MAGPI controller chip V1.00

[moodz]

Magpi V22 release.

After a long time in the nest ( due to slackness mostly ;-) ) the magpi egg has hatched.

Attached you will find the schema for zero point damping PI for mono with nested noise cancelling and damping loops.

The damping system uses a transimpedance amplifier as the main loop amplifier and there is no damping resistor as such ( in the conventional sense ).
The secondary nested control loop cancels noise ( eg mains 50/60 Hz and mag fields etc ).

There is also a pcb and software and I will shortly post up some sims to play with.

moodz.

MAGPI_22.pdf

[moodz]

..improved the active damping time to 1.5 microseconds.

[WM6]

.

.. the green trace is a 1 inch foil target on the coil at the o/p of the preamp.

Excellent!

[6666]

Strange, was only just thinking about this

[moodz]

...so having some time up my sleeve and having the PCBs in my desk since two years ago I assembled the MAGPI chip and all the components which are thru hole except for one SMD mosfet ( SOT223 ) and the results are quite good.




It is a mono coil Pi with 300uh coil / 0.5R and a peak flyback voltage of about 250 volts and sampling at about 3 us ... the green trace is a 1 inch foil target on the coil at the o/p of the preamp.

[liudengyuan]

hi

[moodz]

..on a drip feed due to time available. Currently rewriting code for cpu and revising pcb.

[ricalbertvig]

Hello, is this project still alive? Is there an updated pbc board and a .HEX file to program?

[moodz]

Bullet fragments ....

[simplejohn]

Hey Moods , any luck with that rock?

[waltr]

..yes .. found this on a reef at 30 cms ... strong signal from a rock composed of sedimentary with a quartz boundary in ferrous matrix. Signal is too localised on the rock for a hot rock .. or it could be a hot rock LOL.
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Crush and pan to see if there's gold in there.

[moodz]

..yes .. found this on a reef at 30 cms ... strong signal from a rock composed of sedimentary with a quartz boundary in ferrous matrix. Signal is too localised on the rock for a hot rock .. or it could be a hot rock LOL.

[6666]

Any plans to try again ?

[moodz]

...yeh drove out into the bush for 1 1/2 hours and couldn't find the battery cable when I got there. DOH ....... had to make do with a commercial detector I had in the truck. Found a small piece 0.4g ...

[6666]

I will find out how big in the bush this weekend

how did it go ?