoqI_M2J6b0wxxbMBTN2PkF3w55hMsQUEW6gLAwggAQd5CLt7Qso

[Carl-NC]

QED was sold by the author to a company. so the project ripped.

So the QED is no longer being produced?

[kt315]

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[kt315]

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[kt315]

hi
QED was sold by the author to a company. so the project ripped.
i have some files in archive. but i did delete access in gmail. people are very cynical and vile, overloading my email by bare request to give GERBER files.
ok. wait and i will load all files in QED thread.

Hi kt315, do you have new latest info about QED? I want buy info

[Jumper]

***Hold in Reset mode is enabled***
Can you help me with what is causing this problem?

[ivconic]

Detecto, the private messaging system doesn't work well for me.
It is best to contact me by email: [email protected]

[detecto]

I think original schematic has some problems where V+ or V- signals of +-7.2V are connected straight to micro controller. That will damage the internal MCU circuitry for sure. All of that was because of voltage level shifting.
I made a version with STM32 controller and with new voltage level shifting with DG213 instead of original IC.

[ivconic]

It is possible.
Knowing my usual luck; probably these are pcbs with some kind of error.
I also have a couple of schematic versions.
I wouldn't know which one is correct and which one is not.
I am too tired of such jobs and have been putting off sitting down and checking the schematic and pcb properly for months.

[Mdtoday]

I do recall someone posted schematics on a site years ago and they were incomplete and from memory had mistakes.
If these boards were produced from those schematics there would be problems.
Given this is still a current commercial product, BW would be the only source of reliable info unless someone has reverse engineered.

Adding to the above, some 3 hours later, I see quite a few changes to the original, Soft power switch, Slope ADC components, snubber and display, so this is either a late version by BW and someone has copied, or reverse engineered. What is the IC in bottom left near the inductor? If it’s a Simple Switcher, then it’s close to original but I can’t tell from photo. Either way I think it’s a hybrid with authors input required….

cheers

[ivconic]

As much as I managed to understand my friend; the code in the processor is not adequate to the hardware and it happens that the dc/dc does not receive the correct signal from the processor and results in incorrect operation, which leads to burning.
Also, the other signals coming from the processor are not adequate for the hardware. There are too many problems, so we concluded that it is an inappropriate code for the given hardware.
These are slightly clearer pictures of the pcb. Maybe someone will recognize the version.

[ivconic]

[detecto]

Don't thank me because I'm not doing you any favors!
On the contrary; I can only do you harm with this!
So watch what you do!

Thank you very much for sharing this.
I am mainly interested in timing sequence.
I am working on some custom STM32F4xxx powered pulse induction detector for hobby purpose and i wanted to take this design as a reference.

I go through QED assembly code from somewhere and from what i found out is that after threshold of 0.85V is reached, comparator is triggered, time delay is measured and according to that PWM that drives audio changes frequency so that algorithm got my attention

Best regards,
Detecto