SSLV1.1 builds & fairytales - Page 185

janos_904 · 16th October 2012, 04:56 PM

I do have strong GR-s, all of them has more than 5 mA. Ok, the red led was in the wrong way. Is the BIB guide schematic ok, or the red led anode is on the opposite side than the green one? Thank you very much! Is OsCon SEPC a good Vref?

Quote:

Originally Posted by Salas

No or too weak current in the ref from its associated K117 or the red is put in the wrong way blocking? Blue leds can be noisy VS green, then again only 2V per blue, maybe those GRs are too weak? Did you get their idss before installing?

Salas · 16th October 2012, 05:05 PM

The schematic is OK. Shows an optional Zener also that may had tricked you. Objectively yes, OSCON is a good filter. Subjectively not my preference there.

ombudsmann · 22nd October 2012, 01:16 PM

Hi all,

I just happen to be in the middle of a SSLV1.1 board PSU build for a standard Pass B1 Buffer PCB (the original from Pass Labs). Target voltage is +18V single rail.
I already built one successfully for my phono pre-amp and had no issues at all. But for this one, the two red LEDs in the voltage reference area do not light up. The 4 green LEDs do. I used the calculator to get the right parts (although I don't really know the load current), used 15R/5W for R301, 2 Wima Mks 4,7 uF Caps for C303 and C301, 1K8 for R303 and a Bourns W502 5K trimmer. D301 jumpered. I used BYV28-200 diodes for D311-314 as rectifier that I had lying around (instead of the MUR120). Nichicon Gold Tune 4700uF 100V as C305 (polarity is correct)
I had no visible signs of bad soldering, so I thought it would be good to build a second board with a different set of parts to be sure there is no bad part involved (I had a second board and IRF+ set on hand). Unfortunately with the same result.
Since building a shunt regulator with Salas and teabags boards for a B1 has been done loads of times in the community, could anyone give me a hint where I went for the wrong path?

Any help appreciated,

cheers

roender · 22nd October 2012, 01:33 PM

Most probably you are exceeding the CCS current with the load needed current, hence running into no juice for the shunt FET transistor.

ombudsmann · 22nd October 2012, 02:12 PM

Thanks for the suggestion. That means lowering the value for R301 would do the trick?

Tea-Bag · 22nd October 2012, 02:18 PM

I think the IRF9530 might be shorted. Measure voltages there, and all the T0-92 devices.
15R @ 18v should work, but 10R might be better if Roender is right.

Salas · 22nd October 2012, 02:22 PM

What is the dummy load used? That will say something certain about the set current sufficiency.

ombudsmann · 22nd October 2012, 02:26 PM

The dummy load is 1R. Thanks for your quick response, amazing service!!!

Salas · 22nd October 2012, 02:29 PM

1R is effectively a short circuit. Thumbs up if with 2 surviving regulators, but to simulate a B1 make that 1K 1W.

ombudsmann · 22nd October 2012, 02:34 PM

Seems like we have found a source for my issues: myself. Thanks for your help, will see what I can rescue....

best

22nd October 2012, 01:16 PM	#1843
ombudsmann diyAudio Member Join Date: Aug 2010 Location: Munich	Red LEDs not lit Hi all, I just happen to be in the middle of a SSLV1.1 board PSU build for a standard Pass B1 Buffer PCB (the original from Pass Labs). Target voltage is +18V single rail. I already built one successfully for my phono pre-amp and had no issues at all. But for this one, the two red LEDs in the voltage reference area do not light up. The 4 green LEDs do. I used the calculator to get the right parts (although I don't really know the load current), used 15R/5W for R301, 2 Wima Mks 4,7 uF Caps for C303 and C301, 1K8 for R303 and a Bourns W502 5K trimmer. D301 jumpered. I used BYV28-200 diodes for D311-314 as rectifier that I had lying around (instead of the MUR120). Nichicon Gold Tune 4700uF 100V as C305 (polarity is correct) I had no visible signs of bad soldering, so I thought it would be good to build a second board with a different set of parts to be sure there is no bad part involved (I had a second board and IRF+ set on hand). Unfortunately with the same result. Since building a shunt regulator with Salas and teabags boards for a B1 has been done loads of times in the community, could anyone give me a hint where I went for the wrong path? Any help appreciated, cheers

22nd October 2012, 02:18 PM	#1846
Tea-Bag not politcally affiliated diyAudio Member Join Date: Feb 2006 Location: Kennebunk Blog Entries: 7	I think the IRF9530 might be shorted. Measure voltages there, and all the T0-92 devices. 15R @ 18v should work, but 10R might be better if Roender is right. __________________ Salas Boards 2013 #2 CLICK HERE \| F6 Covertible PCB GB Boards Available \|DCB1 boards and KITS available PM\|SemiSouth R125, R100, R100A Available CLICK HERE \|F5TC Boards Sign UP CLICK HERE

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16th October 2012, 05:05 PM	#1842
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	The schematic is OK. Shows an optional Zener also that may had tricked you. Objectively yes, OSCON is a good filter. Subjectively not my preference there.

22nd October 2012, 01:33 PM	#1844
roender diyAudio Member Join Date: Sep 2006	Most probably you are exceeding the CCS current with the load needed current, hence running into no juice for the shunt FET transistor.

22nd October 2012, 02:12 PM	#1845
ombudsmann diyAudio Member Join Date: Aug 2010 Location: Munich	Thanks for the suggestion. That means lowering the value for R301 would do the trick?

22nd October 2012, 02:22 PM	#1847
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	What is the dummy load used? That will say something certain about the set current sufficiency.

22nd October 2012, 02:26 PM	#1848
ombudsmann diyAudio Member Join Date: Aug 2010 Location: Munich	The dummy load is 1R. Thanks for your quick response, amazing service!!!

22nd October 2012, 02:29 PM	#1849
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	1R is effectively a short circuit. Thumbs up if with 2 surviving regulators, but to simulate a B1 make that 1K 1W.

22nd October 2012, 02:34 PM	#1850
ombudsmann diyAudio Member Join Date: Aug 2010 Location: Munich	Seems like we have found a source for my issues: myself. Thanks for your help, will see what I can rescue.... best