extra depth on surf pi pro, maybe more power.

[gdogg]

hi all, im thinking about changing the parts, to say equivocate something more or less to heavy duty standards, i want to run say a 48v system (the system would consist of 4x 12v 7ah battery on a backpack) without destroying the pi, because the surf pi is a easy build more or less, i want more depth with more precision, which that may indicate a need for more power. does anyone know what parts would need to be updated, or has anyone thought about this idea before, and is the idea feasible.

Just a thought. cheers all.

by the way im all new to this so, sorry for asking a stupid question if it is.

[Silver Dollar]

Well a new patent from White's uses +- 75V so 48V should be doable. It's not as easy
as you might think (or everybody would be doing it).

If you look in the average PI unit the power supplies are kind of funny. The FET runs off
the battery but it's drive voltage doesn't. Also a + and - supply is needed for the opamps
and all these supplies need to be referenced to each other.

It would be cool to develop this and have different model depending on how far you want
to go "Super Surf 96", "Surf PI 48", "64 PI's", "Old 108" for different voltages...

[kt315]

you misleaded that 48V will give you the depth. not the voltage, but PULSE WIDTH increasing will give it. Delta Pulse is working from 150 to 500microsec PULSE WIDTH (vs 50 in surf pi). it is enough for ultradepth. while it possible to encrease PULSE WIDTH to 1000usec easely. more ultradepth = more PULSE WIDTH

[Silver Dollar]

Well there are different ways to obtain depth. Changing the pulse width will go deeper but
mainly on bigger objects. Changing the current in the coil will make a stronger field. Increasing
the voltage will increase the current. Now maybe you need 64X power to double the depth
or the huge field will magnetize the object and make it invisible but it is an avenue to explore...

I have heard of someone using 24v to good effect...

[kt315]

increasing of power suppply is effective for a case with VLF tipe of detector, not so good fo PI. for PI PULSE WIDTH is given you what you dream.
if 50us is small you guess so try encrease it to 100us. if again it is not enough so do 200. or get a huge battery and bring it like a 'power knapsack'
pickaback.

[gdogg]

well ive just tested the surf pi 1.2, ive bought voltage adjustable 6v-24v dc regulator


http://www.ebay.com.au/itm/DC-DC-Aut...9%26rkt%3D4%26

and to much of my suprise ive increased the voltage up to 16v and ive able to get another upto 5cm in depth on most objects, still playing around

ive also changed my capacitors to a higher v 35, 1000 uf, 25 v 220uf

thats right, ive regulated my 12v dc 7ah battery to 16v output. i think it will need more charging as it may drain the power more frequently.

I could go more, but im worried if i cook the board. LOL

[gdogg]

my next question is, how can i modify this pi board, to handle up to 48v dc, as there are step up regulators that can increase min to max output

[zelkos]

... how can i modify this pi board, to handle up to 48v dc...

I would left everything to 12V, with the exception of the output FET and C2.
Thus, the stabilizer 12V to the existing 12V power connector, and the source of the FET and + capacitor (1000uF / 63V) to + 48V.
Attention! 7812 not suitable for stabilization at 12V, has a lower maximum operating voltage, in fact 35V.




I'm not sure and I'm not tried! All you do is at your own risk!




Good luck!

[kt315]

my next question is, how can i modify this pi board, to handle up to 48v dc, as there are step up regulators that can increase min to max output

no chance. make something from deepers. maybe Delta Pulse.

Anatloy