IGSL

[eduardo1979]

Mr. fisherman, you are confusing the first version with the second and the third is the Minelab TX. The first version has bugs, if you read though the posts from the beginning you will notice that Ivconic has been reported that version 1 has failed and can not be taken into account

[ivconic]

And here is the second version update:

[ivconic]

Ok, let's "draw the line" here and agree on those 2 final versions!
To void further confusions i will repost again both FINAL versions. From this point we can agree on further works that Silverdog may accept to do. So Silverdog, take those 2 final versions and decide which to make.
Cheers!

[eduardo1979]

Excellent work. I think from now nobody will have more doubts. Congratulations to Ivconic.

[simonbaker]

It is interesting that minelab version has extra 7809 regulator for TX oscillator, is that crucial?

Could a single 7809 regulator be used for entire circuit?

It looks like Schottky diode would be preferred choice for D17, or maybe just leave it out?

-SB

[ivconic]

It is interesting that minelab version has extra 7809 regulator for TX oscillator, is that crucial?

Could a single 7809 regulator be used for entire circuit?

It looks like Schottky diode would be preferred choice for D17, or maybe just leave it out?

-SB

Oscillator presented there is pretty good indeed. More voltage you apply - higher the amplitude you will get.
Of course some limits must exist.
So gain of 1V more in supplying that oscillator will give us more comfort to adjust nice and stable oscillations and a bit higher amplitude than if it was supplied with 8V (in reality it is usually 7.8 - 7.9v because of the overall draw at 7808 output) .
It can be done without 7809 - of course. First i did it without 7809 and it worked just fine.
But than i think - is better to disengage oscillator from the main 7808 because some transients still can occur under certain conditions.
So what we gained here is 1V higher oscillator supply (higher amplitude too) and separate stabilization just for oscillator stage.
Diode 01 there is not necessary - i put it just to have 2 more holes on the pcb!
Of course it is there to preserve space for some experiments later too....
Also; 78L09 is quite sufficient for that role.. but than again i still put 7809, because later i could use that separated voltage (and power) for something else more....

P.S.

Right now i don't have neither one low drop regulator in my workshop, otherwise i would experiment with some higher voltages to supply oscillator. I would like to see what would be the limit for amplitude rise. For example; i would use 10V low drop... or even 11V, if i had it.
But since battery is 12V and i don't have modern low drops here - i used just 7809 for now...

[der_fisherman]

Mr. fisherman, you are confusing the first version with the second and the third is the Minelab TX. The first version has bugs, if you read though the posts from the beginning you will notice that Ivconic has been reported that version 1 has failed and can not be taken into account

I admit I am confused at this time, I am hoping it will get cleared up in the next few days.

Thanks

Andy

[ivconic]

I admit I am confused at this time, I am hoping it will get cleared up in the next few days.

Thanks

Andy

Andy no need to be confused.
All the guilt is my; because i was to lazy to update second schematic at the right time.
I posted second version of pcb without to be followed with proper schematic update. Sorry! Now all is corrected and updated.
Your job is just to choose one of those 2 versions and to make it.
Just pick which version will suit you more and inform Silverdog.

[Qiaozhi]

Your chance to vote.

As you may have noticed, I have created a poll where you can vote for either (or both) the Musketeer or TGSL version of Ivconic's IGSL design. I will leave the poll open indefinitely. Then Silverdog can decide how long to wait before placing an order for the PCBs. Please remember that Silverdog is going on holiday very soon, so be patient and don't keep pushing for a quicker response that you're going to get.

[ivconic]

As you may have noticed, I have created a poll where you can vote for either (or both) the Musketeer or TGSL version of Ivconic's IGSL design. I will leave the poll open indefinitely. Then Silverdog can decide how long to wait before placing an order for the PCBs. Please remember that Silverdog is going on holiday very soon, so be patient and don't keep pushing for a quicker response that you're going to get.

Cool!
Poll will make much easier job to Silverdog - that's for sure!
Splendid!
Cheers!

(I already voted! )

[Wiltran]

igsl2

Ivconics, I just finished tr coil 1mh, and it peaks my curiosity thicker wire for tr coil, bigger transistor thus more power for tr thus explaining better performance over TGSL! right?

[ivconic]

...

Could a single 7809 regulator be used for entire circuit?

...
-SB

I just spotted this!? Must be that i gone blind lately!?
Yes; it is good question!
But than i am not sure about swing at some opamps? 1V difference (on positive side) seems not relevant.... but!
Pity, i can't elaborate that right now (for each claim i could make right now - you would expect me to prove on examples, right?)
It's been a while since i was whole in TGSL "business" - many things i forgot!
Making IGSL i just took the good old (and many times proven) "symmetry" principle from TGS/TGSL.
Simply didn't wanted to waste time on "philosophy" and reinvent another way to supply those opamps.
Also i am sure that there is a reason for origin Tesoro decision to use such "symmetry" as +8V/-6.2V in many of their designs.
It could be much simpler, otherwise.
It is much easier simply to "split" battery voltage to half... and there you go with "symmetry"!
Just like it was done at White's Classic....
But i am afraid that TGS/TGSL and now IGSL will not work "in range" with such "symmetry"...
It is indeed very interesting question. I would like to elaborate it in details later... or on some other topic maybe...

[simonbaker]

Oscillator presented there is pretty good indeed. More voltage you apply - higher the amplitude you will get.
Of course some limits must exist.
So gain of 1V more in supplying that oscillator will give us more comfort to adjust nice and stable oscillations and a bit higher amplitude than if it was supplied with 8V (in reality it is usually 7.8 - 7.9v because of the overall draw at 7808 output) .
It can be done without 7809 - of course. First i did it without 7809 and it worked just fine.
But than i think - is better to disengage oscillator from the main 7808 because some transients still can occur under certain conditions.
So what we gained here is 1V higher oscillator supply (higher amplitude too) and separate stabilization just for oscillator stage.
Diode 01 there is not necessary - i put it just to have 2 more holes on the pcb!
Of course it is there to preserve space for some experiments later too....
Also; 78L09 is quite sufficient for that role.. but than again i still put 7809, because later i could use that separated voltage (and power) for something else more....

P.S.

Right now i don't have neither one low drop regulator in my workshop, otherwise i would experiment with some higher voltages to supply oscillator. I would like to see what would be the limit for amplitude rise. For example; i would use 10V low drop... or even 11V, if i had it.
But since battery is 12V and i don't have modern low drops here - i used just 7809 for now...

I agree, might as well have higher voltage -- and I'm thinking, why not use 7809 for whole circuit as well (less parts), but maybe that would make some levels off, so OK.

Of course, the good thing with lower voltage is battery lasts longer -- so must decide if you like more oscillator voltage, or longer battery life.

With rechargable batteries, not really an issue -- life about the same I think.

-SB

[simonbaker]

I just spotted this!? Must be that i gone blind lately!?
Yes; it is good question!
But than i am not sure about swing at some opamps? 1V difference (on positive side) seems not relevant.... but!
Pity, i can't elaborate that right now (for each claim i could make right now - you would expect me to prove on examples, right?)
It's been a while since i was whole in TGSL "business" - many things i forgot!
Making IGSL i just took the good old (and many times proven) "symmetry" principle from TGS/TGSL.
Simply didn't wanted to waste time on "philosophy" and reinvent another way to supply those opamps.
Also i am sure that there is a reason for origin Tesoro decision to use such "symmetry" as +8V/-6.2V in many of their designs.
It could be much simpler, otherwise.
It is much easier simply to "split" battery voltage to half... and there you go with "symmetry"!
Just like it was done at White's Classic....
But i am afraid that TGS/TGSL and now IGSL will not work "in range" with such "symmetry"...
It is indeed very interesting question. I would like to elaborate it in details later... or on some other topic maybe...

Yes I wonder too about symmetry and whether we can use other V+ and V- voltages -- I think it would work the same with just tiny adjustment to sensitivity circuit (or just ignore it). Maybe audio volume change slightly.

Isolation of oscillator is fair point also, although doesn't seem to be problem with TGSL.

Anyway, 7809 is small part, not expensive! I just like to ask circuit questions to learn more. Important thing is we have a PCB and lots of interest, thanks!

-SB

[ivconic]

Ivconics, I just finished tr coil 1mh, and it peaks my curiosity thicker wire for tr coil, bigger transistor thus more power for tr thus explaining better performance over TGSL! right?

TGSL could use a bit more TX power - i agree. That's why i suddenly decided to mod IGSL just few days after i made first version!
But my goal was not to gain extreme high power - but just a bit more than on TGSL, enough to experiment with "hysteresis issue" i met on previous TGSL works.
My initial motif was simple - but later turned that it will gain me more benefits than i could anticipate at the beginning!
(good things are almost always happening without direct intentions!! )
So.. along with solved previous issue - i also got adjustable TX, much more power if i need, better filtration, interesting frequency, chance to use original coils (variety of those made for Musketeer) ....etc..etc..
So... more TX power will give better performances - that's for sure.
But be careful! Do not expect miracles.
On contrary; boosting up TX to much may cause unwanted side effects.
If i remember good; Qiaozhi elaborated very nicely pro&contra of boosting TX, somewhere on these forums. Would be nice to find those posts.
Point is: there is not much benefit from boosting TX power to much - more likely it will turn contra productive.
But here, at TGSL (IGSL) all we needed was just a bit more power - not much.
TGSL already worked very well, already gained good depths.
So.. you will notice that 220 trimmer (P5). Adjust it just to get nice sinus on TX out.
It's been experienced in the past that good TX at TGSL can even produce a small "notch" on the top of the sinus, so if you want (literally) more power than on TGSL - just rise a bit more amplitude with P5 to provoke appearance of that small "notch" on the top of the sinus.
Experiment more if you want. Rise up amplitude to maximum level and check overall behavior of the GEB and Disc.
You will easily establish the right adjustment by checking those, during experimenting with P5.
All you need is some scope and .. good will!