Mosfet switching time

[PierreJ]

I was making multiple pulse induction circuits using IRF9630 p-channel mosfet but the range is very low (couple of centimeters for 10*10*10 cm hollow iron cubes), even after trying multiple coil designs and 3S lithium batteries
I suspect the problem is that the mosfet doesn't cut the current...

[Tripalium44]

Hello,

I'm making my first detector, a surf pi. I took the pcb from pcbway. I am a total beginner in electronics.
I have a problem with my R25 resistor, it doesn't seem to be connected to anything...
I also have holes where nothing is indicated, do I need to make bridges? Where...

[bishop_slayer]

Hi, I am planning to build a mono coil for a surf PI that has a diameter of around 10 inches. Are there any key factors that influence the depth? I am aiming for a coil inductance of around 400uH. Should I try and maximise or minimise the coil resistance? i.e. should I use thin or thick enamelled wire?...

[Haabe]

Hi all, i'm going to try to build a detector with the SilverDog Surf PI kit. (I couldnt see a section of the forums dedicated to this type of board or 'project builds' so i've posted here, please inform me if it's wrong and where it should go - i will deleted this and repost elsewhere if needed)....

[Polymer]

I am getting my Surf PI ready for testing with oscilloscope in the sea to see what happens when dunked.

I had adjusted the null a while back with a multimeter when I had no oscilloscope.

Now looking at the trace of Pin 6 I saw that the null is below zero by a whopping 320mV....

[Polymer]

Yes, I have a new toy now (oscilloscope) measuring all kinds of stuff on the Surf PI.

I can now see what happens when battery voltage drops from nominal.

Gosh, was I in for a surprise. Quite a lot changes when that happens.

Would it make sense to have more stable...

[Polymer]

I've had my oscilloscope for a week now and have been looking at many curves on the Surf PI 1.2
and trying to make sense out of what I'm seeing.

In this case I'm looking at the sample width (Pin 3 U4), which seems to be around 40us.
A lot of that covers the flat part of the...

[geoscash1]

I'm looking to sell this board to fund a personal project I'm currently working on. Its an sm pro surf pi, complete. It was purchased from
one of the vendors on ebay last may as a completed board. It will come with on/off switch wired, pots wired, 5.5x2.1mm DC jack wired and
headphone...

[Matt_Rowe]

Does anyone know what and if there is a difference between the SM Pro PI diy metal detector and the surf pi or the hammerhead, or anything else it might be related to.
And, is it a decent diy Md.
I also own a Whites Goldmaster V/Sat.
Would any of these diy pi setups work better than...

[chiuino]

Hi there!!!
I have read this post http://www.geotech1.com/forums/showt...314#post129314
Tepco wrote:
My detector is not exactly Surf, but similar, just works whit different timing. I believe this component values will be good for Surf and mod's will work on different boards and...

[Garagescience]

Wanted to get the inductance right, and know I can make a simple wound coil of magnet wire for a search coil using the coil calculators, but I want to wrap around a soft iron ferrite rod. Is there a different calculation for that? Could I just use a couple fixed inductors at the right total inductance...

[bernte_one]

hello

for a new project i want to try i´m looking for a smd longboard version
of the surf pi or the surf pi pro
the layout should be single sided if it has some bridges no problem
and so small if possible

for a tested layout in sprint-layout or eagle format...

[Garagescience]

As my soldering skills are (ahem) lacking, anyone got a completed Surf Pi kit they are no longer using? If not, anybody got a coil (hopefully waterproof and working) that would work well with a Surf Pi? Willing to pay a reasonable price for one or both.

Any help for a newbie would be...

[Garagescience]

First off, thank you for this forum, and the volunteers and others who make it possible!

Next: I'm an absolute beginner, so be gentle!

I'm looking into getting a Surf Pi from Silverdog.co.uk as my first kit. Doing this as it looks easy enough for my soldering ability, and...

[bravodenisu]

I made this beautiful Metal detector and I am very satisfied with it.
He made some changes that have given better results for metal products.
He completed so I made some footage that you can see how it goes and what I am all has changed in Detector .

http://www.youtu...

[Freediver]

Hi all,

I just finished a Surf Pi (my first detector project), that I bought from Silverdog's shop and when testing it in air I have found that I get a consistently strong tone from 0 cm to about 15.5 or 16 cms with a 1 euro coin. Between 16 and 17 cm I get a weak tone and after 17cm...