Salas low shunt Group-design by Salas

[merlin el mago]

I did the layout for low shunt Salas, just watch and comment me!
Thank you all!

Pm: on PCb have 5 shunt supply, you can separate them
2. x 1.5 to 5V
2 x 5 to 35V
1 x -5V to -35V

Looking at the layout, it's not the latest 1.2 version, what's the plan about the new boards ?

As I can see is the same version like the 1st GB: V1.0 remote sense.

 

[back]

What's your Vout target? could you post some pics?

my vout target is 2x+-15volt and +5v.

i will see what i can do.

 

[merlin el mago]

my vout target is 2x+-15volt and +5v.

i will see what i can do.

For +5Vout you need 9VAC transformer, are you using this tx?

For +-15Vout you need 15VAC transformer, are you using this tx?

When you can post pics.

 

[back]

For +5Vout you need 9VAC transformer, are you using this tx?

For +-15Vout you need 15VAC transformer, are you using this tx?

When you can post pics.

i used 12vac transformer and i take 15volt output and i adjust don`t work.

the led l4 don`t light up.

do you know where is the schematic to try to figure out what is wrong?

unfortunately i didn`t find a camera yet.

 

[back]

merlin i think that voltage drop is 10v so for 15 volt is 18vac and for 5v is about 11vac.

 

[andRookie]

I´m building two regs and aim for 35Vout. In the position q4 on the board there should be a bc550 transistor, but I have the bc546 availible. As far as I understand from searching the forum they are quite similar. I read from the datasheet that the 550 have higher Hfe (depending on samples and all that) and the 546 higher Vmax. Is it ok to use the bc546 in position "q4"?

 

[merlin el mago]

@back
@adnRookie

Will be better If you ask all your questions in this thread: Salas Low Voltage Shunt Regulator http://www.diyaudio.com/forums/power-supplies/143693-simplistic-salas-low-voltage-shunt-regulator.html here Salas will aanswer you all your questions regarding is nice shunt regulator

 

[back]

@back
@adnRookie

Will be better If you ask all your questions in this thread: Salas Low Voltage Shunt Regulator http://www.diyaudio.com/forums/power-supplies/143693-simplistic-salas-low-voltage-shunt-regulator.html here Salas will aanswer you all your questions regarding is nice shunt regulator

as you see i discovered it in the meantime.

 

[merlin el mago]

Yes

 

[Nikon1975]

I did not really follow the thread lately, so I pop up just to report another success. Attached the picture of the +-12 V and +5V for my dual mono buffalo + legato.

The 12V are biased at 340mA for a load of 240mA and the 5V is biased around 830mA for a load around 500mA. The latter gets a bit hot, the heatsink is around 55 C.

My only remark is that if you leave the Quanchao boards in a drawer for long, like I did, then they are a bit hard to solder, as they get oxidized pretty quickly.

Thanks,

Davide

 

[merlin el mago]

I'm living in the coast with a high humidity & not oxidized.

 

[AndrewT]

My Quanghao PCBs had some "film" on the solder pads.
It had to be scrubbed off and soapy water cleaned before soldering. The first board I tried without cleaning was a near disaster.
Bad PCBs
The double sided PCB is not through hole plated. Another bad mark.
The pads are not heat resistantly secured to the GRP substrate. More bad marks.
The PCB designer does not respond to feedback. That is not good service.

 

[gabanyayaya]

I did not really follow the thread lately, so I pop up just to report another success. Attached the picture of the +-12 V and +5V for my dual mono buffalo + legato.

The 12V are biased at 340mA for a load of 240mA and the 5V is biased around 830mA for a load around 500mA. The latter gets a bit hot, the heatsink is around 55 C.

My only remark is that if you leave the Quanchao boards in a drawer for long, like I did, then they are a bit hard to solder, as they get oxidized pretty quickly.

Thanks,

Davide

Davide

Did you experience any V out instability with the shunt????

Did you modify the board according to discussion on this thread or running it in stock configuration ???

 

[analog_sa]

More bad marks.

Very informative. Thanks.

 

[stephen1212]

I am noticing that it is unusually difficult to solder these boards. I don't observe any film and thought that the gold would prevent oxidation. I will try washing the next one to see if there is a difference. Most of the drill sizes seem too large, but the holes are plated through. Perhaps Andrew T yours are as well ? You might have been looking at the ventilation holes which of course are not connected electrically and therefor not plated through.

 

[AndrewT]

I have looked at all the holes. None are PTH.
I have lifted pads because they are not PTH.
I have lifted pads because they do not adhere well at soldering temperatures.

 

[gjfim]

I have looked at all the holes. None are PTH.
I have lifted pads because they are not PTH.
I have lifted pads because they do not adhere well at soldering temperatures.

FWIW- my experience has been different. I have completed and tested two boards (+/- 24V), and nearly completed soldering two more boards. My boards have PTH, no film, and I have had no problems with soldering or lifted pads.

Perhaps the boards were produced in two or more separate batches?

 

[quanghao]

My Quanghao PCBs had some "film" on the solder pads.
It had to be scrubbed off and soapy water cleaned before soldering. The first board I tried without cleaning was a near disaster.
Bad PCBs
The double sided PCB is not through hole plated. Another bad mark.
The pads are not heat resistantly secured to the GRP substrate. More bad marks.
The PCB designer does not respond to feedback. That is not good service.

I know this feedback is very important!
I will repair it in this round!
Thanks, and I promise to do better!

 

[Sergelisses]

To MISTER AndrewT

Even if the remarks are justified ,i find the comments very severe .

Serge

 

[merlin el mago]

To MISTER AndrewT

Even if the remarks are justified ,i find the comments very severe .

Serge

AdrewT's style...