The simplistic Salas low voltage shunt regulator

[Salas]

See that it works subjectively any good for what you want it first. It was meant as a hum free voltage source for a valve heater initially.

 

[qusp]

yeah will do a perfboard version first

 

[merlin el mago]

That will do to mount both Mosfets at circa 200mA. Use isolation pads. You can find something like that in a local shop too I guess?

Farnell it's very expensive 14€76 unit, can I use this 0€673 unit at Mouser?: 206-1PABH Wakefield Heatsinks

 

[Salas]

No way. Extremely small. Keep in mind that you are about to make the low MC simplistic phono, with 45V B+. You also want to run the reg at circa 200mA CCS. Assuming 50mA load for 2 channels, there is a 150mA @ 45V excess to burn on the shunt Mosfet at ALL time. That means 6.75W dissipation. Plus 2W on the CCS Mosfet assuming 10V Vin minus Vout. Look for 1C/W sink spec to mount both on.

P.S. That link shows 6.5 Euro.

 

[merlin el mago]

Salas, the price shown is Sterling Pounds not €, as I understand the recommended heat sink is for two IRFP9140 so I need two units one per channel ok?

 

[merlin el mago]

The same heat sink at RS Amidata cost 14€46: ABL Components | Semiconductores | Zócalos, Disipadores y Accesorios | Disipadores de calor | Resistencia térmica de hasta 1,3 °C / W |345AB1000B

 

[merlin el mago]

That will do to mount both Mosfets at circa 200mA. Use isolation pads. You can find something like that in a local shop too I guess?

I'm handicapped so prefer to buy on line.

 

[Salas]

Salas, the price shown is Sterling Pounds not €, as I understand the recommended heat sink is for two IRFP9140 so I need two units one per channel ok?

One for both. Pound and Euro are close nowadays.

 

[merlin el mago]

Do you know if are drilled?

So I need 2 heatsinks for 4 IRFP9140, right?

 

[iko]

It's ok to have two mosfets on one heat sink of proper size, just don't forget that they have to be isolated from the heat sink.

 

[merlin el mago]

Thks Iko

 

[iko]

No problem. You know, lots of people throw out those old CRT monitors. Plenty of nice heatsinks for free if you have access to them. It does involve a bit of disassembly though. I use them sometimes for prototypes and my own projects.

 

[merlin el mago]

Good idea Iko, thks again.

 

[merlin el mago]

Two questions more:

1-Value for fuse?
2-Value in wats & omhs for dummy load to check the voltage before connect to the Simplistisc phono RIAA?

 

[iko]

Two questions more:

1-Value for fuse?
2-Value in wats & omhs for dummy load to check the voltage before connect to the Simplistisc phono RIAA?

Are you going to use one regulator per channel? Or one regulator for both L and R channels?

It also depends on what current limit you will set the regulators. Let's say, for example, that you will use one regulator for each channel. Let's say that you set the current limit to 300mA for each regulator. That would be a total of 600mA being drawn from the wall. A 750mA or 1A fuse is OK.

I forgot how much current draws the phono stage, but it's not more than 100mA total. The regulator is probably set to something like 22V - 25V. So a resistor in the range 150R - 250R 5W would be good for testing.

Hope this helps.

 

[merlin el mago]

Thks for help Iko, B+ is 45V & current is 200-220mA, I will do one reg. per each channel.

When I get your pcb rgs. I will compare with Salas regs. & I will post mine opinion.

 

[iko]

Then the load resistor better be more than 12W.

 

[merlin el mago]

Thks Iko, the fuse 750mA or 1A right?

 

[qusp]

I have added myself to your list for the pro PCB simplistic, can this PCB also be used for the low voltage simplistic? that, as well as price will effect whether I increase the amount I get. thanks for putting this together both you, salas and everyone involved to this day!!

 

[audiodesign]

Salas, I and Quang Hao are using your design in this project.

DAC End - the AD1865N-K with single ended vacuum output stage