Work continues on the Metal Detector apace…Before I continue installing the controls to the electronics enclosure, I have temporarily assembled the work so far so as to give a progress report…With illustrations…
The first panel consists of the potentiometer which will adjust sensitivity. It just requires calibration. I had already secured the circuit board inside the enclosure…
At the other end of the enclosure is panel number two, and it contains the red and blue input sockets from the search coil, and single power socket that will provide the supply. I’ve kept the battery separate from the enclosure until I can determine how long the battery will last under normal conditions, I might then provide a more permanent site. It’s also a good idea to keep batteries separate if the unit will not be used for long periods of time, if the battery deteriorates and leaks, It will corrode the terminals…
Other Jobs to be continued…
A further panel will house the on/off switch, and a stereo output socket for the attachment of headphones. The top of the enclosure will house the small speaker.
A method of clamping the enclosure to the shaft of detector will have to be designed and fixed.
Thanks JB…
Yes size is something that should be kept to a minimum for a tidier job and ease of handling. After everything has been fitted and tested, I’ll tart it up a bit…
Today’s delivery arrived as expected and consisted of plugs and sockets. I always order more than I’ll need and put some into stock. I did make a mistake with ordering, I ordered 3.5 mm mono audio sockets, and for headphones they should be stereo ones… They are the little square ones top left…
On the subject of Oscilloscopes, this was a duel oscillator producing a pair of sine wave outputs, it also has ‘Steam’ (white noise generator) for producing a steam train whistle, but it will do much more. It was a test circuit I built many years ago for inclusion into a proposed synthesiser. The beauty of these oscillators is that they can be mixed together to produce a ‘Polyphonic’ instrument…(It can play chords)…Somehow I got sidetracked… Perhaps one day…
I don’t recognise any of that kit except the moving needle meter.
Your enclosure looks very neat.
The purpose built oscillator looks fascinating.
We had a whole design department that would produce drawings for something like that, then another department would make it.
We used all sorts of instrumentation connectors from single pin to about 200 pin plug and socket affairs.
When ordering parts it always seemed to me that the smaller the component, the longer the part number.
I’m guessing that somehow you will be able to set up and calibrate the system to discriminate between different types of metal.
My Dad used to be able to work out what some objects were by the sound they made when he went metal detecting.
Blip-blip was an upturned bottle cap, bzt, was a coin on edge, buzz was a coin lying flat, bzt-buzz was a ring pull (not so prevelant now). Something with a high iron content would be louder because it was more dense than aluminium or coins.
Most of the equipment is continuity testers and signal injectors Fruitcake.
The analogue meter is a home rolled battery tester with a facility for testing NPN and PNP transistors. It can also calibrate high voltage output (low current) up to and including 20,000 volts when working with spark generators.
The traffic lights is just a project that interested me at the time…
The project on the left of picture is a homemade light beam based on a laser, I was going to set it up across the drive but was disappointed with the results so I intend to turn it into something else. The drive is now protected by a PIR.
I’m not sure if the metal detector will discriminate until I have tested it in the field…:-p
Thanks Minx…
There is a way to go yet, and I might have a few weight saving ideas later. First I must make sure it will do everything I expect it to do. sometimes I seem to spend more time organising and tidying the workshop than I do building anything…
Yes, makes sense, I’m always thinking with the end in mind. Nice to see the steps in between as well.
Well it looks very tidy. One can’t work in a mess. I often feels it’s an outward reflection of your mind and thoughts.
Really impressed hey.
Over the last couple of days I’ve been designing a way of fixing the control box containing the electronics to the shaft of the detector. It had to clamp to the shaft in any position ( depending on the height of the user) And it couldn’t be slid onto the shaft from the top due to the handle. So I came up with this…
If you find it doesn’t do want you want it to - you could always sell it to the Tate as a modern art installation. It is much more attractive than some of the stuff in there.
Since you mention it, It might not get used to it’s full potential. Obviously I’ll give it a go on a beach somewhere or a discrete patch of promising land (not the ‘promised’ land I hasten to add :-D) but for me, it’s mostly in the design and build…
They are the little square ones top left…
Perhaps one day…
