Whites Surf PI schematic

[Qiaozhi]

hy all

can use 79l05 for icl7660?

No.
The 79L05 is a negative voltage regulator with a -5V output, and the ICL7660 is being used to convert a positive to a negative voltage.

[bebe2010]

hy all

can use 79l05 for icl7660?

[oros27]

and

[cristi71]

a minimum of 5 cm from the coil.http://www.youtube.com/watch?v=hjfbA_b14xw

[satdaveuk]

Hi
Another interesting subject although by many years not new, I recommend you get advise from Garry who ownes Chelmec electronics
He has done quite alot with etched and wired spirel coils for Pulse induction metal detectors.

Last time I spoke to him he didnt rate them at all, alot of the cheapy china detectors use or did uses this format to keep costs down , but maybe different now, worth asking him.
thread

Regards

[porkluvr]

hello all

can be made a coil pcb? some dimensions?

waiting for answers

Thank you

I don't know if this is relevant to the Surf PI schematic but I'll answer anyway.

This spiral coil would be more useful if it were compressed towards the outside. The inside diameter is almost zero (I'll say it's 0.5 inch for the sake of my calculator not liking the number zero). I used the spiral coil calculator in MiscEl and plugged in values of 0.5" for inside diameter and 11" outside diameter. The calculated inductance was only 59uH.

Keeping the 11" outside and increasing inside diameter to 7.5" would give a more useful 221uH. (Watch out for the traces being too wide and contributing excess interwinding capacitance).

Now, if you were to use two of the zero i.d. coils etched on PCB, stacked one on top of the other and wound in series, you would probably obtain almost 4x the inductance of a single coil (depending on mutual coupling). That could be useful but may be tricky to implement successfully.

[cristi71]

surely go (merge sigur)

[bebe2010]

hello all

can be made a coil pcb? some dimensions?



waiting for answers

Thank you

[cristi71]

with strange noises bc337 audio. put 2x BC547 in Darlington configuration and will go well. (in the absence of MPSA13) Regards, Cristi.

[yhl]

Thank you and I think Gary and the maximum distance is the same.
However, sensitive to small things. Gary is not sensitive.
SURF PI can be used to locate and search for a small coil of small objects.
Gary PI / bigger objects can be detected with a large coil.

[WM6]

SURF PI I have build up.
Today, the actual use, the effect is still good, but full of nails, depth can be. Is not discriminatory. To find a few ancient coins.

Good work yhl. You are young, you do not need discrimination, you can easily dig 100 hole per day, which is only way to your gold treasure and well build musculature.

[yhl]

SURF PI test

SURF PI I have build up.
Today, the actual use, the effect is still good, but full of nails, depth can be. Is not discriminatory. To find a few ancient coins.

[DIRCEU]

Surf Long PCB Single Side

Hi! All

[Qiaozhi]

Hi! Amtech and Qiaozhi

Many thanks.

OK! But in "preview Post" the PCB is very large. May be need resise it. How???

Regards

Dirceu

Hello . Should be around 600 by 600 dpi ? or you can convert to a zip-file like Qiaozhi suggested or e-mail me and I will post it to correct dimensions .
I will be on the forum here all day working on "Lobo" mess.

Again , do not be afraid to ask Qiaozhi [administrator] he is very helpful !!!

Best Regards..........Eugene

If you find it's not possible to reduce the file size, then WINRAR can compress it over multiple RAR files. This will allow you to post them here.

[amtech2005]

Hello . Should be around 600 by 600 dpi ? or you can convert to a zip-file like Qiaozhi suggested or e-mail me and I will post it to correct dimensions .
I will be on the forum here all day working on "Lobo" mess.

Again , do not be afraid to ask Qiaozhi [administrator] he is very helpful !!!

Best Regards..........Eugene