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

[Emersonpaz]

found INA125PA and LM6171BIN at Texas Instruments

[Emersonpaz]

Does anyone have stock of Ci's that they want to sell or suggest where to buy?

[Dean Sarelius]

I'm not moodz, but... we ordered them directly from TI!

Looks like TI are out of stock also..?

[Dean Sarelius]

I'm not moodz, but... we ordered them directly from TI!

Thanks KJ will give that a go..cheers

[KingJL]

Hi Moodz,
I am just ordering the parts and there seems to be a lack of stock of the INA125UA chips, tried Digikey, Mouser and Element14 but nothing..?
Would you know where I could purchase these from stock..?

I'm not moodz, but... we ordered them directly from TI!

[Dean Sarelius]

Looking at the original schematic.

Change R11 and R16 to 5.6 mH neosid or similiar inductors.
Change c9 and c16 to 10uF electrolytic.

Change R13 to 100k
Change R14 to 100k

Change C4 to 1uF
Change C5 to 1uF

Result = supersmooth audio tone :-)

Easily drives a 4 ohm speaker to 250 mW at full volume ( ... approx ) with V1.2 firmware

moodz

Hi Moodz,
I am just ordering the parts and there seems to be a lack of stock of the INA125UA chips, tried Digikey, Mouser and Element14 but nothing..?
Would you know where I could purchase these from stock..?

[moodz]

I will publish an updated schematic soon ....

Looking at the original schematic.

Change R11 and R16 to 5.6 mH neosid or similiar inductors.
Change c9 and c16 to 10uF electrolytic.

Change R13 to 100k
Change R14 to 100k

Change C4 to 1uF
Change C5 to 1uF

Result = supersmooth audio tone :-)

Easily drives a 4 ohm speaker to 250 mW at full volume ( ... approx ) with V1.2 firmware

moodz

[moodz]

UPDATE, I increased the TX time to the full 15us and the warbling has significantly reduced, sensitivity to small nuggets after tuning out ground is better now.
I will need to re-do those graphs.

Tony

I had a detector that warbled alot and another that was rock solid .... even though both had exactly the same components. After about a week of changing components in and out etc ... it turns out that there was stray capacitive coupling from the TX circuit to the linear 7805 regulator. The fix was simply soldering the tab of the 7805 to the shielding ground. This feedback was causing slight variation of the regulated 5 volts hence causing a warble as it would have been modulating the TX current.

This feedback also caused burst oscillation in the TX mosfet on turnoff .... also solved. The heatsink was orginally bolted ... hmm

moodz.

[IBGold]

Thats weird ... I checked the programmer and it was set for 250MX orginally so I sent you the 150 code incase.

However here is the 250MX firmware ....

[ATTACH]n412278[/ATTACH]

Hi Paul Bingo got it second try will keep you informed how it goes when I have leant how to drive it.

Regards, Ian.

[moodz]

I really like the sound, it's very nice. How can I modify the output filter for 64 or 16 Ohm? since most headphones have 32 ohms in each speaker (64 in series or 16 connected in parallel) tnx

Dario

I will publish an updated schematic soon ....

[moodz]

But it is the MX250F that I am trying to reprogram but I will add that to the file in case.

Regards, Ian

Thats weird ... I checked the programmer and it was set for 250MX orginally so I sent you the 150 code incase.

However here is the 250MX firmware ....

MAGPI008.X.production.V1.2_MX250.zip

[darov922]

... in the mean time here is a video of the V3 working on the bench. The foil target is varying 70 to 50 cm from the coil.

https://www.youtube.com/shorts/l1yw4BJoVeU

I really like the sound, it's very nice. How can I modify the output filter for 64 or 16 Ohm? since most headphones have 32 ohms in each speaker (64 in series or 16 connected in parallel) tnx

Dario

[IBGold]

here is a hex file for the MX150 chip.

But it is the MX250F that I am trying to reprogram but I will add that to the file in case.

Regards, Ian

[moodz]

Paul I tried reprogramming the existing 250F by hitting the program button and switching the detector on at the same time and having the detector running then hitting program and all I get is Target Device Not found (Could Not detect Target Voltage VDD) I have tried to PM you but it does not seem to be getting through to you can I give you a ring for instruction.

Regards, Ian.

here is a hex file for the MX150 chip.

[moodz]

Hi.
I ask if the MAGPI V3 can detect a gold in rocks such as quartz!!??

Sure it can if .... Quartz will not affect it.

moodz