The simplistic Salas low voltage shunt regulator

[merlin el mago]

My voltages are both 12V out......

It's the 8ma on the -12V rail that I'm questioning.

Use mosfet, do you have afraid for only 8mA: use big heatsink to dissipate the rest of current not used by the load.

 

[merlin el mago]

For negative bias the range is typically 25-50V.

Regal BiB max. Vout 45V Current 100mA-1.5A with IRF9610

Go Salas BiB thread to download the pdf http://www.diyaudio.com/forums/power-supplies/192625-sslv1-1-builds-fairytales.html

 

[merlin el mago]

Hello Salas,
i've build some of your regulators and now I'm working on a 3,3V using the old Quanghao PCB board.
I'd like to know if there is a maximum output capacity that I can put on the load.
Also I'd like to use this circuits as AVCC of my ES9018.
Normally many people use preregulation like "Placid" on Buffalo DAC and after an integrated regulator like LT1963 or "trident".
What do you think if I connect directely your simplistic Salas low voltage shunt regulator from the dedicate transformer winding to the ES9018 analog voltage pin?
I don't use Buffalo dac but a diy board.
Ciao
Guglielmo

If I remember corectly the output cap is 47uF, why do you want to increase the value?

It's a good idea power AVCC of ESS9018 directly with Salas shunt regulators.

 

[Salas]

why there are various values of resistors used as a gate stoppers
I see 100 - 470 R Is used
what Is benefit of using lower / higher value

That's integral to the open loop calculations of each. Just use what is listed in each schematic.

 

[Salas]

Question: if i use a Salas shunt to power a DAC and between shunt and DAC chip or Receiver chip i have some other regs like lm1117-3.3 or lm1117-5 do i still benefit of advantages of using a Salas shunt ?

No

 

[Salas]

My voltages are both 12V out......

It's the 8ma on the -12V rail that I'm questioning.

Run the minus reg at 100mA with a Mosfet output config.

 

[Salas]

Hello Salas,
i've build some of your regulators and now I'm working on a 3,3V using the old Quanghao PCB board.
I'd like to know if there is a maximum output capacity that I can put on the load.
Also I'd like to use this circuits as AVCC of my ES9018.
Normally many people use preregulation like "Placid" on Buffalo DAC and after an integrated regulator like LT1963 or "trident".
What do you think if I connect directely your simplistic Salas low voltage shunt regulator from the dedicate transformer winding to the ES9018 analog voltage pin?
I don't use Buffalo dac but a diy board.
Ciao
Guglielmo

Listen to others with experience in combining with such DACs me I don't use them to tell you my subjective comments.

 

[guglielmope]

Thank Salas,
I'll use the only way I know: make comparison tests.
Ciao e grazie.
Guglielmo

 

[dimkasta]

I did some changes to the calculator excel.
It now can calculate the dummy load resistance and its watt rating based on the expected consumption, and then the total mA consumption based on the voltage across the CCS resistor

 

[boywonder]

Run the minus reg at 100mA with a Mosfet output config.

Thanks Salas!

 

[canvas]

Hi Salas,

From the HV 1.2R schema, how can I increase the input voltage from 45v to 60v?
And, what is the requirement for Q5? I only know if I want LV output, I need to pick a low threshold version. How about capacitance and rise/fall time? Thanks.

 

[massimo]

...and what about BC547B instead of BC546B (Vceo 45 vs. 65 and Vcbo 50 vs 80) for Q7 when Vout 35V?

 

[canvas]

...and what about BC547B instead of BC546B (Vceo 45 vs. 65 and Vcbo 50 vs 80) for Q7 when Vout 35V?

How about BC550C/560C? Do you think they will work at 60Vin?

 

[marcus1]

Thanks dimkasta. Great calculator, now better.

I did some changes to the calculator excel.
It now can calculate the dummy load resistance and its watt rating based on the expected consumption, and then the total mA consumption based on the voltage across the CCS resistor

 

[Salas]

Hi Salas,
From the HV 1.2R schema, how can I increase the input voltage from 45v to 60v?
And, what is the requirement for Q5? I only know if I want LV output, I need to pick a low threshold version. How about capacitance and rise/fall time? Thanks.

R5 & R6 break the output voltage referenced across Q3 & Q4 in two. I don't see what is may hinder you for feeding 60Vin beyond the extra heat created across Q1 the larger the Vin to Vout DC difference becomes. The higher the DC across Q1, its parasitic capacitance tames lower. Just know to have Vout/(R5+R6)~3 to 5mA for the LED with resistors that handle the dissipation (Vo/2)*IR5,6 and adequate Q1 sinking with calculated Q1 temp to be still safe. Q5 should sustain the Vout and have capacitance specs similar to what used in the regular schematic. Dropping with RC,RC if the Vi-VoDC is very large is to be also considered.

 

[RCruz]

Thanks dimkasta. Great calculator, now better.

+1

 

[canvas]

R5 & R6 break the output voltage referenced across Q3 & Q4 in two. I don't see what is may hinder you for feeding 60Vin beyond the extra heat created across Q1 the larger the Vin to Vout DC difference becomes. The higher the DC across Q1, its parasitic capacitance tames lower. Just know to have Vout/(R5+R6)~3 to 5mA for the LED with resistors that handle the dissipation (Vo/2)*IR5,6 and adequate Q1 sinking with calculated Q1 temp to be still safe. Q5 should sustain the Vout and have capacitance specs similar to what used in the regular schematic. Dropping with RC,RC if the Vi-VoDC is very large is to be also considered.

Sorry, I should have mentioned earlier. I am going to build a 1.2R regulator for my amplifier VAS stage. My Vin is about 60V, but Vout is around 50V@20ma max. There is only 8V~10V in difference. So, I guess the original schema is fine?

 

[Salas]

Q7 will have problems with its dissipation sooner or later at 50V Vo. Better use some TO-126 there with highest beta and lowest Cob you can get.

 

[Salas]

Also watch what I wrote for R5, R6.

 

[masterat]

Bib user Manual

I did some changes to the calculator excel.
It now can calculate the dummy load resistance and its watt rating based on the expected consumption, and then the total mA consumption based on the voltage across the CCS resistor

Hi all,
Have some one guide me how to use?