Problem with TGSL EDU

[Comp]

Hiya!!!! Bit late onto this one, only just spotted the thread, as I am building a IGSL with a Tesoro coil,... here is the board.......



It now has the coil plugged in, and those sexy knobs in the packets attached to the pots...
& I have , what I would guess is the same problem,... if I touch any of the pots, pot shafts, or even the ribbon cables to the pots, or touch around the board, it 'falses', or beeps, which is what I think the OP is complaining of, if I read it right.
The board detects, high & low tones for ferrous and non, and I can disc out Ali foil. It also GB's out a lump of ferrite, so most of it must be working!!!!!

My take of it is, it is picking up/falsing, because things arent grounded/earthed, as some have said,... next test is to mount in a metal box, or fit onto a piece of plain copper clad pcb, make sure all the pots are mounted on an earthed strip, and try again.
Pretty sure that is where the problem will be, though.

Cheers, hope that helps, Fred

[simonbaker]

Try comparing the TX and RX signals from the two coils. How do they differ regarding the residual voltage and phase-offsets ... and how do the RX signals react when ferrous and/or non-ferrous targets are placed near the coil. Also, is the electrostatic shielding the same on both coils?

Right on; I'm slowly trying to sort out these differences with various tests; lots of combinations.

Stinker is that due to workshop noise, I can never test depth sensitivity to various changes. I'll have to come up with some solution, like living in an old mine shaft...

-SB

[Qiaozhi]

Right on; I'm slowly trying to sort out these differences with various tests; lots of combinations.

Stinker is that due to workshop noise, I can never test depth sensitivity to various changes. I'll have to come up with some solution, like living in an old mine shaft...

-SB

You need to get yourself one of these ->
http://www.herzan.com/products/elect...day-cages.html

[simonbaker]

You need to get yourself one of these ->
http://www.herzan.com/products/elect...day-cages.html

That is fantastic, I was going to try to make my own!

I'm actually looking for a giant cardboard box which I can wallpaper with aluminum foil, and see how it does.

Although actually don't even have room for it anywhere in our cramped quarters... I'll try to make it happen... has to be big enough the MD doesn't detect the cage...

I wonder if such cages are effective against 60 Hz, or only high freq'n stuff? (well, I see they rate it at down 81 db at 50 Hz - that's respectable...) (oops... that 50 MHz -- slight difference! Will it work I wonder?)

You're definitely on my wavelength.

-SB

(how long could you work in one of those igloos before running screaming naked in the street?)

[paku]

I have Problem My TGSL Long Beep Only

I Just Got Long Beep
what is that problem
Need Change Some IC or What I need To Replace Help! Help Help! Help!!

[Davor]

You'll have to do some testing first. What happens when you wave some big metal object over a coil? Any change?

[paku]

i have test put big metal object at the coil
still just long beep only

[Davor]

Can you measure DC voltage values at pin6 of both U104 and U105? You can use pin3 as reference (ground).

[paku]

ok i will chek now

[paku]

i get 1.5 from U104 and U105 same 1.5 without coil

[Davor]

And there is your problem :scratches a belly:
Could you make a photo that shows these two chips and the surrounding parts? 1.5V is 2 orders of magnitude too much.

[paku]

It True The Test is Look like This Bro

[Davor]

Maybe your testing method is not perfect. Your instrument is set to 200V range, which is far far away from the expected +/- 2V. Could you repeat measurements with instrument set to 2V range. Before you start measurement, please connect the instrument pins together so that you can confirm 0V, or whatever value you get so that you can deduct it later. If it remains firmly around 1.5V you must have some completely unexpected problem.

[paku]

i have set meter to 200v and i get 2.7v U104 and U105
is that right test or rong

[Davor]

Wrong. Put your instrument to 20V, confirm 0V by short-circuiting the instrument pins and repeat measurement. If you get results below 2V, put your instrument to 2V and repeat. If there is nothing moving on top of your coil, you should measure very little voltages in mV range.