Garrett (pulse) XL 500

[ripsdevala]

Sorry no. The vertical line should be here 0,3 mm.

Ok then, the lay file need correction

[blobber]

corrected layout file


motion PI_blobber_09.09.2016.zip

[reptooyep]

I made mods on your layout to avoid wires. I made it double side.
motion PI_blobber_2016.zip
I think i made mistakes on the board, i have to check everything cause first time with a battery, i did not have my +5v (-0.9v instead).
I put a NE555 instead of a a TLC555 (schematic). Fortunatly for me, i have a LM555 wich is the same.
After changing a 220nF by a 220p (second mistake), the charge pump gives the good voltage. I still have troubles making it to work.
The LED is always ON, on all 10k pot. position. i replaced all transistors by those i had avaible (BC547 instead of BC548, BD911 instead of BD241A, BC327 instead of BC328 and MPSA13 by BC517).
Maybe there is an incompatibility between some of these but i checked on alltransistors.com for replacement.
Is there anything i can check with the scope to troubleshoot the board ?

[ripsdevala]

Fred sir, please what value is this caps? May i have picture of your board? This lay file components is different with the scheme, I already buy some of the ic and transistor from the scheme, is those is equivalent for this mod version?

[reptooyep]

Fred sir, please what value is this caps? May i have picture of your board? This lay file components is different with the scheme, I already buy some of the ic and transistor from the scheme, is those is equivalent for this mod version?
[ATTACH]37081[/ATTACH]

The capacitor is the 100uf of the charge pump.
The differences between the schematic and the layout come from transistors caus many equivalences exist (see www.alltransistors.com).
Regards

[blobber]

The capacitor is the 100uf of the charge pump.
The differences between the schematic and the layout come from transistors caus many equivalences exist (see www.alltransistors.com).
Regards

That's correct.

[blobber]

I made mods on your layout to avoid wires. I made it double side.
[ATTACH]37080[/ATTACH]
I think i made mistakes on the board, i have to check everything cause first time with a battery, i did not have my +5v (-0.9v instead).
I put a NE555 instead of a a TLC555 (schematic). Fortunatly for me, i have a LM555 wich is the same.
After changing a 220nF by a 220p (second mistake), the charge pump gives the good voltage. I still have troubles making it to work.
The LED is always ON, on all 10k pot. position. i replaced all transistors by those i had avaible (BC547 instead of BC548, BD911 instead of BD241A, BC327 instead of BC328 and MPSA13 by BC517).
Maybe there is an incompatibility between some of these but i checked on alltransistors.com for replacement.
Is there anything i can check with the scope to troubleshoot the board ?

Your file is looking good.

You could check:
Look for traces with short circuit, because some lines are very close, to eachother and to the pads too!!
Did your power supply is working? -5V on 79L05 output and +5V with 555 on 78L05 output?
Check the voltage on every IC socket, before you put the IC in the board!
Start then with oscillator 555, look at the output, you should have a needle wave form 380 - 400 Hz.
Look also at the hot end your coil.
Than put step by step 709, 4066, 324 and both 4538 while checking all outputs step by step.


When your LED shines always, could be your battery voltage too low? Measure your voltage after switched on!
Do you have adjustable power supply, for example with LM317 regulator? So you could simulate low battery, the point when LED has to shine.

[blobber]

Fred sir, please what value is this caps? May i have picture of your board? This lay file components is different with the scheme, I already buy some of the ic and transistor from the scheme, is those is equivalent for this mod version?
[ATTACH]37081[/ATTACH]

Lots of resistors are standing yes. 100uF is the cap.
I have only this picture here.



The values in the layout file, should be what I have in my board, maybe some caps are different, I had taken what I found in my work shop, for example 330nF instead 470nF, in my opinion not critical.

[reptooyep]

Your file is looking good.

You could check:
Look for traces with short circuit, because some lines are very close, to eachother and to the pads too!!
Did your power supply is working? -5V on 79L05 output and +5V with 555 on 78L05 output?
Check the voltage on every IC socket, before you put the IC in the board!
Start then with oscillator 555, look at the output, you should have a needle wave form 380 - 400 Hz.
Look also at the hot end your coil.
Than put step by step 709, 4066, 324 and both 4538 while checking all outputs step by step.


When your LED shines always, could be your battery voltage too low? Measure your voltage after switched on!
Do you have adjustable power supply, for example with LM317 regulator? So you could simulate low battery, the point when LED has to shine.

Hi Fred,
Thank you for your support.
I've already checked all the points that you said. Short-cut, Power supply +5v, -5v.
Then, i've checked the TX signal which is nice.
I don't have LM709 avaible, so, i tryed with LM380 and LF357 without 3pf and 10pf compensation caps. The output seems OK.
I can see the 4066 command from 4538 but output of 4066 (1 and 4) are very low (10mv peaks).
The SENS pot (10k) does not change a lot the input signal on pin5 (LM324) and the outputs of each stage are very low too.
I think that it should work better with a LM709, like the schematic.
I have a regulated power supply, so, later, i'll try to change the input voltage.
I use a 9V battery (8.5v load).
I've already checked all transistors and they are all OK.

[blobber]

For LM709 you can also try LM308 or CA3510 or CA3130. I had that also tried this IC's.
I think I should open my box, to make some measurements, tomorrow late evening I have time.tomorrow evening

[mungos]

Best replace for LM709 is LM318.

[reptooyep]

Which one is the best ? CA3130 or LM308 ?
I have several of theese..
Tomorow morning, i'll check more things

[ripsdevala]

Which one is the best ? CA3130 or LM308 ?
I have several of theese..
Tomorow morning, i'll check more things

Addition, i have LF353, TL072, TL082, TL071, UA741 i think i can use it, yes?

[ripsdevala]

Coil spec? 100uh R?, wire size?

[blobber]

Double op amps like 072, 082, 353 will not working, for replacment of 709!

For your coil. Any wire or flex wire 0,4 - 1,0 mm with plastic isolation, 20 turns, 20 cm diameter, will work just fine.