Zener + Emitter Follower voltage regulator

[Alcaid]

Thank you, both.

It's a 15V zener.

 

[Bricolo]

I think the higher the better

noise and impedance reduce when you increase the bias
I'm not aware of any drawback (except power consumption and dissipasion)

 

[Jocko Homo]

Ah....but......

What happens to the impedance of the part that feeds current to the zener????

Time to calculate PSRR.

Jocko

 

[Werner]

Wasn't "Catch 22" an electronics primer?


BTW, how goes zener noise with temperature?

 

[jan.didden]

Re: Ah....but......

What happens to the impedance of the part that feeds current to the zener????

Time to calculate PSRR.

Jocko

Indeed! But if you use a current source to feed the zener, more current may still mean more PSRR. If not, the decrease in zener dynamic impedance will be offset by the decrease in series R, and you'll go in the wrong direction I think.

Here is a typical curve (fig 2):
http://www.vishay.com/docs/85782/85782.pdf

Jan Didden

 

[Jocko Homo]

It may......

It may not. There is no answer that fits all applications. You have to decide what you are trying to accomplish, and the best way to get there.

And then resist the tempatation to make it more complex than it needs to be.

Jocko

 

[jan.didden]

Indeed.

Jan Didden

 

[steenoe]

Hi Alcaid.
Sorry for bugging you again about this psu Could you please post the latest schematic for this psu? I find myself searching for it now and then. Its just for ease of searching
Here is a link to the board and silkscreen.
Zener-emitter/follower PCB
I attach a picture of two of them boards

Steen.

 

[Alcaid]

http://www.diyaudio.com/forums/showthread.php?s=&postid=587354&highlight=#post587354

 

[CBS240]

What is wrong with this modification on the zener regulator?

Seems like it works fine and has a better load rejection than the zener + EF stage.

I used it with a half wave rectifier.

 

[simonov]

Anyone considered using CCS like this: