XP Deus 2 Transmit frequencies

[Skippy]

I agree, Marchel needs his own thread dedicated to his own project ....
For interest, the FMF coils have already been opened up, the board is near identical to the HF coils for the Deus1. My guess is XP were developing the D2 coils, and realised they could make a dedicated single-frequency version that's D1 compatible - and the HF was 'born'.

[Skippy]

If you were wanting to dispense with the opamp I-to-V converter, and just 'near-short' the coil, I suggest a 'load' resistor for current sensing that has a resistance 1/3rd (one third) that of the pickup coil.
And yes, Altra, the ToneOhm is a good tool, I have one .. I haven't used it in a while, though.

[Riss]

Hi Riss, I think you are confused. This is a non contact, transformer-less oscilloscope probe. It's for relative visualization of the coil current. Carl posted the idea above, which I have never seen before. Maybe he can explain it. All I know is it works!

Hi Altra , I understood , that you are confused that I am confused .I know the scheme Current probe sch.pdf from kindergarten 2 years ago I made a "field meter", it has several sizes of "voltage" coils and one "current" one - a coil of 4 mm copper wire closed through 1 winding of the primary winding on current transformer( isn't it the same ? – a closed current loop of 4 mm copper wire passed through a toroid -White's TM808 Euro) if anyone is interested, I will take pictures of the circuit, coils, appearance. It is primitive, but it works for me to measure the energy and field configuration in the near and far zone (more than 1 meter).

[Altra]

Yes I understand the closed loop current transformer. I normally use a series resistor with the tx coil to monitor the current. The op amp c to v circuit is good for testing when you cannot insert a xformer or resistor. Post some pictures of your sensors,

[Mark-VA]

yes, please post

[Riss]

And I really like a series resistor 0.05 to no more than 0.33 ohms to see the current. I will take the pictures of the "field meter" soon. but don't laugh at my design... Mark-VA - now it's sunrise for me, the air is scented with linden trees , I have a lot of tasks waiting for me. I will take the pictures in a few days

[Marchel]

I haven't found any photos of the open coil for the XP Deus 2 anywhere yet, but I'm sure that the new Deus uses STM32 instead of PIC24 processors. I will finish the last version of the PCB and create a new thread for my project and hopefully together we will work towards the first freely available multi-frequency metal detector :-)

[Mark-VA]

There will be no laughter on my side

[moodz]

Hi Riss, I think you are confused. This is a non contact, transformer-less oscilloscope probe. It's for relative visualization of the coil current. Carl posted the idea above, which I have never seen before. Maybe he can explain it. All I know is it works!

Just having the inductor for the sensor by itself will distort the flat frequency response if the TIA.The input impedance must be loaded up to preserve low frequency response. Eg for 20 hz to 150 khz see below ...

[Altra]

Thanks that's some good information. When I get some time, I try your circuit.

[Carl-NC]

Just having the inductor for the sensor by itself will distort the flat frequency response if the TIA.The input impedance must be loaded up to preserve low frequency response. Eg for 20 hz to 150 khz see below ...

For detector fields you don't need to go that low. Here is the (more) complete circuitry for my field probe:


For the sensor, I use a Wurth 7447480331 which has L = 330uH and R = 0.3Ω, or a tau of 1100us. This is plenty low enough (145Hz) for detectors. Here is the measured field for a Vanquish 540:



The slight bowing you see in the B-field waveform is due to the resistance of the Vanquish's TX coil, which has a tau of 260us.

ITMD-3 Appendix A will give all the details for this probe. Soon.

[Riss]

Excellent I don't have an operational amplifier with such datasheet . it's a real beast,

[Riss]

ok

[Riss]

My project is based on the STM32H7 processor and, unlike the XP Deus, does not have an external ADC but uses an internal 16bit ADC. Here are my final PCBs which still contain small errors. I am testing the project on the original coil X35 22cm, if anyone is interested in working together on this project, we can create a special contribution on this forum.

Marchel , you probably you understand from software - are you good at programming? how many years of experience do you have with detectors - in the field?

[Marchel]

Marchel , you probably you understand from software - are you good at programming? how many years of experience do you have with detectors - in the field?

I'm not that good at programming because I'm just self-taught, but I've been working with metal detectors for about 15 years.