complete project

[mschmahl]

The tinkerer_sb is working. After rewound my RX-coil all is better now.
Here are some clip´s.
The paper-roll in the mid of the coil is 30 cm long. All is done without the BU controll connected. It is not easy to find the point, where i get the tinkerer_sb working and with switching off and than on i have to find this point again.
But when it is working, it is very nice.
For silver, cooper, gold the tone goes higher. For iron and steel the tone goes deeper or get away.
Sorry for the bad quality of this clip´s. You have to turn up the volume full.

[mschmahl]

Hello Tinkerer,
now i have some new fet´s, so i can test the Tinkerer_SB more. My TX-Board look´s good only the flyback-voltage is a bit weak, about 330 V. This could be better with the new timing.
Can i get the original-file for the Pic?
Thank´s a lot.

[Tinkerer]

Tinkerer

I haven't even had a chance to study all the schematics yet, what do you need written for the pic? If I have a chance this weekend I can maybe thrash something out.

Charles

Charles, thank you for the offer.
The code for the TINKERERS_SB, is just a simple timing sequence for the TX pulse and 2 sample pulses.
To avoid the problem at switch ON, we need to add a delay of about 100ms, initially, to give the storage capacitors the time to charge fully.
I can send you my asm file by email, to change, or you could just write a whole new one.

There are of course many more features we could implement with the PIC16F690, it is just a matter of writing the code and add the hardware to the simple basic circuit.

Thanks for the help.

Tinkerer

[charleskerr]

Tinkerer

I haven't even had a chance to study all the schematics yet, what do you need written for the pic? If I have a chance this weekend I can maybe thrash something out.

Charles

[Tinkerer]

There is less current and less flyback, because of the higher resistance of the 6n60. If you have no oscillations during the rest of the cycle, it is OK to uses it as is. You can test the rest of the circuit now and change the Mosfet at a later time.

I will try to change the PIC code to add an initial delay of 100ms, before starting the TX cycles, but I have no way to test the code. Maybe somebody is willing to write some code for the PIC 16F690????????????

[mschmahl]

Hello Tinkerer.
I have soldered the 18nm80 in and short circuited Pin 2+3 by my clumsiness. Now it is dead. So i have use the 6n60 again.
Here are some pictures. It is the TX-Controll-window (5V/div) and the flyback (50V/div) in 2us/div. They look´s better than the pictures from 18nm80. First picture is with 10nF Flyback-Cap. Second is with 20 nF. The flyback is reduced with the 20 nF cap for 75 V. I think, that is not so good.

[Tinkerer]

Hi Tinkerer

Great! would it be possible to get a summary of the designs done so far and the sections done. I need to get an idea of where to start.
Basically a project roadmap.
BTW, any luck with your drive, in the last month I had 2 terabyte drives I bought just over a year ago (just out of warranty) doing the click dance.
All my data from the past 20 years is on them!!

Cheers
Charles

Here we are talking about the TINKERERS_SIMPLE_BASIC_MOTION (TINKERERS_SB_MO) design and the TINKERERS_SIMPLE_BASIC_NON-MOTION (TINKERERS_SB_NM).

The PSU is reduced to an absolute minimum for the sake of simplifying the design.

This simplified design uses only 2 samples, but a more complete design for version 2 will use several samples and DSP for GB etc.

These are simplified designs, mainly with the purpose to give people the opportunity to see the advantages and possible disadvantages of this method.

Although the TINKERERS TX waveform, at first sight, looks somewhat similar to the one of a traditional PI, it is actually very different.
There is high current running in the TX coil at all times. We can also sample the RX at all times.
The current remains in a resonant tank and therefore the power consumption is very low, relative to the high current of the TX transient.

The TX is bi-polar.

The combination of the very high power TX and the very high pulse repetition rate (PRR) give a good S/N and very good depth and sensitivity.

The downside is that all sorts of problems may still turn up, as seen above.

I have built some prototypes but not really field tested them.

Another problem is that my programming skills are about nil.

Any help is much appreciated.

Tinkerer

[Tinkerer]

Hi Tinkerer
If you still got problems recovering imformation from your hard drive I have a advanced industrial recovery tool that may well do the job.
Im not offering it as a open give away as I use it for work and it was very exspensive but if you want a copy and promise not to distribute it your welcome, just drop me a email.

Will be starting your project here really soon just need to finsh refitting the office so I have more room in the workshop because both are like a tip at the moment.

Warm regards

Thank you for the interest and the offer. I have packed and shipped the hard drive, together with half my electronics lab. In about 6 weeks I will unpack in my new home. At that time I will be very glad to accept your kind offer.

[Tinkerer]

The problem with the TX could be:

We reduce the inrush current into the capacitors C13, C14, with R2, therefore we delay the capacitors from reaching their full voltage.
Switching the TX pulses on immediately, with a source that has a relative high internal resistance, does then not let the voltage reach full level for some time.

An initial delay in the timer will probably fix that.
An alternative solution would be to add a second switch to switch on the PIC timer after the rest of the circuit is powered up.

Tinkerer

I simulated the delay. About 100ms should be fine. Got to change the PIC code for that now.

The simulation is really quite useful. Many things are so much easier to observe on the simulation than on the scope. I first made the real circuit, then tried to make a simulation that reproduces the results of the real circuit. The problem above, occurred because of subsequent changes, to improve details. It clearly shows that any change, anywhere in a circuit, causes possibly many subtle changes somewhere else in the circuit.

The more people tinkering with the design, the sooner we will have uncovered all possible problems.

Tinkerer

[satdaveuk]

Advanced hard drive recovery

Hi Tinkerer
If you still got problems recovering imformation from your hard drive I have a advanced industrial recovery tool that may well do the job.
Im not offering it as a open give away as I use it for work and it was very exspensive but if you want a copy and promise not to distribute it your welcome, just drop me a email.

Will be starting your project here really soon just need to finsh refitting the office so I have more room in the workshop because both are like a tip at the moment.

Warm regards

[charleskerr]

Hi Tinkerer

Great! would it be possible to get a summary of the designs done so far and the sections done. I need to get an idea of where to start.
Basically a project roadmap.
BTW, any luck with your drive, in the last month I had 2 terabyte drives I bought just over a year ago (just out of warranty) doing the click dance.
All my data from the past 20 years is on them!!

Cheers
Charles

[Tinkerer]

The problem with the TX could be:

We reduce the inrush current into the capacitors C13, C14, with R2, therefore we delay the capacitors from reaching their full voltage.
Switching the TX pulses on immediately, with a source that has a relative high internal resistance, does then not let the voltage reach full level for some time.

An initial delay in the timer will probably fix that.
An alternative solution would be to add a second switch to switch on the PIC timer after the rest of the circuit is powered up.

Tinkerer

[Tinkerer]

Hi All
I've been following this thread off and on. Looks very interesting. I'm an electronics design engineer designing smd boards and use mainly pic processors, my design skills are a lot stronger than my programming skills. I have built silverdogs pi and but lost interest a while ago. I would be interested in doing an smd version of this board. Could someone please just summerise this design with a block diagram and post the pro's, con's and features. I think quite a few would be helped with this information. (How well would this work in water being a hybrid design)
Regards
Charles

Charles,

your help will be most welcome.
For use in the water the non motion version might be better, but you could also try the motion version, changing the "Motion filter" for slower sweep speed.

If you want to get deeper involved, we could work on version 2, with a few improvements.
Also some programming help would be very welcome. I suggest we still keep the designs very simple, good for beginners. Later we can look at version 3, a bit more sophisticated, with full GB.

All the best

Tinkerer

[mschmahl]

@tinkerer
The first and the second picture are the same. Only the first with 2uS/div and the second with 10uS/div. It is done with the STW18nm80 but wired with cable clamp. I think too, that the current is to weak. What batteries did you use in your rig? Is there a possibility to check the current from this 2 capacitors? I have 2x 2200uF not 2x 4700uF how it is in the spice-simulation.
Thank´s a lot.

@charlesker
This design cries for a smd board especially the RX-Part. It would be very nice.
The Pro´s for me are: deep seeing with good sensitivity for small part´s and a possibility to distinguish between ferrous and non-ferrous.

[charleskerr]

Hi All
I've been following this thread off and on. Looks very interesting. I'm an electronics design engineer designing smd boards and use mainly pic processors, my design skills are a lot stronger than my programming skills. I have built silverdogs pi and but lost interest a while ago. I would be interested in doing an smd version of this board. Could someone please just summerise this design with a block diagram and post the pro's, con's and features. I think quite a few would be helped with this information. (How well would this work in water being a hybrid design)
Regards
Charles