The simplistic Salas low voltage shunt regulator

[Salas]

Yes, thank's ikoflexer.

I think that dissipation at 2SK170 is a little bit high for this version which i intend to use. I am thinking right now to increase value R3, about 3Kohm.In that case Uds will be 10V, dissipation is 10V*5mA=50mW, that is safe for TO92. Voltage at R3, if i use 3K will be around 15V. Is that OK?

Naah, its been working for ages like that and harder, in many phono stages. Don't increase the tail impedance that much if it worries you still (246 is 100mW less capable than 170). Back down the Idss instead, the way I mentioned.

 

[iko]

Ikoflexer knows the topology inside out, don't worry.

Salas knows I've spent waaaay too much with this circuit in front of my eyes

But he's right, I didn't realize which circuit he referred to so my answer was wrong

 

[iko]

I'd listen to salas. People don't realize how many people are using this circuit totally without a problem.

 

[Salas]

I even don't realize. They live among us!

 

[viktor1986]

Naah, its been working for ages like that and harder, in many phono stages. Don't increase the tail impedance that much if it worries you still (246 is 100mW less capable than 170). Back down the Idss instead, the way I mentioned.

OK, thank's Salas! I will report results when I finish.

 

[Salas]

OK. Good luck. Cook it up with whatever you have and let us know. I gave you a tip about upping the Vbe margin if without low pinch off there in hand, keep it.

 

[nicoch58]

the Erno 2SK170 working incandescent (too much for JC ,at last for j74)

 

[viktor1986]

One more question

What value for R1 to R8 schould I use? Current will be 100mA, 50mA goes through preamplifier and 50mA goes through shunt, total 100mA.

Is it Ok tu use 2.2ohm for R1 to R8??? Proposal? Transformer is dual secondary, it is not central taped. I have modified pcb a little bit...

 

[stormsonic]

@Viktor1986
Increase capacitance there, C9 - C12, and increase shunt current to 250 mA

 

[Salas]

One more question

What value for R1 to R8 schould I use? Current will be 100mA, 50mA goes through preamplifier and 50mA goes through shunt, total 100mA.

Is it Ok tu use 2.2ohm for R1 to R8??? Proposal? Transformer is dual secondary, it is not central taped. I have modified pcb a little bit...

Maybe 1R is enough to smooth out the sawtooth without losing much voltage and heating the resistors too much. As Stormsonic said, at about 200-250mA there is better performance if you can accept the heat waste on sinks. I like your decision to use LEDS for Vref on the schematic.

 

[viktor1986]

Thank's for replay Salas!

Are you watching basketball game Olympiakos - Partizan ?!

Well Salas, I will see, maybe I will make dual mono contruction and then current throug the preamplifier is 25mA, through the shunt 75mA, total 100mA. I will see!

I plan to mount IRFP to metal chasis...

I expect two pcb's next week...

http://img705.imageshack.us/img705/4273/salaspcb.gif

 

[Salas]

Yes 15-15 the score. Looks like a good board. To listen with more current if the chassis takes it its just a matter of changing 2 set resistors. No big deal. You can test subjectively at your leisure. Depends on how ''responsive'' the client circuits will be.

 

[RCruz]

I like the idea of leds for vref but can not identify parts DS7 and DS8 What are those parts ?

 

[Salas]

Maybe just connectors so to connect any voltage ref led string sub system?

 

[RCruz]

Ok so no high tec leds here

 

[viktor1986]

Yes 15-15 the score. Looks like a good board. To listen with more current if the chassis takes it its just a matter of changing 2 set resistors. No big deal. You can test subjectively at your leisure. Depends on how ''responsive'' the client circuits will be.

Congratulations on your win Salas!

First at all it's important to work, second is adjustments for this regulator.

 

[viktor1986]

I like the idea of leds for vref but can not identify parts DS7 and DS8 What are those parts ?

Part's DS7 and DS8 is Vref. It's small board(8.13mm*35.56mm) on which are mounted Led's, there are 2*7Led's=14 led diode. You only need attention in orientation of led's on that small board. I think's that this small board is good idea.

http://img35.imageshack.us/img35/9607/ledsforvref.jpg

 

[Salas]

All shunties made in Serbia are traditionally glowing a lot.

 

[viktor1986]

All shunties made in Serbia are traditionally glowing a lot.

I fully agree with you Salas! Especially Shiney!!!

 

[RCruz]

Thank you viktor.

I have the same solution in one of my projects.... I call it the glowing bug