Foxy's Latest Project

Hobbies & Pastimes Hobbies & Pastimes: Chat / Discussions
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I was that soldier Spitty (to coin a phrase)…
I used to arrive home from work and there would be a telly or radio on the step for me to repair…I would accept the folding stuff or a packet of fags for my trouble though…
In the end I was spending all my free time mending stuff instead of inventing stuff, so I packed it in…Now I can build what I like because I don’t do digital (computers and such) and when it’s broke today, it usually stays broke…:frowning:

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You’re a star Besoeker…:wink: I’ve always thought that you and me had a lot to talk about…:smiley:

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Right! On with the show…
There was this drawing on the net that appears to offer a much better version of a metal detector, and that will be the basis for this project. Because the circuit uses a different approach to the BFO detectors I have built in the past (even the ones that worked…:-D) it also uses a couple of IC’s (Integrated Circuits) which will probably make it easier to construct and less chance of errors.
I have posted the drawing on it’s side to get it all in without screwing it up and making it unreadable. It will probably be quite familiar to Besoeker…:wink: Enjoy…:smiley:

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Well done Bob, so you’re not just a pretty pair of fast legs.;-):slight_smile:

Enjoy doing it and the best of luck, who knows there might be gold in them thar Yorkshire hills.;-):slight_smile:

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Spookily!:smiley:

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I laughed and laughed at The Detectorists but I still wonder how many of those holes it took to fill the Albert Hall.

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Wishing you success with the project OGF. :slight_smile:

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Matchsticks … and I’ll challenge you in a game of cribbage.

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That circuit board looks fab foxy. :023:

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Too complex for me Bob, I’m pretty handy at most things but electronics really are the black art. Good luck with the project though, and I look
forward to seeing the finished product. :smiley:

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Transistors work with electrons and holes. The unused holes on the board are spares. :wink:

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Perhaps Harbal’s post was tongue in cheek? :wink:

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I think so. Mine too. :slight_smile:

Edit: Sorry, it was a technical joke…

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I’ve been looking at the circuit. Which/where is the part that runs over the ground and does the metal sensing? I see there is a vertical dotted line down the circuit. Is it that the detecting end of things? What is the block (IC?) on the left?

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Thanks Jem, I don’t know if I’ll ever getting out detecting, the enjoyment is more in the journey than the destination…:wink:
I’ve always got me legs to fall back on if it doesn’t work…:smiley:

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I’m not sure if I will ever get out detecting Bruce, but if I do it would be great to come to Australia where all the professionals hang out…:cool:
One of my favourite Beatles songs by the way …:smiley:

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Thanks Mart…Appreciate the support…:023:

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Wait until you see ‘Mark 2’ d00d, and this time it might even work.
I’ll keep Mark 1 and keep coming back to it in an attempt to get it working, I’m nothing if not persistent!..And It’s not over until the fat lady sings…:wink:

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Thanks Barry, I’ll keep looking in with a report of my progress…:wink:

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Yes sorry Mart, I forgot to label ‘IC 1’…And the detecting end of things is the coil marked ‘L1’ next to the diode…
The dotted grey line separates the first stage from the second stage. The first stage is an oscillator based on a 555 timer chip and sets up a pulse frequency that is sent into the ground through the coil L1. When the pulse returns it is collected in the coil as a magnetic disturbance created by any metal it has come into contact with below ground. The magnetic disturbance is separated by the MOSFET and passed on to IC2 which is an operational amplifier which also acts as a comparator and sends the signal on to a final stage of amplification provided by Q3, which can be heard in the speaker…