New Stasis front end

[konst]

Built the boards, just waiting for the case to arrive... 🙂

Pix or it didn't happen 😀

 

[AlexRivera]

you know stubborn me

no spades, strictly soldering

Will scratch that then, ordering right now!!

 

[chiily]

Pix or it didn't happen 😀

2021-03-25_02-51-35 by Garf Arf, on Flickr

 

[AlexRivera]

you know stubborn me

no spades, strictly soldering

ZM, I need to order some multi colored cooper wire for this project, you know for all the interconnects, etc. what gauge can the holes on the PCBs handle, 14, 16, 18?

In general what gauges does everybody use?

Tanks,
Alex

 

[Zen Mod]

each power pad accepting standard needle shaped wire connector of 2.5sqmm, which means hole is 2mm Dia

remove plastic (heat gun, lighter) , crimp wire and solder, put appropriate color heatshrink, solder in pcb, cut leftower

 

[AlexRivera]

Perfect!!! 😎

 

[xman2005]

Thank you for good project from NP and great effort of pcb file revised by ZM. I plan to use this FE drive for modify my broken vintage 400A.

 

[Blk Dynamite]

What’s a good tolerance for matching the output stage BJTs?

 

[thimios]

https://flic.kr/p/2kNUUsH2021-03-25_02-51-35 by Garf Arf, on Flickr

Please, can you remind me the gerbers post?

 

[hirscwi]

Please, can you remind me the gerbers post?

Page 29 - post 281 is the start.

 

[thimios]

Thanks!

 

[Zung]

What’s a good tolerance for matching the output stage BJTs?

It's a compromise between what you want and what you get.

I bought a batch of 40 pulls (used) from Ali and managed to get 3.5 sets of 2 x (1 driver + 3 outputs), with a Vbe match < 1.5% and a Hfe match < 5%. The .5 set (light blue) is because I ran out of suitable driver, so, the Hfe match is off; the Vbe match is still good though. Anyway, 2 sets is all I need.

Interesting to note: in the world of semiconductors, sexual equality doesn't exist, and the PNP's/P-channel's always perform better. 🙂

 

[AlexRivera]

Does anyone have a Greedy Boy Power Supply that can recommend for 80V rails ??

 

[Zen Mod]

making welder.......... or having Apogees?

 

[Blk Dynamite]

It's a compromise between what you want and what you get.

I bought a batch of 40 pulls (used) from Ali and managed to get 3.5 sets of 2 x (1 driver + 3 outputs), with a Vbe match < 1.5% and a Hfe match < 5%. The .5 set (light blue) is because I ran out of suitable driver, so, the Hfe match is off; the Vbe match is still good though. Anyway, 2 sets is all I need.

Interesting to note: in the world of semiconductors, sexual equality doesn't exist, and the PNP's/P-channel's always perform better. 🙂

Ah I see. I was looking at 1% tolerance on the Vbe and 10% on the Hfe so I’ll tighten up the Hfe tolerance. Thank you

 

[AlexRivera]

making welder.......... or having Apogees?

Hahahaha, almost!!!

I’m going all in, 12 pairs per channel 😉

 

[Zen Mod]

aha, now I see

you're going to open Welding Service, flying on Apogees to working site

 

[wildlaurel]

can the frontend be fed with regulated rails and if so, would it be worth the trouble?

 

[Zen Mod]

yes, feel free to do that, but don't make FE rails smaller than OS rails

 

[wildlaurel]

i am planning to use a 910va transformer (+/-57vdc after rectifier/C filter). would it be enough to power 5 x 100w channels if bias is kept on the conservative side for stable low impedance load?

is this a reasonable pi topology for the rails regulation?