Building a symmetrical PSU B1 buffer

I also have a build guide v4.4(2)....dont know the difference

I think it is the same as mine. Yours is 4.1 too.


Merlin, I'm going to use an old telecom equipment case. Quite robust and heavy, and fits everything nicely inside. Curiosly, this are the only ones where I work that are made in Spain:
http://www.dycec.com/pdf/ADI-SG.pdf

I have tons of router's cases at work, from all diferent sizes and shapes, but almost none of them are suitable for doing casework. Too much plastic, strange shapes and pre-drilled holes :mad: The older ones are the better ones, period.
 
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I have tons of router's cases at work, from all diferent sizes and shapes, but almost none of them are suitable for doing casework. Too much plastic, strange shapes and pre-drilled holes :mad: The older ones are the better ones, period.

That's what I used, an old WAN router. I cut out some of it and placed in a sheet of aluminum for some RCAs. It's galvanized steel, but it seems to work without issue.
 
I would prefer it under 11V for both in general. Are your JFETs under the LEDs a bit strong for IDSS? Maybe you could put there your weakest ones and both Vouts shall drop if the LEDs are in a current area that gain Vf fast now.

So I try to put 2 weaker K170s for the positive reg? What's a easy way to test Idss for the K170 pls? Should I even fiddle around with the LEDs?
 
I have what it seems to be quite enthusiastic leds. They are the ones from the BOM. I've measured 50 of them, and the vast majority are matched at 1,92v.
Seems some kind of pre-matched leds :D

So the question is, does it matter if the whole Vf is 1,92 x 5 = 9.6v? A bit more above the recommended 9v.

Thanks

Same here. Almost every one measured the same as you are suggesting.
Uriah
 
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So I try to put 2 weaker K170s for the positive reg? What's a easy way to test Idss for the K170 pls? Should I even fiddle around with the LEDs?

Put a weak 170 in the place of the one you have now on the positive side, the one in line with the 10R. Easy way is with a 9V battery, 100R and a DVM. Google for matching JFETS. To change all leds for lower Vf would be a pain.
 
I changed both to the weakest ones I have, measuring 0.6+v across 100R and the v+ is now 11.76v, looks like not much decrease! :p

Maybe you should only change the one in line with the 10R?
Just suggesting to salas, because I don't exactly know how does it works. In fact, I didn't knew anything about IDSS interacting with final voltage.

Sorry for my ignorance in shunt supplies :rolleyes: