Both of them? There is your problem.
It happened to me once when doing initial tests, but that was due to a wrong connection when trying different transistors.
It happened to me once when doing initial tests, but that was due to a wrong connection when trying different transistors.
Did you replace the sa1381?
Did you measure (hfe) the replaced part to check that it was ok or not?
Did you measure (hfe) the replaced part to check that it was ok or not?
Then maybe 117 is gone. GS voltage of 117 should be around 1.5V. If gone you should check his zener also.
This seems low.
Maybe this is your problem.
I can' t think of anything else. If you want, I can take some readings on my board tomorrow.
Maybe this is your problem.
I can' t think of anything else. If you want, I can take some readings on my board tomorrow.
The 1K trimmer is damaged measure always 1K😡 I will change for the Vishay precision 1260W tol. 5%.
How long have you been building Salas style regulators?
Do you know how they work?
Then why are you dabbling in HV stuff?
Do you know how they work?
Then why are you dabbling in HV stuff?
If you change it, measure idss to see if dead or not.
According to datasheet, vgs should be -.2 to -1.5V.
You can adjust current, so front stage is OK, and we have checked that 840 and ksa1381 are not damaged, there is nothing else to go wrong. If you replace the 117, check d3 too. It could have gone south too.
According to datasheet, vgs should be -.2 to -1.5V.
You can adjust current, so front stage is OK, and we have checked that 840 and ksa1381 are not damaged, there is nothing else to go wrong. If you replace the 117, check d3 too. It could have gone south too.
I taked it out but still 15-17Vout
OK I used the 117 supplied with the mini-kits without measuring the Idss now I will use one near 4mA of Idss also I will check D3. I disconnect D3 schematic that is D1 in the GB pcb that I have but still 15-17Vout.
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