Ideal PI coil current

[CAS]

I am working on a CCPI circuit but just want people who have a little more experience with MD circuits as to put forward their ideas what the 'ideal' coil current should be.

I have been setting it around 1.8A at the moment, but if it doesn't need to be that high I can have a lot shorter pulse widths and will get better battery life.

[Silver Dollar]

Not sure anybody knows the answer to this. To build a bigger field and thus go deeper you
want the biggest current you can manage. A large field can magnetize particles in the ground
so that you cannot see as deeply.

[CAS]

I figured as much. Do you know what current model PI machines run, ignoring pulse shape, width etc? ie ML machines vs Whites etc?
Would using a lower current, even though depth may be sacrificed a little, be better for use in highly mineralised ground?
Perhaps it may be useful to allow the value of the CC to be adjusted to allow for different ground conditions?

[Silver Dollar]

No idea what current models run. The limiting factor to me is how deep do you want to dig.
(And what size object do you want to see how deep?)

On a beach looking for gold necklaces you might use 5 amp pulses (very short pulse) but
in other places you might want to turn it down to 1/2 amp to see more clearly. The big problem
is how to set it up in the field?

So a variable setting would be useful and max power is as much as you can give for a reasonable
run time without anything overheating...

[Carl-NC]

I recall the TDI runs around 2A, Minelab may run a little higher.

[CAS]

Thanks for the replies. I think I am going to experiment with a variable CC circuit and see what the 'real world' results are. I have access to some light weight battery packs that come in various voltages (used in some of the items I repair) that will allow me to move away from the 'standard' 12v battery pack I seem to see in most MD circuits. I am just waiting for some soic to dil adapters to arrive so I can use some ic's I have in a breadboard for testing.