GOLDSCAN 5 SCHEMATIC QUESTION

[dbanner]

By the way, is the sd200 schematic(the front end) accurate?

[daverave]

does anyone know the setting up for the GS 5 ??

[Idefix]

By the way, is the sd200 schematic(the front end) accurate?

Hi,
Looking at this schematic : it is made for a 2 coils detector. The MOS in this part are small current devices, and their gate control needs additional circuitry.
And , LM394 is very good matched pair , but it is now not available . (May be THAT300 is a good remplacement.)
I think there is easier way to improve the front end of the GS5. Was it the goal while asking this question?

[dbanner]

does anyone know the setting up for the GS 5 ??

Check out the first page, it has the timings setup, i guess you need scope to do this?

[dbanner]

Hi,
Looking at this schematic : it is made for a 2 coils detector. The MOS in this part are small current devices, and their gate control needs additional circuitry.
And , LM394 is very good matched pair , but it is now not available . (May be THAT300 is a good remplacement.)
I think there is easier way to improve the front end of the GS5. Was it the goal while asking this question?

I was looking at possible modifications to GS5. But I like the sd2000 audio circuit. LM394 is no problem. Suitable replacement can be found.

[Geo]

Check out the first page, it has the timings setup, i guess you need scope to do this?

As i know TDI and TDI pro have the same schematic.
So the timing schematic is wrong. TDI don't use 4538 for timing but a uc (ATINY).
However i want to believe that the times of GS5 and TDI are the same.

[Altra]

As i know TDI and TDI pro have the same schematic.
So the timing schematic is wrong. TDI don't use 4538 for timing but a uc (ATINY).
However i want to believe that the times of GS5 and TDI are the same.

Hi Geo,

The first TDI's used 4538's, and later switched to a microcontroller. Some where on one of the forums Reg or Carl mention that there was a first run of TDI's with through hole components and not smd. I recall it was less than a 100 units.

Here is a photo of a proto type just like the one I have

[dbanner]

As i know TDI and TDI pro have the same schematic.
So the timing schematic is wrong. TDI don't use 4538 for timing but a uc (ATINY).
However i want to believe that the times of GS5 and TDI are the same.

Just out of curiosity, can't someone scope out the timings of the two for comparison? This would be informative? Here i post nice schem of front end GS5.

[eclipse]

I'm doing the timings with microcontroller, I may offer pieces for sale in future. It reduces complexity alot.

[dbanner]

Which micro do you plan on using, will it be a PIC?

[Geo]

Hi Geo,

The first TDI's used 4538's, and later switched to a microcontroller. Some where on one of the forums Reg or Carl mention that there was a first run of TDI's with through hole components and not smd. I recall it was less than a 100 units.

Here is a photo of a proto type just like the one I have

I agree but these TDI are collectively now

[Idefix]

I was looking at possible modifications to GS5. But I like the sd2000 audio circuit. LM394 is no problem. Suitable replacement can be found.

The LM394 with an opamp will do nothing better in a TDI /GS5 , comparing to a modern opamp. At least the same. The noise from 1000 ohms is worse than the one of the amplifier, 4.1 nVsqrHz@ 25°.

[dbanner]

The LM394 with an opamp will do nothing better in a TDI /GS5 , comparing to a modern opamp. At least the same. The noise from 1000 ohms is worse than the one of the amplifier, 4.1 nVsqrHz@ 25°.

I was referring to single cap integrator implementaion or mods done on TDI (https://www.youtube.com/watch?v=s0DXQFCF8F0) for noise reduction.

[dbanner]

Maybe someone might find this layout useful.

[Idefix]

Hi,
What kind of VCO do you choosen, finally?