Double coill differential ground balance mods

[SaltyDog]

HiYa all,

Just had an idea about using the MiniPulse RevE circuit, and adding another op-amp pre-amp stage, together with a double overlapping coil + FET driver, so that it would do automatic ground balance as in the attached document.

Seems like Minipulse has a better front end than the old document circuit so might go quite well ..

What do you all think?/

I am all for keeping it simple, so if the addition of a preamp and a different coil + driver, can do away with a complicated ground balance circuit, uP based or otherwise, then I am all for it.

Seems like getting rid of the ground effect the closest to the source would be the answer to me ..

My 2c

[Carl-NC]

Sure, it'll cancel ground pretty well and even EMI. But it also gives a slightly odd target response, one coil always produces a rising signal and the other coil a falling signal. I think if you remember to always pinpoint off the rising-signal coil it won't be too bad.

[SaltyDog]

Thanks for the feedback Carl,

I will give it a try once I have built up the standard Minipulse board. If anyone has a bare RevE board, I would be interested in buying it, I will put the extra FET driver on that and the extra pre-amp stage, and then cobble it into the integrator of the main board ..

Cheers