GOLDSCAN 5 SCHEMATIC QUESTION

[DELAY888]

A great phrase

[ivconic]

my wife found a nice palladium ring with the tdi pro...my wife has become better than me in finding rings...maybe she got more patience than me

Patience is the key word.
We keep forgetting simple truth; it is the person who find the finds: not detector.

[daverave]

when you say about bipolar transmission similar to fisher...are you refering to the old fisher impulse or their latest AQ ???

[daverave]

my wife found a nice palladium ring with the tdi pro...my wife has become better than me in finding rings...maybe she got more patience than me

[6666]

my detector based on conventional tdi pro...i have not used a micro processor...and detector works very well on the beach and detects very tiny items...my next project will improve a bit more and lighter design.

Thanks Dave, had any good finds ?

[daverave]

my detector based on conventional tdi pro...i have not used a micro processor...and detector works very well on the beach and detects very tiny items...my next project will improve a bit more and lighter design.

[6666]

im also thinking about making another TDI this winter with a few mods to get lower noise and lighter design...without using SM components....my second TDI i made has a delay of 8 uS which has made it even more sensitive to tiny items.

Hi Dave, congrats on getting a TDI built and working, they are not an easy build, would you mind saying which timings you used ? thanks

[6666]

Of course,and now I'm drawing a TDI -SL original, I intend to draw several versions, one will be with bipolar transmission similar to fisher impulses!
otherwise on the drawing is TDI -PRO except I use my controller and little modification in the power supply and I don't use an integrated circuit for sound as with pro already from the TDA family- ....I can set different times with my controller and a frequency of 800hz to 3.3khz..I have drafts of several versions from the original to my modifications which mainly relate to noise reduction!

Hello Orbit will you be posting any information or drawings here ?

[Orbit]

This table I need to draw will be in sm components, i prefer my pcb to look smaller.like the previous two versions one I think I posted pictures and the second version in sm I did not each has some differences, and you know that little difference means a lot!

[daverave]

im also thinking about making another TDI this winter with a few mods to get lower noise and lighter design...without using SM components....my second TDI i made has a delay of 8 uS which has made it even more sensitive to tiny items.

[Orbit]

Of course,and now I'm drawing a TDI -SL original, I intend to draw several versions, one will be with bipolar transmission similar to fisher impulses!
otherwise on the drawing is TDI -PRO except I use my controller and little modification in the power supply and I don't use an integrated circuit for sound as with pro already from the TDA family- ....I can set different times with my controller and a frequency of 800hz to 3.3khz..I have drafts of several versions from the original to my modifications which mainly relate to noise reduction!

[daverave]

did you design this TDI..Orbit ???

[Orbit]

Another version of the TDI -PRO with a new controller !

[DonCaffeDelaSkobalj]

Tanks you Eric.

I hope you will be lucky with Australian rocks.

Regards
Don

[Ferric Toes]

Hello Eric

You can contact me via e-mail if you want. We can talk about new input frontend with your time-code 12-4-4-4. All your designs are very good. We could improve input stage and rx stage, while keep your original design. About Rx at nano seconds time frame,OP slew rate and settling time are two opposite stuffs. I would point out for improving settling time, because we have deal with nanosecond pulses with very sharp front and back eadges and very fast transients.

Regards
Don

Hi Don,
Thanks for your offer of private discussions. Yes, improvements can be made in many aspects of PI detectors and instrumentation. For my part, I am already working on some of them; one being my Mk2 version of the Magnetic Viscosity Meter, MVM2, which has proportional timing all the way up tp 1mS Tx pulses. With the MVM I am able to plot magnetic decay curves with great accuracy, which will be useful when improving PI detector designs for nugget hunting. I have rocks and soil from many different countries, including Australia, which incidentally, exceeds anything else I have for VRM. This and two other projects are running behind schedule for various reasons, so I must concentrate on them and hold fire on doing any additional design work. I help out where I can on forum discussions but that has to be my limit at present and for the foreseeable future.

Eric.