TL12000

[GeoMax]

Hi Roshik,

The TL1200x circuit I drew also has an op-amp as a buffer circuit. This consists of the second half of the LM358N op-amp.

What actually do you want to "auto-tune" in this circuit? Or do you mean that the TL12000 circuit is drifting away and you always need to re-adjust the threshold?

[roshik]

In this metal detector, if the parts used are of poor quality, usually due to changes in the ambient temperature, etc., we need to adjust the threshold, which is not what I mean.
But if for any reason we want to change the "pulse sample delay time" according to our needs, we need to adjust the balance again, for example, when changing the loops in different sizes or using the selector key for selection modes(all metal or gold position...)in choosing the delay time in the sample pulses, which I mean the regulation of these situations.

[GeoMax]

Hi roshik,

I am curious... where do you see the "....selector key for selection modes(all metal or gold position...)" in the schematic? I do not see any "all metal/gold switch" in the whole schematic. Are you maybe refering to the sample delay rotary switch? Because this is not an "All Metall/Gold switch" like you might think of. And what "balance" are you need to re-adjust? What poti are you using to re-adjust the "balance"?

[haylaz0036]

I found something called Sx500, it looks very similar to TL12000.

[haylaz0036]

And I don't know this working pcb I'm a newbie

[haylaz0036]

And this is what I found on the new Internet

[haylaz0036]

This card is on sale in Iran for TL12000

[roshik]

Hi roshik,

I am curious... where do you see the "....selector key for selection modes(all metal or gold position...)" in the schematic? I do not see any "all metal/gold switch" in the whole schematic. Are you maybe refering to the sample delay rotary switch? Because this is not an "All Metall/Gold switch" like you might think of. And what "balance" are you need to re-adjust? What poti are you using to re-adjust the "balance"?

Yes, exactly, I mean the sample delay rotary switch.
The delay time of the sample can be customized
It was considered as possible
It discriminat between magnetic and non-magnetic metals, although in this case about twenty percent of the power of the metal detector is reduced.
If we can remove the tune volume and use a push button key, it will be easier to use.
For this, we should take a sample voltage from the output part of the 358 opamp(or The collector of the positive transistor)and give the corresponding voltage to its input.
Actually, we need a feedback circuit.
The problem is that the release the key,
the voltage applied to the input
358 should be preserved and not changed.

[haylaz0036]

This friend made the working pcb, it works now, I will do it just so I don't make any mistakes.

[haylaz0036]

This is me

[Asanka Sanjeewa]

This is a very good metal detector but due to some weaknesses in the circuit diagram it does not properly. I have made TL12000 MD several times for friends. Insulates iron objects very well [ on the conductivity of target object]. I hope to present the circuit diagram and PCB that i have modified in the future for the benefit of everyone on this forum.

[GeoMax]

This is a very good metal detector but due to some weaknesses in the circuit diagram it does not properly. I have made TL12000 MD several times for friends. Insulates iron objects very well [ on the conductivity of target object]. I hope to present the circuit diagram and PCB that i have modified in the future for the benefit of everyone on this forum.

Hi Asanka Sanjeewa,

can you post your schematic diagram here in the forum? And maybe some pictures of your detector?

[Asanka Sanjeewa]

Hi Geo Max
I will certainly help. I have made these amendments to the old board. Give me about a week to send the revised circuit diagram and printed board to the forum.

[Asanka Sanjeewa]

This is my old TL12000 Board [ this forum published board ] . It works but can't iron rejection.

[Detectorist#1]

Hi Asanka,
One week is not so much time for waiting of the schematics of PI MD with good iron rejection.